Module 5 Reviewer

7/29/2019 Module 5 Reviewer

1/22Compiled by donrichardmacapagal SBCM 1A 2012 1

Reminder for FCM: 5th Long Exam on Feb. 09, 2013

(Saturday) 10:00am

Topics are:

1. Alcohol

2. Basic Principles of Exercise

3. Nutrition

4. Family wellness

5. Biostat2

6. Intro to EBM

7. Intro to Epidemiology

8. Population At Risk

HEALTH EFFECTS OF ALCOHOL

Ethyl Alcohol

(CH3CH2OH)

Absorption

Rapidly absorbed from stomach, small intestine, andcolon

Maximal blood concentration within 30 to 90 minutes Can be absorbed through the lungsDistribution

Uniformly distributed throughout tissues and body fluids Readily crosses placenta, to exposure fetusElimination

Urinary Excretion Exhalation MetabolismMetabolism I

(ADH Alcohol Dehydrogenase)

Metabolism II

(ALDH Acetaldehyde Dehydrogenase)

Metabolism III

Acetate Acetyl-CoA Carbon dioxide and water

Ethanol in:

Lite Beer 2.5 - 3.5% Beer 4.0 - 6.0% Wine 10 - 18 % Flavored Liquors 15 - 25% Distilled Liquors 22 - 50%

Proof is double %

One drink equals:

12 ounces beer 5 ounces wine 1.5 ounces distilled liquor

70 kg person metabolizes approximately one drink/hour 7 calories per gram vs. fat @ 9 calories/gmAlcohol Dependence

Craving: A strong need, or compulsion, to drink Loss of control: The inability to limit ones drinking on

any given occasion

Physical dependence: Withdrawal symptoms occur whenalcohol use is stopped after a period of heavy drinking

Tolerance: The need to drink greater amounts of alcoholin order to get high.

Alcohol and Alcoholism

Alcoholism

Addiction to alcohol or abuse of alcohol to a degree thatproduces problems in one or more of these areas:

Health Social relationships Economic status Interpersonal relationships

Phases of alcoholism

Problem drinking Drinks to relieve stress Abstinence does not cause physical symptoms

Alcohol addiction Abstinence produces physical symptoms

Acute Effects

CNS Depressant Depression of inhibitory control Vasodilation, warm, flushed, reddish skin Emotional outbursts Decreased memory & concentration Poor judgment Decreased reflexes Decreased sexual response

Acute Alcohol Effects

Hangover

Mild withdrawal with volume depletion (due to increaseddiuresis)

Treatment Fluids Paracetamol for headache

Stupor-Coma


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Compiled by donrichardmacapagal SBCM 1A 2012 2

Acute overdose Coma Depressed respirations Hypotension Hypothermia

Hypoglycemia

Inhibition of protein to sugar conversion in liver(gluconeogenesis)

Trauma

Drunks fall down and hit their heads. Concussion Subdural hematoma

Mixed drug overdose

Tranquilizers Barbiturates Anti-depressants

Worsening of other problems

Peptic ulcer disease Liver disease Pancreatic disease Heart disease (decreased pump strength)

Long Term Adverse Effects

Obvious Alcoholism, death, cancer (oral cavity,

esophagus, liver), fetal effects (FAS)

Alcoholism

Cirrhosis of liver, appetite loss, poor judgmentSubtle

Lost productivity, impaired performance, motorimpairment, cost to society

Alcoholism - Disulfiram

Alcoholism Treatment with Disulfiram

Inhibits acetaldehyde dehydrogenase (ALDH)

Exposure to EtOH while taking causes sudden, severe

vasodilation:

Hot, flushed face Dizziness Pounding heart, hypotension Nausea, vomiting Headache

Associated Medical Problems

Hepatic cirrhosis

Ascites Jaundice Palmar erythema Spider angiomata, Caput medusa Gynecomastia (males)

Effects

Impaired glucose metabolism, hypoglycemia Portal hypertension, esophageal varices Coagulopathies Hepatic encephalopathy

Pancreatitis

Nausea, vomiting

Severe upper abdominal pain radiating to back Hypovolemic shock Secondary diabetes Pancreatic necrosis and hemorrhageWernickes encephalopathy

Ocular disturbances Changes in mental state Unsteady stance and gaitKorsakoffs syndrome

Anterograde amnesia Apathy Aphasia, apraxia or agnosiaNutritional deficiencies

Beriberi Paresthesias, burning of feet Cardiovascular failure

Peripheral vasodilation Biventricular myocardial failure Na+ and water retention

Fetal Alcohol Syndrome (FAS) Most common preventable cause of adverse CNS

development

4,000-12,000 infants per year in US Characteristics Growth retardation Facial malformations Small head Greatly reduce intelligence Milder form of FAS 7,000-36,000 infants per year in US Characteristics Growth deficiency Learning dysfunction Nervous systems disabilitiesAlcohol & Cancer

Ethanol consumption increases risk of cancer Oral Cavity Pharynx and Larynx Esophagus LiverAlcohol Withdrawal Effects

Tremor Nausea Irritability Agitation Tachycardia Hypertension Seizures Hallucinations


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Basic Principles of Exercise

Exercise stressor

Why do we exercise?

1. Controls weight2. Combats health conditions and diseases3. Improves mood4. Boosts energy5. Promotes better sleep6. Improves sex life

What happens to the body when we exercise?


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Exercise Prescription

Types of Exercise

Anaerobic

intense exercise strength and speed does not need oxygen

aerobic

endurance needs oxygen

How do I know whether I am doing aerobic or anaerobic

exercise?

Heart Rate Monitoring

1. Compute your maximum heart rate. 220 age = MHR

2. Determine your training ranges. warm-up/cool-down: 85% of MHR

MHR =

warm-up =

aerobic =

anaerobic =

Aerobic vs Anaerobic Exercise

Aerobic Exercise

-running

Anaerobic Exercise

-weight lifting

Exercise Prescription

1. Determine the level of fitness of your patient.2. Determine goals for your patient.3. Determine training ranges.4. Advice.

Introduction to Nutrition

Compute your Body Mass Index:BMI = weight (kg)

Height (m)2

Computing for degree of obesity

Underweight 30


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GETTING THE WAIST CIRCUMFERENCE AND THE WAIST TO

HIP RATIO [WHR]

Men waist circumference > 90 cm WHR = > 1

Women waist circumference > 80 cm WHR > 0.85

What is nutrition?

Sum total of processes: intake and utilization of foodsubstances by living organisms

Ingestion Digestion Absorption Transport Metabolism

The Role of Nutrition in Health Promotion What you eat plays an important role in the development

or progression of a variety of chronic diseases:

Coronary artery disease Diabetes High blood pressure Osteoporosis Obesity Cancers

Six major nutrients in food

1. Carbohydrates Provision of energy2. Fats3. Proteins growth and development4. Vitamins Regulate metabolism5. Minerals6. WaterEssential Nutrients

Nutrients that the body needs but cannot produce inadequate quantities

Must be obtained from the food we eatNUTRIENTS ESSENTIAL OR PROBABLY ESSENTIALS TO

HUMANS

CARBOHYDRATES

FiberPROTEINS

Histidine Isoleucine

Leucine Lysine

Methionine Phenylalanine

Threonine TryptophanValine

VITAMINS

Thiamine Riboflavin

Niacin Pyridoxine

Pantothenic Acid Biotin

Folate Cyanocobalamin

C

MINERALS

Calcium Chloride

Magnesium Phosphorus

Potassium Sodium

Sulfur

VITAMINS

A D E KMINERALS

Boron Chromium

Cobalt Copper

Fluorine IodineIron Manganese

Molybdenum Nickel

Selenium Silicon

Vanadium Zinc

WATER


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Nutrients

Macronutrients

Carbohydrates (4 kcal/g)

Proteins (4 kcal/g)

Fats (9 kcal/g)

Micronutrients

Vitamins (13)

Minerals (~ 25)

Chemical Content of Nutrients

Inorganic Nutrients

Water Minerals

Organic Nutrients

Carbohydrates Proteins Lipids (fats) Vitamins

Carbohydrates

main sources of energy 40-80% of the total energy intake

Glycemic Index how much of a rise in circulating blood sugar a

carbohydrate triggers

the higher the number, the greater the bloodsugar response.

HIGH = 70 or more MEDIUM = 56 69 LOW = 55 or less

Brown.55 Long grain, White.44 Short grain, White.72 Glutinous (Sticky).98 All bran with fiber .38 Oatmeal 43 Raisin bran ..61 Cheerios ..74 Rice krispies 82 Corn flakes 92 Spaghetti, whole wheat..37 Fettuccini ...32 Spiral Pasta43 Linguine..46 Macaroni.47 Rice vermicelli 58Glycemic LoadThe glycemic load (GL) combines quality and quantity of carbs

in one number.

The carbohydrate in watermelon, for example, has ahigh GI. But there isn't a lot of it, so watermelon's

glycemic load is relatively low.

HIGH GL 20 +

MEDIUM GL 11-19

LOW GL 10 or less

Carbohydrates

Sugars

Monosaccharides- glucose, galactose, and fructose Disaccharides- sucrose (table sugar), maltose and lactose

(milk sugar)

Complex carbohydrates (polysacharides)

Starches are polymers of glucose Dietary fibers are mainly indigestible complex

carbohydrates in plant cell walls such as cellulose,

pectins and gums

Dietary Fiber

provides bulk modulation of peristalsis and the prevention of

constipation

soften the stool and hence promote normal elimination may also increase satietySoluble fibers

cholesterol-lowering effects increases fecal excretion of bile acids reduces cholesterol formation in the liver

increase production of short-chain fatty acids byfermentation in the large intestine

Insoluble fibers

found in vegetables, whole wheat grain, andwheat and corn bran

increases bulk in the gastrointestinal tract promotes gastrointestinal motility

Fats

Lipids: water-insoluble include triglycerides (the main constituent of fats and

oils) and sterols such as cholesterol

HDL good cholesterol LDL bad cholesterol


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Proteins

constitute the major part of the body's building blocks function as enzymes and hormones 12% of dietary calories in the Filipino diet

one third: animal sources such as fish, poultry,meat, eggs and milk

rest comes from rice, corn, bread and otherplant sources

Protein from animal sources better than from plantsources

Beans, legumes like mongo and other dried beansincluding soy beans: cheap meat substitutes

Vitamins

Fat-soluble

Vitamins A, D, E, and KWater-soluble

ascorbic acid and the B-complex vitamins

*subnotes

The amount of a vitamin in any specific food depends on two

main factors: the amount originally present in the food and

the amount of the vitamin that is destroyed or lost during

harvesting of plants or slaughtering of animals, and

subsequent storage, processing, and cooking. In general,

vitamin losses are greater at higher temperatures, prolonged

exposure to sunshine and air, and increased length of

storage. Dietary deficiencies are rare in people who eat well-

balanced diets and are usually associated with diets that have

an over-reliance on a restricted range of foods, often with

little or no fresh fruits and vegetables.

Minerals

macro-minerals (e.g. calcium and phosphorus which account

for 0.05% or more of total body weight)

micro-minerals (e.g. iron and iodine which account for much

less than 0.05% of body weight)

*subnotesMinerals are involved in a wide variety of biochemical

processes within the body. A large variety of essential

compounds in the body include mineral atoms or ions as part

of their structure. A few of the key roles are summarized

below for quick reference.


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*subnotes

Because minerals are essentially just atoms or ions, they

cannot be synthesized in they body. So all of the minerals

have to be derived from food or water.

Water most essential of all the nutrients

regulates temperature transports electrolytes and other nutrients excrete waste products from the lungs, skin and

kidneys

lubricate joints cushion the nervous system

Water (fluid) requirement 110 ml/kg for infants (3 glasses) 25 ml/kg body weight for adults (6-8 glasses)

A balanced diet is one that contains all the nutrients andother substances found naturally in food, in proper amounts

and proportions needed by the body to function well. Eating

a diet that includes a wide variety of foods in the right

amounts chosen from different food groups helps individuals

to meet the RDA.

Milk, yogurt, cheese

1 cup of milk or yogurt

1 ounces of cheese

Meat, poultry, fish, dry beans, eggs, and nuts

2-3 ounces of cooked meat, poultry, fish

cup of cooked beans

1 egg

2 tablespoons of peanut butter

Bread, cereal, rice and pasta

1 slice of bread

1 ounce ready-to-eat cereal

cup cooked cereal, rice, pasta

Vegetable

1 cup raw leafy vegetables

cup cooked

cup vegetable juice

Fruit

1 medium banana, apple, orange

cup chopped, cooked or canned fruit

cup fruit juice

Fats, oils and sweets

No serving size

Dietary Reference Intakes

Recommended nutrient intake (RENI) The average amount of a nutrient

considered adequate to meet the known

nutrient needs

Adequate Intake (AI) based on observed or experimentally

determined approximations of nutrient

intake by a group of healthy people

Tolerable Upper Intake Level (UL) highest level of daily nutrient intake that is

likely to pose no risks of adverse health

effect to most individuals in the general

population

Recommended Diet Composition

Carbohydrates

55 - 60 % Fruits, vegetables, grains

Lipids

20-30 % < 10% should be saturated fats Proteins 10-15 % Meat and meat products

*subnotes

The RDAs do not provide the additional nutrients required by

persons afflicted with diseases, traumatic stresses or nutrient

inadequacies. The recommended amounts depend on one's

body size, age, sex, physiological state and level of physical

activity.


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Prescribing Diets

1. Estimate the desirable body weight (DBW) Males: DBW 5 feet is 106 lbs. Add 6 lbs for

every inch above 5 feet

Females: DBW 5 feet is 100 lbs. Add 5 lbsfor every inch above 5 feet

Tannhausers method= [ Ht in cm 100] 10 %

2. Determine the total energy allowance (TEA) of theindividual by multiplying his DBW with the following

values, according to activity

Activity kcal/kg

DBW/day

Bed rest but mobile (hospital patients) 27.5

Sedentary (mostly sitting) 30

Light (tailor, nurse, physician, jeepney driver) 35

Moderate (carpenter, painter, heavy housework 40

Very active (swimming, lumberman) 45

3. Determine the carbohydrates (CHO), proteins (PRO)and fat by percentage distribution

Carbohydrates 55-70% TEA

Proteins 10-15% TEA

Fats 20-30% TEA

4. Calculate the number of grams of CHO, PRO and FATby dividing the equivalent grams per calories for

each nutrient

Carbohydrates 4 Cal/g

Proteins 4 Cal/g

Fats 9 Cal/g

For simplicity and practicality of the diet

prescription, round off calories to the nearest 50, and

carbohydrates, proteins and fats to the nearest 5 grams

5. Design a practical meal pattern by consulting thepatient, taking into consideration patients food

habits, food behavior and preferences

Example:

1. Make a diet prescription for a 5 foot femalesecretary. Assume CHO 65%, PRO 15% and

FAT 20%

The 10 Nutritional Guidelines for Filipinos

1. Eat a variety of foods everyday The human body needs more than 40 different

nutrients for good health.

No single food can provide all the nutrients in theamounts needed

To achieve good nutrition:

Plan and consume a balanced diet from a variety offoods

Eat the recommended amounts of food from eachfood group

Pay particular attention to the increased food needsduring pregnancy and lactation

If you eat convenience foods, choose those withhigher nutritional value and observe the principle of

variety

To achieve good nutrition:

Select fortified foods, whenever possible especiallythose with Sangkap Pinoy seal

Read food labels to make healthier choices Take nutritional supplements only upon expert

advice

Take care of the increased nutritional needs ofadolescents by giving adequate and varied meals to

get them ready for adulthood

2. Breast-feed infants exclusively from birthto 4 to 6 months, and then give appropriate

foods while continuing breast-feeding

Infants and children up to 2 years of age are mostvulnerable to malnutrition

Breastfeeding is one of the most effective strategiesto improve child survival

Nutritional requirements of an infant can beobtained solely from breast milk for the first six

months of life

At the sixth month of life at the latest, breast milkmust be complemented with appropriate foods, and

breastfeeding should be continued for up to two

year of age.

3. Maintain children's normal growth throughproper diet and monitor their growth regularly

Include milk in the child's daily diet or incorporatemilk in other foods

Use fortified foods Provide nutritious meals and snacks Continue feeding a sick child appropriately Encourage nutrient supplementation when

necessary

Take care of the increased nutritional needs ofadolescents by giving adequate and varied meals to

prepare them for adulthood

4. Consume fish, lean meat, poultry ordried beans

not only enhance the protein quality of the diet butalso supply highly absorbable iron, preformed

vitamin A and zinc

Fish, lean meat, poultry without skin and driedbeans, in contrast to fatty meats, are low saturated

fats, which are linked to heart disease.

5. Eat more vegetables, fruitsand root crops

Encourage consumption of at least two to threeservings of vegetables each day Advise intake of two servings of fruit daily, of which

one serving is a vitamin C-rich fruit

Include root crops in your meals at least three timesa week


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6. Eat foods cooked in edible/cookingoil in your daily meals

To increase energy intake of the diet, include somefoods cooked in edible/cooking oil daily

If you are at risk of heart disease, limit your intake ofcholesterol, saturated fats and fatty meats

*subnote

In general, Filipinos use very little oil in their cooking. Boiling

is the most common method of food preparation. Hence, the

total fat and oil consumption in a Filipino diet is low. Fats and

oils are concentrated sources of energy. A low-fat and oil

consumption results in a diet low in energy value,

contributing to chronic energy deficiency. Fats and oils are

also essential for absorption and utilization of fat-soluble

vitamins such as vitamin A, D, E, and K. A low fat intake may

be one of the causes of vitamin A deficiency among Filipinos.

To ensure adequate fat intake, Filipinos should be

encouraged to stir-fry foods in vegetable oil or to add fats and

oils whenever possible in food preparation. This will guard

against chronic energy deficiency and help to lower the risk of

vitamin A deficiency.

The excessive use of saturated fats and oils, however, may

increase the risk of heart disease. The proper choice of fats

and oils therefore is essential.

7. Consume milk, milk products and other calcium-rich foods, such as small fish and dark green leafy

vegetables everyday

Adequate amounts of calcium in the diet startingfrom childhood all through adulthood will help

prevent osteoporosis in later life

Everyone should include milk, milk products in thedaily meals. Otherwise, consume other calcium-rich

foods such as small fishes (eaten with the bones like

"dilis"), sardines, soy bean curd "tokwa" or "tofu",

small shrimps and green vegetables like "malunggay"

leaves, "saluyot", "alugbati" and "mustasa".

8. Use iodized salt, but avoidexcessive intake of salty foods

Helps eradicate goiter and iodine deficiency To help prevent hypertension, limit intake of salt and

salty foods.

When using salt, use iodized salt9. Eat clean and safe foodsTo help prevent food-borne diseases:

Eat clean and safe food. Drink safe water. Practice good personal hygiene. Practice environmental hygiene and sanitation. Clean and sanitize food preparation area. Practice

pest control.

Practice safe food storage, handling, preparation andservice.

10. For a healthy lifestyle and good

nutrition,exercise regularly, do not

smoke and avoid drinking alcoholic beverages

To achieve and maintain desirable body weight,balance food intake with physical activity and

exercise.

To obtain all the benefits of exercise, performaerobic exercise regularly for at least 3 to 5 times a

week for 20-30 minutes or more.

As a further hedge against chronic degenerativedisease, do not smoke. If you have acquired the

habit, stop smoking.

It is strongly advised to drink in moderation, ifalcohol is used at all.

FAMILY WELLNESS

Wellness is

An integrated method offunctioning which is orientedtoward maximizing the potential of which the individual

is capable.

It requires that the individual maintain a continuum ofbalance and purposeful direction within the environment

where he is functioning.

A life-long process of moving toward enhancing yourphysical, intellectual, emotional, social, spiritual, and

environmental well-being.

Composed of six dimensions

How WELLTHYAre You?

Many of us recognize the importance of wellness, but itis easy to get caught up in our busy schedules and find

were not maintaining a holistic regimen that consistently

meets our needs.


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Definitions of Health

"Health is a state of complete physical, mental, and social

well-being and not merely the absence of disease"

(WHO, 1947, p. 1)

GOOD HEALTH MEANS

Preventing premature death Preventing disability Promoting an environment that supports life Cultivating community and family support Enhancing individuals ability to respond and to take

action

Assuring that all people achieve and maintain amaximum level of functioning

The positiveness of health does not lie in the state , but in

the struggle-- the effort to reach a goal

Gordon, I . 1958

Wellness is a choice

Self-regulation

Cornerstone of health and wellness Taking control of ones lifestyle and health behaviors

so that lifestyle is the result of choice and not the

result of chance and ignorance

Conscious, willful, internally directed behavior thatpromotes health and homeostasis

Ingredients of self-regulation

Information and knowledge Decision making Commitment Goals Skill acquisition

GREEN & SHELLENBERGER, 1991

THEORETICAL CONSTRUCTS

CONSUMER INFORMATION SOCIAL LEARNING HEALTH BELIEFS MODEL TRANS - THEORETICAL MODEL

TRANS-THEORETICAL MODEL

CHANGE IS A DYNAMIC CONCEPT.

CHANGING BEHAVIOR GOES THROUGH STAGES

A MODEL OF HEALTH BEHAVIOR CHANGE

PROCHASKA & VELICER, 1997

PRE-CONTEMPLATION CONTEMPLATION PREPARATION ACTION MAINTENANCE TERMINATION

Physician recommendations have been demonstrated to

significantly improve patients efforts to change behaviors.

Rippe J et al., Lifestyle Medicine, 1999

Natural Course of Disease

every consultation is an opportunity for preventive care

WELLNESS GUIDE

What does it include?

Risk assessment Counseling for the prevention of disease and

maintenance of health

Screening and health protection packages Immunizations ChemoProphylaxis

RISK ASSESSMENT

Basis is still a comprehensive clinical history Past medical and surgical history (childhood

illnesses) Immunizations given Medications (prescriptions and over the

counter, supplements)

Disabilites / handicaps And pertinent Physical Examination General Data (age, sex, educational level, socio-economic

status)

Family History (genogram) Personal Social History (include lifestyle check, stressors

and coping mechanisms)

TRAVEL HISTORY


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HOME ENVIRONMENT WORK ENVIRONMENT Basic Physical Examination (height, weight, BMI, waist

circumference)

THE WELLNESS GUIDE TO

PREVENTIVE CARE

Education/Counseling about healthy habits and injuryprevention

Screening tests for early detection of disease Immunizations ChemoprophylaxisHow to change a behavior?

- Lifestyle check- Life is about behavior- Do I really have to change everything

Lifestyle - Specific Recommendations

DIET & NUTRITION PHYSICAL ACTIVITY TOBACCO (active, passive) ALCOHOL (# of drinks) Stress Coping and MENTAL HEALTH SLEEP CAFFEINE INTAKE SEXUAL ACTIVITIES

Caffeine

Caffeine contained in two cups of coffee may raise the BP by

5 mm Hg in infrequent users. In habitual users, caffeine has

minor effect on the blood pressure.

Ruhl et al, 2000

Drinking more than five cups of coffee per day was more

common among patients with subarachnoid aneurysmal

hemorrhage (85%) than controls (59%) (p = 0.004).

Isaksen, 2002

SLEEP

At least 8 hours of sleep per day poor sleep with initiation difficulties is an

independent risk factor for cardiac events

among men

reduced stage 3-4 sleep predicted poorer overallhealth

Poorer quality of life was predicted by reduceddeep sleep

Promoting Sleep Hygiene

American Academy of Family Physicians Go to bed and wake up at the same time every day even

if you didn't get enough sleep.

Develop a bedtime routine. Do the same thing everynight before going to sleep.

Use the bedroom only for sleeping or having sex. Don'teat, talk on the phone or watch TV while you're in bed

Make sure the bedroom is quiet and dark. Avoid alcohol, it interrupts the body's sleep rhythms

and can cause sleep disturbances

Avoid caffeine less than six hours before bedtime Avoid eating a big meal too close to bedtime

LIVE SENSIBLY!

Among a thousand people , only one dies a natural death..

the rest succumb to irrational modes of living.

Maimodes 1135-1204 AD


PREVENTIVE CARE

Screening tests for early detection of disease Education/Counseling about healthy habits and

injury prevention

Immunizations Chemoprophylaxis

Screening

Executive check up

Periodic checkup

WHAT IS IT?

A group of tasks designed either to determine the risk of

subsequent disease or to identify disease in its early

symptomless state.

- Feightner et al., 1995

Periodic Health Examinations

Applying Evidence-Based Medicine in Maintaining Wellness

Periodic Health Examinations:

Is It Needed?

Prevention of Illness Chronic Illness Infectious diseases Malignancies Injuries

Screening Detection of unrecognized health risks Diagnosis of asymptomatic disease

Screening Tests for Men

General Adult Population

Body mass index OR Height in cm and Weight in kg[Yearly]

Waist hip ratio (Waist in cm/Hip circumference incm) [Yearly]

Auscultatory BP [Yearly] Eye examination [Yearly] Smoking history Level of activity

Adults 40 yrs and older

total cholesterol [q 2 yrs] Fasting blood sugar [q 2 yrs


Visual examination of oral cavity [yearly] Fecal occult blood [yearly] DRE, PSA


General health questionnaire [Once] Visual acuity with Snellen Chart [Yearly] Functional reach [Yearly] Colonoscopy


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Men's Health Check-up List

Cholesterol checks: every 5 years, starting at age 35. Ifsmoking, have diabetes or if heart disease runs in the

family, start having cholesterol check at age 20

Depression: feeling "down," sad, or hopeless, and havelittle interest or pleasure in doing things for 2 weeks

straight

Sexually Transmitted DiseasesScreening Tests for Women

General Adult Population

Body mass index OR Height in cm and Weight in kg[Yearly]

Waist hip ratio (Waist in cm/Hip circumference incm) [Yearly]

Auscultatory BP [Yearly] Eye examination [Yearly] Smoking history Level of activity Pap smear

Women 40 59 years old

Clinical breast examination [Yearly] Screening mammography [Yearly]

Adults 40 yrs and older total cholesterol [q 2 yrs] Fasting blood sugar [q 2 yrs


Visual examination of oral cavity [yearly] Fecal occult blood [q 2 yrs]


General health questionnaire [Once] Visual acuity with Snellen Chart [Yearly] Functional reach [Yearly]

Women's Health Check-up List

Depression: feeling "down," sad, or hopeless, and havelittle interest or pleasure in doing things for 2 weeks

straight

Osteoporosis Tests: bone density test at age 65 to screenfor osteoporosis. If between the ages of 60 and 64 and

weigh 154 lbs. or less, talk to HCP

Chlamydia Tests and Tests for Other Sexually TransmittedDiseases

Mammograms: every 1 to 2 years starting at age 40.Optional 40-49, yearly 50-75

Pap Smears: Every 1 to 3 years if sexually active or areolder than 21. Maximum interval every 3 yrs after 3

consecutive normal exams, yearly until 75, >75 optional

Cholesterol checks: At least every 5 years, starting at age35. If smoking, have diabetes, or if heart disease runs inthe family, start cholesterol check at age 20.

Recommended Tests for Selected Populations

Adults in occupational setting

Chest X-ray [Yearly]Healthcare workers

Chest X-ray [Yearly] Mantoux test [Once]

Caregivers

General health questionaire [Yearly]Retirees

General health questionaire [Yearly]Truck and bus drivers, security personnel & pilots

12-L ECGOccupational exposure to noise >85 decibels for 8 hours daily

Pure tone audiometryContacts of active or potentially active TB disease

Chest X-ray [Once] Mantoux test [Once]

Sex with multiple partners

STD panel [Yearly]CSW; partners of patients with STD

STD panel [q 6 mos]Close household contacts

HbsAg and Anti-HBs using enzyme immunoassay[Once]

Anti HAV IgG enzyme immunoassay [Once]Adults who chew or smoke tobacco; Adults who smoke

cigarettes

Visual Examination of the Oral Cavity [Yearly] FBS Ankle-Brachial index

Heavy alcohol drinkers

Visual Examination of the Oral Cavity [Yearly]Family history of early CVD

Fasting Lipid ProfileFamily history of DM

Any of the ff: FBS, RBS, 75g OGTT, FCG or RCG [q 2yrs]

History of Familial dyslipidemia

Ankle brachial index [q 2 yrs] Lipid profile [q 2 yrs] Any of the ff: FBS, RBS, 75g OGTT, FCG or RCG [q 2

yrs]

Family history of gout

Serum uric acid [q 2 yrs]Family history of glaucoma

Intraocular pressure [q 2 yrs]Two or more of the ff on PE: obesity, smoking, HPN

Lipid profile [q 2 yrs] 12 L ECG

Xanthoma

Lipid profile [q 2 yrs]Obesity

Any of the ff: FBS, RBS, 75g OGTT, FCG or RCG [q 2yrs]


PREVENTIVE CARE


injury prevention



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Adult immunization

H. Influenza vaccine every year starting at age 50 Tetanus-diphtheria, 3-dose-series for previously

unvaccinated, booster dose every 10 years

Pneumococcal vaccine once at age 65 (earlier if (+) forcertain health problems, such as lung disease)

Hepatitis A & B shots Varicella vaccine for all adults without prior infectionChildren immunization

BCG DPT OPV Measles MMR Hepatitis B Varicella Tetanus-diphtheria boosters(Td)-11-16 yrs Rubella (females > 12 yrs)Adult Immunization

For women aged 19 through 26 years, either HPV2 orquadrivalent (HPV4) can be used for vaccination; alsoused a permissive recommendation for use of HPV4 in

men.

Revision to the measles, mumps, rubella (MMR) footnotenow notes in the beginning of the footnote that adults

born before 1957 generally are immune.

Further revisions clarify which adults born during or after1957 do not need 1 or more doses of MMR for the

measles and mumps components.

New interval dosing information states that a seconddose of MMR should be given 4 weeks after the first

dose.

Another revision to this footnote highlights that womenin whom rubella vaccination is not documented should

receive a dose of MMR.

A new section added to this footnote provides guidelinesfor vaccinating healthcare personnel born before 1957

routinely and during outbreaks.

Revision to the hepatitis A footnote now includes anindication for administering this vaccine to unvaccinated

persons who expect to be in close contact with an

international adoptee.

Revision to the hepatitis B footnote now includesschedule information for the 3-dose hepatitis B vaccine.

Revision to the meningococcal vaccine footnote explainsthat the meningococcal conjugate vaccine is preferredfor adults not older than 55 years and that the

meningococcal polysaccharide vaccine is preferred for

adults who are at least 56 years or older

For adults previously vaccinated with meningococcalconjugate vaccine or meningococcal polysaccharide

vaccine, revaccination with meningococcal conjugate

vaccine is recommended.

Revision to the selected conditions portion of the H.influenzae type B footnote now elucidates which high-

risk persons can receive 1 dose ofH. influenzae type B

vaccine.

Chemoprophylaxis

THE WELLNESS GUIDE TO PREVENTIVE CARE


injury prevention


Aspirin

older than 40 or younger than 40 who have highblood pressure, high cholesterol, diabetes, or if

smoking

Hormonal Replacement Therapy

risks of taking the combined hormones estrogen andprogestin after menopause to prevent long-term

illnesses outweigh the benefits

Iron

in pregnant women helps both the mother andbaby's blood carry oxygen

Folic acid

-women of child bearing age- 400 micrograms (or 0.4mg) every day could prevent up to 70 percent of

neural tube defects

CalciumGuidelines from the National Academy of Sciences says that

the Adequate Intakes (AIs), in milligrams (mg), each day for

calcium are:

Infants 0-6 mo - 210 mg7-12 mo - 270 mg

Children 1-3 yrs - 500 mg4-8 yrs - 800 mg

9-13 yrs - 1,300 mg

4-18 yrs - 1,300 mg

Adults 19-50 yrs - 1,000 mgOver 51 yrs - 1,200 mg

During Pregnancy & LactationUnder 18 yrs - 1,300 mg

19 yrs and older - 1,000 mg

Calcium and Vitamin D

A serving of milk or yogurt contains around 300 mgcalcium

Vitamin D is needed to help the body absorb calciumcorrectly

FAMILY WELLNESS

Family wellness is a bigger picture than personal

wellness. And while it includes the same individual wellness

factors for each member of your family, it also includes the

wellness factors of the family as a group.

Family well-being depends on the quality of the

communication and time shared between everyone

in the family.


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How to know if the family is healthy?

Using tools of family assessment

- Genogram- Family apgar- Lifestyle- DIET- ACTIVITIES FOR FITNESS- Life cycle stage- History of diseases- History of dysfunctions- FAMILY MAPPING

BIOSTATISTICS in EPIDEMIOLOGY

Definitions

Statistics is the science and art of collecting,summarizing, and analyzing data that are subject to

random variation (Last, 1995).

Biostatisticsis the application of statistics tobiological problems.

Review of Concepts

Data refers to a collection of items of information. A variable is any quantity that varies. It is any

attribute, phenomenon, or event that can havedifferent values.

Uses of statistics

Statistics is an indispensable tool in medicine andhealth.

Almost all medical and health studies rely on thequantification of health and disease events in

populations.

Data collected in medical and health studies usuallyinvolve several observations on several variables.

Analyzing and presenting such large volumes of rawdata can be very cumbersome and painful.

Describe large data sets using only few numbers (likemean, range, etc.,)

Generalize the results of a small sample to the largerpopulation from which the sample is drawn

(extrapolation)

Compare different variables and test an underlyinghypothesis

Types of measurements

The basic building blocks of any study are the data - the

measurements which describe the factors being studied

Nominalvariables are observations which can beclassified into one of a number of mutually exclusive

categories

Ordinal variables are slightly more sophisticatedmeasures than nominal data Ratio and intervalscales are called continuous data.

The most sophisticated measures are those where

individuals are placed on a scale of continuous scale

in which the distance between two measurements

are well define

Summarizing data

Measures of central tendencymean, median and mode

Measures of dispersionVariance (s

2) is the mean square deviation

Standard deviation (s) is nothing but the square root

of the variance.

Inferential Biostatistics

Estimation

Why do we need to study samples? In an ideal world, if one

had find out, say, the mean birth weight of all babies born in

India during a year, one would weigh allthe babies born in

India during a year. By using samples we may able to

estimate a value that will represent the mean birth weight of

all babies in India.

Hypothesis-testing

Hypothesis testing (tests of significance)

involves ascertaining whether an

observed difference could have occurred

purely due to chance. This probability is

quantified as a P-value.

In hypothesis testing, one first starts with theassumption that the observed difference is not a rea

difference but one produced merely due to play of

chance. This is called the null hypothesis

One then tries to disprove the null hypothesis bycalculating the probability of the observed differencebeing due to chance. This probability is given by the

P value

If the P value is lower than a predetermined figure(0.05 by convention) obtained from the statistical

table for normal distribution, then one infers that

the observed difference is real and cannot be

explained purely by chance. The null hypothesis is

thus rejected.

The P value tells us only whether there is astatistical significance or not.

OBSERVATIONAL STUDY DESIGNS

Descriptive studies or case series

A descriptive study is the weakest epidemiologicaldesign.

The investigators merely describe the health statusof a population or characteristic of a number of

patients.

Description is usually done with respect to timeplace and person

Cohort Studies

Cohort studies are considered the strongest of allobservational designs.

A cohort study is conceptually very straightforward. The idea is to measure and compare the incidence ofdisease in two or more study cohorts Cohort studies are usually prospective or forward

looking


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Cohort Studies

New cases of the disease are picked up during followup and the incidence of the disease is computed on

the basis of the exposure status.

The incidence in the exposed cohort is thencompared with the incidence in the unexposed

cohort.

This ratio is called Relative Risk (RR) or Risk RatioRelative Risk = Incidence in the exposed cohort

/Incidence in the unexposed cohort

The relative risk is a measure of association betweenthe exposure and the outcome.

The larger the RR, the stronger the association. As it can be seen, the cohort study is the only study

design in which the true incidence of a disease can

be estimated.

The RR therefore is considered the best measure ofassociation

Relative Risk

Data for relative risk for myocardial infarction in patients

taking aspirin

RR= 139/11,037 0.0126 = 0.581

239/11,034 0.0217

The Relative Risk is less than 1

Case Control Studies

Conceptually, case control studies are more difficultto comprehend than cohort studies

In a cohort study, disease free exposed and non-exposed cohorts are followed up and then outcome

events are picked up as and when they occur. In a

case control design, sampling starts with diseased

and non-diseased individuals

They are called-cases and controls The exposure status is then determined by looking

backward in time (using documentation of exposures

or recall of historical events). For this reason, case

control studies are also called as retrospective

studies

The measure of association in a case control study iscalled an Odds Ratio (OR).

The OR is the ratio of the odds (chance) of exposureamong cases in favor of exposure among controls

Odds Ratio

Data for odds ratio for stroke with history of drug abuse

73/214 = 0.518 18/214 =0.092

141/214 196/214

OR = 0.518/0.092=5.64 therefore the patient who has had a

stroke is almost 6 times more likely to have abused drugs

than the patient who has not had a stroke

If the disease is rare, then the OR tends to be a goodapproximation of the Relative risk (RR). However, true

incidence estimates can not be generated from a case

control study.

CLINICAL TRIALSThe Randomized Controlled Trial (RCT)

The RCT is widely held as the ultimate study design;the "gold standard" against which all other designs.

The subjects are usually chosen from a large numberof potential subjects.

Sampling includes prescreening using a set ofinclusion and exclusion criteria.

After this, an informed consent is obtained fromeach participant.

Randomization is then done to allocate subjects toeither the treatment group or the placebo group

Ideally, intervention should be done in a blindedfashion.

Neither the investigator nor the subject should knowthe nature of the treatment that is being

administered.

After the intervention, the key outcomes that arebeing studied need to be measured by a blinded

investigator

Analysis involves looking for differences in theoutcome rates in the two arms of the clinical trial


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Double-Blind Cross-Over Design

What are the phases of clinical trials?

Clinical trials are conducted in phases. The trials at each

phase have a different purpose and help scientists answer

different questions:

InPhase I trials, researchers test a experimental drugor treatment in a small group of people (20-80) for

the first time to evaluate its safety, determine a safe

dosage range, and identify side effects.

Initial studies to determine the metabolism andpharmacologic actions of drugs in humans, the side

effects associated with increasing doses, and to gain

early evidence of effectiveness; may include healthyparticipants and/or patients.

InPhase II trials, the experimental study drug ortreatment is given to a larger group of people (100-

300) to see if it is effective and to further evaluate its

safety.

Controlled clinical studies conducted to evaluate theeffectiveness of the drug for a particular indication

or indications in patients with the disease or

condition under study and to determine the

common short-term side effects and risks.

InPhase III trials, the experimental study drug ortreatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side

effects, compare it to commonly used treatments,

and collect information that will allow the

experimental drug or treatment to be used safely.

InPhase IV trials, post marketing studies delineateadditional information including the drug's risks,

benefits, and optimal use

THE ABCs of EVIDENCE-BASED MEDICINE (EBM)

Why Doctors Bother With EBM?

Doctors are unable to read original research articleor fully understand the results;

This inability to critically appraise a study and graspall that is implied in its findings limits the doctors

independence; thus,

There is reliance on expert opinion, the practices ofcolleagues and the pharmaceutical industry.

With the enormous volume of l iterature, doctorsapply EBM to clinical practice in order to

differentiate a good study from a trash; that is, a

study that is valid with credible results that they can

apply to their patients.

EBM A AQUIRE THE SKILLS

The 3 skills of EBM: how to acquire the information,appraise articles and apply the evidence.

VALIDITY versus RELIABILITY

Validity

Validity refers to how close we think the studyresults are to the truth

AccuracyReliability

Reliability means hitting the same objectiveconsistently.

Precision Intra-observer or inter-observer

EBM B BIAS

In general, the key word in the understanding of theconcept of bias is different.

If the way in which participants are selected into thestudy is different for example.

Similarly, if the manner in which information isobtained, reported, or interpreted is different

between groups in the study, then an inaccurate

impression of the true relationship may be obtained

In Summary:

There are 2 general types of observation bias,depending on the source of non-comparability:

1. recall bias 2. interviewer bias

EBM C CLINICAL TRIALS

Randomized controlled trials or RCTsThe Role of Bias in Clinical Trials

Achieve control for any influence of unknownvariables due to randomization (controlled biases).

The favorable impression (good) that this designstrategy may have on those reading the publishedresults of a trial.

How about those trials not published? Publication bias The burden of proof is on the investigator to show

that all possible biases in the allocation of patients to

a study group or confounding effects of known or

unknown factors that may differ between the study

groups did not account for the observed result.
http://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossaryhttp://clinicaltrials.gov/ct/info/glossary


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Subjects in a trial of medical therapy may deviatefrom the protocol for a variety of reasons.

Developing side effects, forgetting to take theirmedication, or simply withdrawing their consent

after randomization.

Randomized patient rapidly worsens to the pointwhere therapy becomes contraindicated.

The extent of non-compliance in any trial is relatedto the length of time that participants are expected

to adhere to the intervention, as well as to the

complexity of the study protocol.

EBM D Design of the study

STUDY METHODOLOGYSTUDY BLINDS

BLINDING is an attempt to make the treatmentsbeing compared indistinguishable.

Allocation concealment is an attempt to preservethe random order by which the patients are assigned

to the groups.

Blinding is impossible when the interventions involvediet, educational maneuvers or surgical procedures.

Single blind versus double-blindRANDOMIZATION

Random assignment of patients to treatment groupsin a trial is the best technique to ensure that

treatment groups are truly comparable.

Such that each individual will have an equal chanceof being selected.

Known as well as unknown factors are equallydistributed to the groups.

Appraisal Form for Therapy

Directness Validity Results Applicability

Directness

Population Intervention or exposure Outcome

Population

Children Adults Elderly Certain class or severity of illnesses

Exposures

Behaviors Treatments Patient characteristicsOutcomes Treatment or cure Alleviation of symptoms or symptom control Quality of life Survival Morbidity Mortality Adverse events or harm

ASSESSMENT OF VALIDITY

Were patients randomly assigned to treatmentgroups?

Was allocation concealed? Were baseline characteristics similar at the start of

the trial?

Were patients blinded to treatment assignment? Were caregivers blinded to treatment assignment? Were outcome assessors blinded to treatment

assignment?

Were all patients analyzed in the groups to whichthey were originally randomized?

Was follow-up rate adequate?What are the results?

1. How large was the effect of treatment?2. How precise was the estimate of the treatment

effect?

-- p-value

-- confidence interval

-- standard error

RR, ARR, NNT

A measurement of how large was the effect oftreatment (RR, ARR and NNT)

RR is relative risk or comparison (ratio) of the risk ofoutcome in the treatment and control groups.

RRR is relative risk reduction or 1-RR. ARR is absolute risk reduction is difference in risk in

the control and treatment groups.

NNT is number-needed-to-treat and is the reciprocalof the ARR.

Can the results be applied to my patient care?

1. Are there biologic issues that may affect applicabilityof treatment?

2. Are there socio-economic issues affectingapplicability of treatment?

Individualizing the Results

What is the likely effect of the treatment on yourindividual patient?

EBM E EVIDENCE

What is the level of evidence?HIERARCHY OF EVIDENCES

(Strength of evidence for treatment decisions)

N of 1 randomized controlled trial Systematic reviews of randomized trials (meta-

analysis)

Single randomized trial Systematic review of observational studies Single observational study Physiologic studies Unsystematic clinical observations


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Statistical versus clinical significance

Statistical significance means the study has enoughpower to detect a difference between or among

treatment groups and that means, p-value is less

than 0.05.

Clinical significance means that the study did notreach enough power to detect a difference but in

the real-world scenario, there is a difference or at

least a trend along this line.

EPIDEMIOLOGY

Greek words: epi(upon)

demos (people)

Definition

The study of both the distribution of diseases inhuman populations and the determinants of the

observed distribution

It began as the study of infectious diseases but hasexpanded to include the study of chronic diseases,

health care organization, health care delivery,

occupational and environmental health

COMPONENTS

DISEASE FREQUENCY

The measurement of disease frequency involvesquantification of the existence or occurrence of

disease

The availability of such data is a prerequisite for anysystematic investigation of patterns of disease

occurrence in human populations

DISTRIBUTION OF DISEASE

Considers such questions as who is getting thedisease within a population as well as where and

when the disease is occurring

Derives from the first two since the knowledge offrequency and distribution of disease is necessary to

test an epidemiologic hypothesis

Describe patterns of disease as well as to formulatehypotheses concerning possible causal or preventive

factors

FOURTH ASPECT OF THE DEFINITION OF EPIDEMIOLOGY

STUDIES ARE DONE IN HUMAN POPULATIONS EPIDEMIOLOGY MAY BE VIEWED AS BASED ON TWO

FUNDAMENTAL ASSUMPTIONS

2 BASIC ASSUMPTIONS

1. That human disease does not occur at random 2. That human disease has causal and preventive

factors that can be identified through systematic

investigation of different populations or subgroups

of individuals within a population in different places

or at different times.

HISTORY OF EPIDEMIOLOGY

Hippocrates, Graunt, and Farr each contributed to anincreasing sophistication in the understanding of

disease frequency and distribution - two of the three

components of the definition of epidemiology.

HIPPOCRATES

THE DEVELOPMENT OF HUMAN DISEASE RELATEDTO THE EXTERNAL & PERSONAL ENVIRONMENT OF

THE INDIVIDUAL

Whoever wishes to investigate medicine properly should

proceed thus: in the first place to consider the seasons of

the year, and what effects each of them produce. Thenthe winds, the hot and the cold... the waters which the

inhabitants use... The mode in which they live, what are

their pursuits, whether they are fond of drinking and

eating in excess, and given to indolence, or are fond of

exercise and labor. - HIPPOCRATES

JOHN GRAUNT

In 1662, published The Nature and PoliticalObservations Made Upon the Bills of Mortality

Analyzed the weekly reports of births and deaths inLondon

For the first time, quantified patterns of disease in apopulation

Noted an excess of men for both births and deaths,high infant mortality and the seasonal variations in

mortality

Attempted to provide a numerical assessment of theimpact of plaque on the population of the city

Examined characteristics of the years in which suchoutbreaks occurred

Recognized the value of routinely collected data inproviding information about human illness (forms

the basis of modern epidemiology)

WILLIAM FARR In 1839, responsible for medical statistics in the

Office of the Registrar General for England and

Wales

Set up a system for routine compilation of thenumber and causes of deaths

Established a tradition of careful application of vitalstatistical data to the evaluation of health problems

of the general public

Recognized that data collected from humanpopulations could be used to learn about illness


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Compared mortality patterns of married and singlepersons and workers in different occupations (metal

mines & earthenware industry)

Noted the association between the elevation abovesea level and deaths from cholera

Attempted to ascertain the effect of imprisonmenton mortality

Addressed many major methodologic issues relevantto modern epidemiology

Defined the exact population at risk Chose an appropriate comparison group Considered whether other factors could affect the

results such as age, duration of exposure or general

health status


Two decades after Farr began his work, theavailability of routinely collected data on the

population and mortality patterns of England

enabled another British physician, John Snow, to

formulate and test a hypothesis concerning the

origins of an epidemic of cholera in London.

On the basis of the available descriptive data,including the observations made by Farr, Snowpostulated that cholera was transmitted by

contaminated water through a then unknown

mechanism.

He observed that death rates from cholera wereparticularly high in areas of London that were

supplied with water by the Lambeth Company or

the Southwark and Vauxhall Company, both of which

drew their water from the Thames River at a point

heavily polluted with sewage.


Between 1849 and 1854, the Lambeth Companychanged its source to an area of the Thames where

the water was quite free from the sewage of

London. The rates of cholera declined in those area

of the city supplied by the Lambeth Company, while

there was no change in those areas receiving water

from the Southwark and Vauxhall Company.

In 1854, Snow noted that the most terribleoutbreak of cholera which ever occurred in this

kingdom, is probably that which took place in Broad

Street, Golden Square and the adjoining streets, a

few weeks ago. Within two hundred and fifty yards

of the spots where Cambridge Streets joins Broad

Street, there were 500 fatal attacks of cholera in tendays.

Snow tabulated the number of deaths from cholerathat occurred from the commencement of the

epidemic in August 1853 to January 1854 according

to the two water companies supplying the various

sub-districts of London.

The areas of London supplied entirely by theSouthwark and Vauxhall Company experienced a

rate of 114 deaths from cholera per 100,000

persons, whereas there were no deaths from cholera

during that time in the districts supplied entirely by

the Lambeth Company.

A large area supplied by both companiesexperienced a rate midway between those for the

districts supplied by either alone.

These observations were consistent with Snowshypothesis that drinking water supplied by the

Southwark and Vauxhall Company increased the risk

of cholera compared with water from Lambeth

Company.

Snow also recognized the possibility that manyfactors other than the water supply differed

between the two geographic areas and thus could

account for the observed variation in cholera rates.

His unique contribution to epidemiology lies in his

recognition of an opportunity to test the hypothesis

implicating the water supply.

Snow outlined his natural experiment in his book Onthe Mode of Communication of Cholera: In the sub-

districts as being supplied by both companies, the

mixing of the supply is of the most intimate kind. The

pipes of each Company go down all the streets, and

into nearly all the courts and alleys.

A few houses are supplied by one Company and afew by the other, according to the decision of the

owner or occupier at that time when the Water

Companies were in active competition. In many cases

a single house has a supply different from that on

either side.

Each company supplies both rich and poor, bothlarge houses and small; there is no difference either

in the condition or occupation of the persons

receiving the water of the different Companies.

Now it must be evident that, if the diminution ofcholera, in the districts partly supplied with the

improved water, depended on this supply, the houses

receiving it would be the houses enjoying the whole

benefit of the diminution of the malady, whilst the

houses supplied with the water from Battersea Fields

(Southwark & Vauxhall Co.).

These houses supplied by the Southwark andVauxhall Company would suffer the same mortality

as they would if the improved supply did not exist at

all.

As there is no difference whatever, either in thehouses or the people receiving the supply of the two

Water Companies, or in any of the physical

conditions with which they are surrounded, it is

obvious that no experiment could have been devisedwhich would more thoroughly test the effect of

water supply on the progress of cholera than this,

which circumstances placed ready made before the

observer.

The experiment, too, was on the grandest scale. Nofewer than 300,000 people of both sexes, of every

age and occupation, and of every rank and station,

from gentlefolks down to the very poor, were divided

into 2 groups without their choice, and, in most

cases, without their knowledge...


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... One group being supplied with water containingthe sewage of London, and amongst it, whatever

might have come from the cholera patients, the

other group having water quite free from the

impurity. To turn this grand experiment to account,

all that was required was to learn the supply of

water to each individual house where a fatal attack

of cholera might occur.

Within the area supplied by both companies, Snowwalked from house to house and, for every dwelling

in which a cholera death had occurred, was able to

determine which company supplied the water.

The data provided convincing evidence that watersupplied by the Southwark & Vauxhall Co. was

responsible for the outbreak of cholera in London.

Thus, Snow charted the frequency and distributionof cholera and also ascertained a cause, or

determinant, of the outbreak.

Snow was the first investigator to draw together all 3components of the definition of epidemiology

Snows approach in the investigation of the choleraepidemic of 1853 to 1854 was applied primarily to

outbreaks of infectious diseases throughout the 19th

and early 20th

centuries. Thus the term epidemiologywas originally used

almost exclusively to mean the study ofepidemics of

infectious disease.

EPIDEMICS

Over the past 80 years, patterns of mortality indeveloped countries have changed markedly, with

chronic diseases assuming increasing importance.

As a consequence, the concept of an epidemic hasbecome much broader and more complex,

necessitating more advanced methods than the first

developed by Snow.

During the 20th century, changes in diseasedistributions have resulted in a broadening of the

term epidemic to include any disease, infectious or

chronic, occurring at a greater frequency than

usually expected.

DEFINITION OF TERMS

Epidemic the occurrence of an illness, in a specifiedgeographic area, that clearly exceeds the normal,

expected incidence (new cases). Ex. HIV

Hyperendemic a situation in which there is apersistent transmission of a disease among most of a

population. Ex. Malaria in certain parts of Africa

Endemic the constant presence of a disease in aspecific geographic area. Ex. Schistosomiasis inSamar

Pandemic the worldwide spread of an epidemicdisease. Ex. SARS

In the U.S., coronary heart disease is clearlyepidemic. Despite a recent period of decline,

mortality from this disease remains the chief cause

of death among both men and women, occurring at

one of the highest rate in the world.

ANOTHER EXAMPLE

Lung cancer in the U.S. today is also epidemic, sincethe overall mortality rate from this disease tripled

between 1950 and 1983, rising from 12.8 to 38.1 per

100,000 population, even after taking into account

the increasing age of the general population.

DEVELOPMENTS IN MODERN EPIDEMIOLOGY

1. DESIGN OF STUDIES AND TECHNIQUES FOR

COLLECTING AND ANALYZING DATA TO FACILITATE THE

EVALUATION OF RISK FACTORS FOR CHRONIC DISEASES.

2. APPLICATION OF EPIDEMIOLOGIC PRINCIPLES AND

METHODS TO THE DESIGN, CONDUCT AND ANALYSIS OF

CLINICAL TRIALS, STUDIES IN WHICH THE INVESTIGATORS

THEMSELVES ALLOCATE TO PARTICIPANTS THE

EXPOSURES BEING STUDIED.

BROAD CATEGORIES 0F DESIGN STRATEGIES IN

EPIDEMIOLOGIC RESEARCH

1. DESCRIPTIVE EPIDEMIOLOGY

2. ANALYTIC EPIDEMIOLOGY

Descriptive Epidemiology

Is concerned with the distribution of disease,including consideration of what populations or

subgroups do or do not develop a disease, in what

geographic areas it is most or least common, andhow the frequency of occurrence varies over time.

Analytic Epidemiology

Focuses on the determinants of disease by testingthe hypotheses formulated from descriptive studies,

with the ultimate goal of judging whether a

particular exposure causes or prevents disease.

Population At Risk: Health Risks And Risk Assessment

POLLUTION

Land Pollution

harmful substances introduced to the soil

May be consequences of: unsanitary habits various agricultural practices

Ex. soil fertilizers incorrect methods of waste disposal

Prevention: Education of farmers on the effects of nitrates in

fertilizers

Instruction to follow sound practices in their use Pesticide formulation should be registered

before being allowed in the market

Training of health care workers in the recognition andmanagement of poisoning

Air Pollution

Smog a.k.a phytochemical haze Oxidation of hydrocarbons and nitrogen oxide Mild: Irritate eyes, nose and throat Danger: sulfur dioxide and other materials

generated by burning of fuels

Prevention: Implementation of strict regulation Covering of mouth and nose whenever exposed

Clean Air Act of 1999 or Republic Act No. 8749


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Holistic national program of air pollutionmanagement

Emphasis: prevention rather than control, publicinformation and education and cooperation and

self-regulation among citizens

Water Pollution

any change in natural water which may impair their future

use

Causes: Dirty drainage systems Dirty recreational water Dirty sewage Industrial waste

Effects: Change in temperature of water Introduction of organic or inorganic substances Depletion of oxygen: death of aquatic life

World Health Organization (WHO): 80% of all disease are related to drinking

contaminated water

10million people worldwide die from water-related diseases

50% are infants and children Control measures:

Physical treatment by filtration Chemical treatment using coagulants Biologic treatment by transformation in the

earths crust

RADIATION

Emission of discrete particles or rays from asubstance

Produces charge ions that produce abnormalchemical reactions

Early effects in large doses cause complete halt inblood cell formation

Prolonged and continuous exposure lead to physicaland genetic defect

OCCUPATIONAL HAZARDS

- Disease resulting from exposure to toxic chemical agentso Ex: Asbestosis, silicosis, lead, arsenic and

organophosphate poisoning

- Disease due to physical agentso Ex: Asphyxia, Caissons disease, altitude

sickness, heat stroke

- Diseases due to mechanical factorso Ex: postural problems and back pains

- Diseases due to infectious agentso Ex: Tetanus, rabies, ringworm, erysipelas

- Control measures:o Isolationo Substitutiono Alteration of work processeso Ventilationo Proper waste disposalo Adequate sanitary facilitieso Personal protective devices

PESTS

Belong to the group of mans natural enemies that causedamage, discomfort and displeasure to life:

Bee and wasp stings anaphylactic shock Rats rat-bite fever Ticks, mites, bedbugs, cockroaches and

mosquitoes itchiness

Houseflies - diarrheaPOVERTY

Common denominator of various diseases: malnutrition,tuberculosis, venereal diseases

Higher rates of infant and perinatal mortality Prominent environmental hazards due to poor

housing

Overcrowding: fire hazard Poorly lighted streets and lack of safe area for

children in the community breed crime and

accidents

Infrequent garbage collection and improperdisposal give rise to breeding place for rats and

insects

Module 5 Reviewer

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