Transcript of BIO4503 APPLIED EPIDEMIOLOGY NON-COMMUNICABLE DISEASES 1.
- Slide 1
- BIO4503 APPLIED EPIDEMIOLOGY NON-COMMUNICABLE DISEASES 1
- Slide 2
- DEFINITION AND RELATED CONCEPTS Def: noncommunicable disease,
(NCD) are no-transmissible between persons, medical conditions
Chronic vs, acute: NCDs may be chronic or acute Some examples:
autoimmune diseases, heart disease, stroke, many cancers, asthma,
diabetes, chronic kidney disease, osteoporosis, Alzheimer's
disease, cataracts, and so on Risk factors: In opposition to
infectious diseases, risk factors dont include an infectious agent
but are found in the persons background: LIFESTYLE and
ENVIRONMENT
- Slide 3
- 3 The rise of NCD started after the II WW. Most prevalent
leading causes of disease and mortality in developed countries
Increased burden in low- and middle- income countries Already
leading cause of death in developing countries!: MORTALITY IN 2008:
57 million 1 NCD ASSOCIATED MORTALITY IN 2008: 36 million (2/3 of
total) Main NCDs mortality causes: cardiovascular diseases,
cancers, diabetes and chronic lung diseases SOME MACRO-FIGURES AND
FACTS
- Slide 4
- WORLD 10 LEADING CAUSES OF MORTALITY. 2008 4 Deaths [millions]
%of deaths Ischaemic heart disease7.2512.8% Stroke and other
cerebrovascular disease6.1510.8% Lower respiratory
infections3.4661% Chronic obstructive pulmonary disease3.2858%
Diarrhoeal diseases2.4643% HIV/AID1.783.1% Trachea, bronchus, lung
cancers1.3924% Tuberculosis1.3424% Diabetes mellitus1.2622% Road
traffic accidents1.2121%
- Slide 5
- 5 NCD MORTALITY. 2011
- Slide 6
- CRITERIA FOR CAUSATION OF CHRONIC DISEASE. EVANS POSTULATES [I]
6 1.Prevalence of the disease should be significantly higher in
those exposed to the hypothesized cause than in controls not so
exposed. 2.Exposure to the hypothesized cause should be more
frequent among those with the disease than in controls without the
disease, when all other risk factors are held constant. 3.Incidence
of the disease should be significantly higher in those exposed to
the hypothesized cause than in controls not so exposed, as shown by
the prospective studies. 4.The disease should follow exposure to
the hypothesised causative agent with a normal or long-normal
distribution of incubation periods. 5.A spectrum of host responses
should follow exposure to the hypothesized agent along a logical
biological gradient from mild to severe.
- Slide 7
- CRITERIA FOR CAUSATION OF CHRONIC DISEASE. EVANS POSTULATES
[II] 7 6. A measurable host response following exposure to the
hypothesized cause should have a high probability of appearing in
those lacking this before exposure [e.g.: antibody, cancer cell] or
should increase in magnitude if present before exposure. This
response pattern should occur infrequently in persons not so
exposed. 7. Experimental reproduction of the disease should occur
more frequently in animals or humans appropriately exposed to the
hypothesized cause then in those not so exposed: this exposure may
be deliberate in volunteers, experimentally induced in the
laboratory, or may represent a regulation of the natural exposure.
8. Elimination or modification of the hypothesized cause should
decrease the incidence of the disease [e.g.: attenuation of a
virus, removal of tar from cigarettes].
- Slide 8
- CRITERIA FOR CAUSATION OF CHRONIC DISEASE. EVANS POSTULATES
[III] 8 9. Prevention or modification of the hosts response on
exposure to the hypothesized cause should decrease or eliminate the
disease [e.g.: immunization, drugs to lower cholesterol, specific
lymphocyte transfer factor in cancer] 10. All the relationships and
findings should make biological and epidemiological sense. Source:
Evans, AS. (1976). Causation and disease. The Henle-Koch postulated
revisited. Yale Journal of Biology and Medicine. 49:175-195
- Slide 9
- NCD and globalisation NCDs are caused, to a large extent, by
four behavioural risk factors that are pervasive aspects of
economic transition, rapid urbanization and 21st-century
lifestyles: 1.tobacco use, 2.unhealthy diet, 3.insufficient
physical activity 4.harmful use of alcohol. Current population-wide
initiatives fall short in the global context. E.g.:
- 1. BEHAVIOURAL FACTORS Prevalence of current daily tobacco
smoking among adults. Prevalence of insufficiently active adults
defined as: than 25 kg/m2 for overweight or 30kg/m2 for obesity or
for adolescents according to the WHO Growth Reference). Prevalence
of low weight at birth (< 2.5 kg). Prevalence of raised total
cholesterol among adults (total cholesterol 5.0 mmol/l or
190mg/dl). 17
- Slide 18
- 3 MORTALITY and 4. MORBIDITY All-cause mortality by age, sex
and region (urban and rural, or by other administrative areas, as
available). Cause-specific mortality data (urban and rural, or
other administrative areas, as available). Unconditional
probability of death between ages 30 and 70 years from
cardiovascular diseases, cancer, diabetes, and chronic respiratory
diseases. Cancer incidence data from cancer registries, by type of
cancer. 18
- Slide 19
- GLOBAL HEALTH STRATEGY Major global political statement on NDC:
Global strategy for the prevention and control of non communicable
diseases Endorsed by the WHA (2000). Three main objectives:
1.Mapping the epidemic of NCDs and their causes 2.Reducing the main
risk factors through health promotion and primary prevention
approaches 3.Strengthening health care for people already afflicted
with NCDs. 19
- Slide 20
- ACTION PLAN FOR THE GLOBAL HEALTH STRATEGY. SIX OBJECTIVES 1
1.To raise the priority accorded to NCD in development work at
global and national levels, and to integrate prevention and control
of NCDs into policies across all government departments. 2.To
establish and strengthen national policies and plans for the
prevention and control of NCD 3.To promote interventions to reduce
the main shared modifiable risk factors for NCD: tobacco use,
unhealthy diets, physical inactivity and harmful use of alcohol
4.To promote research for the prevention and control of NCD 5.To
promote partnerships for the prevention and control of NCD 6.To
monitor NCD and their determinants and evaluate progress at the
national, regional and global levels 20
- Slide 21
- FRAMINGHAN HEART STUDY Longitudinal study aiming to better
understand the epidemiology of CVD. Started in 1948 [original
cohort had not yet developed symptoms of CVD] and the on going
follow up is in already its 6 th cohort. 21 SOME MILESTONES: 1960:
Cigarette smoking found to increase the risk of heart disease 1967:
Physical activity found to reduce the risk of heart disease and
obesity to increase the risk of heart disease 1970: High blood
pressure found to increase the risk of stroke 1978: Psychosocial
factors found to affect heart disease 2002: Lifetime risk of
developing high blood pressure in middle-aged adults is 9 in 10.
2002: Obesity is a risk factor for heart failure. 2010: First
definitive evidence that occurrence of stroke by age 65 years in a
parent increased risk of stroke in offspring by 3-fold
- Slide 22
- RECOMMENDED READING WHA 2000. Global strategy for the
prevention and control of NCD. Report by the Director-General: A
challenge and an opportunity. WHA 53 rd session. WHO (2008)
2008-2013 Action Plan for the Global Strategy for the Prevention
and Control of NCD. WHO (2013) World health statistics 2012 WHO
(2013) Non communicable diseases. Country profiles 2011 WHO (2003)
WHO Framework Convention on Tobacco Control WHO WHO Global Strategy
on Diet, Physical Activity and Health 2004 22
- Slide 23
- RECOMMENDED READING [cont] Beaglehole R and Yach D (2003)
Globalisation and the prevention and control of non-communicable
disease: the neglected chronic diseases of adults. The Lancet,
Volume 362, Issue 9387, 13 September 2003, p 903-908 Banerjee A.
Tracking global funding for the prevention and control of
noncommunicable diseases. Bull World Health Organ. At:
2012;90:479479.
http://www.who.int/bulletin/volumes/90/7/12-108795/en/
http://www.who.int/bulletin/volumes/90/7/12-108795/en/ Alleyne G.
(2011) Whos Afraid of Noncommunicable Diseases? Raising Awareness
of the Effects of Noncommunicable Diseases on Global Health.
Journal of Health Communication, 16:8293, 2011 23