Study Designs in Hand Therapy Research - Punita V. Solanki

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Punita V. SolankiMSc (O.T.), YFT-ISSA, Level I PIA Trainer, ADCR-ACEConsultant Occupational Therapist, Mumbai

Mobile: +91-9820621352Email id: [email protected]

Study Designs in HandTherapy Research

3rd Annual National Conference of Society forHand Therapy, India,

13th September 2014, SaturdayThane, Mumbai

Table of Contents

1. Research Pathway to Study Design

2. Study Design Selection based on Research Question.

3. Common Terms Used in Research Studies.

4. Types of Study Designs with Examples.

5. Types of Controls Used in Experimental Studies.

6. Types of Randomization & Blinding.

7. Level of Evidence & Grades of Recommendations.

8. Quiz

Disclaimer

The presentation is entirely the effort of thepresenter, based on the past and present experiencesin clinical research; academic training and fromthorough literature search on the related topic.The company, organization and the hospitals wherethe presenter is associated, has no bearing with thepresentation. It is entirely the view of the presenterbased on the existing evidence.

mailto:therapistindia:@gmail.com

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Punita V. SolankiOccupational

Therapist

13th September 20143rd Annual NationalConference of SHT,

India

Research Pathway to Selection of Study Design

Study Design

Hypothesis

Specific Research Question

Research Problem

Review of Literature

Novel Idea


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Study Design Selection

The clinical question determines whichstudy designs are appropriate. So firstselect the research objective and aim of thestudy and then choose the study design.

One clinical question can be answeredby more than one study design.

No single study design can answer allthe clinical questions.

No single study design fits all the needs& circumstances of the research.


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Study Design Selection

The Clinical Research QuestionThe Study Aims & ObjectivesSample Population & Sample Size AvailabilityTime & Cost ConcernsEthical ConcernsHow, When & Where the Study findings are to be

Used.Concerns about the Robustness of the Study for

its efficacy (internal validity) and its effectiveness(external validity) for application of findings ingeneral population.

Factors affecting the selection of study designcould be many and they are:


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Classification of Medical Research

*1, sometimes known as experimental research; *2, analogous term: interventional; *3, analogous term: noninterventional or nonexperimental


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Research Method Approaches


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QualitativeResearch MethodApproach

QuantitativeResearch MethodApproach

Mixed MethodsResearchApproach

Ethnography ObservationalDescriptive Research

SequentialProcedures

Grounded Theory ObservationalAnalytical Research

ConcurrentProcedures

Case Study Experimental/Interventional Research

TransformativeProcedures

PhenomenologicalResearch

Narrative Research

Source: Research Design: Qualitative, Quantitative and Mixed Methods Approaches. JohnW. Creswell. Second Edition. 2003. Sage Publications . In Chapter 1: A Framework forDesign.


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Qualitative Versus Quantitative Study Designs


India Understands theoryFavors FieldworkInterview/ObservationDiscovering frameworksTextual (words)Theory (Hypothesis)

generatingQuality of informant is

more importantSubjectiveEmbedded knowledgeMultiple sources of

evidence (triangulation)Models of analysis: text

or words of intervieweesOpen (Inductive) Vs Pre-

Structured (Deductive)

Predicts theoryFavors Laboratory workTest/Scale/Score/SurveyExisting frameworksNumericalTheory (Hypothesis)

testing (experimental)Sample size core issue in

reliability of dataObjectiveFrom PublicSingle-criterion outcome

(albeit multidimensional)Model of analysis:

parametric, non-parametricObservational Vs

Experimental/Interventional

Qualitative: Quantitative:

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Quantitative Study Designs

Treatment Assigned

No YesObservational Study Experimental or

Interventional StudyComparator

Randomized

No YesNo Yes

Descriptive Study

Analytical StudyNon RCT

RCT


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Observational:Descriptive

• Case Report• Case Series

Observational:Analytical

• Cohort• Case Control• Cross

Sectional

Experimentalor

Interventional• Single Group• Parallel• Cross Over• Factorial• Withdrawal• Latin Square• Sub Groups• Pilot Groups• Group

Allocation

Randomization& Blinding

Methods to Reduce Bias inExperimental Studies:


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Other Types of Study Designs:

AuditsSurveysEconomic Analysis (Cost Analysis, Cost

Effectiveness Analysis, Cost-BenefitAnalysis, Cost-Utility Analysis)

Systematic Reviews & Meta-AnalysisNarrative Reviews


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TherapistCommon Terms Used to Describe Studies:

LongitudinalCross SectionalProspective (Before & After Design)RetrospectiveRetrospective - ProspectiveEcologicalExplanatoryPragmaticClusterEfficacyEffectivenessRandomizationBlindingControlsPlacebo/Sham


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India Observational StudyDesigns


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Observational Descriptive Study Designs

The researcher is looking atwhat is happening to a group of

people

Does the researcher have acontrol group with which to

compare these people?

IF No: ObservationalDescriptive Study Design

What is Happening in the Study?

Example: Case Report and Case Series (Useful for generating ideasfor research projects). Researcher reports what was observed in oneperson or in a group of people

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Observational Analytical Study DesignsWhat is Happening in the Study?

The researcher is looking atwhat is happening to a group

of people

Does the researcher have acontrol group with which to

compare these people?

IF YES: ObservationalAnalytical Study Design

Researcher reports the similarities and differences betweentwo or more groups of people.


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• Something happened tothe people. Theresearcher wants toobserve the outcome.

CohortStudy

• The outcome is alreadyknown. The researcherwants to know why somepeople got this outcome.

CaseControl

Study

• The researcher alreadyknows what happened tothe people and what theoutcome was.

CrossSectional

Study

Observational Analytical Study Designs


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Cohort Study Design

PAST PRESENT FUTURE

Subjects Exposedto Risk Factor

Matched Controls NotExposed to Risk Factor

Follow UpEveryone to

See WhoGets the

Outcome

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Cohort Study Design: Example

PAST PRESENT FUTURE

Professional Computer UsersExposed to Risk of Repetitive

Reaching Tasks

Professional Computer Usersnot Exposed to Risk of

Repetitive Reaching Tasks

Follow UpEveryone toassess the

symptoms ofRepetitive

Strain Injuriesof Upper Limb


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Case Control Study Design

PAST PRESENT FUTURE

Subjects with theOutcome

Matched Controlswithout the Outcome

Look Back toSee WhichRisk FactorsThey HaveBeenExposed To.


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Case Control Study Design: Example

PAST PRESENT FUTURE

Subjects with CMCJoint OA

Matched Controlswithout CMC Joint OA

Look Back toSee Which WorkRelated RiskFactors TheyHave BeenExposed To.

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Survey: One Time Assessment.

Subjects are questioned for the presence of riskfactors and outcomes.

Useful for establishing Prevalence.

Establish Association but Not Causality.

Are cheap, simple and ethically safe.

Large study sample required.

Useful in studying rare diseases/disorders.

Cross Sectional Study Design


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The groups can be unequal, confounders can beasymmetrically distributed and recall bias is aproblem.

Used to collect information on a Sample of thePopulation.

Special kind of Survey: Example: Census.

Academic Perspective: Can be a chosen studydesign for dissertation study [Which has limitedTime Duration for the Conduct of the Study]



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Example:

1. Prevalence of Repetitive Stress Injuries of UpperLimbs in Secondary School Children, who areComputer Users, as assessed by one timeQuestionnaire.

2. Severity of CMC Joint Osteoarthritis amongst theAdult Female Chefs Aged 20 to 40 years into dailyprofessional catering business as assessed on a onetime Questionnaire.


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Observational Study Design SelectionBased on Time Availability


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Cause to EffectStarts with ExposureTests Disease

FrequencyLarge Sample SizeLong Term Follow UpExpensiveLess Recall BiasGreater Level of

Evidence (Level: 2)Prospective

Effect to CauseStarts with DiseaseTests Cause

FrequencySmall Sample SizeShort Term Follow UpInexpensiveRecall Bias +Lower Level of

Evidence (Level: 3)Retrospective

Cohort Versus Case Control Study Designs

Cohort Study Design Case Control Study Design


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Designs

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What is happening in the study?

The researcher has introduced a treatmentto some or all of the people and is looking

at what the effects are

Were the people who received the newtreatment chosen at random?

YES No

RCT NRCT


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Single Group Study Design (Interventional Study)

Enrollment:Baseline

Treatment

Screening

Example: Population: Infants with Club Hand DeformityIntervention: Novel Club Hand SplintComparator: NoneOutcome: Functional Hand ScoreStudy Design: Single Group Study


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Parallel Groups Study Design

Enrollment:

Run In PeriodRandomization

Rx: A

Rx: B

Baseline

Example: Population: Infants with Club Hand DeformityIntervention: Novel Club Hand Splint (Rx: A)Comparator: Resting Pan Splint (Rx: B)Outcome: Functional Hand ScoreStudy Design: Parallel Group Study


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Cross Over Study Design

Enrollment:

Baseline

Randomization

Wash Out Period

ScreeningRx: A

Rx: BRx: B

Rx: A

Example: Population: Male Adults with HTN & DMIntervention: Conventional Exercises (Rx: A)Comparator: Conventional Exercises with

Isokinetic Hand Training (Rx: B)Outcome: Hand Strength; Functional EnduranceStudy Design: Cross Over Study


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Parallel Versus Cross Over Study Design

Between PatientsMore VariabilityLess SensitiveMore PatientsRobustNo Wash Out PeriodNo Test Retest EffectNo Need for Stable

Disease

Within PatientsLess VariabilityMore SensitiveFewer PatientsLess RobustWash Out PeriodTest Retest EffectMust have Similar

Baseline & StableDisease

Parallel Study Cross Over Study13th September 20143rd Annual NationalConference of SHT,

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Factorial Study DesignExercise Therapy +Stimulator (Rx: B)

YES Placebo B0

ExerciseTherapy +ManualTherapy(Rx: A)

YES Group IRx: A + B

Group IIRx: A + B0

PlaceboA0

Group IIIRx: A0+ B

Group IVRx: A0 + B0

E.g.: Population: Adult Industrial Male Workers with Hand InjuryIntervention: Exercise Therapy + Manual Therapy (Rx: A) &

Exercise Therapy + Placebo MT (Rx: A0)Comparator: Exercise Therapy + Stimulator (Rx: B) & Exercise

Therapy + Placebo Stimulator (Rx: B0)Outcome: Perdue Dexterity Test & the Time to Return to WorkStudy Design: Factorial Study


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Factorial Study Design

E.g.: Population: Adult Industrial Male Workers with Hand InjuryIntervention: Exercise Therapy + Manual Therapy(Rx: A) &

Exercise Therapy + Placebo MT (Rx: A0)Comparator: Exercise Therapy + Stimulator (Rx: B) & Exercise

Therapy + Placebo Stimulator (Rx: B0)Outcome: Perdue Dexterity Test & the Time to Return to WorkStudy Design: Factorial Study

Enrollment: Baseline

Randomization

Run InPeriod/Screening

Rx: A + B

Rx: A0 + B0


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Withdrawal Study Design

Treatment A

Group I: Continued onTreatment A

Group II: WithdrawnFrom Treatment A

Advantages:• Easy access to subjects.• Show whether proven treatment remains beneficial.

Disadvantages:• Selected population.• Different stages of disease.

E.g. Population: Adults with CMC Joint OA; Intervention:Intra-articular Therapy; Comparator: Subjectswithdrawn from the study; Outcome: Effect on ArticularCartilage as assessed on MRI & Study Design:Withdrawal Study Design


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Latin Square Study Design

Example: Population: Adults with Upper Limb CRPSIntervention: Drug A (3 Formulations: 1, 2 & 3)Comparator: Drug B & C (3 Formulations: 1, 2 & 3)Outcome: Pain Assessment on VAS, Functional Score & Effecton QoL.Study Design: Latin Square Study Design

VolumeNumber

Period 1 Period 2 Period 3

1 A B C

2 B C A

3 C A B


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Types of Controls Used in Experimental Studies

No Control Group (Single GroupInterventional Study Design)

Experimental Studies: (Control Group AlwaysPresent)

Historical ControlsPlacebo Therapy/Sham TreatmentStandard of Care/Conventional TherapyOther Treatment Methods (To be proved

superior or inferior to the experimental noveltreatment method)


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Random Number Generation &Concealed Allocation

There are a variety of techniques to generate arandom sequence that can be used to decideallocation:

Computer random number generationRandom number tablesShuffled cards or envelopes.

This ensures that the group assignment cannot bepredicted in advance.


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Random Number Generation &Concealed Allocation

Concealment means the interventions in thedifferent arms of the study are kept secret. So theresearchers are unaware of the intervention in thegroup to which a subject will be allocated.

Advantage: It avoids both conscious &subconscious selection of patients into the study. Itprevents selection bias. A good study will havedifferent investigators recruiting and randomizingsubjects. Alternatively randomization can be doneelectronically on internet or with sealed opaqueenvelops or coded containers.


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Types of RandomizationFixed Randomization: The randomization

methods are defined and allocation sequences areset up before the start of the study. E.g.: Simple,Block, Stratified & Randomized Consent. Othertypes are Quasi-Random Allocation, ClusterRandomization.

Adaptive Randomization: The randomizedgroups are adjusted as the study progresses toaccount for imbalances in the numbers in thegroups or in response to the outcome data. Anexample is minimization.

Randomization reduces:Selection Bias &

Confounding Bias


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Types of Fixed RandomizationSimple Randomization:Random assignment of

treatments per participant; independently of anyother factors.

Method: Flipping a coin (2 Groups), rolling a die(> 2 Groups), Random number tables, Computergenerated random numbers.Advantage: Simple and Practical to implement.

Disadvantage: Unequal distribution ofconfounding factors; particularly in small trials.


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Types of Fixed RandomizationBlock Randomization:Randomization within

blocks of sequential participants. Some refer tothis method as “Permuted Block Randomization”.Method: Subjects are put into blocks which whenfilled are divided equally into the different armsof the study. The order of this allocation withinthe block is randomly permuted.Advantage: Equal numbers of patients in eacharm are ensured.

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Types of Fixed RandomizationStratified Randomization: Randomization

within clusters of participants. It has better controlof potentially important prognostic factors (age,gender, race, clinical centres, geographical regionsetc.)Method: Subgroups containing confounding factorsare formed. Block randomization takes place withineach subgroup.Advantage: Confounding factors are equallydistributed in the different arms.Disadvantage: Impractical in smallstudies; so minimization is analternative method for achievingsimilarity between groups.


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Adaptive RandomizationThe probability of being allocated to a certain armin the study is adjusted to maintain similaritybetween the arms. E.g. Minimization.

Minimization:At the outset of the study it isdecided which factors would be present in equalnumbers in the different arms.


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Types of BlindingOpen Label Study.Single Blind Study. {Usually the research

participant is blinded}Double Blind Study. {The investigator and the

research participants are blinded}Triple Blind Study. {The investigator, research

participant and the statistician are blinded}

Double Blind Double Dummy

Blinding Reduces:Observation Bias &

Analysis Bias

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Level of Evidence of Various Study Designs


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Quiz Time

Title 1: Efficacy of pressure therapy in themanagement of hand oedema in patients with crushhand injury - A randomised controlled trial.Objective: To compare pressure therapy withconventional therapy in terms of oedemamanagement and functional improvement.

P: Patients with Crush Hand InjuryI: Pressure TherapyC: Conventional TherapyO: Reduction of Oedema and Improvement of HandFunctionS: RCT


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Quiz Time

Title 2: Efficacy of Static Serial Versus StaticProgressive Hand Splint as an Adjunct to ExerciseTherapy in the Functional Management of PostBurn Hand Contractures : A 12 month randomisedcontrolled trial.

P: Patients with Post Burn Hand ContractureI: Static Serial Splint & Exercise TherapyC: Static Progressive Splint & Exercise TherapyO: Improvement of Hand ROM and FunctionS: RCT


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Quiz TimeSay True or False:1. Randomized Controlled Trial offers the best evidence for allclinical research questionsAnswer: False

2. To study the prevalence of sports injuries amongst theschool children we should select RCT study design.Answer: False

3. Randomized Controlled Trials offer Level Ib evidence onanalysis.Answer: True

4. To study the efficacy of a novel occupational therapytreatment method we should select RCT study designAnswer: True

5. Randomization in an RCT study design reduces observationbias.Answer: False


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Quiz TimeSay True or False:6. Cohort studies are relatively cheap as compared to CaseControl studiesAnswer: False

7. Cohort studies require a small sample size as compared toCase Control studiesAnswer: False

8. The best observational study design for studying thefunctional outcome in Mucopolysaccharidosis patientsattending the genetic clinic of the hospital with an incidence of1 in 25,000 born babies, would be Case Control Study?Answer: True

9. Case Control studies are prospective study designsAnswer: False

10. Cross sectional study design is the best for studyingprevalence of any conditionAnswer: True


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Quiz TimeSelect the Best Correct Response:1. Two novel occupational therapy treatment methods werepublished independently in a journal. If we plan to comparethese two novel treatment methods in the same study for aprogressive condition, which study design would be the best?a. Withdrawal Studyb. Parallel Group Studyc. Cross Over Studyd. Factorial StudyKEY: d2. Two treatment methods are proved to be efficacious in themanagement of spine degenerative conditions independently.If we plan to compare these treatment methods which studydesign would be the best?a. Withdrawal Studyb. Parallel Group Studyc. Cross Over Studyd. Factorial StudyKEY: b

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Select the Best Correct Response:3. The strongest evidence for causality comes from which ofthe following research methods/designs?a. Experimentb. Case control study.c. Correlation study.d. Ethnography.KEY: a

4. An investigator takes a sample of healthy individuals,records their ongoing exposure to the treatment with novellow temperature thermoplastic splint and relates that to thesubsequent occurrence of skin irritation in the same group.a. Case-control studyb. Ecological studyc. Cohort studyd. Cross-sectional studyKEY: c


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Quiz TimeSelect the Best Correct Response:5 . Recall Bias is encountered in which of the followingobservational study design?a. Case Seriesb. Cohortc. Cross Sectionald. Case ControlKEY: d

6. Which of the following is an advantage of a case-controlstudy?a. There is little or no bias in assessment of exposure.b. Multiple disease outcomes following a selected exposurecan be readily studied.c. Dependence on recall by subjects in the study minimized.d. It is possible to determine the true incidence of the disease.e. It may be used to study etiology of a rare diseaseKEY: e


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Acknowledgements:I am extremely thankful to my mentor for criticallyreviewing my presentation & guiding me withvaluable comments to improvise on mypresentation:

• Dr. Sandeep B. Bavdekar Sir (HOD - PaediatricMedicine Department at B. Y. L. Nair Hospital & T. N.Medical College, Mumbai Central).


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References:1. The Doctor’s Guide to Critical Appraisal by Dr. Narinder KaurGosall, Dr. Gurpal Singh Gosall. 3rd Edition, 2012. Published by PasTestLtd. Cheshire (UK)2. Research Methodology: A step by step guide for beginners byRanjit Kumar. 2nd Edition, 2005. Published by Pearson EducationAustralia.3. ABC of Research Methodology and Applied Biostatistics: A Primerfor Clinicians and Researchers by M. N. Parikh and Nithya Gogtay. 1st

Edition; 2009.4. Foundations of Clinical Research: Applications to Practice by LeslieGross Portney & Mary P. Watkins. 2nd Edition; 2000. Published byPrentice Hall Inc.5. Principles and Practice of Clinical Research by John I. Gallin &Frederick P. Ognibene. 2nd Edition, 2007. Published by Elsevier Inc.Burlington, MA, USA.6. Bernd Röhrig, Jean-Baptist du Prel, Daniel Wachtlin, Maria Blettner.Types of Study in Medical Research. Part 3 of a Series on Evaluation ofScientific Publications. Dtsch Arztebl Int 2009; 106(15): 262–8. DOI:10.3238/arztebl.2009.02627. Research Design: Qualitative, Quantitative and Mixed MethodsApproaches. John W. Creswell. Second Edition. 2003. SagePublications . In Chapter 1: A Framework for Design.

Presentation Time Duration:1 Hour

Study Designs in Hand Therapy Research - Punita V. Solanki

Healthcare

Transcript of Study Designs in Hand Therapy Research - Punita V. Solanki