Introductory course on Field EpidemiologyIntroductory course on Field Epidemiology

Prof.Dr.Pirom Kamol - RatanakulProf.Dr.Pirom Kamol - RatanakulJune 27, 2006 09.00 - 12.00 a.mJune 27, 2006 09.00 - 12.00 a.m..

EXPERIMENTALEXPERIMENTALSTUDYSTUDY

RESEARCHRESEARCH

A STUDY IN SEARCH FOR A STUDY IN SEARCH FOR FACTSFACTS

OR OR NEW KNOWLEDGENEW KNOWLEDGE USING THE RELIABLE USING THE RELIABLE

AND VALID METHODOLOGYAND VALID METHODOLOGY

DESIGN METHODOLOGYSTATISTICS

VALIDITY

RESULT ERROR(เท็จ)

True Value(จรงิ)+

RANDOM(NOISE)

SYSTEMATIC(BIAS)

Drug ANOYES

IMPROVEMENT Improvement Rate

Drug B

10 10 20 1020 = 50 %

5 15 20 20 = 25 %5

Drug A LOOKS TWICE AS GOOD

Drug ANOYES

IMPROVEMENT Improvement Rate

Drug B

500 500 1,000 5001,000 = 50 %

Drug A ONLY MARGINALLY BETTER

450 550 1,000 1,000 = 45 %450

BUT x2 = 5.01 AND P < .05

Drug ANOYES

IMPROVEMENT Improvement Rate

Drug B

10 10 20 1020 = 50 %

5 15 20 20 = 25 %5

Drug A LOOKS TWICE AS GOOD

BUT x2 = 2.67 AND P > .05

WEIGHT IN (Lb.)

200

201

202

203

204

205

1 2 3 4 5

DAYS ON TREATMENT

0

30

100

130

200

250

1 2 3 4

DAYS ON TREATMENT

Wt (1b)

SUPPRESS THE ZERO

esearch design

esearch methodology

tatistics

RESEARCHDESIGN

HYPOTHESIS

Expected Relationship between 2 (or more) Variables

CAUSEDETERMINEINFLUENCE

INDEPENDENTVARIABLES

DEPENDENTVARIABLE

CLEAR VALUE-FREE SPECIFICTESTABLE

c AVAILBLE METHODS

INDEPENDENTVARIABLE

DEPENDENTVARIABLE

เหตุExposure

(Risk Factor)

ผลOutcome

INTERVENTION OUTCOME

X - sectional

Cohort(Prospective)

Case-control(Retrospective)

ClinicalResearch

Experimental

Assign Exposure

Natural Exp.

Laboratory

Animal

Human

Descriptive

Analytical

X-sectional

Longitudinal

Observational

NO comparison group

Comparisongroup

O+

(CASE)O-

(CONTROL)

E ORETROSPECTIVEEXPOSURES

E1

E1

E1

.

.

.

EE OOPROSPECTIVEPROSPECTIVE

OOUUTTCCOOMMEESS

OO11

OO22

OO33EE++ PROSPECTIVEPROSPECTIVE

EE-- PROSPECTIVEPROSPECTIVE

COHORTCOHORT

X-SECTIONALX-SECTIONAL

SAMPLESAMPLE

EE OO

PRESENT SITUATIONPRESENT SITUATION

X-XECTX-XECT

RETROSPECTIVERETROSPECTIVECASE-CONTROLCASE-CONTROLE OE O

PROSPECTIVEPROSPECTIVECOHORTCOHORT E OE O

(Natural E)(Natural E)

EXPERIMENTALEXPERIMENTAL E OE O (Assign E)(Assign E)

RETROSPECTIVE PROSPECTIVERETROSPECTIVE PROSPECTIVEE

O

PAST FUTUREPAST FUTURE

PRESENTPRESENT

EE--

EE++

O-

(Control)

O+

(Case)

OUTCOMEOUTCOME

EXPOSUREEXPOSURE

EXPOSUREEXPOSURERISK FACTORSRISK FACTORS

OUTCOMEOUTCOMEEFFECTEFFECT

PastPast Present SituationPresent Situation FutureFuture

Cross - sectionalCross - sectional

Case – ControlCase – Control(Retrospective)(Retrospective)

CohortCohort(Prospective)(Prospective)

ASSIGN EXPOSURE or INTERVENTION ?ASSIGN EXPOSURE or INTERVENTION ?

RETROSPECTIVERETROSPECTIVECASE-CONTROLCASE-CONTROL

PROSPECTIVEPROSPECTIVECOHORTCOHORT

CROSS-CROSS-SECTIONALSECTIONAL

E OE O E OE O E/OE/O

START FROM “O” or “E” ?START FROM “O” or “E” ?

ANALYTICANALYTIC DESCRIPTIVEDESCRIPTIVE

CAMPARISON GROUP ?CAMPARISON GROUP ?YES NOYES NO

OBSERVATIONALOBSERVATIONALEXPERIMENTALEXPERIMENTAL

YESYES NONOOBSERVEOBSERVE

RESEARCH QUESTION (S)

BURDEN OF ILLNESS

EFFICACY

ETIOLOGY ORCAUSATION

EFFECTIVENESS

EFFICIENCYIMPLEMENTATION

ทกุข์

สมุทัย

นิโรธ

มรรค

Natural Hx. Diagnostic test

RESEARCH METHODOLOGY

Population & Sample INTERVENTION Outcome Measurement

TARGET POP.

POPULATIONto be

SAMPLED

Sampling Technique

SAMPLE

N = ?

Allocation

EXPERIMENTIntervention

CONTROLStandard Placebo

OUTCOMEMEASUREMENT

Primary OutcomeSecondary Outcome

1

2

3

BURDENNATURAL HISTORYDIAGNOSTIC TEST

CAUSATIONTHERAPY?

EXISTING DATACRITICAL APPRAISAL

VALIDITY / APPLICABILITY

YES NORESEARCH

ORIGINAL DO IT BETTER

ME TOO !

LEVEL OF SCIENTIFIC WORK

METHODOLOGY & STATISTICS

RESEARCH DESIGN

GOOD QUESTION ?

NO YESREQUIRED RESEARCH ?

YESNORESEARCH DESIGN ?

Pop. Intervention MeasurementRESEARCH METHODOLOGY

STATISTICS ?

WHAT IS A CLINICAL TRIAL?

Assign intervention techniques

Prospective study Follow forward in time From a well-defined pt. (baseline)

Contain a “CONTROL GROUP”

Comparable to the exp.gr. in every wayComparable to the exp.gr. in every wayexcept for the intervention being studiedexcept for the intervention being studied

Randomized assigning subjects to control & exp.gr.

IDEAL CLINICAL TRIAL

RANDOMIZED DOUBLE-BLINDRANDOMIZED DOUBLE-BLINDCLINICAL TRIAL (RCT)CLINICAL TRIAL (RCT)

PHASE OF CLINICAL TRIALSPHASE OF CLINICAL TRIALS

PHASE I :PHASE I :PHASE 2 :PHASE 2 :PHASE 3 :PHASE 3 :PHASE 4 :PHASE 4 :PHASE 5 :PHASE 5 :

First test on humanFirst test on humanLimitted clinical trialLimitted clinical trialLarge scale clinical trialLarge scale clinical trialLarge scale field trialLarge scale field trialSurveillanceSurveillance

SAMPLE

ExperimentalGroup

R

ControlGroup

POST

TEST

Intervention(New Drug)

Standard Rx(Placebo)

- Pretest Posttest Control Group Design Classical or Full Experimental Design

Assignment

PROSPECTIVEPROSPECTIVE

PRE

TEST

SAMPLE

Experimenta1 Group

R

POST

TEST

Posttest - Only Control Group Design

Intervention (New Drug)

Control Group

Standard Rx or Placebo

Assignment

PROSPECTIVE

- BEFORE AFTER STUDY

INTERVEN

TION

SAMPLE

BEFOREBEFOREASSESSMENTASSESSMENT

AFTERAFTERASSESSMENTASSESSMENT

BEFOREBEFORE AFTERAFTER

20%

80%

100

80

60

40

20

0

% K

TIME SERIES DESIGN

SAMPLEO1 O2 O3 O4 O5 O6

INTERVENTIONINTERVENTION

- PRE TEST - POST TEST

TIME

001 1 002 2 003 3 004 4 005 5 0066

INTERVENTIONINTERVENTION

- -Pre test Post test

- - - -Pre test Post test Pre test Post test

OO 1 1 OO 2 2 OO 3 3 OO 4 4 OO 5 5 OO66 INTERVENTIONINTERVENTION

OO 1 1 OO 2 2 OO 3 3 OO 4 4 OO 5 5 OO 6 6

INTERVENTIONINTERVENTION

OO 1 1 OO 2 2 OO 3 3 OO 4 4 OO 5 5 OO66 INTERVENTIONINTERVENTION

CROSS-OVER DESIGN

SAMPLE

S1S1

Carry-overCarry-overEffectEffect

(PLACEBO)(PLACEBO)

Intervention BIntervention B(Drug B)(Drug B)

Intervention AIntervention A(Drug A)(Drug A)

Run inRun inperiodperiod

INTERVENTIONPOPULATION OUTCOME

Experimental Group

Control Group

POPULATION

SampledPopulation

Sampling

SAMPLE R

Allocation

Follow-up

OUTCOMEPrimary

1.)……….2.)……….3.)……….4.)……….5.)……….

secondary

RiskComorbidity

Age ; sex ; etc.

stratabalance

ContaminationCointerventionCompliance

DropoutDuration

RelevantCapableCredibleAccuracyAvailable

Blinding

HEART FAILURE

EXERCISEEXERCISENO EXERCISENO EXERCISE

205070

YES NO8050

130

100100200

Extraneous to the question R.F. of the “outcome” Associated with “exposure” (Not equally distributed)

CONFOUNDING FACTORCONFOUNDING FACTOR

Angina PectorisAngina Pectoris

Restriction inclusion criteria Restriction inclusion criteriaMatchingMatching

Stratified Sampling (Prognostic Stratification) Stratified Sampling (Prognostic Stratification)RandomizationRandomization

-Stratified Analysis (Post stratification) -Stratified Analysis (Post stratification)AAjjustment/Standardizationustment/StandardizationModelingModeling

HOW TO AVOID CONFOUNDING

TARGET POPULATION

POPULATIONto be

SAMPLED

SAMPLING TECHNIQUES

SAMPLE

N = ?

Agent Host Unequilibrium Diseases

Seeking CareSeeking Care

30

20

10

Care Death

HealthHealth

CareCare

SystemSystem

DisabilityDisability

Env.

CureCureDisabilityDisabilityDeathDeath

Restriction inclusion criteria Restriction inclusion criteriaMatchingMatching

Stratified Sampling (Prognostic Stratification) Stratified Sampling (Prognostic Stratification)RandomizationRandomization

-Stratified Analysis (Post stratification) -Stratified Analysis (Post stratification)AAjjustment/Standardizationustment/StandardizationModelingModeling

HOW TO AVOID CONFOUNDING

PROBLEMS OF CLINICAL TRIAL

PATIENT (SUBJECT) VARIATION RACE

GENETIC AGE, SEX, HIEGHT, BODY WEIGHT

PHYSIOLOGY PROCESS BIOCHEMISTRY LEVEL

DISEASE VARIATIONTYPESTAGEDURATION EARLY

LATESEVERITY

CONCOMITANT DISEASE

BIOLOGICAL VARIATION

INCLUSION EXCLUSIONSAMPLE

AgeAge Confounders ConfoundersSexSex Unethical Unethical

Dx. Criteria Dx. Criteria Not feasible Not feasibleDis.SeverityDis.SeverityDis.DurationDis.Duration

Referal Filter Referal Filter

PRIMARY OUTCOME EVENT RATE (CONTROL GROUP)

CLINICAL SIGNIFICANCE TYPE I & TYPE II ERROR

VARIATION OR STAND. DEVIATION

JUSTIFICCATION OF THE SAMPLE SIZE

2 POSSIBLE ERRORS OF INTERPRETATION

CONCLUSION[drawn from

analysiswhen the trialis completed]

TREATMENTBENEFIT

NOTREATMENT

BENEFIT

CORRECT

TYPE II ERROR

TYPE I ERROR

CORRECT

TREATMENTBENEFIT

NO TREATMENTBENEFIT

THE TRUTH

EXPERIMENT GR.INTERVENTION

CONTROL GR STD. Rx.

PLACEBO

OUTCOMES

SUBJECT

ALLOCATION

A

B

STRATA BALANCE?BLIND?

100

100

Each subject has the same chanceEach subject has the same chanceof being assigned to eitherof being assigned to either‘‘Experimental’ or ‘Control Group’Experimental’ or ‘Control Group’

COMPARABILITYCOMPARABILITY

Prognostic factors (Baseline characteristics)Prognostic factors (Baseline characteristics)

Statistical test will have valid significance levelsStatistical test will have valid significance levels

RR

SAMPLE ALLOCATION(Randomization)

Control Group

Experimental Group

Standard TreatmentPlacebo

InterventionNew Treatment

BLIND

Simple Randomization

Chronologicalpatient No.

112233445566778899101011111212

1048022368241304216737570

7792199562963018957985475

2891863553094291036507119

5108502368010115216207056

0153625595225270624381837

1100856420054636366153342

8823148235526368572971048

5182152404333624636933787

1501146573483609309339975

0690772905919771434236857

6957840961939696112997336

1276521382540925391697628

0201185393972656168016656

4275169994079721028153988

3326703427927378568908178

5125960268949045858609998

9164689198648091637691782

5349831016209221810359533

7993669445334885226713916

1630819885041461451306691

8164730995763950785606121

2775698872188761745353060

7099749626889474823777233

7745289368312732321642698

RANDOM NUMBER

Simple Randomization

Chronologicalpatient No.

Randomnumber

112233445566778899101011111212

112222443377999988882266

Simple RandomizationIf Random number is even assign treatment AIf Random number is odd assign treatment B

Chronologicalpatient No.

Randomnumber Assignment

112233445566778899101011111212

112222443377999988882266

Simple RandomizationIf Random number is even assign treatment AIf Random number is odd assign treatment B

Chronologicalpatient No.

Randomnumber Assignment

112233445566778899101011111212

112222443377999988882266

BBAAAAAABBBBBBBBAAAAAAAAA7A7B5B5?

BLOCK RANDOMIZATIONBLOCK RANDOMIZATION

AVOID AVOID IMBALANCEIMBALANCE IN NO. SUBJECTS ASSIGNED IN NO. SUBJECTS ASSIGNED TO EACH GROUPTO EACH GROUP

NO. SUBJECTSNO. SUBJECTS IN EACH gr. WILL IN EACH gr. WILL BE EQUALBE EQUAL

METHODMETHOD

CHOOSE CHOOSE BLOCK BLOCK OF OF EVEN SIZEEVEN SIZE (e.g.4) (e.g.4)(ENSURE THAT AFTER EVERY 4 R SUBJECT(ENSURE THAT AFTER EVERY 4 R SUBJECTNO. SUBJECTSNO. SUBJECTS IN EACH gr. IS IN EACH gr. IS EQUALEQUAL))

WRITE DOWN ALL WRITE DOWN ALL POSSIBLE WAYSPOSSIBLE WAYS OF OF gr. ASSIGNMENTgr. ASSIGNMENT

R THE R THE ORDER ORDER IN WHICH THESE COMBINATIONA ARE IN WHICH THESE COMBINATIONA ARE SELECTEDSELECTED

All possible ways of ‘Group assignment’All possible ways of ‘Group assignment’

I II III IV V VI

All possible ways of ‘Group assignment’All possible ways of ‘Group assignment’

I II III IV V VIA B A B A BA B B A B AB A A B B AB A B A A B

R the ‘order’ in whichR the ‘order’ in whichthese combinationthese combinationare selectedare selected

BLOCKBLOCKII, VI, IV, III, I, VII, VI, IV, III, I, V

ChronologicalPatient No.

Block Assignment

1234

II BBAA

5678

VI BAAB

9..

IV BA

PROGNOSTIC STRATIFICATIONPROGNOSTIC STRATIFICATION

H.T.H.T.

MildMild

ModerateModerate

SevereSevere

SEVERITYSEVERITY

Prognostic factorPrognostic factor

RR

EE

CC

RR

EE

CC

RR

EE

CC

Prognostic Stratification

SEX

40 - 49

50 - 59

60 - 69

MildModerateSevere

EC

40 - 49

50 - 59

60 - 69

MildModerateSevere

+

AGE SEVERITY

R

EC

R

R

R

R

R

INTERVENTION (MANOEUVRE)

PRECISIONPRECISION POTENCYPOTENCY COMPARISONCOMPARISON MULTIPLICITYMULTIPLICITY CONCURRENCYCONCURRENCYSENSIBILITYSENSIBILITYAVAILABILITYAVAILABILITYACCEPTABILITYACCEPTABILITYAVOID BIASESAVOID BIASES CONTAMINATIONCONTAMINATION COINTERVENTIONCOINTERVENTION COMPLIANCECOMPLIANCE

HISTORICAL CONTROL TRIAL

333328285513139944INH + PASINH + PAS2020191911INH + RFINH + RF

NONOYESYESDEATHDEATH

5.05.0%%30.8%30.8%

4141303011111919141455INH + PASINH + PAS2222161666INH + RFINH + RF

NONOYESYESDEATHDEATH

27.3%27.3%26.3%26.3%

CONTAMINATION

SAMPLE R

CONTROLGROUP

INTERVENTION

EXPERIMENTALGROUP

INTERVENTION 10

SECONDARY

1.1.2.2.3.3.

F.U.

F.U.

OUTCOMEMEASUREMENT

SAMPLE R

CONTROLGROUP

STANDARD RxPLACBBO

EXPERIMENTALGROUP

INTERVENTION 10

SECONDARY

1.2.3.

F.U.F.U.

F.U.F.U.

OUTCOMEMEASUREMENT

CO-INTERVENTION

THE USEFULNESS OFTHE USEFULNESS OF

BLINDNESSBLINDNESS

Avoid CO-INTERVENTIONAvoid CO-INTERVENTION

Avoid Biased of OUTCOME MEASUREMENTAvoid Biased of OUTCOME MEASUREMENT

FIVE YEAR MORTALITY IN THE CORONARY DRUG PROJECTFIVE YEAR MORTALITY IN THE CORONARY DRUG PROJECT

POORPOORCOMPLIANCECOMPLIANCE

<80%<80%

GOODGOODCOMPLIANCECOMPLIANCE

>>80%80%

# ofPts.

357

882

%mortality

24.6

28.2

# ofPts.

708

1813

%mortality

15.0

15.1

Clofibrate

Placebo

COMPINANCE IMPROVING STRATEGIES(SHORT-TERM Rx)

1.1. Clear verbal and written instructionClear verbal and written instruction2.2. Patient CounsellingPatient Counselling3.3. Intramuscular injectionIntramuscular injection4.4. Pill calendarsPill calendars5.5. Unit dose packagesUnit dose packages6.6. Signal-alarm pill containersSignal-alarm pill containers

COMPINANCE IMPROVING STRATEGIES(LONG-TERM Rx)

1.1. Increased supervision Increased supervision (especially by paraprofessionals)(especially by paraprofessionals)2.2. Rewards and positive reinforcement for complyingRewards and positive reinforcement for complying3.3. Cueing (tailoring of the regimen to the patient’s Cueing (tailoring of the regimen to the patient’s

habits)habits)4.4. Self-monitoringSelf-monitoring5.5. Contingency contractingContingency contracting6.6. Counselling, instruction, and group discussionsCounselling, instruction, and group discussions7.7. Parenteral treatment under supervisionParenteral treatment under supervision8.8. Increased convenience of care-regimenIncreased convenience of care-regimen

- Follow up - Self report

Pill count Home Surprise Visit

Laboratory Test

Compliance MonitoringRx

OUTCOME

HARDOBJECTIVE

SOFTSUBJECTIVE

V.S.V.S.INDICATOR CRITERIA

P.E.P.E.LAB.LAB.

PAINPAINANXIETYANXIETYNAUSIANAUSIA

RELEVANT TO THE STUDY QUESTIONRELEVANT TO THE STUDY QUESTION

CAPABLE OF OPERATIONAL DEFINTIONCAPABLE OF OPERATIONAL DEFINTION

CREDIBLECREDIBLE

COMPREHENSIBILITYCOMPREHENSIBILITY

ACCEPTANCEACCEPTANCE

ACCURACYACCURACY

RELIABILITYRELIABILITY

RESPONSIVENESS TO CHANGERESPONSIVENESS TO CHANGE

AVAILABILITY & COSTAVAILABILITY & COST

CRITERIA FOR SELECTING HEALTH MEASURES

Consequence ofConsequence of‘‘Cholesterol - lowering drug therapy’Cholesterol - lowering drug therapy’

TCTC

LDL - CLDL - C

HDL - CHDL - C Mortality

CHDOther Causes

Prevent‘atherosclerosis’

CHD

QOL

OutOutputput Outcome Impact Outcome Impact

LEVEL OF OUTCOME MEASUREMENT

Intermediatelevel

Tertiarylevel

Secondarylevel

HEALTHCARE

PROGRAM

เท่ียง ตรง(RELIABILITY) (VALIDITY)

CONTENTCONTENT

FACEFACE

CRITERIONCRITERION

DISCRIMINANTDISCRIMINANT

CONSTRUCTCONSTRUCT

VARIATIONVARIATION

Observer Instrument Subject

Intra-Observer

Inter-ObserverQuestionnaire

Record Form

Enumeration/Measurement

SOURCES OFOBSERVERS VARIATIONS

MULTIPLE OBSERVERS

DIFFERENT INSTITUTIONS

DIFFERENT TECHNICAL CONSTRAINS

DIFFERENT Dx. PRACTICES

DIFFERENT IN COMPLETENESS OF

MEDICAL RECORDS

APPROACH TO VARIATIONS

COMMON PROTOCOL

STANDARDIZATION OF METHODS

TRAINING OF PERSONNELS

OUTCOMEOUTCOMEMEASUREMEASURECRITERIA FOR SELETING OUTCOME MEASURECRITERIA FOR SELETING OUTCOME MEASURE

RELEVANCEOPERATIONALDEFINITIONCREDIBLEACCURACYAVAILABLE

Low Cost?

OUTCOMEMEASURE

DataSourc

e

HOWto

Measure ?

WHOwill

measure ?

REMARKS(U of Analysis)

WHENwill

measure ?OBJECTIVES

1………………….

2………………….

3………………...

1.1)….....……1.2)…………..1.3)…………..

2.1)…………..2.2)…………..

3.1)………….

……………..……………..……………..

……………..……………..

……………..

……………………….……………………….……………………….

……………………….……………………….

……………………….

……………………….……………………….……………………….

……………………….……………………….

……………………….

……………………….……………………….……………………….

……………………….……………………….

……………………….

………………………………………………………………

…………………………………………

……………………

APPROACH TO VARIATIONS

COMMON PROTOCOL

STANDARDIZATION OF METHODS

TRAINING OF PERSONNELS

OUTCOMEOUTCOMEMEASUREMEASURECRITERIA FOR SELETING OUTCOME MEASURECRITERIA FOR SELETING OUTCOME MEASURE

RELEVANCEOPERATIONALDEFINITIONCREDIBLEACCURACYAVAILABLE

Low Cost?

OUTCOMEMEASURE

DataSourc

e

HOWto

Measure ?

WHOwill

measure ?

REMARKS(U of Analysis)

WHENwill

measure ?OBJECTIVES

1………………….

2………………….

3………………...

1.1)….....……1.2)…………..1.3)…………..

2.1)…………..2.2)…………..

3.1)………….

……………..……………..……………..

……………..……………..

……………..

……………………….……………………….……………………….

……………………….……………………….

……………………….

……………………….……………………….……………………….

……………………….……………………….

……………………….

……………………….……………………….……………………….

……………………….……………………….

……………………….

………………………………………………………………

…………………………………………

……………………

Long Term Clinical TrialsLong Term Clinical TrialsFor Possible Early TerminationFor Possible Early Termination

Unexpected HarmUnexpected HarmClear Therapeutic BenefitClear Therapeutic Benefit

would we want to stop ?would we want to stop ?

Optimal care of study patientsOptimal care of study patientsOptimal care of nonstudy &Optimal care of nonstudy &future patients through quickerfuture patients through quickerpublication of the resultspublication of the resultsEfficient use of time & resourcesEfficient use of time & resources(invertigators)(invertigators)

would we want to stop ?would we want to stop ?

MONITORINGMONITORING

WHENWHEN

WHYWHY

QUALITY OF RESEARCH WORK

DESIGN METHODOLOGY

STATISTICS

Adm.KNOWLEDGEOF

THE SUBJECT

STATE-OF-THE-ART

TEAM WORKrust (เชื่อใจซึง่กันและกัน)

nthusiasm (กระตือรอืรน้)greement (ประคับประคอง)

utual Benefit (ผลประโยชน์รว่มกัน)illingness (ต้ังใจ & เต็มใจ)pportunity (ให้โอกาสฯ)

ecognition (ยอมรบันับถือ)nowledge Transfer (แลกเปลี่ยนความรู)้

TEAMWORK

ETHICS : NORMETHICS : NORM

Scientifit DesignScientifit DesignCompetent InvestigatorCompetent InvestigatorRisk / Benefit BalanceRisk / Benefit BalanceInform ConsentInform ConsentConfidentialityConfidentialitySelection of SubjectsSelection of SubjectsCompensation of InjuryCompensation of Injury

THANKTHANK