COMMUNITY INTERVENTION TRIALS

AUTHOR

Dr. A. K. AVASARALA MBBS, M.D. PROFESSOR & HEADDEPT OF COMMUNITY MEDICINE & EPIDEMIOLOGYPRATHIMA INSTITUTE OF MEDICAL SCIENCES, KARIMNAGAR, A.P..INDIA: +91505417avasarala@yahoo.com

PROMPT

• I WISH TO DEVELOP AN EPIDEMIOLOGY COURSE FOR TEACHING, AS THERE IS GOOD RESPONSE, NATIONALLY AND INTERNATIONALLY FROM THE FACULTY TEACHING EPIDEMIOLOGY, FOR MY PREVIOUS THIRTEEN EPIDEMIOLOGY LECTURES

LEARNING OBJECTIVES

1. READER IS EXPECTED TO LEARN THE NATURE & SCOPE OF COMMUNITY INTERVENTIONS

2. THE PRECAUTIONS AND STEPS IN CONDUCTING COMMUNITY TRIALS

3. ABLE TO ANALYSE AND INTERPRET THE RESULTS

PERFORMANCE OBJECTIVES

• READER CAN DESIGN AND PERFORM COMMUNITY INTERVENTION TRIALS

• HE CAN PROMOTE THE HEALTH OF THE COMMUNITY AS A WHOLE BY RISK FACTOR REDUCTION TRIALS

TYPES

• PRIMARY PREVENTIVE TYPE (COMMUNITY INTERVENTION TRIALS (CIT)

NATURE OF STUDIES

• INTERVENTION STUDIES

• NOT JUST OBSERVATIONS

• EXPERIMENTATIONS

COMMUNITY INTERVENTION TRIALS (CIT )

• THE MAIN PURPOSE IS TO REDUCE THE OCCURRENCE OF DISEASES AND DEATHS EARLY IN LIFE IN THE WHOLE COMMUNITY, HENCE THE NAME.

WHY CIT ?

.THE HEALTH STATUS OF

A COMMUNITY.

CHANGE TO HEALTHIER LIFESTYLE BY HIGH-RISK GROUPS

CHANGE THE BEHAVIOR OF OTHER MEMBERS

OF THE SOCIETY

INTERVENTIONS AIMED AND FOCUSED AT SPECIFIC DISEASES

HEALTH ACTIVITIES IN COMMUNITIES

THE CONFIDENCE IN THE PEOPLEAND THEREBY THEIR INVOLVEMENT

AND ACCEPTANCE

REDUCTION IN RISK FACTORS

THE INCIDENCE OR COURSE OF OTHER DISEASES.

IMPACT ON

LEADS TO

AFFECT

ENHANCE

GENERAL OBJECTIVES•TO INCREASE HEALTH KNOWLEDGE

OF THE WHOLE COMMUNITY ,

• TO DEVELOP POSITIVE AND RIGHT ATTITUDE •IN THE COMMUNITY

• TO INCREASE THE PRACTICE OF POSITIVEHEALTH BEHAVIOR OF THE WHOLE COMMUNITY

•THEREBY PREVENTING EARLY DISEASES AND DEATHS IN THE COMMUNITY

HEALTHEDUCATION

SPECIFIC OBJECTIVES

TO MEASURE VERIFIABLE CHANGES IN:

1. HEALTH KNOWLEDGE IMPROVEMENT

2. ATTITUDE

3. BEHAVIOR

STEPS OF CONDUCTING CIT

1. SETTING2. STUDY DESIGN 3. INTERVENTION METHODS4. EVALUATION OF INTERVENTION 5. LIMITATIONS OF STUDY

IDEAL SETTING

• COMMUNITY IS THE IDEAL SETTING

STUDY DESIGN

• QUASI - EXPERIMENTAL TYPE

THE INVESTIGATOR WILL NOT BE HAVING AS MUCH OF A CHANCE OF RANDOM ALLOCATION OF THE INDIVIDUALS TO THE TWO GROUPS AS IN CLINICAL TRIALS.

SELECTION OF REFERENCE AND INTERVENTION

POPULATIONS

• DESIRABLE TO HAVE ALMOST IDENTICAL REFERENCE AND INTERVENTION POPULATIONS TO GET THE VALID RESULTS OUT OF COMMUNITY TRIALS.

NESTED OR EMBEDDED DESIGN

Pooled intervention

REFERENCE POPULATION

EMBEDDED DESIGN

EMBEDDED TYPE WILL HELP• IN REDUCING SECULAR

DIFFERENCES • IN REDUCING CONFOUNDING

BIAS AS THE BOTH KNOWN AND UNKNOWN VARIABLE FACTORS WILL BE EQUALLY DISTRIBUTED IN BOTH THE POPULATIONS.

REFERENCE POPULATION

THE ONE WITH WHICH THE RESULTS OBTAINED FROM THE TRIAL ON THE INTERVENTION POPULATION ARE COMPARED, ANALYZED, INTERPRETED AND UTILIZED FOR PREPARING PUBLIC HEALTH POLICY.

INTERVENTION POPULATION

• THE EXPERIMENTAL POPULATION RANDOMLY SELECTED FROM A COUNTRY OR REGION AND ALMOST IDENTICAL AND COMPARABLE WITH THE REFERENCE (CONTROL) POPULATION IN POSSESSING ALL ITS CHARACTERISTICS.

UNDERSTANDING SOCIETAL CONDITIONS

• COMMONNESS OF TERRITORY,• MORTALITY PATTERN,• MORBIDITY PATTERN, • FERTILITY PATTERN, • CUSTOMS ,• SECULAR TRENDS

COLLECTING BASE LINE INFORMATION

• PREPARING THE BASE LINE LEVELS OF RISK FACTORS, MORTALITY RATES

INTERVENTION CONCEPT

• IDEA IS TO BRING ABOUT THE ATTITUDINAL CHANGE IN THE PEOPLE TO ALTER THEIR NEGATIVE LIFE STYLES AND TO SUSTAIN.

• THIS CAN BE ACHIEVED BY MEANS OF THE FOLLOWING SOCIAL SKILL LEARNING TECHNIQUES.

INTERVENTION BY SOCIAL COGNITION/LEARNING

SOCIAL COGNITION/LEARNING WHEREIN THE CHANGE OF BEHAVIOR CAN BE ACHIEVED THROUGH INTENSIVE EXPOSURE TO IMPORTANT MODELS LIKE POP STARS, PLAYERS.

INTERVENTION BY REASONED ACTION AND PLANNED

BEHAVIOR

WHERE THE CHANGE CAN BE BROUGHT ABOUT BY ADAPTING THE INFORMATION GIVEN BY CREDITABLE PERSON FIRST AND SUSTAINING IT BY SELF MANAGEMENT LATER I.E. BY LEARNING THE NECESSARY SKILLS.

INTERVENTION BY

PERSUASIVE COMMUNICATION

• CONTINUOUS PERSUASIVE COMMUNICATION TO THE PEOPLE THROUGH MASS MEDIA LIKE MOVIES, TELEVISION ETC TO CONVINCE THEM TO ADOPT POSITIVE LIFE STYLES CAN ALSO BRING ABOUT A CHANGE IN LIFE STYLE.

PRECEDE-PROCEED MODEL INTERVENTION

The PRECEDE process• Predisposing, • Reinforcing, and • Enabling• Constructs in• Educational-environmental • Diagnosis and• Evaluation)PROCEED process follows with

implementation, process, and impact and outcome evaluation.

SOCIAL MARKETING INTERVENTION

• PREVENTIVE HEALTH SERVICES ARE THE PRODUCTS TO BE MARKETED AND THE TARGET AUDIENCE, COSTS AND BENEFITS HAVE TO BE DEFINED.

• PROPER MESSAGES HAVE TO BE DEVELOPED AND EFFECTIVE CHANNELS FOR ACCEPTANCE HAVE TO BE SELECTED.

EVALUATION OF INTERVENTION 1. ENDPOINTS TO BE MEASURED2. CHANGES IN KNOWLEDGE, ATTITUDE AND

PRACTICE 3. MEANS AND PREVALENCES OF RISK

FACTORS4. SYMPTOMS/SIGNS/PAIN REDUCTION5. SPECIFIC MORBIDITY (OBTAINED FROM

PRACTITIONERS, HOSPITALS, AVAILABILITY OF MEDICAL SERVICES AND TREATMENT)

6. SPECIFIC MORTALITY RATES OF THE MOST COMMON DISEASES

7. TOTAL MORTALITY IN THE BOTH COMMUNITIES

EVALUATION METHODS

• POPULATION SURVEYS ARE CARRIED OUT BOTH IN THE REFERENCE AND INTERVENTION POPULATIONS SIMULTANEOUSLY THRICE I.E. BEFORE, DURING AND AFTER THE INTERVENTION.

TECHNIQUES OF MEASUREMENT

• QUESTIONNAIRES – ORAL WRITTEN, OR COMPUTERIZED ONES ARE USED DURING THE SURVEYS

• *ANALYTICAL METHODS – LABORATORY TESTS FOR PHYSICAL AND BIOCHEMICAL PARAMETERS BY TRAINED PERSONNEL DONE BEFORE AFTER CIT TO AVOID OBSERVER VARIATION

ROSENTHAL EFFECT

• THE INDIVIDUAL’S NATURE OR PREFERENCE TO ENHANCE OR REDUCE THE VALUE OF THE ENDPOINT WHILE TESTING OR READING THE LABORATORY FINDINGS BECAUSE OF HIS PERSONALITY INFLUENCE HAS ALSO TO BE TAKEN CARE OFF.

CEILING EFFECT

• CEILING EFFECT IS SAID TO BE PRESENT IN THE COMMUNITY WHEN A PART OR WHOLE OF THE COMMUNITY POSSESSES PERSONS AT HIGH RISK.

PRECAUTIONS:

1. NET CHANGES ARE MEASURED UNIFORMLY IN A STANDARDIZED AND SIMILAR MANNER IN BOTH THE REFERENCE (CONTROL) AND INTERVENTION POPULATIONS

2. INITIAL DIFFERENCES BETWEEN THE TWO POPULATIONS HAVE TO BE GIVEN DUE CONSIDERATION. THESE MAY BE DUE TO CHANCE OR REGRESSION TO THE MEAN.

INTENTION TO TREAT PRINCIPLE

• THE “INTENTION TO TREAT” PRINCIPLE, THAT IS, ONCE RANDOMIZED, ALWAYS ANALYZED – IS TO BE STRICTLY FOLLOWED

NET CHANGE MEASUREMENT

I0

I1R0

R1

RELATIVE

CHANGE

FINAL SURVEYBASE-LINE

RISK FACTOR LEVEL

MULTIVARIATE REGRESSION MODEL

• FORMULA:

Y = AGE + TIME1 +TIME2

+(COMMUNITY * TIME1)

+(COMMUNITY * TIME2)

FACTORS AFFECTING THE EVALUATION:

1. DELAY OF THE DEVELOPMENT OF THE RISK FACTORS HINDERS THE EVALUATION

1. INTENSITY AND DENSITY OF INTERVENTION DETERMINES THE EVALUATION STRATEGY

1. STATISTICAL POWER OF THE SAMPLES DETERMINES EVALUATION

THE SUCCESS OF CIT

1. THE SOCIETAL CONDITIONS AND ENVIRONMENT

2. AVAILABILITY OF THE OTHER HELPING SOCIAL HEALTH STRUCTURES

3. POSITIVE PREVENTIVE CLIMATE 4. THE NEED FOR THE TRIAL MUST BE

FELT BY THE COMMUNITY AS A DIRE NECESSITY

5. PRACTICAL FEASIBILITY, FINANCIAL AND TIME CONSTRAINTS

LIMITATIONS-1

• THE RANDOMIZATION CAN NOT BE ACHIEVED STRICTLY

The sampling method may be having inherent error or the sampled communities may be having inherent differences which can, of course, be minimized with difficulty.

LIMITATIONS-2

• CHANGES IN MORTALITY AND MORBIDITY TAKE SEVERAL YEARS TO OCCUR

Though it is true to larger extent particularly with the non-infectious diseases, biochemical/ risk factors changes may be seen comparatively earlier in the intervention community.

EFFECT OF IMMIGRATION INTO AND EMIGRATION

• IMMIGRATION INTO AND EMIGRATION FROM ANY OF THE TWO COMMUNITIES UNDER TRIAL WILL AFFECT THE EVALUATION AND TRIAL OBJECTIVES.

• ONLY THE LIVING PART OF THE COMMUNITY CAN SERVE AS THE USEFUL DENOMINATOR FOR CORRECT ASSESSMENT. HENCE MIGRATION FACTOR HAS TO BE GIVEN DUE CONSIDERATION.

PERSONAL EXPERIENCECOMMUNITY FLUORIDATIONFOR DENTAL CARIES 1990

• START / DURATION: 1992,

5 YEARS

• POPULATION: 8000, SHIELANAGAR, VISAKHAPATNAM,

• INTERVENTION: FLOURIDATION OF MUNICIPAL WATER SUPPLIES.

NORTH KARELIA PROJECT

• START / DURATION: 1972; 10YEARS INTERVENTION.• POPULATION: 180000 INHABITANTS, AGES 25–59

YEARS.• INTERVENTION: COMPREHENSIVE COMMUNITY INTERVENTION,

REDUCTION OF ARDIOVASCULAR RISK FACTORS.

CORONARY RISK FACTOR STUDY (CORIS)

• START / DURATION: 1979; 4 YEARS OF INTERENTION.• POPULATION: 11700 WHITE PERSONS, AGES 15 – 64 YEARS.• INTERVENTION: COMPREHENSIVE COMMUNITY INTERVENTION, SMALL

MASS MEDIA AND INTERPERSONAL (HIGH INTENSE) INTERVENTION; REDUCE CHOLESTOAL BP, SMOKING STRESS, INCREASE PHYSICAL ACTIVITY.

STANFORD FIVE CITY PROJECT

• START / DURATION: 1980; 5 YEARS INTERENTION.• POPULATION: 122800, AGES 12 – 74 YEARS.• INTERVENTION: COMPREHENSIVE COMMUNITY INTERVENTION,

REDUCE CHOLESTEROL, BP, SMOKING, WEIGHT, INCREASE PHYSICAL ACTIVITY.

MINNESOTA HEART HEALTH PROGRAM

• START / DURATION: 1980: 5 – 6 YEARS OF INTERVENTION.

• POPULATION: 231000 ADULTS.

• INTERVENTION: IMPROVE HEALTH BEHAVIOUR, REDUCE CHOLESTROL, 7 MG/DL, BP 2MMHG, SMOKING 3%, INCRESE PHYSICAL ACTIVITY 50KCAL /DAY, REDUCE CARDIOVASCULAR DISEASE MOBIDITY AND MORTALITY 15%.

PAWTUCKET HEART HEALTH STUDY

• START / DURATION: 1981,

7 YEARS INTERVENTION.

• POPULATION: 72000 WORKING CLASS PEOPLE.

• INTERVENTION: COMMUNITY ACTIVATION

CONCLUSIONS

• DUE TO OUR INTERVENTIONS, REDUCTION IN HARMFUL LIFESTYLES/RISK FACTORS WILL OCCUR THEREBY LEADING TO THE REDUCTION IN MORBIDITY, MORTALITY OR DISABILITY RATES.

REFERENCES• Brian Mac Mahan - Epidemiology:

principles & methods

• Roger Detels, James Mc Even-Oxford Text Book of Public Health

• Maxcy-Rosenau-Last, Public Health & Preventive medicine

• Brett & Cassens- Public Health Medicine,National Student Series.