COMMUNITY INTERVENTION TRIALS

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COMMUNITY INTERVENTION TRIALS
AUTHOR Dr. A. K. AVASARALA
MBBS, M.D. PROFESSOR HEAD DEPT OF COMMUNITY
MEDICINE EPIDEMIOLOGY PRATHIMA INSTITUTE OF
MEDICAL SCIENCES, KARIMNAGAR, A.P.. INDIA
91505417 avasarala_at_yahoo.com
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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

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LEARNING OBJECTIVES

• READER IS EXPECTED TO LEARN THE NATURE SCOPE OF
  COMMUNITY INTERVENTIONS
• THE PRECAUTIONS AND STEPS IN CONDUCTING
  COMMUNITY TRIALS
• ABLE TO ANALYSE AND INTERPRET THE RESULTS

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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

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TYPES

• PRIMARY PREVENTIVE TYPE (COMMUNITY INTERVENTION
  TRIALS (CIT)

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NATURE OF STUDIES

• INTERVENTION STUDIES
• NOT JUST OBSERVATIONS
• EXPERIMENTATIONS

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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.

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WHY CIT ?
THE HEALTH STATUS OF A COMMUNITY.
IMPACT ON
REDUCTION IN RISK FACTORS

• .

CHANGE TO HEALTHIER LIFESTYLE BY HIGH-RISK
GROUPS
CHANGE THE BEHAVIOR OF OTHER MEMBERS OF THE
SOCIETY
LEADS TO
INTERVENTIONS AIMED AND FOCUSED AT SPECIFIC
DISEASES
THE INCIDENCE OR COURSE OF OTHER DISEASES.
AFFECT
HEALTH ACTIVITIES IN COMMUNITIES
THE CONFIDENCE IN THE PEOPLE AND THEREBY THEIR
INVOLVEMENT AND ACCEPTANCE
ENHANCE
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GENERAL OBJECTIVES

• TO INCREASE HEALTH KNOWLEDGE
• OF THE WHOLE COMMUNITY ,

H E A L T H E D U C A T I O N

• TO DEVELOP POSITIVE AND RIGHT ATTITUDE
• IN THE COMMUNITY

• TO INCREASE THE PRACTICE OF POSITIVE
• HEALTH BEHAVIOR OF THE WHOLE COMMUNITY

• THEREBY PREVENTING EARLY DISEASES
• AND DEATHS IN THE COMMUNITY

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SPECIFIC OBJECTIVES

• TO MEASURE VERIFIABLE CHANGES IN
• HEALTH KNOWLEDGE IMPROVEMENT
• ATTITUDE
• BEHAVIOR

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STEPS OF CONDUCTING CIT

• SETTING
• STUDY DESIGN
• INTERVENTION METHODS
• EVALUATION OF INTERVENTION
• LIMITATIONS OF STUDY

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IDEAL SETTING

• COMMUNITY IS THE IDEAL SETTING

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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.
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SELECTION OF REFERENCE AND INTERVENTION
POPULATIONS

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

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NESTED OR EMBEDDED DESIGN
Pooled intervention
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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.

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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.

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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.
  

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UNDERSTANDING SOCIETAL CONDITIONS

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

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COLLECTING BASE LINE INFORMATION

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

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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.

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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.

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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.

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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.

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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.

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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.

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EVALUATION OF INTERVENTION

• ENDPOINTS TO BE MEASURED
• CHANGES IN KNOWLEDGE, ATTITUDE AND PRACTICE
• MEANS AND PREVALENCES OF RISK FACTORS
• SYMPTOMS/SIGNS/PAIN REDUCTION
• SPECIFIC MORBIDITY (OBTAINED FROM PRACTITIONERS,
  HOSPITALS, AVAILABILITY OF MEDICAL SERVICES AND
  TREATMENT)
• SPECIFIC MORTALITY RATES OF THE MOST COMMON
  DISEASES
• TOTAL MORTALITY IN THE BOTH COMMUNITIES

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EVALUATION METHODS

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

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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

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ROSENTHAL EFFECT

• THE INDIVIDUALS 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.

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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.

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PRECAUTIONS

• NET CHANGES ARE MEASURED UNIFORMLY IN A
  STANDARDIZED AND SIMILAR MANNER IN BOTH THE
  REFERENCE (CONTROL) AND INTERVENTION POPULATIONS
• INITIAL DIFFERENCES BETWEEN THE TWO POPULATIONS
  HAVE TO BE GIVEN DUE CONSIDERATION. THESE MAY BE
  DUE TO CHANCE OR REGRESSION TO THE MEAN.

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INTENTION TO TREAT PRINCIPLE

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

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NET CHANGE MEASUREMENT
I0
R1
RELATIVE CHANGE
I1
R0
FINAL SURVEY
BASE-LINE
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MULTIVARIATE REGRESSION MODEL

• FORMULA
• Y AGE TIME1 TIME2
• (COMMUNITY TIME1)
• (COMMUNITY TIME2)

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FACTORS AFFECTING THE EVALUATION

• DELAY OF THE DEVELOPMENT OF THE RISK FACTORS
  HINDERS THE EVALUATION
• INTENSITY AND DENSITY OF INTERVENTION DETERMINES
  THE EVALUATION STRATEGY
• STATISTICAL POWER OF THE SAMPLES DETERMINES
  EVALUATION

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THE SUCCESS OF CIT

• THE SOCIETAL CONDITIONS AND ENVIRONMENT
• AVAILABILITY OF THE OTHER HELPING SOCIAL HEALTH
  STRUCTURES
• POSITIVE PREVENTIVE CLIMATE
• THE NEED FOR THE TRIAL MUST BE FELT BY THE
  COMMUNITY AS A DIRE NECESSITY
• PRACTICAL FEASIBILITY, FINANCIAL AND TIME
  CONSTRAINTS

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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.

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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.

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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.

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PERSONAL EXPERIENCECOMMUNITY FLUORIDATIONFOR
DENTAL CARIES 1990

• START / DURATION 1992,
• 5 YEARS
• POPULATION 8000, SHIELANAGAR, VISAKHAPATNAM,
• INTERVENTION FLOURIDATION OF MUNICIPAL WATER
  SUPPLIES.

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NORTH KARELIA PROJECT

• START / DURATION 1972
• 10YEARS INTERVENTION.
• POPULATION 180000
• INHABITANTS, AGES 2559 YEARS.
• INTERVENTION COMPREHENSIVE
• COMMUNITY INTERVENTION, REDUCTION OF
  ARDIOVASCULAR RISK FACTORS.

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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.

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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.

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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.

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PAWTUCKET HEART HEALTH STUDY

• START / DURATION 1981,
• 7 YEARS INTERVENTION.
• POPULATION 72000 WORKING CLASS PEOPLE.
• INTERVENTION COMMUNITY ACTIVATION

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CONCLUSIONS

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

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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.