48. Dr. Raheel Shaikh 49. Dr. Ajay Shinde 50. Dr. Saiprasad Shinde 51. Dr. Shilpa Shinde 52. Dr. Amit Shingade 53. Dr. Pradnya Sonawane group no. 9 Good afternoon to all.dr sai d gr8.

Field trials community intervention studies.dr sai d gr8.

What is community intervention study.? In field trials the unit of randomization is individual, when this unit is group called as community interventional studies..dr sai d gr8.

效 果效 果 This character combination means effect, effectiveness, efficacy and result. –Meaning from the first character, which can mean efficacy, efficiency, merit, or benefit. –Meaning from the second character, which can mean carry out, complete, end, finish, fruit, achieve, reward, or succeed..dr sai d gr8.

Experimental studies differ from observational studies described /reported rather than simply to observe, the exposure of interest. There are many different approaches used in experimental studies, from very tightly controlled laboratory experiments to large scale community intervention. Experimental studies either focus on assessing change at the level of the individual or the group. The most important aspect of experimental studies, no matter what study group is used., is to ensure that the allocation of the study group to the different treatments/ interventions / exposures under investigation is done randomly. The development of the research protocol will then focus primarily on how to measure the effect of an exposure on an outcome with consideration of the effects of other factors (potential confounders as well as factors related to the efficacy of the delivery of the intervention).dr sai d gr8.

History Lind and Louis are two notable workers who used experimentation to attempt objectively to assess the effect of a treatment on a disease. In 1753, Lind described an experiment in which 12 sailors with scurvy were put on the same standardized diets, and then allocated to one of six treatment groups for 14 days. In 1834, Louis articulated further guidance to follow regarding study design. –the number of subjects required to show benefit of one treatment over another; (sample size) –The need to observe disease progress accurately in treated and controlled groups; (end point) –the need to define precisely disease state before the experiment;(inclusion criteria) –and the importance of observing deviations from intended treatments..dr sai d gr8.

Unit of measurementDescription Selection of subjects in relation to exposure and outcome Whole communities/ populations Community trials -Community intervention studies Whole towns and villages without regard to exposure or outcome (unless initial screening removes clinically diagnosed subjects at baseline) Individuals Clinical trials -therapeutic trials -secondary or tertiary prevention trials Selected on basis of outcome; may have additional criteria Field trails -primary prevention trials Usually no selection, healthy volunteers, with range of exposure and level of the outcome variable (for continuously distributed measures e.g. blood pressure) Field intervention studies Usually no selection, but clinically diagnosed outcomes may be excluded at baseline.dr sai d gr8.

Clinical or field trials Community or field intervention studies Outcome Measures exposure and outcome under controlled conditions Measures exposure and outcome under less well controlled conditions Measures effectivenessMeasures efficacy Question answered Does the treatment work in theory (Is it theoretically feasible) without consideration of the practical constraints imposed in the ‘real world’ Does the treatment work in practice under day-to-day conditions which apply in the ‘real world’ Major objective Explores casual mechanismsAssesses factors, which affect implementation.dr sai d gr8.

Methodology There are a number of general principles that are relevant to all experimental studies. (1) selection of the study population; (2) allocation of treatment regimes; (3) length of observation; (4) observer effects; (5) participant effects; (6) compliance; (7) ascertainment of exposure and outcome; (8) statistical power; (9) analysis and interpretation..dr sai d gr8.

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.dr sai d gr8.

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..dr sai d gr8.

ENDPOINTS TO BE MEASURED 1. CHANGES IN KNOWLEDGE, ATTITUDE AND PRACTICE 2. MEANS AND PREVALENCES OF RISK FACTORS 3. SYMPTOMS/SIGNS/PAIN REDUCTION 4. SPECIFIC MORBIDITY (OBTAINED FROM PRACTITIONERS, HOSPITALS, AVAILABILITY OF MEDICAL SERVICES AND TREATMENT) 5. SPECIFIC MORTALITY RATES OF THE MOST COMMON DISEASES 6. TOTAL MORTALITY IN THE BOTH COMMUNITIES.dr sai d gr8.

Validity and Reliability Validity very high –Can document complexity of human behaviour –Detailed descriptions Reliability low –Subjective –Difficult to replicate.dr sai d gr8.

Advantages Provide a great amount of detailed descriptive information. very useful for forming hypothesis. Enables an immense amount of data to be collected quickly and inexpensively. May clarify relationship between variable that cannot be examined by other means. Control of variable enable one to draw cause and effect conclusion..dr sai d gr8.

Disadvantages  Not applicable to the investigation of large social settings  Making generalizations can be problematic  Biases, attitudes, and assumptions of the researcher can be problem  Selective perception and memory  Selectivity in data collection  Presence of the researcher may change the system or group being studied  Virtually impossible to replicate the findings.dr sai d gr8.

Examples.dr sai d gr8.

COMMUNITY FLUORIDATION FOR DENTAL CARIES 1990 START / DURATION: 1992, 5 YEARS POPULATION: 8000, SHIELANAGAR, VISAKHAPATNAM, INTERVENTION: FLOURIDATION OF MUNICIPAL WATER SUPPLIES..dr sai d gr8.

NORTH KARELIA PROJECT START / DURATION: 1972; 10YEARS INTERVENTION. POPULATION: INHABITANTS, AGES 25–59 YEARS. INTERVENTION: COMPREHENSIVE COMMUNITY INTERVENTION, REDUCTION OF CARDIOVASCULAR RISK FACTORS..dr sai d gr8.

CORONARY RISK FACTOR STUDY (CORIS) START / DURATION: 1979; 4 YEARS OF INTERENTION. POPULATION: 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..dr sai d gr8.

References 1. Porta M. A dictionary of epidemiology. 5 th edition. Oxford, New York: Oxford University Press, Rothman J, Greenland S. Modern epidemiology. Second edition. Lippincott - Raven Publishers, Bhopal R. Study design. University of Edinburgh. 4. NLM. An introduction to Clinical trials. U.S. National Library of Medicine, Songer T. Study designs in epidemiological research. In: South Asian Cardiovascular Research Methodology Workshop. Aga-Khan and Pittsburgh universities..dr sai d gr8.

Thanks for your kind attention and listening.dr sai d gr8.