Page 49 - Ethical Guidelines for Conducting Research Studies Involving Human Subjects

population based on census data & using questionnaires for measuring the
prevalence of diseases & it’s effect as well as to test hypotheses about the
possible cause of disease or suspected risk factors. Informed consent is
required from the participants who are directly involved only once in the
defined period.

b. Case Control Studies: This usually compares the past history of
exposure to risks among patients who have a specified condition/disease
(cases) with the past history of exposure to this among persons who
resemble the cases in such respects as age, sex socioeconomic status,
geographic location, but who do not have the disease (controls). Case
control studies can be done by following up available records, usually
records in a hospital, but in the context of a country like ours it may
require direct contact between research workers and study participants
and informed consent to participate in the study is necessary. However, if
it entails only a review of medical records, informed consent may not be
required and indeed may very often not be feasible. But for such waiver of
consent approval from NREC would be necessary.

c. Cohort Studies: These are longitudinal or prospective studies of a
group of individuals with differing exposure levels to suspected risk
factors. They are observed over a long period usually several years. The
rate of occurrence of the condition of interest is measured and compared in
relation to identified risk factors. It requires a study of large number of
participants for a long time and involves asking questions, checking of
records, routine medical examination and sometimes laboratory
investigations. Individuals are being followed up as the cohort and it is
essential to identify precisely every individual to be studied.

Experimental Epidemiology: In this study the investigators find out the
effects of the intervention on health by altering one or more parameters
under controlled conditions. Usually Experimental epidemiology done to
test a preventive or therapeutic regimen or the efficacy of a diagnostic
procedure by randomized controlled trials. Clinical evaluation of drugs
/devices / products / vaccines etc is done under these epidemiological
studies. Use of placebo as one of the arm of this trial that should be
explained and informed consent taken from the participant is mandatory
of this studies.

11.3 GENERAL PRINCIPLES

In principles of ethics it is always considered to respect the persons, duty
to maximize possible benefits and minimize possible harm. It is also
essential that all individuals in an epidemiological research are treated
alike keeping in mind the rules of distributive justice. The welfare of the
individual has to be balanced against the welfare of the community and
society at large. The CIOMS / WHO Guidelines for Epidemiological
Research assume that the individuals or populations being studied are

BMRC ETHICAL GUIDELINE ON HUMAN SUBJECTS Page 45