srakaislam.blogg.se - Types of studies

If the incidence of the disease is significantly higher in the exposed cohort, the association is confirmed Both the cohorts are regularly followed up for a definite period and examined for development of the disease at regular intervals It is made sure that none of the members in both the groups have the disease under investigation.

The groups are similar except for the ‘exposure’ to the risk factor. – This is the ‘Control or Non-exposed cohort’. Another group of people similar to the exposure cohort, but DEFINITELY NOT EXPOSED are identified.

One group of people exposed to the suspected RF is identified. Odd’s ratio (OR) is calculated in case – control studies to estimate the risk associated with each risk factor By same argument, factors which are significantly higher in the controls are noted as the possible protective factors. Factors which are significantly more in the cases group as compared to the control are reaffirmed as the risk factors The prevalence of the exposure among the cases is compared with that in the controls. The history of exposure to the suspected risk factor is ascertained in all the members of both the groups Another group of matched ‘controls’ (free from disease) is assembled. A group of ‘cases’ of a disease is assembled.

This study can give clues about the ‘risk factors’ and the cause.

The disease distribution in a community is described in terms of Time, Place and Person.

Randomized controlled trials (RCT) – uses patients as units of study, mostly for assessing a new therapyĢ.ğield trials – uses healthy individuals as units of study, mostly for assessing preventive agents like vaccinesģ.Ĝommunity trials – uses communities as units of study for assessing community based interventions like health status in villages with a training program versus in those without There are three main types of experimental studies.ġ. Experimental studies – deliberate intervention is made and the effect of such intervention is observed.Īnalytical study – Case control and cohort studies are the two types of analytical observational studies Observational studies – we do not interfere in the process of the disease, but simply observe the disease and the associated factors.Ģ.

There are two broad types of epidemiological studies:ġ.