COHORT STUDY - Dr Muhammad Tareque Hasan Teaching Assistant Department of Epidemiology COHORT STUDY BUHS 1 Concept of cohort The word cohort is derived

COHORT STUDY - Dr Muhammad Tareque Hasan Teaching Assistant...

This preview shows page 1 - 8 out of 23 pages.

COHORT STUDY Dr. Muhammad Tareque Hasan Teaching Assistant Department of Epidemiology BUHS 1
Concept of cohort The word cohort is derived from the Latin “cohorts” meaning an enclosure, company, or crowd. In Roman times a cohort was a body of 300–600 infantry. In epidemiological terms the cohort is a group of people with something in common, usually an exposure or involvement in a defined population group. 2
Definition Cohort study is a type of analytical study which is undertaken to obtain additional evidence to refute or support existence of association between suspected cause and diseases. Other names of cohort study are Longitudinal study, Incidence study and forward looking study 3
Features of cohort studies Cohorts are identified prior to appearance of disease under investigation The study groups are observed over a period of time to determine the frequency of disease among them The study proceeds from cause to effects 4
Design of Cohort Study EXPOSED NOT EXPOSED DISEASE DEVELOPS DISEASE DOES NOT DEVELOP DISEASE DOES NOT DEVELOP DISEASE DEVELOPS 5
Steps of Cohort Study 1 Selection of study population 2 Obtaining Data on exposure 3 Selection of comparison group 4 Follow up 5 Analysis 6
1. Selection of study subjects The usual procedure is to locate or identify the cohort, which may be a total population in an area or sample thereof. Cohort can be: community cohort of specific age and sex; exposure cohort e.g. radiologists, smokers, users of oral contraceptives; birth cohort e.g. school entrants; occupational cohort e.g. miners, military personnel; marriage cohort; diagnosed or treated cohort, e.g. cases treated with radiotherapy, surgery, hormonal treatment.

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture