Retrospective Studies

Matching in retrospective studies.

Retrospective studies have always taken for granted that matching should be done on factors which affect the incidence of the disease. Worcester stated that when that "when a disease group is being compared with another group, matching is usually done on variables known to be related to the disease rather than on variables related to the outcome." Miettinen et al. however disagrees. They bel...

Retrospective studies and chart reviews.

A retrospective study uses existing data that have been recorded for reasons other than research. A retrospective case series is the description of a group of cases with a new or unusual disease or treatment. With a case-control study, cases with and without the condition of interest are identified, and the degree of exposure to a possible risk factor is then retrospectively compared between th...

Cohort studies: prospective versus retrospective.

Cohort studies form a suitable study design to assess associations between multiple exposures on the one hand and multiple outcomes on the other hand. They are especially appropriate to study rare exposures or exposures for which randomization is not possible for practical or ethical reasons. Prospective and retrospective cohort studies have higher accuracy and higher efficiency as their respec...

Retrospective studies: excellent tools to complement surveillance.

Emerging infectious diseases pose an important challenge to public health globally. The identification of an etiologic pathogen responsible for an emerging infection in humans can be a major task. The time required to isolate and characterize a new infectious agent sufficiently to adopt control measures and, when possible, to select and make available curative and preventive treatments can be c...

Threats to Validity in Retrospective Studies