Case-Series and Case-Report Studies
Contrasting with cohort studies, case-series are descriptive studies following one small group of people. They are additions or supplements of case reports. A case report is a detailed report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient. Usually the cases are obtained from the authors experiences, generally involve one patient or a small number of patients, and more importantly, lack a control group. There is often confusion in naming studies as ‘cohort studies’ when only one group of people is examined. Yet, unless a control group is present, these studies are defined as case-series. The next step in strengthening an observation from a case-series is selecting appropriate control groups to conduct a cohort or case-control study, as described above.