ABSTRACT
Formulating an answerable clinical question is critical to generating any data on the predictive validity of clinical information in addition to identifying work that has already been undertaken by other researchers. In adopting a primary care approach, it is important to have robust information in relation to the concurrent validity and the reliability of the clinical information being used. In generating indicants to support diagnosis in primary care settings, two broad study designs have been adopted: case-control and cross-sectional. The case-control approach starts from the disease whereas the cross-sectional approach commences with the patient and their problem. Traditionally many case-control studies were undertaken amongst groups of hospital patients. Working backwards to obtain data on potential clinical indicants may be difficult due to the time lapse with individuals having moved or died. A cross-sectional study seeks to compare items of clinical information against a 'reference standard' within a pre-defined group of patients.
