Cost of case-control studies.

A financial review of five case-control studies concerning the relationship of birth control methods to the occurrence of disease was conducted. The review had two major objectives: first, to identify costs associated with the planning, conduct and analysis of case-control studies; second, to assess whether sample size determination based on optimal allocation would have resulted in a significant reduction in cost. The data collection phase represented about 75% of the total cost of a study, whereas the costs of planning and analysis were roughly 10% and 15% of total cost, respectively. The typical cost in mid-1970s dollars was from +100-+200 per subject. Evaluation of an optimal allocation procedure based on the relative cost of cases and controls demonstrated that such a method was likely to reduce total study cost by at most 2 per cent.