Using case-control studies to assess the prevention of inflicted traumatic brain injury.

Because the incidence of inflicted traumatic brain injury (inflicted TBI) is low, even in populations at increased risk, very large samples are necessary to have adequate statistical power to conduct a randomized clinical trial of the effectiveness of a potential intervention to prevent inflicted TBI. This requirement for large samples, in addition to the logistic demands of prospective clinical trials, makes it prohibitively expensive to conduct such studies. Case-control studies provide a statistically efficient and logistically and economically feasible alternative approach to evaluating such interventions. However, because these are observational studies, they are susceptible to bias. Approaches are presented to conducting and analyzing case-control studies to evaluate interventions to prevent inflicted TBI while assessing and minimizing possible bias.