Methodologic Issues in the Evaluation of Service Screening

With the conclusive evidence from randomized controlled trials of the efficacy of mammographic screening in reducing mortality from breast cancer, the emphasis for the public health community has shifted to evaluation of service screening programs. Here, we briefly review the major approaches available for mortality-based evaluation of breast cancer screening programs and identify some design and analytic issues arising from these methodologic approaches. If care is taken to avoid or correct for biases, reliable evaluation of the mortality effect of service screening is possible. Results suggest that service screening programs are achieving breast cancer mortality reductions at least as great, and sometimes greater, as those observed in the trials.