Simplified models of screening for chronic disease: estimation procedures from mass screening programmes.

The performance of a screening programme depends on a number of parameters, which may need different types of information for their estimation. In this paper, two characteristics of interest, the sojourn-time distribution and the sensitivity, are considered, and estimation procedures, based on data which should be available from a mass screening programme, are proposed. The methods are applied to published data from the HIP breast cancer screening project, to which a negative exponential distribution for the sojourn-time distribution fitted better than the other families of distribution considered.