How many hysterectomies should purchasers buy?

In the reorganized British National Health Service (NHS), purchasers are supposed to assess the health care requirements of their resident populations and contract for an appropriate volume of services. In the case of elective surgical procedures this can be problematic when there is no reliable information on health needs and no consensus on appropriate rates of use. An examination of hysterectomy rates in 8 districts in 1 Regional Health Authority found a nearly 2-fold variation in population-based rates, a difference which had persisted for at least 12 years. A detailed comparison of a high- and a low-rate district was conducted to assess the extent to which the variations in the rates were related to indices of data quality, resource availability, use of alternative surgical procedures, use of private hospitals, differences in gynaecologists' admission thresholds and differences in demand. The difference was not accounted for by supply factors, but there were significant differences between the 2 districts in levels of demand for specialist gynaecology services and differences in gynaecologists' admission thresholds. It seems likely that the low-rate district contained a greater number of general practitioners who were willing to treat patients themselves rather than refer them to specialists. Because of the sparsity of scientific evidence on which to base judgements about appropriateness and the lack of consensus about need, it will be impossible to specify a target figure for an optimal hysterectomy rate.