Encouraging the development of integrated health centres: a critical analysis of lower referral rates.

Dutch government policy places considerable emphasis on the strengthening of the primary health care sector. In this connection, it has been shown that health centres tend to reduce costs. The referral rate for GPs in health centres is considerably lower than for GPs practising alone. The question this raises is whether the lower rates are due to the performance of the GPs or to intermediate variables. Three research projects which cast some light on this issue are examined. The first dealt with a possible explanation by means of structural variables, such as differences in the level of urbanization and the availability of hospital services. The second addressed itself to the question of 'patient mix' and asked whether this is responsible for differences in referral rates, which the third project put the same question in respect to the selection of physicians. All results supported rejection of the hypothesis that the statistical relation between the practice-setting and the referral rate was spurious. A clear result concerning the causality of the relation is not yet available.