Therapeutic substitution and therapeutic conservatism as cost-containment strategies in primary care: a study of fundholders and non-fundholders.

backgroundGeneral practice (GP) fundholders contained prescribing costs by restricting the rise in volume of prescribing and by increasing generic prescribing. It is uncertain whether they used more sophisticated approaches to medicine choice in attempts to contain costs.

aimTo examine whether fundholding practices have adopted medicine-specific strategies to contain prescribing costs--i.e. switching to less expensive but equally effective medicines or resisting the uptake of newer more expensive medicines--by examination of the prescribing of ulcer-healing and antidepressant medicines in the period before and after practices became fundholders.

methodComparison of prescribing data of 52 fundholding practices before fundholding and after fundholding with that of matched non-fundholding practices. Measures examined were prescribing costs (net ingredient cost in each therapeutic area per ASTRO-pu); prescribing volume (defined daily doses per ASTRO-pu); the proportion of all ulcer-healing medicines prescribed as cimetidine, ranitidine, nizatidine, and as proton pump inhibitors; and the proportion of all antidepressant medicines prescribed as selective serotonin re-uptake inhibitors.

resultsIn comparison with non-fundholding practices, fundholders increasingly prescribed less expensive medicines (cimetidine and nizatidine) within the class of histamine2 receptor antagonists. However, fundholders adopted proton pump inhibitors or selective serotonin re-uptake inhibitors at the same rate as non-fundholders.

conclusionFundholders have used therapeutic substitution with medicines of equal effectiveness to contain prescribing costs. There is no evidence that fundholders have been slower than non-fundholders to use newer, more expensive medicines.