Impact of a generic substitution reform on patients' and society's expenditure for pharmaceuticals.

Sweden's pharmaceutical expenditure has increased during the last decades. On 1 October 2002 mandatory generic substitution was introduced in Sweden with the purpose to reduce the growth in pharmaceutical expenditure. The aim of the present study was to investigate if the implementation of generic substitution was associated with changes in patients' expenses and reimbursed cost for prescribed pharmaceuticals included in the Swedish Pharmaceutical Benefits Scheme (PBS). Monthly pharmacy sales data was obtained from the National Corporation of Swedish Pharmacies (Apoteket AB). The study period ranged between 1 January 2000 and 31 December 2004. Changes in pharmaceutical expenditure associated with the introduction of generic substitution were analysed with a linear segmented regression. The study comprised outpatient prescription pharmaceuticals encompassed by PBS for Sweden in total and each county council. Two different data sets were analysed. The first comprised all prescribed pharmaceuticals. The second contained only pharmaceuticals on regular prescriptions (i.e. exclusion of multidose dispensed drugs). Changes in patient co-payment per 1000 inhabitants and working day and subsidised cost per 1000 inhabitants and working day associated with the introduction of generic substitution were analysed. Expenditure was expressed in Swedish krona, SEK (SEK 1=US$ 0.14/euro 0.11, 7 July 2006). The Swedish Consumer Price Index was used to inflation-adjust expenditures with 2004 as base. The introduction of generic substitution was associated with a significant change in slope for patient co-payment in both all prescribed pharmaceuticals and pharmaceuticals on regular prescriptions (p<0.005) for Sweden in total. The slope shifted direction from a slight increase before the reform into a decline after the reform was implemented. This was also found for the average slope of patient co-payment for all county councils (p<0.0001). The introduction of generic substitution was associated with a statistically significant shift in slope for subsidised cost for Sweden in total (p<0.001). The slope shifted from a monthly increase before October 2002 to a monthly decline for all prescribed pharmaceuticals afterwards. Similar results were found for the average slope of subsidised cost for all county councils both for all prescribed pharmaceuticals and pharmaceuticals on regular prescriptions (p<0.0001). The introduction of generic substitution was associated with a shift in trend from an increase into a decrease both for patients' and society's expenditures. This suggests that generic substitution has contributed to a reduction in the growth of pharmaceutical expenditure.