Adherence to hospital drug formularies and cost of drugs in hospitals in Denmark

Abstract

To investigate adherence rates to hospital drug formularies (HDFs) and cost of drugs in hospitals. Data on drugs used during 2010 were analyzed for ten hospitals (two hospitals from each of the five regions), constituting 30 % of hospitals and 45 % of hospital beds in Denmark. Drug use data from individual hospitals were retrieved from the hospital pharmacies. Adherence to the HDFs was analyzed for selected substances characterised by extensive use both in primary and secondary sectors (ATC codes A10, B03, C03, C07, C08, C09, C10, J01, N02, N05 and R03). Within each group, we also identified the drugs constituting 90 % of the volume (= DU90%) and the adherence to the HDF in this segment (Index of Adherence). Substances used by hospitals varied between 598 and 1,093. The proportion of used substances that were on the HDF varied between 14 % and 44 %. University hospitals used a significantly higher total number of substances (median 165 vs. 139, p = 0.019) and cost/DDD [(median 5 vs. 2 Euros, p = 0.033), p = 0.033] in the DU90% segment than the regional hospitals. Index of adherence varied between 43 % and 91 %. For the selected ATC codes, the index of adherence was between 76 % and 100 %. Adherence to the selected ATC groups was high, which means that the most commonly used substances are included in the HDFs, even though a variation existed. A large variation existed between the hospitals in the number of substances at HDFs.