Dutch Hospital Drug Formularies: pharmacotherapeutic variation and conservatism, but concurrence with national pharmacotherapeutic guidelines

Aims This research examines current hospital drug formularies (HDFs) of all Dutch general hospitals. It assesses the extent to which they recommend th e same drugs, the breadth of their coverage in terms of therapeutic areas, drug groups incorporated and individuals drugs included, and their extent o f conservatism by considering the year of introduction of the drugs include d within groups. Furthermore, it considers the extent to which their recomm endations concur and comply with those of national pharmacotherapeutic guid elines and the WHO Essential Drugs List (EDL). Methods Seventy-eight (81%) out of all 96 current Dutch HDFs were received of which 62 were suitable for study. Differences between HDFs and eventual associations with hospital characteristics were researched by statistical t esting and case-control studies. To evaluate HDFs' concurrence with nationa l guidelines and compliance with the WHO EDL, nine drug groups were studied in detail: benzodiazepines, calcium channel blockers, beta-adrenoceptor bl ocking agents, ACE-inhibitors, angiotensin-II inhibitors, NSAIDs, H-2-recep tor antagonists, 5HT(3)-antagonists, and H+-pump inhibitors. Concurrence an d compliance with national guidelines and the WHO EDL was defined as inclus ion of recommended drugs. Non-concurrence was defined as inclusion of nonre commended drugs. Results The total number of indications addressed and drug groups incorpora ted within HDFs varied from 28 to 72 (median 56) and from 30 to 123 (median 97), respectively. The total number of individual drug entities (pharmacol ogical substances) included ranged from 239 to 658 (median 430) and the tot al number of drug products, including all different dosage forms, from 412 to 1121 (median 655). Within drug groups, drug entities first marketed were most frequently included. Teaching hospitals were most likely to include r ecently marketed drugs. Depending on the drug group, HDFs' concurrence and compliance with national guidelines and the WHO EDL ranged from 35% to 100% . Conclusions Findings indicate that Dutch HDFs are rather uniform in the ind ications addressed and the drug groups incorporated. However, the number of individual drug entities and drug products included within groups varies c onsiderably. Furthermore, Dutch HDFs are considered rather conservative, as older drugs are favoured over more recent drugs. Generally, with some drug exceptions, Dutch HDFs concur and comply with recommendations in national pharmacotherapeutic guidelines and with the WHO EDL over 90%.