The influence of hospitalisation on drug prescription in primary care - a large-scale follow-up study

Objective To explore the influence of hospitalisation on the prescription of drugs in the primary care sector using prescription data of a major statutory health insurance (SHI) organisation, with a special focus on the so-called "Me-Too" drugs - in particular, 3-hydroxy-3-methyl-glutaryl (HMG) CoA reductase inhibitors (statins) and proton pump inhibitors (PPIs). Methods A comprehensive outpatient drug prescription analysis was conducted on members of a SHI who had been hospitalised during the first 3 months of 2004. The number and costs of all prescriptions of 2426 patients during a 3-month period before admission and after discharge, respectively, were compared using Wilcoxon's signed rank test. Data are shown in absolute and relative numbers as well as relative risks (RR) and their 95% confidence intervals (CIs). Results The total number of prescriptions before hospitalisation and after discharge remained nearly the same, while the number of different active substances prescribed per patient decreased by 4%. However, overall costs increased after discharge by 15% due to the higher cost per prescription. Changes in medication affected nearly every patient (98.1%), and 60% had at least five changes. Of the substances prescribed to an individual before admission, 57% were cancelled after discharge, and 55% of all substances prescribed after discharge were novel prescriptions. Significantly more patients received a PPI or statin after hospitalisation (RR for a PPI: 1.27; 95% CI: 1.12 -1.45; RR for a statin: 1.16; 95% CI: 1.02-1.32). The increase in PPI medication was due to a 58% increase in the number of patients receiving pantoprazole, a "Me-Too" drug. Conclusion Hospitalisation exerts a marked influence on drug therapy in ambulatory care, with a significant increase in the prescription of novel, on-patent drugs instead of less expensive alternatives.