Use of medication among nursing home residents: a Danish drug utilisation study.

BACKGROUND: Data on drug utilisation patterns in nursing home populations is scarce. We aimed to describe drug use patterns in Danish nursing home residents. METHODS: We established a cohort of 5,179 individuals (63% women; median age of 84 years) admitted into 94 nursing homes across Denmark during 2015-2017. Data on prescription drug use and other census data were obtained from the nationwide Danish health registries. RESULTS: The total number of drug classes filled increased from a median of 6 drugs (interquartile range [IQR] 3-9) at 18-24 months before nursing home admission to a median of 8 drugs (IQR 6-11) just after admission, with the most common drug classes comprising paracetamol (61%), platelet inhibitors (41%), proton pump inhibitors (34%), statins (33%) and potassium supplements (31%). The incidence rate of new drug treatments increased from 21 new treatments/100 residents/month at 12-24 months before admission to a peak of 71 new treatments/100 residents/month in the month prior to admission, while it levelled off to about 34 new treatments/100 residents/month after 6-9 months. The drug classes primarily responsible for this peak were laxatives, antibiotics and analgesics. The largest absolute increases were seen for laxatives (53%), paracetamol (43%) and antidepressants (36%), all showing a marked increase up to and following admission. A high proportion of residents remained on therapy in the 3-year period following admission, with users of antidepressants and antidementia drugs being most persistent. CONCLUSION: Nursing home admission is associated with an increase in use of both predominantly preventive and non-preventive drug classes.