Increasing polypharmacy - an individual-based study of the Swedish population 2005-2008

By applying individual-based data on dispensed drugs, we have studied all dispensed prescribed drugs for the entire Swedish population during four 3-month periods 2005-2008. Five or more (DP ≥5) and ten or more (DP ≥10) dispensed drugs during the 3-month period was applied as the cut-offs indicating the existence of polypharmacy and excessive polypharmacy respectively.During the period 2005-2008, the prevalence of polypharmacy (DP≥5) increased by 8.2% (from 0.102 to 0.111), and the prevalence of excessive polypharmacy (DP≥10) increased by 15.7% (from 0.021 to 0.024).In terms of age groups, the prevalence of polypharmacy and excessive polypharmacy increased as regards all ages with the exception of the age group 0-9 years. However, the prevalence of excessive polypharmacy displayed a clear age trend, with the largest increase for the groups 70 years and above. Furthermore, the increase in the prevalence of polypharmacy was, generally, approximately twice as high for men as for women. Finally, the mean number of dispensed drugs per individual increased by 3.6% (from 3.3 to 3.4) during the study period.The prevalence of polypharmacy and excessive polypharmacy, as well as the mean number of dispensed drugs per individual, increased year-by-year in Sweden 2005-2008.It is clear that a continuous increase in the overall level of drug use, especially among elderly, has been noted in several countries. Moreover, an increase in the number of individuals experiencing polypharmacy, ie. the concurrent use of several different drugs, has also been reported [1-3].Whilst the use of a number of different drugs for many individuals appears to be a rational drug therapy, and polypharmacy is assumed to provide major health benefits for the well being of large groups of individuals suffering from different diseases, polypharmacy is also a well known risk factor due to adverse drug reactions, drug-drug interactions, and low adherence to drug therapy [3-5].In addition, it is also assumed