Factors associated with excessive polypharmacy in older people

Older people are a growing population. They live longer, but often have multiple chronic diseases. As a consequence, they are taking many different kind of medicines, while their vulnerability to pharmaceutical products is increased. The objective of this study is to describe the medicine utilization pattern in people aged 65 years and older in Belgium, and to estimate the prevalence and the determinants of excessive polypharmacy.

Data were used from the Belgian Health Interview Survey carried out in 2008. Each respondent was asked to show to the interviewer all medicines that he/she had taken in the 24 h prior to the interview. Excessive polypharmacy was defined as the use of nine different kind of medicines or more in the past 24 h; the relation with the Region of residence, age, gender and additional factors, such as socioeconomic status, living situation, health status and contacts with health services, was explored through multivariate models.

Eight percent of the older people (65 years or more) belong to the excessive polypharmacy group. Factors most strongly associated with excessive polypharmacy are: having a longstanding illness, chronic condition or handicap, at least 1 contact with a general practitioner in past 2 months and self-reported depression during the last year. Ninety percent of persons in the excessive polypharmacy group are taking medicines active on the cardiovascular system.

In order to optimize the use of medicines, it is necessary to find a balance between adequate treatment of diseases and avoiding adverse effects of medicines. Interventions should aim to increase awareness among healthcare professionals and patients; they should focus on general practitioners and patients with cardiovascular diseases, those suffering from depression and those aged 80 years and over. Monitoring excessive polypharmacy in the older population remains important. Further studies should explore more in depth other and more specific determinants of excessive polypharmacy.