1. Introduction

Polypharmacy is the concurrent use of multiple medications and is commonly defined as the chronic use of five or more medications daily [1]. Older people are often seen as a high-risk group but polypharmacy is not restricted to the age. Significant increases in polypharmacy prevalence have also been observed in middle-aged people [2-4]. With increasing polypharmacy, the risk of medication-related harm increases. On the other hand, the use of multiple medications can provide clinical benefit and may be needed, especially for people with comorbidities [5,6]. Polypharmacy is common in people with diabetes, and having diabetes is a risk factor for polypharmacy [7,8]. Many diabetes patients are prescribed more than eight different drugs to treat their diabetes and related diseases [5].
In general, polypharmacy is associated with more use of potentially inappropriate medication (PIM) [9]. Not much is known about polypharmacy in relation to PIM in people with diabetes. It seems that PIM use is more common in older people with diabetes as compared to younger people with diabetes or older people with hypertension [10,11]. There is a worrying increase in the prevalence of diabetes in younger age groups [12]. The extent of polypharmacy and PIM use have not been investigated in detail in this age group. Better insights into the trends of polypharmacy and PIM in older and middle-aged people with diabetes are needed to guide the development of medication optimization interventions.
The aim of our study was to assess (1) the trends in polypharmacy in older and middle-aged people treated for diabetes, and (2) the trends of PIM in those patients on polypharmacy.