Prevalence and Factors Associated With Polypharmacy Use Among Adult Patients in Saudi Arabia.

Background: Polypharmacy is very common in clinical practice, especially among adult patients. The use of multiple medications may increase the risk of adverse drug events, medication cost, and medication errors. In addition, polypharmacy exacerbates treatment complexity, which consequently leads to poor patients' adherence to their medications. Despite being a well-recognized problem, few studies have investigated the prevalence and predictors of polypharmacy in Saudi Arabia.

Objectives: The aims of the study were to investigate the prevalence of polypharmacy among adult patients in a tertiary teaching hospital and to determine patients' characteristics that are associated with polypharmacy.

Methods: This was a retrospective cross-sectional study using data extracted from the electronic health records database for a period of 6 months between January and June 2016 in outpatient setting. Descriptive statistics were used to analyze the study sample. A multivariate logistic regression model was used to examine the association between different variables and polypharmacy. Statistical analysis software (SAS 9.2) was used to analyze the study data.

Results: A total of 17,237 observations (67.2% females) were included in the final analysis. Of these, nearly 54% (n = 9222) of reported observations were found using up to four prescription drugs and the other 46% (n = 8015) were using five or more prescription drugs. Interestingly, the prevalence of polypharmacy use was doubled among adults with hypertension as compared with those without hypertension (odds ratio [OR] = 2.68, 95% confidence interval [CI] = 2.51-2.87). In addition, polypharmacy use was two times more prevalent among adults with diabetes as compared with those without diabetes (OR = 2.31, 95% CI = 1.99-2.28) and five times more prevalent in patient with dementia (OR = 5.57, 95% CI = 1.26-24.7). Moreover, polypharmacy in adult patients was significantly influenced by sex (OR = 1.69, 95% CI = 1.59-1.80) and nationality (OR = 2.15, 95% CI = 2.00-2.31).

Conclusions: Polypharmacy is common among adult patients especially those who are older than 60 years. Polypharmacy may affect the overall process of drug therapy. It can be a risk factor to develop undesirable adverse drug events, especially in those with chronic health conditions. A special care should be taken to manage polypharmacy among adults in Saudi Arabia.