Exploring Polypharmacy in Primary Care

Study Overview

A recent study published in the Annals of Family Medicine examined prescribing patterns to identify instances of polypharmacy in primary care settings. Polypharmacy refers to the prescribing of multiple medications for a single condition or a combination of medications for various health issues. This situation often arises when a medication should be discontinued but remains prescribed. Besides the individual side effects of each drug, interactions between medications can lead to adverse effects.

Context of the Research

Health professionals in primary care frequently manage a diverse array of patient concerns, making these settings prone to inappropriate prescribing and polypharmacy. To delve deeper into this issue, the researchers focused on common medication classes such as antidepressants, bisphosphonates, and proton pump inhibitors (PPIs).

Data Collection

The study utilized data from the McMaster University Sentinel and Information Collaboration, an epidemiological database, covering patients aged 18 and older as of the end of 2016. The researchers aimed to investigate the role of legacy prescribing in contributing to polypharmacy.

Understanding Legacy Prescribing

Legacy prescribing occurs when medications that should be discontinued continue to be prescribed. This was defined by the duration for which each drug class was prescribed. Specifically, prescriptions lasting more than 15 months for antidepressants and PPIs, and over five and a half years for bisphosphonates were categorized as legacy prescribing.

Measurement Methods

The researchers measured prescription durations in two ways:
1. Sum duration – the total number of days from the start to the end date of a prescription.
2. Start-stop duration – the total time from the first prescription of a medication to the last time the patient took it.

Findings on Legacy Prescriptions

The study included data from 50,813 patients, revealing that approximately 10% (5,806) had legacy prescriptions. Among those with multiple legacy prescriptions, the combination of antidepressants and PPIs was the most prevalent at 17%. In contrast, the concurrent use of all three medication classes was only observed in 0.2% of patients. Additionally, older adults were more likely to have legacy prescriptions, with a higher prevalence of antidepressant and bisphosphonate legacy prescriptions noted among women compared to men.

Conclusion and Future Research Directions

In summary, inappropriate prescribing practices, particularly through legacy prescribing, may significantly contribute to polypharmacy. Notably, the co-prescription of antidepressants and PPIs suggests that adverse effects from antidepressants may lead to PPI prescriptions to mitigate these side effects. While this study sheds light on polypharmacy within primary care, future research that includes data from specialist prescriptions could provide a more comprehensive understanding of prescribing patterns among patients.

Written by Monica Naatey-Ahumah, BSc

Reference: Mangin, D., Lawson, J., Cuppage, J., Shaw, E., Ivanyi, K., Davis, A., & Risdon, C. (2018). Legacy Drug-Prescribing Patterns in Primary Care. Annals of Family Medicine, 16(6), 515-520. https://doi.org/10.1370/afm.2315