In a study published in Annals of Family Medicine, researchers investigated prescribing patterns to identify the presence of polypharmacy in primary care.
Polypharmacy occurs when a patient is prescribed multiple medications for one ailment, or when they are prescribed many medications for different health problems. This often occurs when the use of a medication should be discontinued, but it is not. Aside from the individual side effects of each drug, the medications may interact with each other causing harmful effects.
Health professionals in primary care settings oversee a wide range of patient issues and are therefore common settings for inappropriate prescribing and polypharmacy. To better understand polypharmacy, a study published in Annals of Family Medicine examined the prescribing patterns of antidepressants, bisphosphonates, and proton pump inhibitors (PPIs), all commonly prescribed medication classes.
Researchers retrieved data from the McMaster University Sentinel and Information Collaboration, an epidemiological database, on patients who were at least 18 years old by the end of 2016. Of particular interest in this study was legacy prescribing and its contribution to polypharmacy.
What is legacy prescribing?
Legacy prescribing, when prescriptions that should be suspended continue to be prescribed, was defined according to how long each drug class was prescribed for. Prescriptions exceeding 15 months for antidepressants and PPIs and, five and half years for bisphosphonates were classified as legacy prescribing.
Researchers measured durations in two ways: sum duration, which is the total number of days between the start and end date of a prescription, or start-stop duration, which is the total time between the first time a patient was prescribed a medication and the very last time they took the medication.
Legacy prescriptions are common in primary care
In total, the data of 50,813 patients was included in the study, and on average 10% (5,806) had legacy prescriptions. In terms of legacy prescriptions for more than one drug class, prescriptions for antidepressants and PPIs were the highest at 17%, whereas prescriptions for all 3 classes was only 0.2%. Older individuals were more likely to have legacy prescriptions and antidepressants and bisphosphonate legacy prescriptions were more commonly found amongst women than men.
In summary, inappropriate prescribing, by way of legacy prescribing, may, in fact, contribute to polypharmacy. Interestingly, antidepressant and PPI prescriptions were often found together, suggesting the adverse effects of the antidepressants may result in PPI prescriptions to alleviate those side effects. The study provided a glimpse into polypharmacy, but only in primary health care settings, so in the future research including specialist prescription data can help give a more well-rounded 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