Which factors promote inappropriate prescribing among older patients in primary care?

Several factors contribute to potentially inappropriate prescribing (PIP) among older persons in primary care settings, and these elements can be classified into patient, physician, and system, according to a Singapore study. These factors can help in designing complex interventions for PIP and in developing risk prediction tools to identify groups who may need further PIP-related interventions.

“Given the central role that primary care plays in coordinating healthcare, the findings call for prioritization of initiatives to reduce iatrogenic medication-related harm targeting at multiple level (individuals, prescribers, and systems level) in primary care settings,” the researchers said.

In this systematic review that sought to examine factors associated with PIP, the databases of PubMed, Embase, Cinahl, Web of Science, Scopus, and PsycINFO were searched for studies related to ‘older persons’, ‘primary care’, and ‘inappropriate prescribing’.

Two reviewers did the study selection, data extraction, and quality appraisal. Finally, the researchers narratively synthesized all factors that contribute to PIP in the primary care setting.

PIP-related factors

A total of 1,017 articles were identified, of which 25 met the eligibility criteria and included 2,893,925 participants (average age 70.4‒84.0 years). Risk factors associated with PIP were classified into three: patient, physician, and system factors. [Proc Singap Healthc 2023;doi:10.1177/20101058231181478]

Patient factors included the following: patient demographics (advanced age, lower education level, and lower socioeconomic status), medical comorbidities (polypharmacy and multimorbidity), and lifestyle factors (unhealthy habits and use of over-the-counter medications).

Physician or prescriber factors included older, male, and solo general practitioner (GP), higher number of visits of pharmaceutical sales representatives to GP, centrally located GP practice, and smaller number of older patients following up with the GP.

Finally, system factors identified were higher number of primary care visit by patients, lower number of specialist visit by patients, and medication source from public healthcare system.

“The findings provide contextual information to guide our understanding of PIP in primary care,” the researchers said.

Notably, the most common risk factor of PIP was polypharmacy, defined as the concurrent use of multiple medications (generally ≥4 drugs). In previous studies, polypharmacy affected nearly 30 percent of older patients in primary care. [BMC Geriatr 2017;17:230; Fam Pract 2007;24:14-19; Int J Family Community Med 2018;2:310-313]

“The association of polypharmacy with PIP may possibly be explained by the complex phenomenon of ‘prescribing cascade’, which involves the situation whereby a clinician is not being able to link the complaints back to the adverse effects of medication and hence unnecessarily prescribes even more medications to manage the adverse effects,” the researchers said. [Lancet 2017;389:1778-1780]

Risk prediction tool

PIP-related factors identified in this study could be used to develop a risk prediction tool to distinguish high-risk groups who may benefit from further interventions, according to the researchers.

“In the current age of technology advancement, machine learning has been used in multiple healthcare domains to investigate its potential for prognosis, diagnosis, or differentiation of clinical groups,” they said. [J Med Internet Res 2019;21:e12286]

Deep learning methods, a subfield of machine learning, can be used to develop such a tool through the integration of broad and complex information from the electronic health data to identify the risk factors associated with PIP. [Brief Bioinform 2018;19:1236-1246]

“PIP is common in primary care and is associated with adverse outcomes,” the researchers said. “Knowledge of the risk factors of PIP can be critical in designing PIP interventions, especially in guiding our understanding on how PIP occurs in primary care.”