What is the Prevalence of Potentially Inappropriate Prescribing (PIP) in Middle-Aged Adults in South London?

Problem

PIP refers to prescribing medications which may be non-evidence-based, have a higher chance of risk to patients than benefit or may not be cost-effective (Mahony and Gallagher, 2008). Research has primarily focused on PIP in older adults (≥65 years) and has consistently found that a substantial number of prescriptions in primary care may be potentially inappropriate. Polypharmacy, strongly associated with multimorbidity, is a key determinant of PIP in older adults. Research suggests that both polypharmacy and multimorbidity are also prevalent in middle-aged adults (45-64 years), yet there is a paucity of research on the prevalence of PIP within this age group (Barnett et al., 2012; Cassell et al., 2018). The PRescribing Optimally in Middle-Aged People’s Treatment (PROMPT) criteria were developed for this purpose (Cooper et al., 2014) The primary aim of this study was to calculate the prevalence of the top three PROMPT criteria (as per Cooper et al. (2016)) in South London, an area not yet studied:- Strong opioids should not be prescribed without the co-prescribing of at least one laxative- Proton pump inhibitors (PPIs) should not be prescribed at doses above the recommended maintenance dosage for greater than eight weeks- Benzodiazepines should not be used for greater than four weeksThe secondary aim is to to examine which patient and practice factors are associated with PIP.

Approach

A retrospective cross-sectional study was conducted using data from Lambeth DataNet (LDN) in South London (42 general practices, N=342,046). Prescribing, demographic and coding data were extracted for all those aged between 45-64 years who were also administered one or more prescriptions during the study period of January 1st to December 31st 2017. Descriptive analysis of the data, including calculation of the percentage prevalence of the three PROMPT criteria, are reported. Adjusted logistic regression will be performed to investigate the association between PIP and polypharmacy, multimorbidity, deprivation, practice variation, gender and age group.

Findings

This study included 47,775 patients. 17.3% of the study population have been exposed to at least one PIP, the most common criterion being PPIs (12.1%), followed by strong opioids (5.9%) and benzodiazepines (2.6%). Logistic regression analysis and adjustment for covariates is underway.

Consequences

The prevalence of PIP calculated is similar to other studies internationally (Cooper et al., 2016; Moriarty et al., 2016). PIP has been associated with adverse drug events and increased costs from subsequent hospitalisation. Given the prevalence of PIP in middle-aged adults, there may be a significant number of patients exposed to avoidable, costly adverse drug events. It also implies that prescribing quality may be an issue in South London. Efforts should be made to reduce and ultimately prevent PIP in middle-aged adults.