Changing Prevalence of Medication Use in People with Cirrhosis: A Retrospective Cohort Study Using Pharmaceutical Benefits Scheme Data.

Abstract

Safe and appropriate use of medicines is essential to improve health outcomes in cirrhosis. However, little is known about the number and type of medicines dispensed to people with cirrhosis in Australia, as this predominantly occurs in the community. We aimed to characterise the prescriptions dispensed to people with cirrhosis and explore changes in the use of medication groups over time. Pharmaceutical Benefits Scheme data between 1 January 2016 and 30 June 2020 was extracted for consenting CirCare participants (multi-site, prospective, observational study). Prescriptions dispensed from cirrhosis diagnosis until liver transplant or death were included. Safety classifications for dispensed medicines were defined using published evidence-based recommendations. The pattern of medication use was analysed in 6-monthly time intervals. Generalised estimating equations models were used to estimate the change in consumption of medicines over time. Five hundred twenty-two patients (mean age 60years, 70% male, 34% decompensated at recruitment) were dispensed 89,615 prescriptions during the follow-up period, representing a median of 136 [interquartile range (IQR) 62-237] prescriptions and a median of 16 (IQR 11-23) unique medicines per patient (total n=9306 medicines). The most commonly used medicines were proton pump inhibitors (PPIs) (dispensed at least once to 73% of patients), opioids (68%) and antibiotics (89%). Polypharmacy was prevalent, with 59-69% of observed participants in each time period dispensed five or more unique medicines. Prescription medication use increased over time (p<0.001) independently of age, comorbidity burden and liver disease aetiology. The likelihood of taking PPIs, opioids, antidepressants and inhaled medicines also increased with each successive time period. Use of angiotensin therapies, metformin and statins differed over time between patients with compensated versus decompensated cirrhosis. General practitioners prescribed 69% of dispensed medicines, including a higher proportion of 'unsafe' and 'safety unknown' medicines compared with consultants/specialists (p<0.001). Polypharmacy is common in people with cirrhosis and some medication groups may be overused. Pharmacovigilance is required and future medication safety efforts should target high-risk prescribing practices and promote medication rationalisation in the community.