A nationwide study of multimedicine use in people treated with cardiovascular medicines in Australia.

Abstract

Multimorbidity and multimedicine use are common in people with cardiovascular disease and can lead to harms, such as prescribing errors and drug interactions. We quantified multimedicine use in people treated with cardiovascular medicines in a national sample of Australians. Cross-sectional study. Pharmaceutical dispensing claims for a 10% random sample of Australians. Australian adults dispensed any cardiovascular medicine between June and August 2019. None. We quantified the number and type of cardiovascular and non-cardiovascular medicines dispensed during the study period, and the number of unique prescribers, by age and sex. We identified 493,081 people dispensed any cardiovascular medicine (median age=67 years, 50.2% women). The population prevalence of cardiovascular medicine dispensing increased from 1.7% (n= 10,503) in people 18-34 years to 80.1% (n= 99,271) in people 75-84 years. Cardiovascular medicine dispensing varied by sex; women 18-34 years were more likely to be dispensed any cardiovascular medicine than men (male:female prevalence ratio [PR]=0.84, 95% confidence interval [CI]=0.81-0.87), whereas the prevalence of cardiovascular medicine dispensing was higher in men 35-44 years (PR=1.27, 95% CI 1.24-1.30) and 45-54 years (PR=1.24, 95% CI 1.22-1.26) and was similar between sexes in people ≥65 years. Overall, both women and men were dispensed a median of 2.0 (interquartile range [IQR]=1.0-3.0) cardiovascular medicines. Two-thirds of people ≥65 years (73.5%; n= 208,524) were dispensed ≥2 cardiovascular medicines, with 16.6% (n= 6736) of people ≥85 years dispensed five or more. Women and men were dispensed a median of 2.0 (IQR=1.0-5.0) and 2.0 (IQR=0.0-4.0) non-cardiovascular medicines, respectively, to treat comorbid conditions, commonly gastroesophageal reflux disease medicines (32.2% of women and 26.6% of men), antibiotics (28.7% of women and 22.4% of men), and antidepressants (26.3% of women and 15.9% of men). One quarter of both sexes had multiple prescribers for their cardiovascular medicines alone, whereas 54.5% (n= 134,939) of women and 49.9% (n= 122,706) of men had multiple prescribers for all medicines. Multimedicine use is common in people treated with cardiovascular medicines and presents a risk for inappropriate prescribing. Understanding the comorbid conditions commonly treated concurrently with cardiovascular disease can help improve co-prescribing guidelines and develop a person-centered approach to multimorbidity treatment.