Sex differences in health services and medication use among older adults with asthma.

Sex differences are well documented in chronic disease populations with cardiovascular disease and diabetes. Although recent research has suggested that asthma is more severe in older women compared to men, the extent of this difference remains poorly understood. The objective of this study was to compare rates of asthma-specific health services use (HSU) and medication use, between older women and men with asthma. This population-based cohort study included 209 054 individuals aged ≥66 years with asthma from health administrative data in Ontario, Canada. The primary exposure was sex. Outcomes included asthma-specific HSU (spirometry, emergency department (ED), hospitalisation, physician office and specialist visits) and medication use (asthma controller and reliever prescriptions). Negative binomial regression models adjusted for age, socioeconomic status and comorbidities were used to ascertain outcomes by sex from 2010 to 2016. Compared to men, women had lower rates of spirometry (adjusted relative rate (ARR) 0.87, 95% CI 0.85-0.89) and specialist visits for asthma (ARR 0.93, 95% CI 0.90-0.96), but higher rates of asthma-specific ED (ARR 1.43, 95% CI 1.33-1.53) and physician office visits (ARR 1.03, 95% CI 1.01-1.05). Women also had lower asthma controller (ARR 0.98, 95% CI 0.97-0.99) but higher asthma reliever (ARR 1.03, 95% CI 1.02-1.05) prescription fill rates, compared to men. These findings may indicate poorer disease control, greater asthma severity and poorer access to specialist asthma care in women.