Background Advance health directives (AHD) can be used to explore and document patient preferences for treatment and are therefore an important aspect of care planning. Aims To investigate the prevalence and factors associated with AHD among older inpatients. Methods This retrospective study included 6449 patients, aged >= 65 years referred for specialist geriatric consultation between 2007 and 2018 in Queensland, Australia. The interRAI-Acute Care Comprehensive Geriatric Assessment tool was used to calculate a frailty index (FI), range 0-1, based on 52 possible deficits, and categorised into intervals of 0.1 for analysis. FI was also grouped according to previously reported cut points: fit (FI <= 0.25), moderately frail (FI >0.25-0.4), frail (FI >0.4-0.6) and severely frail (FI >0.6). Results An AHD was present in 1032 (16.0%) of 6449 patients. Those with an AHD were significantly frailer than those without an AHD (mean FI 0.52 vs 0.45; P < 0.001). Higher frailty (odds ratio (OR): 1.34 (1.27-1.40)), older age (OR: 1.04 (1.03-1.05)), living in an institution (OR: 1.33 (1.01-1.73)) and recent hospitalisation (OR: 1.42 (1.23-1.62)) were significantly associated with higher prevalence of AHD. Prevalence of AHD increased over time, from 7.6% (n = 66) in 2008 to 35.4% (n = 99) in 2017. Conclusions The presence of AHD is associated with sociodemographic factors, as well as higher frailty levels. Prevalence of AHD among inpatients has increased over the past decade but remains modest.
