PURPOSE To investigate variability in older people's outcomes according to general practitioner (GP) and practice characteristics in New Zealand and the Netherlands.METHODS We used data from 2... Show morePURPOSE To investigate variability in older people's outcomes according to general practitioner (GP) and practice characteristics in New Zealand and the Netherlands.METHODS We used data from 2 primary care-based, cluster-randomized, controlled trials to separately fit mixed models of unplanned admission rates, functional ability, and quality of life (QOL) and examine variation according to GP- and practice-level characteristics after adjusting for participant-level characteristics. For the New Zealand sample (n = 3,755 aged 75+ years in 60 practices), we modeled 36-month unplanned admission rates, Nottingham Extended Activities of Daily Living (NEADL) scale, and QOL domain ratings from the brief version of the World Health Organization Quality of Life assessment tool. For the Netherlands sample (n = 3,141 aged 75+ years in 59 practices), we modeled 12-month unplanned admission rates, Groningen Activity Restriction Scale scores, and EuroQOL 5 dimensions (EQ-5D) summary index.RESULTS None of the GP or practice characteristics were significantly associated with rates of unplanned admissions in the New Zealand sample, but we found greater rates of admission in larger practices (incidence rate ratio [IRR], 1.45; 95% CI, 1.15-1.81) and practices staffed with a practice nurse (IRR, 1.74; 95% CI, 1.20-2.52) in the Netherlands sample. In both samples, differences were consistently small where there were significant associations with function (range, -0.26 to 0.19 NEADL points in the New Zealand sample; no associations in the Netherlands sample) and QOL (range, -1.64 to 0.97 QOL points in New Zealand; -0.01 EQ-5D points in the Netherlands).CONCLUSIONS In the absence of substantial differences in older people's function and QOL, it remains unclear whether intriguing GP- or practice-related variations in admission rates represent low- or high-quality practice. Show less
