Smoking and primary total hip or knee replacement due to osteoarthritis in 54,288 elderly men and women

Table 4 Subdistribution hazard ratios of undergoing total joint replacement in males and females: multivariable competing risk regressions ^! - accounting for the competing risk of death (N = 44,614)

		Male	Female
		N = 19,864	N = 24,750
		TJR: 1,405 (7.1%)	TJR: 2,200 (8.9%)
		Death prior to TJR: 46.8%	Death prior to TJR: 34.2%
Covariates		sHR (95% CI), P value	sHR (95% CI), P value
Age, continuous		0.96 (0.95–0.97), <0.001	0.96 (0.95–0.97), <0.001
Charlson Index, continuous		0.75 (0.68–0.84), <0.001	0.73 (0.66–0.81), <0.001
BMI categories	Kg/m²
Normal weight	18.5-24.9 (ref)	1.00	1.00
Underweight	<18.5	0.41 (0.10–1.67), 0.214	0.31 (0.15–0.61), 0.001
Overweight	25–29.9	1.47 (1.22–1.76), <0.001	1.60 (1.39–1.83), <0.001
Obese	30–34.9	2.05 (1.67–2.52), <0.001	2.31 (2.00–2.67), <0.001
Morbidly obese	≥ 35	2.92 (2.15–3.97), <0.001	2.55 (2.09–3.09), <0.001
Current smoker, yes		0.60 (0.48–0.75), <0.001	0.70 (0.56–0.86), 0.001
Exercise > 30 minutes /per week, yes		1.13 (1.01–1.26), 0.035	1.00 (0.92–1.01), 0.966
SEIFA score, continuous		1.00 (1.00–1.00), 0.049	1.00 (0.99–1.00), 0.213
Screening SBP, continuous		0.99 (0.99–0.99), 0.010	0.99 (0.99–0.99), <0.001

^!Also controlled for alcohol intake, and screening diastolic blood pressure.
Abbreviations: BMI (body mass index), SEIFA (Socio-Economic Indexes for Areas), SBP (systolic blood pressure), TJR (total joint replacement), sHR (subdistribution hazard ratio).

ISSN: 1471-2474