Table 3.

Relation of KR surgery to mortality risk, stratified by deciles of propensity scores, in a propensity score-matched cohort of men and women with knee osteoarthritis

Propensity score* deciles (%)	Score†	Number of pairs	KR			Non-KR			HR (95% CI)
			Death (N)	PY	Mortality rate (N/1000 PY)	Death (N)	PY	Mortality rate (N/1000 PY)
2.5–10	0.010	1052	107	5096.1	21	132	4838.5	27	0.76 (0.57 to 1.01)
10–20	0.019	1404	151	6773.7	22	183	6459.2	28	0.71 (0.56 to 0.91)
20–30	0.029	1405	140	7018.0	20	148	6696.4	22	0.87 (0.67 to 1.14)
30–40	0.040	1404	132	6648.5	20	163	6391.9	25	0.73 (0.56 to 0.95)
40–50	0.055	1404	121	6366.6	19	155	6035.6	25	0.74 (0.57 to 0.97)
50–60	0.073	1404	114	5987.2	19	166	5529.2	30	0.56 (0.42 to 0.73)
60–70	0.095	1404	101	6314.7	18	120	5474.4	22	0.78 (0.58 to 1.05)
70–80	0.125	1405	96	5513.2	17	122	5378.0	23	0.75 (0.55 to 1.02)
80–90	0.170	1404	87	5194.1	17	93	5076.8	18	0.87 (0.62 to 1.21)
90–97.5	0.242	1053	60	3978.4	15	84	3731.3	23	0.62 (0.43 to 0.89)

^*Variables used for calculation of propensity score are listed in table 1.

^†Mean propensity score within the decile.

KR, knee replacement; N, number; PY, person-years.