Table 2. Estimated Mean Physical Function Scores and Odds of Activity Limitations at Selected Points Prior to TKA, Women’s Health Initiative, 1993-2017.

Time prior to TKA	Physical function, estimated mean (95% CI)a	Specific activity limitations, AOR (95% CI)b
		Walking		Climbing a flight of stairs
		1 Block	Several blocks
1 Year
Black	53.6 (51.5-55.8)	1.86 (1.57-2.21)	1.91 (1.60-2.28)	1.55 (1.29-1.85)
Hispanic	56.7 (53.2-60.2)	1.06 (0.75-1.49)	1.29 (0.92-1.80)	1.67 (1.21-2.31)
White	59.5 (58.9-60.0)	1 [Reference]	1 [Reference]	1 [Reference]
2 Years
Black	59.1 (56.9-61.2)	1.86 (1.57-2.21)	1.96 (1.67-2.31)	1.61 (1.36-1.90)
Hispanic	62.2 (58.7-65.6)	1.06 (0.75-1.49)	1.27 (0.94-1.73)	1.66 (1.23-2.23)
White	64.9 (64.3-65.5)	1 [Reference]	1 [Reference]	1 [Reference]
5 Years
Black	67.1 (65.0-69.3)	1.86 (1.57-2.21)	2.14 (1.83-2.50)	1.81 (1.55-2.12)
Hispanic	70.2 (66.7-73.7)	1.06 (0.75-1.49)	1.22 (0.90-1.66)	1.61 (1.20-2.17)
White	72.9 (72.4-73.5)	1 [Reference]	1 [Reference]	1 [Reference]
10 Years
Black	73.9 (71.7-76.1)	1.86 (1.57-2.21)	2.48 (1.94-3.17)	2.20 (1.72-2.82)
Hispanic	77.0 (73.5-80.5)	1.06 (0.75-1.49)	1.15 (0.68-1.93)	1.55 (0.96-2.49)
White	79.7 (79.0-80.4)	1 [Reference]	1 [Reference]	1 [Reference]

Abbreviations: AOR, adjusted odds ratio; TKA, total knee arthroplasty.

^aPhysical function scores correspond to RAND 36-Item Health Survey physical functioning scale. Mean physical function scores estimated through general estimating equations that included the following covariates: age at TKA and linear, quadratic, and cubic time. Mean values correspond to model fit for an age of 74 years at TKA.

^bActivity limitations correspond to self-reported difficulty in performing the specific item of the RAND 36-Item Health Survey. Adjusted odds ratios determined through general estimating equations that included age at TKA and linear, quadratic, and cubic time. Time by race/ethnicity interaction term additionally included in models for walking several blocks and climbing a flight of stairs.