Impact of gender and race on expectations and outcomes in total knee arthroplasty

Table 1 Summary of initial cohort demographics

		n	Percent
Gender1	Male	29	21.8
	Female	104	78.2
	Total (n)	133	100
Relationship status1	Married	54	40.6
	Single	53	39.8
	Divorced	10	7.5
	Significant other	1	0.8
	Widowed	13	9.8
	Partner	1	0.8
	Total (n)	132	99.2
Race1	African American	69	51.9
	Asian	2	1.5
	Hispanic	3	2.3
	White	55	41.4
	Unknown/Other	4	3
	Total (n)	133	100
Insurance type1	Private	78	58.6
	Medicare	51	38.3
	Workman's comp	3	2.3
	Total (n)	132	99.2

¹The null hypothesis, that the categories occur with equal probabilities, is rejected using the One-Sample Chi-square test, P < 0.01.

Table 2 Summary statistics of pre-operative assessments and expectations

		n		Mean	Median	Mode	SD	Minimum	Maximum
		Valid	Missing
Number of friends		133	0	7.47	5	10	7.7	0	50
Pre-Op Psychometric Scales	Emotional/ Informational support score	133	0	85.34	96.9	100	20.9	3	100
	Tangible support score	133	0	82.02	94	100	24.2	0	100
	Affectionate support score	133	0	88.84	100	100	19.3	0	100
	Overall medical outcomes support index	133	0	85.28	90.8	100	18.7	1	100
	Geriatric depression scale1	133	0	3.39	3	2	3	0	13
	Positive social support	133	0	86.28	100	100	22.5	0	100
Pre-Op Pain Catastrophizing Scale	Rumination2	133	0	7.28	7	16	5.1	0	16
	Magnification3	133	0	2.63	2	0	3.2	0	12
	Helpnessness3	133	0	6.29	4	0a	6.1	0	24
	Total3	126	7	16.2	13	6a	12.9	0	52
Expectations	Pre-op	69	64	81.98	89.5	97	17.7	23	100
	Post-op (4-8 wk)4			70.97	86.8	100	29.8	3	100

¹Using General Linear Modeling (GLM) Multivariate Analysis (MANOVA), differences between groups was observed for Race and Age Group, P < 0.05;

²Using GLM and MANOVA, differences between groups was observed within Age Group, P < 0.05;

³Using GLM and MANOVA, differences between groups were observed for Age Group (P < 0.05), Race (P << 0.01), and Relationship Status (P << 0.01);

⁴Using GLM and MANOVA, differences between groups was observed for Gender (P <0.05).

^aMultiple modes exist. The smallest value is shown.

Table 3 Outcome measures for 3 time points pre-op (T1), post-operative (4-8 wk) (T2), and post-operative (9-14 mo) (T3)

		n	Mean	SD	Mean rank	P
						T2 vs T11	T3 vs T11	T3 vs T21	Overall2
VAS	T1	133	7.64	1.99	2.71	0	0	0.02	0.05
	T2	103	4.81	2.61	1.93
	T3	52	4.02	3.44	1.36
EQ5D	T1	129	0.59	0.193	1.59	0.38	0	0.02	0.05
	T2	103	0.67	0.204	1.91
	T3	54	0.74	0.229	2.5
EQ5D-VAS	T1	131	69.31	20.435	1.71	0.66	0.01	0.2	0.05
	T2	105	75.52	17.04	1.96
	T3	54	76	17.1	2.33
KOOS-pain	T1	130	37.3	18.53	1.3	0.01	0	0	0.05
	T2	104	56	19.51	1.91
	T3	54	70.87	25.38	2.79
KOOS-symptom	T1	130	40.64	15.71	1.27	0	0	0.07	0.05
	T2	105	55.19	14.59	2.14
	T3	56	61.54	18.22	2.59
KOOS-ADL	T1	129	42.22	20.97	1.32	0	0	0.01	0.05
	T2	105	64.42	21.29	2.04
	T3	54	70.7	26.31	2.64
KOOS-sport	T1	130	38.61	37.9	1.51	0.05	0	0.05	0.05
	T2	103	55.16	41.11	2
	T3	55	62.29	37.32	2.49
KOOS-QOL	T1	130	17.17	18.99	1.34	0	0	0.01	0.05
	T2	104	34.31	19.95	2.02
	T3	55	47.29	30.93	2.64

¹Each row tests the null hypothesis that the sample 1 and sample 2 distributions are the same. Asymptotic significances (2-sided tests) are displayed. The significance level is 0.05. Significance values have been adjusted by the Bonferroni correction for multiple tests;

²Related samples, Friedman’s two-way analysis of variance by Ranks.