Increasing obesity and comorbidity in patients undergoing primary total hip arthroplasty in the U.S.: A 13-year study of time trends

Table 2 Time trends in demographics and clinical characteristics of patients undergoing primary THA, in %, unless specified otherwise

	1993-1995	1996-1998	1999-2001	2002-2005	P-value
Age category					0.002
<50	13.7	17.1	16.2	16.0
50- < 65	24.7	25.9	26.6	27.5
65- <80	51.8	48.8	47.2	44.9
≥80	9.8	8.2	10.0	11.6
Mean age (SD)	65.0 (13.2)	63.5 (14.0)	63.9 (14.0)	64.3 (13.9)	0.03
Female gender	51.8	50.0	52.0	51.9	0.67
BMI					<0.001
<25	28.1	26.0	24.0	21.5
25– 29.9	38.8	40.0	37.9	37.2
30– 34.9	23.5	24.1	23.6	25.8
35– 39.9	7.3	6.6	9.1	9.3
≥40	2.3	3.3	5.3	6.3
Mean BMI (SD)	28.0 (5.2)	28.3 (5.2)	29.1 (6.0)	29.6 (6.2)	<0.001
Operative Diagnosis					<0.001
Osteoarthritis	81.8	81.0	88.2	92.2
RA/inflammatory arthritis	3.7	3.7	2.4	1.3
Other	14.5	15.3	9.4	6.5
Deyo-Charlson Index					<0.001
0	61.9	63.2	59.2	56.7
1	17.3	17.2	15.4	16.2
2	8.7	9.3	11.0	11.9
3 or more	12.2	10.2	14.4	15.1
Depression	4.5	4.8	7.2	9.8	<0.001
Anxiety	3.4	3.5	4.9	5.7	0.003

SD, standard deviation; RA, rheumatoid arthritis, BMI, body mass index.
Significant p-values are in bold. We used analysis of variance for continuous variables and, chi-squared test for categorical variables.