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Table 1 Demographic and other cohort characteristics for entire primary THA cohort including people without vs. with acute kidney injury (AKI)

From: Acute kidney injury after primary total hip arthroplasty: a risk multiplier for complication, mortality, and healthcare utilization

 

Entire Primary THA Cohort (N = 4,116,485)a

Primary THA

No Acute Kidney Injury (N = 4,055,407)a

Acute Kidney Injury (N = 61,077) a

Age, Mean (SE); median

65.2 (0.04); 65.9

65.4 (0.04); 65.9

71.5 (0.12); 72.2

Age category, in years

 <50

449,642 (10.9%)

446,863 (11.0%)

2,779 (4.5%)

 50-64

1,364,821 (33.2%)

1,351,472 (33.3%)

13,349 (21.9%)

 65-79

1,732,014 (42.1%)

1,704,496 (42.0%)

27,518 (45.1%)

 ≥80

566,521 (13.8%)

549,094 (13.5%)

17,427 (28.5%)

Gender

 Female

2,330,188 (56.6%)

2,301,645 (56.8%)

28,543 (46.7%)

 Male

1,776,722 (43.2%)

1,744,192 (43.0%)

32,530 (53.3%)

Race

 White

2,882,041 (70.0%)

2,838,722 (70.0%)

43,319 (70.9%)

 Black

225,772 (5.5%)

219,916 (5.4%)

5,856 (9.6%)

 Hispanic

104,385 (2.5%)

102,556 (2.5%)

1,829 (3.0%)

 Other/Missing

904,234 (22.0%)

894,166 (22.0%)

10,068 (16.5%)

Primary Diagnosis

 Rheumatoid arthritis (RA)

29,173 (0.7%)

29,016 (0.7%)

157 (0.3%)

 Avascular bone necrosis

285,623 (6.9%)

281,334 (6.9%)

4,289 (7.0%)

 Osteoarthritis (OA)

3,447,224 (83.7%)

3,405,538 (84.0%)

41,686 (68.3%)

 Other

354,307 (8.6%)

339,372 (8.4%)

14,935 (24.5%)

 Fracture

117 (0.003%)

107 (0.003%)

10 (0.02%)

Deyo-Charlson Score

 0

2,193,575 (53.3%)

2,181,133 (53.8%)

12,442 (20.4%)

 1

926,286 (22.5%)

913,996 (22.5%)

12,290 (20.1%)

 ≥2

996,623 (24.2%)

960,278 (23.7%)

36,345 (59.5%)

Insurance

 Medicaid

138,809 (3.4%)

136,558 (3.4%)

2,251 (3.7%)

 Medicare

2,234,675 (54.3%)

2,190,406 (54.0%)

44,269 (72.5%)

 Other

102,277 (2.5%)

101,017 (2.5%)

1,260 (2.1%)

 Private

1,600,829 (38.9%)

1,588,027 (39.2%)

12,802 (21.0%)

 Self

32,307 (0.8%)

31,939 (0.8%)

368 (0.6%)

Income Categoryb

 0-25th percentile

653,243 (15.9%)

639,522 (15.8%)

13,721 (22.5%)

 25-50th percentile

1,009,678 (24.5%)

994,108 (24.5%)

15,570 (25.5%)

 50-75th percentile

1,086,953 (26.4%)

1,071,309 (26.4%)

15,644 (25.6%)

 75-100th percentile

1,285,854 (31.2%)

1,270,801 (31.3%)

15,053 (24.6%)

Hospital Location/Teaching

 Rural

444,188 (10.8%)

439,410 (10.8%)

4,778 (7.8%)

 Urban

1,722,390 (41.8%)

1,696,986 (41.8%)

25,404 (41.6%)

 Urban Teaching

1,939,988 (47.1%)

1,909,531 (47.1%)

30,457 (49.9%)

Hospital Bed size

 Small

685,208 (16.6%)

676,555 (16.7%)

8,653 (14.2%)

 Medium

1,037,562 (25.2%)

1,021,335 (25.2%)

16,227 (26.6%)

 Large

2,383,797 (57.9%)

2,348,038 (57.9%)

35,759 (58.5%)

Hospital Region

 Northeast

818,699 (19.9%)

807,610 (19.9%)

11,089 (18.2%)

 Midwest

1,089,883 (26.5%)

1,073,918 (26.5%)

15,965 (26.1%)

 South

1,358,857 (33.0%)

1,334,688 (32.9%)

24,169 (39.6%)

 West

849,046 (20.6%)

839,192 (20.7%)

9,854 (16.1%)

  1. aThe national estimates were based on the following from the 20% NIS sample: Entire cohort (N = 855,634); no AKI (N = 843,044); AKI (N = 12,590)
  2. bIncome quartiles were defined as follows: (1) from 2003, ZIPINC_QRTL variable is available, which was used; (2) 1998-2002: another categorical variable (ZIPINC) indicated the median household income of the patient's residential ZIP Code, based on the 1999 demographics. The categories were defined so that the maximum for category 1 ($25,000) was approximately 150% of the 1999 poverty level and the boundary between the second and third categories ($35,000) was approximately the national median household income. As an example, for 2014, Q1 (0-25th percentile) was $1 - 39,999, Q2 was $40,000 - 50,999, Q3 was $51,000 - 65,999; and Q4 was $66,000+. In 1998, Q1 was $1 - 28,999, Q2 (25-50th percentile) was $29,000 - 36,999, Q3 (50-75th percentile) was $37,000 - 49,999; and Q4 (75-100th percentile) was $50,000+
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Arthritis Research & Therapy

ISSN: 1478-6362

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