Table 1 Clinical and demographic characteristics of study cohorts

Mean age (±standard deviation)

68 ± 10

68 ± 10

69 ± 10

69 ± 10

Men/Women (%)

44%/56%

45%/55%

49%/51%

51%/49%

Age groups (%)

 ≤60 yrs

18%

18%

20%

20%

 >60-70 yrs

35%

37%

29%

31%

 >70-80 yrs

38%

38%

42%

41%

 >80 yrs

8%

7%

9%

8%

Body mass index (%)

 <25 kg/m ²

13%

13%

13%

14%

 25-29.9 kg/m ²

35%

36%

36%

39%

 30-34.9 kg/m ²

29%

43%

29%

27%

 35-39.9 kg/m ²

14%

7%

14%

14%

 ≥40 kg/m ²

9%

7%

7%

5%

American Society of Anesthesiologists (ASA) cass

 Class I-II

58%

58%

50%

53%

 Class III-IV

42%

41%

50%

47%

Deyo-Charlson index, mean (±standard deviation)

1.2 ± 1.9

1.1 ± 1.9

1.0 ± 1.7

1.0 ± 1.4

Deyo-Charlson comorbidities (%)

 Myocardial infarction

5%

5%

4%

4%

 Congestive heart failure

4%

3%

4%

2%

 Peripheral vascular disease

5%

4%

3%

2%

Cerebrovascular disease

7%

7%

7%

6%

Dementia

0.2%

0.1%

0.2%

0.1%

Chronic Obstructive Pulmonary Disease (COPD)

11%

10%

9%

9%

Ulcer disease

8%

9%

7%

7%

Mild liver disease

2%

2%

1%

2%

Diabetes

9%

8%

10%

7%

Diabetes with organ damage

2%

2%

2%

2%

Hemiplegia

0.3%

0.2%

0.4%

0.3%

Moderate/severe renal disease

6%

4%

4%

2%

Moderate/severe liver disease

0.4%

0.2%

0.5%

0.5%

Metastatic solid tumor

3%

3%

1%

1%

AIDS

0%

0%

0.1%

0.1%

Rheumatologic disease

7%

8%

8%

8%

Other cancer

14%

13%

10%

7%

Psychological comorbidity (%)

 Anxiety

6%

5%

5%

3%

 Depression

11%

8%

8%

5%

Distance from medical center

 <100 miles

53%

51%

32%

34%

 100-500 miles

39%

41%

57%

54%

 >500 miles

8%

8%

11%

12%

Implant fixation (cement status)

 Uncemented

98%

99.7%

0%

0%

 Cemented/hybrid

2%

0.3%

100%

100%

Operative diagnosis

 Osteoarthritis

94%

93%

 Rheumatoid arthritis

4%

4%

 Loosening/wear/osteolysis

57%

61%

Dislocation/fracture/instability/non-union

22%

20%

 Failed prior arthroplasty with components removed/infection

21%

19%

 Other

2%

3%