Table 1 Descriptive statistics for main outcomes and candidate predictor variables for derivation group and validation group

Main outcomes

 Mortality at the 1st postoperative year (%/n)

22.0% (116)

27.4% (48)

0.142

 Free walking rate at the 1st postoperative year (%/n)

58.4% (308)

53.7% (94)

0.273

Candidate predictors

 Demographic variables

  Age (Year)

77.9 ± 8.4

77.7 ± 7.6

0.774

  Gender (Male)

24.5% (129)

20.0% (35)

0.225

  Resident (Downtown)

82.7% (436)

82.3% (144)

0.893

  Medical insurance (No)

40.2% (212)

42.3% (74)

0.631

  Marriage (With spouse)

72.7% (383)

69.1% (121)

0.368

  Smoking history (No)

81.2% (429)

80.6% (141)

0.843

  Fragility fractures history (No)

94.5% (498)

92.6% (162)

0.352

  Dementia (No)

90.7% (479)

87.4% (153)

0.211

 Preoperative walking ability (ref: Bedridden)

0.847

  Need assistance

25.4% (134)

27.4% (48)

  Free walking

62.9% (332)

61.7% (108)

 Surgery-related variables

  Time from injury to diagnosis (Days)

13.9 ± 20.24

17.7 ± 32.7

0.065

  CCI score (≤ 4)

56.7% (299)

56.6% (99)

0.970

  Vital sign (Normal)

69.6% (367)

68.0% (119)

0.684

  Electrocardiogram (Normal)

38.1% (201)

38.3% (67)

0.973

  Chest radiograph (Normal)

22.2% (117)

22.3% (39)

0.981

  Baseline GLU (mmol/L)

6.34 ± 2.28

6.64 ± 2.64

0.153

  Baseline HGB (g/L)

116.3 ± 17.7

113.9 ± 18.5

0.117

  Baseline ALB (g/L)

33.7 ± 4.57

33.9 ± 4.7

0.576

  Baseline INR

1.14 ± 0.97

1.10 ± 0.25

0.628

  Surgical procedure (THA)

38.1% (201)

33.7% (59)

0.293

Anesthesia procedure (SA)

0.910

  PNB

32.3% (170)

35.4% (62)

  GA

9.3% (49)

13.6% (21)

  Perioperative complications (No)

88.1% (465)

89.7% (157)

0.554