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. 2019 Feb 28;6(1):e13111. doi: 10.2196/13111

Table 1.

Baseline characteristics of the study participants.

Characteristics Total (N=69) Digital intervention group (N=38) Conventional rehabilitation group (N=31) P valuea
Demographics
  Age (years), mean (SD) 68.5 (7.0) 67.3 (6.8) 70.0 (7.2) 0.12b
  Gender, female, n (%) 54 (78.3) 32 (84.2) 22 (71.0) 0.30c
  Operated knee - right, n (%) 38 (55.1) 23 (63.2) 14 (45.2) 0.21c
Comorbidities and known risk factors for adverse events
  Body mass index, mean (SD) 30.9 (4.9) 31.0 (4.5) 30.8 (5.4) 0.84b
  Smoking, n (%) 8 (11.6) 4 (10.5) 4 (12.9) 1.00d
  Hypertension, n (%) 48 (69.6) 25 (65.8) 23 (74.2) 0.62c
  Diabetes, n (%) 11 (15.9) 7 (18.4) 4 (12.9) 0.74d
  Pulmonary disease, n (%) 9 (13.0) 3 (7.9) 6 (19.4) 0.28d
  Cardiac disease, n (%) 4 (5.8) 2 (5.3) 2 (6.5) 1.00d
  Stroke, n (%) 0 (0) 0 (0) 0 (0) N/Ae
  Renal disease, n (%) 2 (1.4) 0 (0) 1 (3.2) 0.45d
  Bleeding disorders, n (%) 0 (0) 0 (0) 0 (0) N/A
  ASAf class 3 or 4g, n (%) 10 (14.5) 5 (13.2) 5 (16.1) 0.74d
  Steroids for chronic condition, n (%) 0 (0) 0 (0) 0 (0) N/A
  Previous contralateral knee replacement, n (%) 17 (24.6) 7 (18.4) 10 (32.3) 0.30c
  Previous hip replacement, n (%) 3 (4.3) 3 (7.9) 0 (0) 0.25d
Hospital admission and surgical procedure
  Time between admission and surgery (hours) <24 <24 <24 N/A
  Operative time (min), mean (SD) 62.6 (11.3) 62.4 (9.87) 62.8 (13.0) 0.89b
  Minor adverse events before discharge, n (%) 1 (1.4) 0 (0) 1 (3.2) 0.45d
  Hospital length of stay (days), median (interquartile range) 6 (1.0) 6 (1.0) 6 (2.0) 0.83c

aMann-Whitney U test.

bIndependent samples t test.

cChi square test.

dFisher exact test.

eN/A: not applicable.

fASA: American Society of Anesthesiology.

gAmerican Society of Anesthesiology physical status classification system.