Table 1 Baseline characteristics and perioperative data of 474 patients with lumbar stenosis who reported to NORspine

Age (years)

N = 140

Missing = 0

63.0 (11.7)

N = 334

Missing = 0

67.7 (9.9)

-4.7 (-6.74 to -2.59)

 < 0.001

Female

N = 140

Missing = 0

71 (51%)

N = 334

Missing = 0

183 (55%)

0.93 (0.77 to 1.12)

0.426

BMI

N = 136

Missing = 4

28.6 (4.5)

N = 329

Missing = 5

28.2 (4.5)

0.4 (-0.48 to 1.33)

0.362

Comorbidities*

N = 135

Missing = 5

93 (69%)

N = 310

Missing = 24

243 (78%)

0.89 (0.77 to 1.00)

0.047

ASA grade I and II

N = 140

Missing = 0

111 (79%)

N = 334

Missing = 0

242 (72%)

1.09 (0.98 to 1.22)

0.100

Smokers

N = 138

Missing = 2

41 (30%)

N = 331

Missing = 3

70 (21%)

1.40 (1.01 to 1.95)

0.044

Norwegian as first language

N = 138

Missing = 2

130 (94%)

N = 331

Missing = 3

324 (98%)

0.96 (0.92 to 1.01)

0.090

University or college education > 4 years

N = 136

Missing = 4

30 (22%)

N = 328

Missing = 6

83 (25%)

0.87 (0.60 to 1.26)

0.463

Single civil status

N = 139

Missing = 1

30 (22%)

N = 332

Missing = 2

85 (26%)

0.84 (0.58 to 1.22)

0.361

Preoperative ODI

N = 136

Missing = 4

42.3 (16.1)

N = 329

Missing = 5

40.4 (15.8)

1.87 (-1.31 to 5.06)

0.248

Preoperative NRS back pain

N = 127

Missing = 13

6.9 (2.0)

N = 312

Missing = 22

6.8 (2.1)

0.17 (-0.26 to 0.61)

0.430

Preoperative NRS leg pain

N = 123

Missing = 17

6.9 (2.2)

N = 311

Missing = 23

7.0 (2.1)

-0.04 (-0.49 to 0.40)

0.844

Decompression only type surgery

N = 140

Missing = 0

122 (87%)

N = 334

Missing = 0

301 (90%)

0.98 (0.84 to 1.15)

0.820

Fusion type surgery

N = 140

Missing = 0

18 (13%)

N = 334

Missing = 0

33 (10%)

1.27 (0.74 to 2.18)

0.393