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Table 1 Baseline characteristics

From: Low back pain is associated with sleep disturbance: a 3-year longitudinal study after the Great East Japan Earthquake

  

Low back pain

  

n (%)

absence

presence

P value

  

2,097

1,536

561

 

Sex

Male

931 (44.4)

677 (44.1)

254 (45.3)

0.624

 

Female

1,166 (55.6)

859 (55.9)

307 (54.7)

 

Age

< 65

826 (39.4)

613 (39.9)

213 (38.0)

0.421

 

≥ 65

1,271 (60.6)

923 (60.1)

348 (62.0)

 

Body mass indexa

≥ 18.5, < 25

1,264 (60.3)

947 (61.7)

317 (56.5)

0.183

 

< 18.5

38 (1.8)

27 (1.8)

11 (2.0)

 
 

≥ 25

720 (34.3)

511 (33.3)

209 (37.3)

 

Living area

Ogatsu

879 (41.9)

642 (41.8)

237 (42.2)

0.698

 

Oshika

750 (35.8)

544 (35.4)

206 (36.7)

 
 

Ajishima

141 (6.7)

109 (7.1)

32 (5.7)

 
 

Wakabayashi

327 (15.6)

241 (15.7)

86 (15.3)

 

Smoking habitsa

Non-smoker

1,687 (80.4)

1,256 (81.8)

431 (76.8)

0.015

 

Smoker

334 (15.9)

233 (15.2)

101 (18.0)

 

Drinking habitsa

0 g of alcohol/day

1,317 (62.8)

988 (64.3)

329 (58.6)

0.031

 

< 45.6 g of alcohol/dayb

442 (21.1)

300 (19.5)

142 (25.3)

 
 

≥ 45.6 g of alcohol/dayb

165 (7.9)

119 (7.7)

46 (8.2)

 

Comorbid conditions

Hypertension

902 (43.0)

624 (40.6)

278 (49.6)

< 0.001

 

Diabetes mellitus

224 (10.7)

155 (10.1)

69 (12.3)

0.147

 

Myocardial infarction

140 (6.7)

81 (5.3)

59 (10.5)

< 0.001

 

Cerebral stroke

35 (1.7)

26 (1.7)

9 (1.6)

0.889

Working statusa

Unemployed

1,061 (50.6)

776 (50.5)

285 (50.8)

0.518

 

Employed

982 (46.8)

724 (47.1)

258 (46.0)

 

Walking time/daya

≥ 1 h

604 (28.8)

446 (29.0)

158 (28.2)

0.064

 

30 min to < 1 h

763 (36.4)

579 (37.7)

184 (32.8)

 
 

< 30 m

701 (33.4)

489 (31.8)

212 (37.8)

 

Living statusa

Same house as before the GEJE

682 (32.5)

492 (32.0)

190 (33.9)

0.651

 

Prefabricated house

86 (4.1)

60 (3.9)

26 (4.6)

 
 

New house

655 (31.2)

493 (32.1)

162 (28.9)

 
 

Others

647 (30.9)

472 (30.7)

175 (31.2)

 

Economic conditiona

Fair

1,040 (49.6)

812 (52.9)

228 (40.6)

< 0.001

 

Poor

497 (23.7)

368 (24.0)

129 (23.0)

 
 

Poorer

327 (15.6)

200 (13.0)

127 (22.6)

 
 

Poorest

195 (9.3)

125 (8.1)

70 (12.5)

 

Psychological distressa

Absence

1,801 (85.9)

1,357 (88.3)

444 (79.1)

< 0.001

 

Presence

261 (12.4)

152 (9.9)

109 (19.4)

 

Social isolationa

Absence

1,480 (70.6)

1,106 (72.0)

374 (66.7)

0.047

 

Presence

616 (29.4)

429 (27.9)

187 (33.3)

 
  1. aBecause each item has a limited number of respondents, the actual number is not necessarily in accordance with the total.
  2. b22.8 g of alcohol amount to 1 go or traditional unit of sake (180ml), which also approximates to two glasses of wine (200ml), or beer (500ml) in terms of alcohol content. Categorical values are presented as numbers and percentages (%). GEJE indicates Great East Japan Earthquake.