TABLE 2—

Low Back Pain and Health Status Variables at Baseline: UCLA Low Back Pain Study, 1995–2000

	Sample (n = 681)
Duration of back pain episode, %
< 3 wk	26.1
3 wk–3 mo	15.6
3 mo–1 y	11.6
> 1 y	46.7
Roland–Morris disability score(0–24 scale)
≤ 5, %	17.5
6–10, %	31.6
11–15, %	27.9
> 15, %	23.1
Mean (SD)	10.9 (5.4)
Median	11
Most severe low back pain in past week (0–10 scale)
Mean (SD)	6.7 (2.1)
Median	7
Average low back pain in past week (0–10 scale)
Mean (SD)	4.6 (1.9)
Median	5
Days with restricted activity owing to low back pain in past month
Mean (SD)	6.9 (8.0)
Median	4
At least 1, %	76.9
History of low back pain episodes, %
Yes	82.2
No	17.8
SF-36 physical functioning score
Mean (SD)	62.2 (24.6)
Median	65
SF-36 role limitations score: physical problems
Mean (SD)	41.3 (40.1)
Median	25
SF-36 role limitations score: emotional problems
Mean (SD)	70.0 (39.2)
Median	100
SF-36 mental health index score
Mean (SD)	71.2 (16.6)
Median	76
SF-36 general health perceptions score
Mean (SD)	67.8 (18.0)
Median	70

Note. Roland–Morris = Roland–Morris Low Back Disability Questionnaire; SF-36 = Medical Outcomes Study 36-Item Short-Form Health Survey.