Cross-cultural adaptation and validation of the NASS outcomes instrument in Spanish patients with low back pain.
OBJECTIVE
The aim of the study was to evaluate validity, reliability, responsiveness and practicality of the NASS-AAOS (North American Spine Society--American Academy of Orthopaedic Surgeons) questionnaire in patients with low back pain.


METHODS
The sample included 70 patients with herniated disk, stenosis, chronic low back pain of unknown etiology or acute low back pain. They were assessed twice before treatment (test--retest) and a third measure six months to one year afterwards.


RESULTS
The mean time of administration was 24 and 20 min for the test and post-treatment evaluation, respectively. Cronbach's alpha coefficient was between 0.78 and 0.92 on the baseline test and 0.90 or higher on the post-treatment evaluation. The test--retest reproducibility was 0.95 (0.91--0.98) for 'neurological symptoms', 0.82 (0.63--0.91) for 'pain/disability' and 0.63 (0.25--0.82) for 'expectations'. The associations with other measures and clinical criteria were generally moderate to high and in the expected direction. The effect size for 'pain/disability' in combination with 'neurological symptoms' was 2.02 for patients who improved versus an effect of -0.09 in patients who were stable between test and retest; the area under the curve on this joint scale was 0.81 (0.69--0.90).


CONCLUSIONS
The instrument is valid, sensitive to clinical changes and reliable for comparisons between groups, but further study is needed for its application in monitoring individual patients.
Sarasqueta
C
C
Clinical Epidemiology Unit, Hospital Donostia, Apdo Correos 477, 20.080 Donostia, Spain. csaras@chdo.osakidetza.net
Gabaldon
O
O
Iza
I
I
Béland
F
F
Paz
P M
PM
D003431:Cross-Cultural Comparison; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000175:diagnosis; D007802:Language; D017116:Low Back Pain / Q000175:diagnosis*; D010147:Pain Measurement / Q000379:methods / Q000592:standards*; D015203:Reproducibility of Results; D013030:Spain; D011795:Surveys and Questionnaires / Q000592:standards*
Ann Otol Rhinol Laryngol. 2000 Sep;109(9):853-8
11007090
Spine (Phila Pa 1976). 1999 Sep 1;24(17):1805-12
10488511
Spine (Phila Pa 1976). 2000 Dec 15;25(24):3115-24
11124727
Spine (Phila Pa 1976). 2000 Dec 15;25(24):3130-9
11124729
Z Rheumatol. 2000 Oct;59(5):303-13
11142925
Spine (Phila Pa 1976). 2001 Aug 1;26(15):E344-7
11474366
Spine (Phila Pa 1976). 2002 Mar 1;27(5):538-42
11880841
Spine (Phila Pa 1976). 1983 Mar;8(2):141-4
6222486
J Chronic Dis. 1986;39(11):897-906
2947907
J Manipulative Physiol Ther. 1992 Jan;15(1):4-9
1531488
Med Care. 1992 Jun;30(6):473-83
1593914
J Clin Epidemiol. 1992 Dec;45(12):1341-5
1460470
Med Care. 1993 Mar;31(3):247-63
8450681
J Clin Epidemiol. 1993 Dec;46(12):1417-32
8263569
Spine (Phila Pa 1976). 1994 Sep 1;19(17):1887-96
7997920
Spine (Phila Pa 1976). 1994 Sep 15;19(18 Suppl):2032S-2036S
7801179
Med Clin (Barc). 1995 May 27;104(20):771-6
7783470
J Manipulative Physiol Ther. 1995 Feb;18(2):79-87
7790787
Qual Life Res. 1995 Aug;4(4):293-307
7550178
Spine (Phila Pa 1976). 1995 Sep 1;20(17):1899-908; discussion 1909
8560339
Spine (Phila Pa 1976). 1995 Sep 1;20(17):1943-9
8560347
Spine (Phila Pa 1976). 1996 Apr 15;21(8):960-2; discussion 963
8726200
Pain. 1996 Apr;65(1):71-6
8826492
Spine (Phila Pa 1976). 1996 Mar 15;21(6):741-9
8882698
Pain. 1999 Mar;80(1-2):365-75
10204750
Jt Comm J Qual Improv. 1999 Apr;25(4):207-18
10228912
Spine (Phila Pa 1976). 1999 Jun 1;24(11):1104-12
10361660
Spine (Phila Pa 1976). 2000 Dec 15;25(24):3100-3
11124724