A prospective validation study.
To validate the Balanced Inventory for Spinal Disorders (BIS), a questionnaire concerning the extent to which pain affects perceived physical health, social life, mental health, and quality of life. The operational definitions of the items and the verbal descriptive scales were compared with corresponding items in the Short-Form 36 (SF-36), European Quality of Life Scale (EQ), and Oswestry Disability Index (ODI).
In validation studies, scales that intend to measure the same variable are compared.
The SF-36, EQ, ODI, and the BIS were filled in by 101 patients before surgical treatment. The comparisons were analyzed by statistical methods that take account of the nonmetric properties of ordered categorical data to obtain reliable results. The level of order-consistency between BIS and comparing items, when present, was calculated. The Spearman rank-order correlation coefficient was also calculated.
In the paired comparisons between the BIS pain scales and the other pain scales about 80% units more pairs were ordered than disordered, and the disorder was explained by the discriminating ability of the BIS back and leg pain items. The BIS and ODI items of limitation in walking were comparable, and the assessments of social limitations on the questionnaires were consistent; the disordered pairs being explained by different coverage of activities in the items. The assessments of physical and mental health on BIS were disordered, with the responses in SF-36 in favor of the BIS type of scale categories. The few items and response categories in the EQ did not discriminate the assessments.
The BIS assessments can be regarded as being a valid disease-specific questionnaire that provides interpretable information regarding the impact of back end leg pain on well-defined physical, social and mental aspects, and on the quality of life.
The assessments on a disease-specific questionnaire, Balanced Inventory for Spinal Disorders, regarding the extent to which spinal disorders affect the physical health, social life, mental health, and quality of life as perceived by patients were found to be valid and useful in clinical practice and research. SUPPLEMENTAL DIGITAL CONTENT IS AVAILABLE IN THE TEXT.
From the *Department of Statistics, Örebro University, Örebro, Sweden; †Clinic of Spinal Surgery, Strängnäs, Sweden; and ‡Statistical and epidemiological unit, Örebro University Hospital, Örebro, Sweden.
Acknowledgment date: January 4, 2009. Acceptance date: January 26, 2009.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Address correspondence and reprint requests to Elisabeth Svensson, PhD, Department of Statistics, Örebro University, SE-701 82 Örebro, Sweden; E-mail: firstname.lastname@example.org