Abstract
Introduction: There is growing interest in Health Related Quality of Life (HRQL) questionnaires to quantitate the impact of a variety of diseases and their treatments. The Short Form-36 (SF3) is a comprehensive measure of health status, consisting of 36 questions related to Physical (PCS) and Mental Component Summary (MCS).1 An abbreviated version of SF36, the SF12 has been described.2 We report on the use of SF12 and SF36 to assess the impact of surgery in patients with cervical spondylotic myelopathy (CSM).
Methods: In this prospective study, patients undergoing anterior or posterior decompressive surgery self completed the SF36 questionnaire pre-operatively and at 6 months post-operatively. The data from the SF36 is categorised into 8 scales: physical functioning (PF), physical role (PR), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), emotional role (ER) and mental health (MH).1 Each scale is scored on a 0 (maximum disability) to 100 (no disability) metric. These 8 scales are reduced to a Physical (PCS) and Mental Component Summary (MCS).1 SF12 utilises only 12 questions of the 8 scales of the SF36.2 We compared the validity, reliability and sensitivity to change in CSM patients.
Results: We studied 105 patients with a median age of 58. Post-operatively, there were improvements in the PCS components of both the SF36 (40 ± 2 to 54 ± 2) and SF12 (34 ± 2 to 48 ± 3) (p< 0.0001; Wilcoxon Signed Ranks test) and MCS component of SF36 (48 ± 2 to 63 ± 2) and SF12 (43 ± 2 to 59 ± 2) (p< 0.001). There were linear relationships between the SF36 and SF12.
Conclusions: Both the SF12 and SF36 scales are valid and sensitive to changes in CSM patients, undergoing decompressive surgery. Despite its abbreviated nature, SF12 appears to be an adequate substitute for SF36 and its brevity should increase its attractiveness to both the clinicians and patients.
Correspondence should be addressed to: Sue Woodward, Secreteriat, Britspine, Vale Clinic, Hensol Park, Vale of Glamorgan, CF72 8JY Wales.
1 Ware JE, Sherbourne CD. The MOS 36-item short-form health survey (SF-36) – I. Conceptual framework and item selection. Med Care1992;30:473–83. Google Scholar
2 Ware JE, Kosinski M, Keller SD. A 12-item Short Form Health Survey. Construction of scales and preliminary test of reliability and validity. Med Care1996;34:220–33. Google Scholar
