The construct validity of the Short Form-36 Health Survey for patients with nonspecific chronic neck pain.

Self-reported disability related to neck pain can be measured using general health questionnaires. The validity of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) in patients with nonspecific chronic neck pain (CNP) in a tertiary outpatient rehabilitation setting is unknown. This study investigates construct validity of the SF-36 in these patients using 16 a-priori formulated hypotheses. Ninety-one patients admitted for rehabilitation completed the SF-36 before the rehabilitation program. SF-36 domain scores of patients with CNP were compared with general population reference values and standardized differences were calculated. For both the SF-36 physical and the mental component summary (PCS and MCS), differences between primary and tertiary care setting, men and women, age groups, litigants and nonlitigants, patients with and without compensation, and with ≥3 versus≤2 concomitant complaints were analyzed using independent t-tests. Differences between PCS and MCS scores were analyzed using a paired t-test. Twelve hypotheses were not rejected and four were rejected. All SF-36 domain scores were significantly lower than the general population references values. The domain scores 'role physical', 'bodily pain', 'vitality', 'social functioning,' and 'role emotional' were relevantly (≥1 SD) lower. SF-36-PCS and SF-36-MCS scores were significantly lower in tertiary care. The SF-36-PCS score was significantly lower for patients with workers compensation and patients with at least three concomitant complaints. The SF-36-MCS score was significantly lower for the age group of at least 39 years. The SF-36 has good construct validity and can be used to measure self-reported general health in patients with nonspecific CNP in outpatient tertiary rehabilitation.