Measuring the outcome of health resort programs

To evaluate the metric properties and practicability of valid, internationally available outcome instruments in the special setting of health resort programs.

A cohort study in a convenience sample of patients with low back pain, upper back pain, conditions of the lower extremities, and conditions of the upper extremities was conducted. Their functioning and health were assessed before and after a health resort program by the disease-specific North American Spine Society (NASS) instruments Lumbar NASS and Cervical NASS; WOMAC Osteoarthritis Index; Disabilities of Arm, Shoulder and Hand Questionnaire; and the general instrument, Medical Outcome Study Short Form-36 (SF-36).

Completeness on the scale level ranged between 1% and 10%. Criterion validity of condition-specific instruments was confirmed by stronger associations of the pain and function scales to the Physical Health component of the SF-36 (r = -0.59 to -0.79, p < 0.001 for all scales) than to the Mental Health component (r = -0.11, NS, to r = -0.42, p < 0.001). Reliability (Cronbach's alpha coefficient) was higher than 0.8 for all scales of condition-specific instruments and for 6 of 8 SF-36 scales. Floor and ceiling effects ranged between 0% and 7%. The condition-specific instruments demonstrated a good responsiveness with an effect size ranging between 0.28 and 0.55 and with a standardized response mean between 0.32 and 0.94. The responsiveness of most SF-36 scales was similar, but the Physical Function scale showed a lower responsiveness than the condition-specific scales.

The evaluated instruments can be recommended for use in clinical trials that assess the outcome of health resort programs.