PREDICTING FOLLOW-UP FUNCTIONAL OUTCOMES IN OUTPATIENT REHABILITATION

Functional outcomes at an average of six months after outpatient rehab ilitation were investigated in a pilot study with a sample of 42 patie nts receiving physical therapy for low back, neck, and other musculosk eletal problems. Logistic regression analyses were used to study varia bles related to the achievement of a predetermined level of physical f unctioning or to whether improvement occurred from initial to follow-u p assessment. Scales used in the analyses were obtained from two measu res of functioning, the Medical Outcomes Trust Short Form 36 (SF-36) a nd the Medical Rehabilitation Follow Along (MRFA(TM) instrument). Demo graphic and program characteristic variables obtained from clinic reco rds were also included in the analyses. The independent variables ente red into two groups of regression equations included age, gender, pres enting problem, workers' compensation coverage, functioning at initial assessment, number of visits, length of program, and intensity of pro gram. For the SF-36, the General Health scale and presenting problem p redicted above or below a level greater than one standard deviation le ss than the mean on the Physical Functioning scale at follow-up. The c ombination of the Role Physical and Role Emotional scales predicted fo llow-up level on the Physical Component Summary (PCS) scale. The inter action of age and intensity of treatment was predictive for both the P hysical Functioning and PCS scales, For predicting improvement or no i mprovement using the SF-36 scales, General Health and the interaction between age and intensity were predictive of change on the Physical Fu nctioning scale, whereas age and the interaction between age and numbe r of visits were predictive of change on the PCS scale. For the MRFA(T M) instrument, the interaction between age and the intensity of treatm ent was predictive for both a predetermined level of physical function ing and amount of improvement in physical functioning at follow-up. An intensity rating of pain and a measure of affective distress at initi al assessment both improved the identification of patients at risk for not reaching a given level of functioning whereas treatment intensity improved the identification of those patients at risk for not showing improvement at follow-up. Length of time between the end of outpatien t therapy and follow-up assessment was generally not related to follow -up physical functioning. Interpretation and implications of these fin dings, as well as applications of this analytic approach to outcomes a ssessment, are discussed.