MOVEMENT IN WORK STATUS AFTER PAIN FACILITY TREATMENT

Study Design. This was a randomized prospective follow-up study of pai n facility treatment of chronic pain patients with low back pain, with return to work and work capacity as the outcome measures. Objectives. To determine if after pain facility treatment chronic pain patients ' 'move''' in and out of work and in their work capacity; to determine t he patterns of ''movement;'' and to determine the post-pain facility t reatment follow-up sampling time points that would maximize the number of chronic pain patients correctly classified according to their fina l work and work capacity status. Summary of Background Data. Past rese arch and empiric observation have indicated that chronic pain patients may ''move'' after pain facility treatment in and out of work and in their job work capacity. Such ''movement'' can affect the results of o utcome studies. Methods. Two hundred thirty-six consecutive chronic pa in patients who fit study selection criteria were followed up at 1, 3, 6, 12, 18, 24, and 30 months after pain facility treatment for determ ination of work and work capacity status and separated according to th e pattern of movement. Stepwise discriminant analysis was used to answ er the study objectives. ''Movement'' in and out of work For these chr onic pain patients also was compared with the US general population. R esults. Chronic pain patients demonstrated eight work and four work ca pacity movement patterns. The 24- and 1-month time paints predicted fi nal work status correctly far 97.0% and 77.0% of the chronic pain pati ents, respectively, whereas the most significant predictor for correct work capacity status was the 24-month point, The annual percentage ch ange in employment status far these chronic pain patients was more tha n in the US general population. Conclusions. Because chronic pain pati ents ''move'' in and out of employment and for work capacity status af ter pain facility treatment, future outcome studies using these measur es will have to consider carefully the impact of ''movement'' on their results.