Effect of an early intervention program on the relationship between subjective pain and disability measures in nurses with low back injury

Study Design. The effect of a workplace-based early intervention program on perceptions of pain and disability in nurses with low back injury was studied using a preintervention Versus postintervention design with concurrent control group. Objectives. To examine the relationship and changes over time between pain and disability measures in two groups of back-injured nurses-those who received the early intervention program (study) and those who were not offered the program (control). Summary of Background Data. The relationship between back pain and disability is not straightforward. The effects of an intervention program on changes in perceptions of pain and disability over time have not been widely reported. Methods. The Oswestry Low Back Disability Questionnaire and a visual analog pain scale were administered to 46 study nurses and 137 control nurses at time of injury and at 6 months after injury. Correlation and regression analyses were used to explore the relationships between the two measures. Changes over time were compared with analyses of variance. Results. Pain and disability were positively correlated in both groups at time of injury and at follow-up evaluation. Mean scores for pain and disability were lower at follow-up evaluation than at initial injury in both groups: study nurses had significantly (P < 0.01) lower scores at 6 months than nurses in the control group. Disability at time of injury predicted disability at 6 months only for nurses in the control group. Conclusions. This workplace-based early intervention program decreased levels of pain and disability in back-injured nurses and altered the relationship between these two variables over a 6-month time interval.