What functional aspects explain patients' impression of change after rehabilitation for long-lasting low back pain?

BACKGROUND

Physical tests and self-report measures are being used to measure physical functioning. The latter tends to be preferred in intervention studies.

PURPOSE

To examine whether the patients' global impression of change (PGIC) after rehabilitation was explained by change in pain, daily functioning, fear-avoidance of activities and various physical aspects, expecting contribution primarily by the self-reported measures.

METHODS

A test-retest design, within a prospective cohort study of patients with long-lasting low back pain. 96 patients were consecutively recruited from an outpatient spine clinic, assessed by three self-report questionnaires and seven physical tests at inclusion and after 3.5 weeks of multidisciplinary treatment. With PGIC as the dependent variable, linear regression analyses of all variables were performed. The study was approved by the Regional Committee for Medical Research Ethics and the National Data Inspectorate of Norway.

RESULTS

In unadjusted analysis, change in pain, daily functioning and change in six physical tests contributed to the explained variance (R2: 6-24%). In the adjusted analysis, only pain and back endurance strength contributed (adjusted R2: 48%). In the final backward stepwise blockwise analyses, daily functioning and spinal mobility were also found to contribute to the explained variance (R2: 48%). The time span of 3.5 weeks of training is too short to give a lasting effect, but the contribution to explained variance of PGIC of self-report measures and physical tests were the focus of this study, not the effect of training.

CONCLUSION

Most measures demonstrated change that was of significance to the patients after rehabilitation. Change in spinal mobility and back strength assessed by physical tests contributed to explain the patients' impression of change after controlling for change in pain and daily life functioning and may seem important to assess in addition to the self-report measures in intervention studies.