Symptom increase following a functional capacity evaluation in patients with chronic low back pain: an explorative study of safety.

Introduction: This study was performed to study intensity and duration of symptom increase following an FCE and to explore safety of an FCE.

Methods: Included were 92 patients with chronic low back pain (CLBP), mean age 38.5 years, mean self-reported disability 12.5 (Roland Morris Disability Questionnaire). All patients underwent an FCE. Symptom increase was measured with a 2-item questionnaire. Operational definition for safety: no formal complaint filed and symptom increase to occur only temporarily.

Results: No formal complaints were filed (n=92). In total, 54 patients returned the questionnaire (59%; 'responders'). Of the responders, 76% reported increased symptom intensity after an FCE, ranging from 'little increase' to 'severe increase'. Symptoms of all responders returned to pre-FCE level. Duration of symptom increase of the responders ranged from 1 day to 3 weeks. Symptom increase resided to pre-FCE level within 1 week in 93% of the responders. Symptom increase was weakly related to self-reported disability (r=0.38, p<0.05). Except for gender, differences between responders and non-responders were non-significant.

Conclusion: A temporary increase in symptom intensity following an FCE is common. Within the operational definitions of safety used in this study, assessment of functional capacity of patients with CLBP appears safe.