Prognostic factors for intervention effect on neck/shoulder symptom intensity and disability among female computer workers.

Introduction: It has been suggested that treatments may be more effective when they are matched to patient characteristics. This study aimed at investigating potential prognostic factors for clinically relevant improvement in symptom intensity and symptom-related disability among employees with symptoms in the neck/shoulder area, receiving either ergonomics counseling or such counseling in combination with myofeedback training.

Methods: A randomized controlled study was performed among female computer users aged 45 or older (n = 36). A clinical examination and a questionnaire survey were performed before inclusion in the study. Symptom intensity and disability was assessed using questionnaires before the start of the interventions (baseline) and at follow-ups directly after the end of the interventions (T0) and after 3 (T3) and 6 (T6) months. Logistic regression analyses were performed in order to assess prognostic factors for clinically relevant improvement in symptom intensity and disability.

Results: Improvement in symptom intensity was consistently predicted by symptom intensity at baseline. Diagnosis and stress-induced lack of muscular rest were prognostic factors for improvement in symptom intensity at short term follow-up. Baseline disability and passive coping consistently served as prognostic factors for outcome in disability. Few substantial differences were found between the interventions in terms of prognostic factors.

Conclusions: Myofeedback training in combination with ergonomics counseling seem to be an especially beneficial tool for secondary prevention among employees with moderate levels of symptom intensity and symptom-related disability, who respond to work-related stress by increased/sustained muscle activation, and who tend to employ passive coping to deal with their neck/shoulder symptoms.