Interdisciplinary treatment for fibromyalgia syndrome: clinical and statistical significance

The primary purposes of the study were to: evaluate the treatment efficacy of an outpatient, interdisciplinary treatment program for fibromyalgia syndrome (FMS); examine whether treatment gains would be sustained for 6 months following the treatment; assess whether improvements were clinically significant; and delineate the factors associated with clinically significant improvement in pain severity.

Sixty-seven FMS patients completed a 4-week outpatient program consisting of medical, physical, psychologic, and occupational therapies. Six-month followup data were available for 66% of treated patients.

Comparisons between pretreatment and posttreatment measures revealed significant improvements in pain severity, life interference, sense of control, affective distress, depression, perceived physical impairment, fatigue, and anxiety; however, there was no improvement in interpersonal relationships or general activities. Clinically significant improvement in pain severity, using the Reliable Change Index, was obtained by 42% of the sample and was predicted by the pretreatment levels of depression, activity, perceived disability, solicitous responses of significant others, and idiopathic onset. Pretreatment level of pain severity was not a significant predictor of the degree of pain improvement. Comparisons among pretreatment, posttreatment, and 6-month followup data revealed that the patients maintained treatment gains in pain, life interference, sense of control, affective distress, and depression. However, the quadratic polynomial analysis revealed that relapse occurred in the subjective rating of fatigue.

The results suggest that, overall, an outpatient interdisciplinary treatment program was effective in reducing many FMS symptoms. Treatment gains tended to be maintained for at least 6 months. However, there were large individual differences in response to treatment. These results suggest that identification of subgroups of FMS patients and their specific clinical characteristics may be useful for maximizing treatment efficacy.