Predictors of a favourable outcome in patients with fibromyalgia: results of 1-year follow-up.

OBJECTIVES

To determine the outcomes of Korean patients with fibromyalgia (FM) and to identify prognostic factors associated with improvement at 1-year follow-up.

METHODS

Forty-eight patients with FM were enrolled and examined every 3 months for 1 year. At the time of enrollment, we interviewed all patients using a structured questionnaire that recorded socio-demographic data, current or past FM symptoms, and current use of relevant medications. Tender point counts and scores were assessed by thumb palpation. Patients were asked to complete the Korean versions of the Fibromyalgia Impact Questionnaire (FIQ), the Brief Fatigue Inventory, the SF-36, the Beck Depression Inventory, the State-Trait Anxiety Inventory (STAI), the Self-Efficacy Scale, and the Social Support Scale. Tender points, FIQ scores, and the use of relevant medications were recorded during one year of follow-up.

RESULTS

Of the 48 patients, 32 (66.7%) had improved FIQ scores 1 year after enrollment. Improved patients had higher baseline FIQ scores (68.4±13.9 vs. 48.4±20.8, p=0.001) and STAI-II scores (55.8±10.9 vs. 11.5±11.5, p=0.022). Patients treated with pregabalin were more likely to improve after 1 year, based on the FIQ scores (71.9% vs. 37.5%, p=0.031). On multivariate logistic regression analysis, a higher STAI-II score at the time of enrollment and pregabalin treatment during one year of follow-up were the predictors of improvement.

CONCLUSIONS

Two-thirds of our Korean FM patients experienced some clinical improvement by 1-year follow-up. A high baseline STAI-II score and treatment with pregabalin were the important predictor of improved FM.