Background Despite positive non-pharmacological treatment effects in fibromyalgia (FM) (1,2) these effects are often modest and show large individual variability. In clinical practice it is very important to assess the effectiveness of treatment for the individual patient in order to tailor further treatment. Responder criteria can assess the effectiveness of treatment and define clinically meaningful change in health outcomes on patient level. However, no specific responder criteria for non-pharmacological treatment in FM currently exist. This warrants further exploration in this field.

Objectives 1) To define responder criteria for multicomponent non-pharmacological treatment in FM; and 2) To estimate and compare their sensitivity and specificity.

Methods Candidate responder sets were 1) identified in literature (3–5); and 2) formulated by expert group consensus. All candidate responder sets were tested for sensitivity and specificity in a cohort of 144 patients with FM receiving multicomponent non-pharmacological treatment. Therapist's judgement about patient's goal attainment and patients' perspective on health status change, assessed at 6 months after the start of treatment, were used as gold standard.

Results Seven responder sets were defined (three identified in literature and four formulated by expert group consensus), and comprised combinations of domains of 1) pain; 2) fatigue; 3) patient global assessment (PGA); 4) illness perceptions; 5) limitations in activities of daily living (ADL); 6) sleep. The sensitivity and specificity of literature-based responder sets (n=3) ranged between 17%>99% and 15%>95% respectively, whereas the expert-based responder sets (n=4) performed slightly better with regard to sensitivity (range 41%>81%) and specificity (range 50%>96%). Of the literature-based responder sets the OMERACT-OARSI responder set with patient's gold standard performed best (sensitivity 63%, specificity 75% and ROC area = 0.69). Overall, the expert-based responder set comprising the domains illness perceptions and limitations in ADL with patient's gold standard performed best (sensitivity 47%, specificity 96% and ROC area = 0.71).

Conclusions We defined sets of responder criteria for multicomponent non-pharmacological treatment in fibromyalgia. Further research should focus on the validation of those sets with acceptable performance.

References

1. Busch AJ, et al. Exercise for treating fibromyalgia syndrome. Cochrane Database Syst Rev 2008; (4).

2. Bernardy K, et al. Efficacy of Cognitive-Behavioral Therapies in Fibromyalgia. A systematic review and Metaanalysis of Randomized Controlled Trials. J Rheumatol. 2010; 37: 1991–2005.

3. Arnold LM, et al. Development of responder defintions for fibromyalgia clinical trials. Arthritis Rheum. 2012;64(3):885–94.

4. Norman GR, et al. Interpretation of changes in health-related quality of life; the remarkable universality of half a standard deviation. Med Care. 2003;41(5):582–92.

5. Pham T, et al. OMERACT-OARSI initiative: Osteoarthritis Research Society International set of responder criteria for osteoarthritis clinical trials revisited. Osteoarthritis Cartilage. 2004; 12(5):389–99.

References

Disclosure of Interest None declared