Associations between illness perception, treatment adherence and functional impact in fibromyalgia: a cross-sectional study.

Objectives: This study aimed to evaluate treatment adherence in patients with fibromyalgia (FM) and to examine its relationship with illness perception and disease severity.

Methods: A cross-sectional study was conducted on 84 FM patients. Treatment adherence, illness perception and fibromyalgia-related impact were assessed using the 8-item Morisky Medication Adherence Scale (MMAS), Brief Illness Perception Questionnaire (BIPQ), and Fibromyalgia Impact Questionnaire (FIQ), respectively.

Results: The majority of participants were female (79.8%) with a mean age of 43.7±11.2 years. The median MMAS, BIPQ, and FIQ scores were 3 (2-4), 50 (42-60), and 48.0 (36.0-57.8), respectively. Patients with higher disease severity, as classified by FIQ, had significantly lower MMAS scores (p<0.05) and higher BIPQ scores (p<0.05). A negative correlation was found between MMAS and BIPQ scores (rho=-0.445, p<0.001), and a moderate negative correlation was observed between MMAS and FIQ scores (rho=-0.275, p=0.011). Illness perception was positively correlated with FIQ scores (rho=0.615, p<0.001).

Conclusions: This study demonstrates that negative illness perceptions are strongly associated with poor treatment adherence and greater disease burden in fibromyalgia. These findings highlight the importance of assessing cognitive and psychosocial factors in routine FM care. Targeted interventions addressing illness beliefs may enhance adherence and improve patient outcomes in this multifaceted condition.