To characterize a representative sample of fibromyalgia women based on a set of relevant factors known to be related to this disease. To distinguish specific factors of the disease from other symptoms that might also exist in non-fibromyalgia women. To test whether fibromyalgia affects more severely physical or psychological outcomes.
A total of 459 fibromyalgia women vs. 214 non-fibromyalgia (control) women from Southern Spain (Andalusia) took part in this cross-sectional study. Several instruments were used to assess tenderness, impact of fibromyalgia, fatigue, health-related quality of life, mental health, and cognitive performance.
Overall, fibromyalgia women showed a worse status in pain, fatigue, health-related quality of life, depression, and anxiety than controls (P < 0.01). In general, the observed associations presented very large effect sizes (Cohen׳s d from ~1 to ~5.5). No differences between fibromyalgia and controls were observed in cognitive and memory performance, except for delayed recall, but the observed effect size was low (~0.25). The effect size observed for the global physical component (~3.3) was larger than that for the global psychological component (~1.3), all P < 0.001.
Our results reinforce the understanding of fibromyalgia as a polysymptomatic distress condition with pain as its main symptom. Our findings support that fibromyalgia seems to have a greater impact on physical than on psychological outcomes, though both are largely affected.