[Measurement of health-related quality of life and functional capacity in patients with chronic tophaceous gout]

Introduction: In gout there are few instruments validated for the evaluation of activity, functional capacity or quality of life. It is not known if generic instruments such as the MOS-20, or specific for other illnesses, such as the AIMS, can be applied to patients with Gout.

Objective: To evaluate the clinimetric characteristic of the MOS-20 and AIMS questionnaires, and their correlation with HAQ-DI, as well as with clinical variables in patient with tophaceous gout (TG).

Methods: 49 patients with TG were included. Demographic and clinical variables were obtained. The 3 questionnaires were applied at the basal evaluation. A second evaluation was applied to 20 patients, 8 weeks later.

Results: All patients were male. The time of since onset of the illness was 14.9±8.3 years. The HAQ-DI was 0.43±0.56 with an alpha of Cronbach (αC) of 0.95 and the intraclass correlation coefficient (ICC) was 0.86. The MOS-20 had an αC of 0.68 to 1.0 and a ICC of 0.27 to 0.61 between the several components. The AIMS had an αC of 0.66 to 0.96, and a ICC of 0.11 to 0.79 between the several components. Reliability was better between the physical components in MOS-20 and AIMS. The MOS-20, AIMS and the HAQ-DI correlated with the presence of joints with functional limitation. There weren't any significant differences among the patients with inflamed joints, nor in those with tophi. The HAQ-DI was best correlated with the physical component than with the mental component of the AIMS and the MOS-20.

Conclusion: The AIMS, the MOS-20 and the HAQ-DI are useful in measuring the functional capacity and the quality of life in patient with TG.