Patient-reported Outcomes in Chronic Gout: A Report from OMERACT 10

Abstract

Objective To summarize the endorsement of measures of patient-reported outcome (PRO) domains in chronic gout at the 2010 Outcome Measures in Rheumatology Meeting (OMERACT 10). Methods During the OMERACT 10 gout workshop, validation data were presented for key PRO domains including pain [pain by visual analog scale (VAS)], patient global (patient global VAS), activity limitation [Health Assessment Questionnaire-Disability Index (HAQ-DI)], and a disease-specific measure, the Gout Assessment Questionnaire version 2.0 (GAQ v2.0). Data were presented on all 3 aspects of the OMERACT filters of truth, discrimination, and feasibility. One PRO, health-related quality of life measurement with the Medical Outcomes Study Short-form 36 (SF-36), was previously endorsed at OMERACT 9. Results One measure for each of the 3 PRO of pain, patient global, and activity limitation was endorsed by > 70% of the OMERACT delegates to have appropriate validation data. Specifically, pain measurement by VAS was endorsed by 85%, patient global assessment by VAS by 73%, and activity limitation by HAQ-DI by 71%. GAQ v2.0 received 30% vote and was not endorsed due to several concerns including low internal consistency and lack of familiarity with the measure. More validation studies are needed for this measure. Conclusion With the endorsement of one measure each for pain, patient global, SF-36, and activity limitation, all 4 PRO for chronic gout have been endorsed. Future validation studies are needed for the disease-specific measure, GAQ v2.0. Validation for PRO for acute gout will be the focus of the next validation exercise for the OMERACT gout group.

Development and First Validation of a Disease Activity Score for Gout

“…Also, because of the lack of gout‐specific restricted joint count, GAS scores without joint count were developed. In the absence of fully validated gout‐specific instruments for the evaluation of disability in gout 23, current instruments may potentially underestimate the impact of the disease on function 24. Similarly, the clinical measurement of tophi is not the most sensitive method available (e.g., ultrasonography, dual‐energy computerized tomography), but is still the most feasible in clinical practice 13.…”

Lifestyle interventions for acute gout

“…The relationship between various lifestyle factors and gout can be summarised according to whether their association is regarded to increase the risk of, have no effect on, or decrease the risk of developing incident and recurrent gout. Lifestyle factors such as high dietary intake of purine-rich foods (particularly meat and seafood), ethanol (particularly beer and spirits), fructose-sweetened drinks and sweet fruits (apples, oranges), and weight gain and obesity are recognised risk factors for gout development (Choi 2004a;Choi 2004b;Choi 2010b;Neogi 2011;Singh 2011b). On the contrary, protein and purine-rich vegetable intake is regarded as having no effect on gout risk, having been vindicated as risk factors for gout, while ingestion of dairy products (low fat or skim milk), decaffeinated coffee, vitamin C and weight loss are considered to exert a protective effect against gout development (Choi 2010b;Neogi 2011;Richette 2010).…”

Racial differences in health-related quality of life and functional ability in patients with gout

“…Patients reported overall gout severity using a 10 cm visual analogue scale [15,29]. Physicians also recorded global assessment of overall gout severity using a 10 cm visual analogue scale [30], and the presence or absence of tophi.…”

“…During each study visit, patients completed a paperbased survey that included the following: generic HRQOL assessment with Short Form 36 (SF-36) [25]; disease-specific HRQOL with the Gout Impact Scale (GIS) of the Gout Assessment Questionnaire [26]; functional ability assessment with HAQ Disability Index (HAQ-DI) [27,28]; patient global assessment [15,29]; and the University of California at San Diego health care utilization survey. Patients also underwent physician assessment at each visit that included a physician global assessment of gout [30].…”