Assessing Reliability of an Electronic Gout Flare Assessment Protocol

Most trials in gout focus on serum urate changes because assessing gout flares is difficult. We evaluated the reliability of an electronic, self-reported gout flare assessment compared to a staff-conducted telephone questionnaire.

A convenience sample of participants from the Treat-to-Target Serum Urate Versus Treat-to-Avoid Symptoms in Gout (TRUST) randomized clinical trial, which examines gout flares as a primary outcome, completed biweekly electronic surveys reporting gout flares. Study staff blinded to treatment assignment conducted a gout flare assessment at standard biweekly telephone visits to confirm electronic reports. We assessed agreement between flare assessment modalities using multiple assessments such as percent agreement, Cohen's kappa, Gwen's AC1 statistic, McNemar's test of equivalence, and intraclass correlation coefficient (ICC). In addition, we accounted for repeated measures within patients using mixed effects models, presenting a mixed effects ICC. Where necessary, 95% confidence intervals were calculated using nonparametric bootstrapping.

A total of 28 patients (mean age 60.5 years, SD 13; 93% male) participated in the 12-week pilot, completing 109 flare periods with 108 electronic and 99 phone assessments. Patients reported 23 flares on electronic surveys and 22 flares on phone surveys. We observed a raw percent agreement between survey types of 96%. All measures of agreement consistently demonstrated strong concordance, with an ICC of 0.880 and a mixed effects ICC of 0.746.

The pilot study shows strong agreement between electronic and telephone gout flare assessments across multiple equivalence tests, supporting electronic surveys as an accurate and efficient alternative to phone assessments.