Performance characteristics of a dialysis-related amyloidosis questionnaire

To evaluate the effects of beta-2 microglobulin amyloidosis on functional status, a 19-item self-administered questionnaire exploring two major domains-symptoms and disability-was developed as part of this study. Fifteen patients with dialysis-related amyloidosis (DRA) were identified and compared with 15 age-matched control subjects who had been on hemodialysis for less than 24 months. Demographic data, Charlson comorbidity scores, and other clinical and laboratory variables were recorded. Total dialysis-related amyloidosis questionnaire (DRAQ) score (52.1 +/- 16.3 versus 24.4 +/- 6.2, P < 0.0001) and the scores of the symptom (24.5 +/- 7.0 versus 11.5 +/- 2.3, P < 0.0001) and disability (27.5 +/- 10.8 versus 12.9 +/- 4.0, P < 0.0001) subscales were markedly increased among patients with DRA. Baseline characteristics among case and control subjects were similar, except for serum creatinine concentration, which tended to be lower among patients with DRA (8.9 +/- 2.6 versus 11.5 +/- 2.3 mg/dL, P = 0.07). Instrument reliability and internal consistency were high. With a total DRAQ score of 30 or more, the sensitivity and specificity of the instrument were 93% and 80%, respectively. The DRAQ is a reliable, internally consistent, and valid instrument that may be suitable for population screening and clinical practice.