Forty ANCA-negative patients with IgAN and 40 AASV patients were selected by stratified random sampling as two control groups, with matching proportions of crescentic glomeruli.
They were compared with ANCA-negative IgAN patients (n = 40) and ANCA-associated systemic vasculitis (AASV) patients (n = 40) with a randomly selected and matched proportion of crescentic glomeruli.
Tables 1 and 2 and Figure 1 show the comparison of clinical and histological data, response to therapy and prognosis among ANCA-positive IgAN, ANCA-negative IgAN and AASV patients with matched proportions of crescentic glomeruli.
With matched proportions of glomeruli with crescents, ANCA-positive IgAN patients showed worse renal function at renal biopsy, but tended to have a better response to aggressive immunosuppressive therapy in the short-term and a greater possibility of withdrawal from dialysis, when compared with ANCA-negative patients, and were similar to patients with AASV.
Regarding the matched proportions of crescentic glomeruli, ANCA-positive IgAN patients showed a trend of lower eGFR compared with ANCA-negative IgAN patients, but were consistent with AASV patients at baseline [21.2 (10.9, 47.7) mL/min/1.73 m versus 47.0 (87.1 87.1) mL/min/1.73 m versus 19.5 (9.2, 52.4) mL/min/1.73 m, P = 0.12].
Birth certificate matches were made for 916 cases, resulting in a match proportion of 83%.
A final algorithm that used multiple combinations of identifying variables resulted in a match proportion of 87%.
There were 186 AML cases eligible to be in the study, of whom 154 matched to birth records, resulting in an estimated match proportion of 83%.
The results would usually be pretty close to matching the proportion of seats with the proportion of votes cast for parties.
We drew random samples from these strata matching the proportion of addresses in rural and urban areas of the QE group.
