Early predictors of one-year mortality in patients over 65 presenting with ANCA-associated renal vasculitis: a retrospective, multicentre study

Table 3 Multivariable analysis for one-year mortality

Third variable added to the model	AIC	AUC	RR [95%CI]	p value
Infection at M1	122.1	0.799	FFS 2.57 [1.30; 5.09]	0.006
			Infection 2.74 [1.27; 5.92]	0.01
			Age 1.05 [0.99; 1.12]	0.09
PS 3–4 vs. 0–2	129.0	0.781	FFS 3.09 [1.51; 6.27]	0.002
			PS 1.92 [0.84; 4.35]	0.12
			Age 1.05 [0.99; 1.12]	0.13
Haemoglobin	126.7	0.761	FFS 3.06 [1.46; 6.40]	0.003
			Hg 0.82 [0.63; 1.06]	0.13
			Age 1.05 [0.99; 1.12]	0.09
Serum creatinine	130.1	0.759	FFS 2.98 [1.45; 6.13]	0.003
			SCr 1.09 [0.97; 1.22]	0.15
			Age 1.05 [0.99; 1.12]	0.07
Dialysis	130.2	0.758	FFS 2.96 [1.44; 6.08]	0.003
			Dialysis 1.66 [0.76; 3.60]	0.20
			Age 1.05 [0.99; 1.12]	0.10
Co-trimoxazole	127.5	0.752	FFS 2.98 [1.40; 6.34]	0.004
			CTZ 0.53 [0.23; 1.20]	0.13
			Age 1.04 [0.98; 1.11]	0.20
CCI	132.4	0.749	FFS 3.43 [1.71; 6.89]	0.0005
			CCI 1.12 [0.80; 1.57]	0.51
			Age 1.04 [0.97; 1.11]	0.22

Given the limited number of events for the primary endpoint (29 deaths) and Peduzzi et al.’s recommendations [26], we built several multivariable models with three variables (including age and the Five-Factor Score (FFS)) known to be prognostic factors. Next, each of the other candidate variables with a univariate p < 0.05 was added as the third variable. Even though age is included in the FFS score, we selected it because all patients were aged 65 or over. The best multivariable model was considered to be that with the lowest Akaike information criterion (AIC) and highest area under the curve (AUC)
RR relative risk, CI confidence interval, PS performance status, Hg haemoglobin, CTZ Co-trimoxazole, CCI Charlson comorbidity index

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