Table 3 Mortality and antibiotic usage in clusters of patients with GPA

 No. of deaths (%)

52 (12.2%)

37 (21%)

14 (29.8%)

 PY, median (IQR)

5.14 (2.00–8.69)

3.35 (1.05–5.75)

3.68 (1.34–7.72)

 Unadjusted HR (95% CI), p value

1 (reference)

2.33 (1.53–3.57), p < 0.001

2.95 (1.63–5.33), p < 0.001

 aHR (95% CI), p value^a

1 (reference)

1.61 (1.03–2.53), p = 0.037

1.95 (1.05–3.62), p = 0.035

 Cumulative period of use of antibiotics, in quarters of year (total number of antibiotic prescriptions)

3844 (9606)

596 (1636)

1339 (2874)

 Unadjusted HR (95% CI), p value

1 (reference)

1.64 (1.52–1.77), p < 0.001

1.15 (1.00–1.33), p = 0.04

 aHR (95% CI), p value^a

1 (reference)

1.46 (1.35–1.58), p < 0.001

1.21 (1.05–1.39), p = 0.009