Table 2

30- and 90-day mortality by amputation type and further stratified by covariates

Major amputationMinor amputation
30-day mortality90-day mortality30-day mortality90-day mortality
n1% (95% CI)2n1% (95% CI)2n1% (95% CI)2n1% (95% CI)2
Total deaths28911.1 (10–12.4)47117.6 (16.1–19.1)1193 (2.5–3.6)2595.6 (4.9–6.4)
Sex
 Female11212.5 (10.5–14.8)18520.2 (17.7–22.9)373.1 (2.3–4.3)825.4 (4.3–6.9)
 Male17710.5 (9.1–12)28616.3 (14.6–18.1)823 (2.4–3.8)1775.8 (4.9–6.7)
Age (years)
 0–2400 (0–0)00 (0–0)00 (0–0)00 (0–0)
 25–49239.7 (6.6–14.3)3113.1 (9.4–18.2)51.1 (0.5–2.6)151.3 (0.6–2.9)
 50–647410.3 (8.3–12.8)11314.9 (12.5–17.8)231.8 (1.2–2.8)553.5 (2.6–4.8)
 65–74669.2 (7.3–11.6)12316.4 (13.9–19.4)302.8 (1.9–4)625.4 (4.2–7)
 ≥7512613.7 (11.7–16.1)20421.8 (19.3–24.6)615.4 (4.2–6.8)1279.8 (8.2–11.7)
Ethnicity
 Māori8813.1 (10.8–15.9)14217.7 (10.2–29.7)233.5 (2.3–5.2)505.8 (2.7–12.5)
 Pacific2010.3 (6.7–15.4)3016.9 (15.2–18.8)123.4 (1.9–5.9)215.7 (4.9–6.6)
 Asian1016.1 (9–27.9)1120 (17.1–23.2)32.9 (0.9–8.8)65.6 (4–7.7)
 European/other17110.3 (8.9–11.8)28814.9 (10.6–20.7)812.9 (2.3–3.6)1825.4 (3.5–8.3)
Deprivation (NZDep)
 1–22212.7 (8.6–18.7)3017.3 (12.5–23.9)92.2 (1.1–4.3)316.9 (4.7–10.1)
 3–4289.6 (6.7–13.5)4815.7 (12–20.5)71.5 (0.7–3.2)172.6 (1.5–4.6)
 5–65111 (8.5–14.3)8517.7 (14.5–21.6)192.9 (1.8–4.5)425.5 (4–7.5)
 7–87511.6 (9.4–14.4)11717.3 (14.6–20.4)373.6 (2.6–5)786.6 (5.2–8.3)
 9–1011211.2 (9.4–13.3)19018.6 (16.3–21.1)473.6 (2.7–4.7)915.9 (4.7–7.3)
Rurality (URPC)
 Urban21111.3 (9.9–12.8)33617.3 (15.7–19.1)782.9 (2.3–3.6)1765.4 (4.6–6.3)
 Independent urban489.8 (7.5–12.8)9118.6 (15.4–22.4)273.8 (2.6–5.6)536.7 (5–8.9)
 Rural2813.9 (9.7–19.6)4219.7 (14.7–26)143.7 (2.2–6.3)307.2 (4.9–10.4)
Hospital volume (amputations/year)
 >50017411.3 (9.8–13)27917.6 (15.8–19.6)683 (2.4–3.8)1485.6 (4.7–6.7)
 100–4999511.3 (9.4–13.7)15517.8 (15.3–20.6)403.4 (2.5–4.7)946.8 (5.4–8.4)
 <100189.4 (6–14.5)3517.3 (12.7–23.5)112.6 (1.3–4.9)173.4 (2–6)
Admission type
 Acute23112.2 (10.8–13.8)37619.2 (17.5–21.1)913.3 (2.7–4.1)1926 (5.2–7)
 Elective588.2 (6.4–10.5)9513.1 (10.8–15.9)282.4 (1.6–3.5)674.7 (3.6–6.1)
Comorbidity (M3 index)
 03111.1 (7.9–15.4)5418.6 (14.5–23.7)122.6 (1.4–4.6)214.5 (2.9–6.9)
 >0–19110.3 (8.5–12.5)14515.5 (13.2–18.1)473.7 (2.8–4.9)966.2 (5–7.6)
 >1–210211.6 (9.6–13.8)16818.7 (16.3–21.5)342.8 (2–3.9)835.7 (4.6–7.2)
 >2–35011.6 (8.9–15.1)7717.4 (14.1–21.4)223 (1.9–4.6)455.7 (4.2–7.8)
 ≥31512.3 (7.6–19.6)2722.1 (15.7–30.6)41.9 (0.7–5.1)143.9 (2–7.7)
  • 1Deaths within 30 (or 90) days of amputation. Deaths in the 90-day columns include those that occurred within 30 days.

  • 2Determined by using Kaplan-Meier survival analysis, with patients who did not die censored at 30 (or 90) days.