Table 2

Incidence of amputations per 1000 patient-years by sex and age categories at baseline with 95% CIs estimated by exact Poisson confidence limits

EventSubgroupStatisticsAllMenWomen
Type 1 diabetesControlsType 1 diabetesControlsType 1 diabetesControls
Any amputationAlln (%, N)1081 (3.0, 36 577)117 (0.1, 182 617)711 (3.6, 20 010)80 (0.1, 99 879)370 (2.2, 16 567)37 (0.0, 82 738)
Event rate (95% CI)3.18 (2.99 to 3.38)0.07 (0.05 to 0.08)3.87 (3.59 to 4.17)0.08 (0.07 to 0.10)2.37 (2.13 to 2.62)0.05 (0.03 to 0.06)
18–49 yearsn (%, N)428 (1.4, 29 578)31 (0.0, 147 804)276 (1.7, 16 305)23 (0.0, 81 463)152 (1.1, 13 273)8 (0.0, 66 341)
Event rate (95% CI)1.54 (1.40 to 1.70)0.02 (0.01 to 0.03)1.82 (1.62 to 2.05)0.03 (0.02 to 0.04)1.21 (1.02 to 1.42)0.01 (0.01 to 0.02)
50–64 yearsn (%, N)474 (8.6, 5533)41 (0.1, 27 588)325 (11.0, 2968)26 (0.2, 14 792)149 (5.8, 2565)15 (0.1, 12 796)
Event rate (95% CI)8.91 (8.13 to 9.75)0.14 (0.10 to 0.18)11.70 (10.46 to 13.04)0.16 (0.11 to 0.24)5.87 (4.96 to 6.89)0.11 (0.06 to 0.17)
65+ yearsn (%, N)179 (12.2, 1466)45 (0.6, 7225)110 (14.9, 737)31 (0.9, 3624)69 (9.5, 729)14 (0.4, 3601)
Event rate (95% CI)18.65 (16.02 to 21.60)0.74 (0.54 to 0.99)24.05 (19.77 to 28.99)1.06 (0.72 to 1.51)13.74 (10.69 to 17.39)0.44 (0.24 to 0.75)
Minor amputationsAlln (%, N)656 (1.8, 36 577)33 (0.0, 182 617)462 (2.3, 20 010)27 (0.0, 99 879)194 (1.2, 16 567)6 (0.0, 82 738)
Event rate (95% CI)1.92 (1.78 to 2.08)0.02 (0.01 to 0.03)2.50 (2.28 to 2.74)0.03 (0.02 to 0.04)1.24 (1.07 to 1.42)0.01 (0.00 to 0.02)
18–49 yearsn (%, N)308 (1.0, 29 578)9 (0.0, 147 804)208 (1.3, 16 305)9 (0.0, 81 463)100 (0.8, 13 273)0 (0.0, 66 341)
Event rate (95% CI)1.11 (0.99 to 1.24)0.01 (0.00 to 0.01)1.37 (1.19 to 1.57)0.01 (0.01 to 0.02)0.79 (0.65 to 0.97)0.00 (0.00 to 0.01)
50–64 yearsn (%, N)276 (5.0, 5533)12 (0.0, 27 588)208 (7.0, 2968)8 (0.1, 14 792)68 (2.7, 2565)4 (0.0, 12 796)
Event rate (95% CI)5.12 (4.54 to 5.76)0.04 (0.02 to 0.07)7.37 (6.40 to 8.44)0.05 (0.02 to 0.10)2.65 (2.06 to 3.36)0.03 (0.01 to 0.07)
65+ yearsn (%, N)72 (4.9, 1466)12 (0.2, 7225)46 (6.2, 737)10 (0.3, 3624)26 (3.6, 729)2 (0.1, 3601)
Event rate (95% CI)7.29 (5.71 to 9.19)0.20 (0.10 to 0.35)9.63 (7.05 to 12.85)0.34 (0.16 to 0.63)5.10 (3.33 to 7.48)0.06 (0.01 to 0.23)
Major amputationsAlln (%, N)638 (1.7, 36 577)87 (0.0, 182 617)405 (2.0, 20 010)56 (0.1, 99 879)233 (1.4, 16 567)31 (0.0, 82 738)
Event rate (95% CI)1.87 (1.72 to 2.02)0.05 (0.04 to 0.06)2.19 (1.98 to 2.41)0.06 (0.04 to 0.08)1.49 (1.30 to 1.69)0.04 (0.03 to 0.05)
18–49 yearsn (%, N)209 (0.7, 29 578)22 (0.0, 147 804)124 (0.8, 16 305)14 (0.0, 81 463)85 (0.6, 13 273)8 (0.0, 66 341)
Event rate (95% CI)0.75 (0.65 to 0.86)0.02 (0.01 to 0.02)0.82 (0.68 to 0.97)0.02 (0.01 to 0.03)0.67 (0.54 to 0.83)0.01 (0.01 to 0.02)
50–64 yearsn (%, N)295 (5.3, 5533)30 (0.1, 27 588)198 (6.7, 2968)19 (0.1, 14 792)97 (3.8, 2565)11 (0.1, 12 796)
Event rate (95% CI)5.45 (4.85 to 6.11)0.10 (0.07 to 0.14)6.96 (6.02 to 8.00)0.12 (0.07 to 0.19)3.78 (3.07 to 4.62)0.08 (0.04 to 0.14)
65+ yearsn (%, N)134 (9.1, 1466)35 (0.5, 7225)83 (11.3, 737)23 (0.6, 3624)51 (7.0, 729)12 (0.3, 3601)
Event rate (95% CI)13.74 (11.51 to 16.28)0.58 (0.40 to 0.80)17.75 (14.14 to 22.01)0.79 (0.50 to 1.18)10.05 (7.48 to 13.21)0.38 (0.20 to 0.67)
  • Event rates are expressed per 1000 patient-years.