Table 1—

Univariate and subsequent multivariate analysis of risk factors for an ulcer in the follow-up period

Follow-up ulcerNo follow-up ulcerP valueOdds ratio (95% CI)Coefficient (logistic regression)Estimated odds ratio (logistic regression)
Male sex73.581.3>0.3
Age >60 years20.434.40.1610.5 (0.2–1,3)
Age (years)52.653.>0.3
Type 2 diabetes95.993.8>0.3
Duration of diabetes >10 years73.556.30.110.2 (0.1–1.6)
Alcohol abuse past and present46.950.0>0.3
Tobacco abuse past and present55.165.6>0.3
Nephropathy (at least microalbuminuria)56.350.0>0.3
Retinopathy (at least background changes)86.179.2>0.3
History of amputation40.834.3>0.3
A1C >9%70.566.7>0.3
Plantar peak pressure >70 N/cm260.055.2>0.3
Peak pressure forefoot (N/cm2)85.783.7>0.3
TcpO2 <30 mmHg41.925.00.150.2 (0.1–1.5)
TcpO2 (mmHg)38.842.3>0.3
Neuropathy (SWM missing or vibratory perception threshold >25 V)91.790.6>0.3
Vibratory perception threshold (V)
Peripheral vascular disease (any pedal pulse missing or ankle-brachial index <0.8)42.99.4<0.0010.3 (0.1–3.2)
Ankle-brachial index0.931.10>0.3
Rigid toe deformity or charcot deformity87.881.3>0.3
Hallux rigidus28.615.60.180.1 (0.1–1.3)
Pes equinus36.728.1>0.3
Any rigid deformity73.565.6>0.3
BMI (kg/m2)29.829.8>0.3
Cholesterol (mg/dl)1961820.21
Smoking: pack-year history (years)17.415.8>0.3
Years of education11.29.1>0.3
Peripheral vascular disease (multivariate)0.0062.310.1
Location of index ulcer at plantar hallux (multivariate)0.0381.75.3
  • Data are percent, unless otherwise indicated. The factors for foot ulceration after a previous ulceration entered into the logistic regression analysis model were age >60 years, duration of diabetes >10 years, peripheral vascular disease (any missing pulse or ankle-brachial index <0.8), presence of hallux rigidus, and location of index. Variables with P < 0.2 in the logistic regression analysis are displayed in the bottom two lines of the table. The χ2 of the Hosmer and Lemeshow goodness-of-fit test was 3.8 with P = 0.81, indicating that the model was well calibrated and that the data fit well. SWM, any missing sensation with the Semmes-Weinstein monofilament 10 g; TcpO2, transcutaneous partial oxygen pressure.