Surrogate End Points for the Treatment of Diabetic Neuropathic Foot Ulcers
Article Figures & Tables
Tables
- Table 1—
Patient characteristics and week 4 surrogate characteristics for those who healed and those who did not by the 20th week of care and who were evaluated at week 4
Variable Healed Unhealed Wounds 15,382 (53.7) 13,242 (46.3) Age (years) 64 (54–73) 65 (54–74) Wound size (mm2) 133 (49–401) 255 (82–827) Wound duration (months) 1 (0.5–3) 2 (0.75–5) Log wound size (mean) 4.97 (0.012) 5.59 (0.014) Log wound duration 0.36 ± 1.40 0.73 ± 0.01 Log rate 0.062 ± 0.0006 0.007 ± 0.0004* Percent change −0.016 ± 0.06* −1.02 ± 0.25* Ratio of log areas 0.64 ± 0.004* 0.99 ± 0.003* Data are n (%), median (25th–75th percentile), or mean ± SD unless otherwise indicated.
- Table 2—
The ROC curve area for surrogate end points measured after 2, 4, or 8 weeks for a 12- or 20-week healed outcome
Surrogate Wound End point ROC curve Week 2 Week 4 Week 8 Log rate Primary Week 12 0.73 0.78 0.85 Percent change Primary Week 12 0.73 0.79 0.85 Ratio of log areas Primary Week 12 0.74 0.79 0.86 Log rate All Week 12 0.75 0.79 0.85 Percent change All Week 12 0.75 0.80 0.86 Ratio of log areas All Week 12 0.76 0.80 0.86 Log rate Primary Week 20 0.69 0.73 0.77 Percent change Primary Week 20 0.69 0.73 0.77 Ratio of log areas Primary Week 20 0.69 0.73 0.78 Log rate All Week 20 0.72 0.76 0.78 Percent change All Week 20 0.72 0.76 0.78 Ratio of log areas All Week 20 0.72 0.76 0.79 - Table 3—
Correct classification maximized dichotomous surrogate end points at 4 weeks for a 20-week healed outcome
Surrogate Wound Cut point Sensitivity Specificity Correct classification (%) Log rate All 0.033 68.2 71.1 69.5 Log rate Primary 0.044 58.4 79.0 68.6 Percent change All 0.61 68.2 71.2 69.6 Percent change Primary 0.71 58.5 79.0 68.6 Ratio of log areas All 1.23 68.8 71.9 70.2 Ratio of log areas Primary 1.34 59.0 79.6 69.2
In this Issue
June 2003, 26(6)
Surrogate End Points for the Treatment of Diabetic Neuropathic Foot Ulcers
