Comorbidity was assessed using the modified
Charlson comorbidity index (CCI, 18) but without
age (i.e., not adding a score of 1 for each decade above
40 years). Since both diabetes and diabetic nephropathy
were included in the calculation, a separate comorbidity
score was also calculated after correcting for diabetes
and/or diabetic nephropathy. The demographic and clinical
data for the diabetic patients with foot ulcers has
been presented previously [16,18], and are therefore
summarised only briefly in the results section.