Long-term prognosis for diabetic patients with foot ulcers.

OBJECTIVE

To evaluate the recurrence of foot ulcers as well as the cumulative amputation and mortality rates in diabetic patients with previous foot ulcers.

DESIGN

A prospective study of consecutively presenting diabetic patients admitted to the Department of Internal Medicine because of foot ulcer with a median follow-up of 4 years.

SETTING

A multidisciplinary foot-care team.

POPULATION

Five-hundred-and-fifty-eight consecutive diabetic patients with foot ulcers treated between 1 July 1983 and 31 December 1990 were followed to final outcome. Out of these patients, 468 healed either primarily (n = 345) or after minor or major amputations (n = 123) and 90 died before healing had occurred. Those 468 patients who healed were included in this prospective study from the time of healing.

MAIN OUTCOME MEASURES

Patients were followed according to a standardized protocol with registration of foot lesions, amputation, morbidity and mortality. Clinical examination was performed twice yearly.

RESULTS

After 1, 3 and 5 years of observation 34%, 61% and 70% of the patients, respectively, had developed a new foot ulcer. The recurrence rate of foot lesions was slightly higher among patients who previously had had an amputation (P < 0.05, P < 0.01 and non-significant, respectively). Among patients with previous primary healing the cumulative amputation rates were 3%, 10% and 12% after 1, 3 and 5 years of follow-up compared with 13%, 35% and 48% among those who previously healed after amputation, irrespective of previous amputation level (P < 0.001 at all time-points). All amputations except three were initiated by a foot ulcer deteriorating to deep infection or progressive gangrene. The long-term survival ratio was lower among patients healed after previous amputation (80%, 59%, 27%) compared with patients with previously primary healing (92%, 73%, 58%) after 1, 3 and 5 years of observation, respectively (P < 0.001, P < 0.01 and P < 0.001 respectively). The mortality rate was twice as high among primarily healed and four times as high among patients with amputation compared to an age- and sex-matched Swedish population.

CONCLUSION

These findings stress the need for life-long surveillance of the diabetic foot at risk and the necessity of preventive foot care among diabetic patients with previous foot lesions, and particularly among those who had had a previous amputation.