A Case-control Study of Risk Factors for Recurrence of Diabetic Foot Ulcer after Complete Healing

Abstract

Background Diabetic foot ulcer (DFU) is a serious diabetic complication with a high recurrence rate after healing. There is a lack of systematic evidence-based studies on multiple risk factors associated with its recurrence. Objective To investigate the risk factors for DFU recurrence after healing, providing evidence to inform the prevention and treatment of DFU. Methods A case-control study design was used. Patients with an initial inpatient diagnosis of DFU were selected from Hospital of Chengdu University of TCM from January 1, 2016 to February 1, 2019 as the source population, among whom those with and without a recurrence within three years after healing were assigned to case and control groups, respectively. Baseline characteristics, information related to diabetes and DFU were collected from both groups. Risk factors for DFU recurrence were screened by unconditional multivariate Logistic regression analysis. The relationships of DFU recurrence with the number of risk factors and the time to recurrence were further analyzed. Results Among the source population (n=256), 210 had healed DFU, and 190 of them were included for final analysis after excluding 12 missing cases and 8 with incomplete information. The overall recurrence rate within three years after DFU healing was 45.3% (86/190). Multivariate Logistic regression analysis showed that age >60 years〔OR=3.270, 95%CI (1.335, 8.005), P=0.010〕, HbA1c >7.5%〔OR=2.691, 95%CI (1.242, 7.687), P=0.045〕, peripheral arterial disease (PAD) 〔OR=2.241, 95%CI (1.185, 5.101), P=0.044〕, osteomyelitis〔OR=3.256, 95%CI (1.369, 7.744), P=0.008〕, callus〔OR=2.068, 95%CI (1.262, 4.446), P=0.043〕, ankle-brachial index (ABI) <0.9〔OR=3.616, 95%CI (1.436, 9.102), P=0.006〕, plantar ulcers〔OR=2.192, 95%CI (1.061, 4.998), P=0.042〕, and Wagner grade ≥3〔OR=5.522, 95%CI (2.484, 12.273), P<0.001〕 were risk factors for DFU recurrence. The number of comorbid risk factors mainly ranged from 5 to 9 in the case group (n=86), and 2 to 5 in the control group (n=104). The number of recurrent cases within one, two and three years in the case group was 35, 28 and 23, respectively. The one-, two- and three-year cumulative recurrence rates were 18.4% (35/190), 33.2% (63/190), and 45.3% (86/190), respectively. Conclusion The high recurrence rate of DFU may be associated with risk factors such as age >60 years, HbA1c >7.5%, PAD, osteomyelitis, callus, ABI <0.9, plantar ulcers, and Wagner grade ≥3.

Keywords

• diabetic foot|ulcer|recurrence|case control study|risk factors|root cause analysis