Background: Diabetic foot infection (DFI) is a limb- and life-threatening complication for diabetic patients needing immediate and comprehensive treatment. Early referral of DFI patients to a diabetic foot center is recommended but there appears limited validated evidence, with the association between referral time and clinical outcomes of limb- preservation or in-hospital mortality still lacking.
Methods: This retrospective research studied consecutive type 2 diabetic patients with DFI treated at the major diabetic foot center in Taiwan from 2014 to 2017. Six hundred and sixty-eight patients presented with limb-threatening DFI. After stratifying their referral days into quartiles, the demographic information and clinical outcomes were analyzed.
Results: One hundred and seventy-two patients were placed in the first quartile (Q1) with less than 9 days of referral time; 164 in the second quartile (Q2) with 9-21 days; 167 in the third quartile (Q3) with 21-59 days; and 165 in the fourth quartile (Q4) with >59 days. End-stage renal disease (ESRD), major adverse cardiac events (MACE) and peripheral arterial disease (PAD) were noted as being higher in the Q4 group compared with the Q1 group (25.45% vs 20.35% in ESRD, 47.27% vs 26.16% in MACE and 78.79% vs 52.33% in PAD respectively). The Q1 group had more patients presenting with systemic inflammatory responsive syndrome (SIRS) (29.07% in Q1 vs 25.45% in Q4 respectively, P=0.019). Regarding poor outcome (major lower-extremity amputation (LEA) or in-hospital mortality), the Q4 group had 21.21% of patients in this category and the Q1 group had 10.47%. The odds ratio of each increased referral day on poor prognosis was 1.006 with 95% confidence interval 1.003-1.010 (P=<0.001). In subgroups, the impact on poor prognosis by day was most obvious in patients with SIRS (OR 1.011, 95% CI 1.004-1.018, P=0.003) and those with PAD (OR 1.004, 95% CI 1.001-1.008, P=0.028).
Conclusions: The deferred referral of DFI patients to the diabetic foot center might be associated with poor treatment outcome either in major LEA or mortality, particularly in patients with SIRS or PAD. Both physician and patient awareness of disease severity and overcoming the referral barrier is suggested.
Trial registration: Not applicable.
Keywords: Diabetic foot infection; Lower-extremity amputation; Referral time.