A Population-Based Analysis of Diabetes-Related Care Measures, Foot Complications, and Amputation During the COVID-19 Pandemic in Ontario, Canada

Abstract

Importance: Deferred diabetic foot screening and delays in timely care of acute foot complications during the COVID-19 pandemic may have contributed to an increase in limb loss.

Objective: To evaluate the association of the COVID-19 pandemic with diabetes-related care measures, foot complications, and amputation.

Design, setting, and participants: This population-based cohort study included all adult residents of Ontario, Canada, with diabetes and compared the rates of selected outcomes from January 1, 2020, to February 23, 2021, vs January 1, 2019, to February 23, 2020.

Main outcomes and measures: Comprehensive in-person diabetes care assessment, including foot examination; hemoglobin A1c (HbA1c) measurement; emergency department visit or hospitalization for diabetic foot ulceration, osteomyelitis, or gangrene; lower extremity open or endovascular revascularization; minor (toe or partial-foot) amputation; and major (above-ankle) leg amputation. Rates and rate ratios (RRs) comparing 2020-2021 vs 2019-2020 for each measure were calculated for 10-week periods, anchored relative to onset of the pandemic on March 11, 2020 (11th week of 2020).

Results: On March 11, 2020, the study included 1 488 605 adults with diabetes (median [IQR] age, 65 [55-74] years; 776 665 [52.2%] men), and on March 11, 2019, the study included 1 441 029 adults with diabetes (median [IQR] age, 65 [55-74] years; 751 459 [52.1%] men). After the onset of the pandemic, rates of major amputation in 2020-2021 decreased compared with 2019-2020 levels. The RR for the prepandemic period from January 1 to March 10 was 1.05 (95% CI, 0.88-1.25), with RRs in the pandemic periods ranging from 0.86 (95% CI, 0.72-1.03) in May 20 to July 28 to 0.95 (95% CI, 0.80-1.13) in October 7 to December 15. There were no consistent differences in demographic characteristics or comorbidities of patients undergoing amputation in the 2020-2021 vs 2019-2020 periods. Rates of comprehensive in-person diabetes care assessment and HbA1c measurement declined sharply and remained below 2019-2020 levels (eg, in-person assessment, March 11 to May 19: RR, 0.28; 95% CI, 0.28-0.28). The rates of emergency department visits (eg, March 11 to May 19: RR, 0.67; 95% CI, 0.61-0.75), hospitalization (eg, March 11 to May 19: RR, 0.77; 95% CI, 0.68-0.87), open revascularization (eg, March 11 to May 19: RR, 0.66; 95% CI, 0.56-0.79), endovascular revascularization (March 11 to May 19: RR, 0.70; 95% CI, 0.61-0.81), and minor amputation (March 11 to May 19: RR, 0.70; 95% CI, 0.60-0.83) initially dropped but recovered to 2019-2020 levels over the study period.

Conclusions and relevance: In this population-based cohort study, disruptions in care related to the COVID-19 pandemic were not associated with excess leg amputations among people living with diabetes. As the pandemic ends, improved prevention and treatment of diabetic foot complications will be necessary to maintain these positive results.

Figure 1.. Major Amputation Rates Among Adults With Diabetes

Major amputation indicates above-ankle amputations. On March 19, 2020, nonessential health services and scheduled procedures were suspended; May 19, 2020, gradual resumption in scheduled procedures and in-person health services permitted; July 24, 2020, provincial state of emergency lifted; September 28, 2020, official recognition of second wave; January 14, 2021 to February 19, 2021, second provincial state of emergency. Error bars indicate 95% CIs. Table 3 contains counts, rates, and rate ratios for 2020-2021 vs 2019-2020 per time period.

Figure 2.. Outcome and Care Measure Rate Ratios for 2020-2021 Periods Relative to 2019-2020 Control Periods

The blue dot indicates the rate ratio during the prepandemic period; orange dots, COVID-19 period, starting on March 11, 2020. C-G, Error bars indicate 95% CIs.