Estimates of hospitalisations and deaths in patients with COVID-19 associated with undiagnosed diabetes during the first phase of the pandemic in eight low-income and middle-income countries: a modelling study

Background Patients with COVID-19 that had diagnosed chronic diseases - including diabetes - may experience higher rates of hospitalisation and mortality relative to the general population. However, the burden of undiagnosed co -morbidities during the pandemic has not been adequately studied. Methods We developed a model to estimate the hospitalisation and mortality burden of patients with COVID-19 that had undiagnosed type 1 and type 2 diabetes (UD). The retrospective analytical modelling framework was informed by country -level demographic, epidemiological and COVID-19 data and parameters. Eight low -and middle -income countries (LMICs) were studied: Brazil, China, India, Indonesia, Mexico, Nigeria, Pakistan, and South Africa. The modelling period consisted of the first phase of the pandemic - starting from the date when a country identified its first COVID case to the date when the country reached 1% coverage with one dose of a COVID-19 vaccine. The end date ranged from Jan 20, 2021 for China to June 2, 2021 for Nigeria. Additionally, we estimated the change in burden under a scenario in which all individuals with UD had been diagnosed prior to the pandemic. Findings Based on our modelling estimates, across the eight countries, 6.7 (95% uncertainty interval: 3.4-11.3) million COVID-19 hospitalised patients had UD of which 1.9 (0.9-3.4) million died. These represented 21.1% (13.4%-30.1%) of all COVID-19 hospitalisations and 30.5% (14.3%-55.5%) of all COVID-19 deaths in these countries. Based on modelling estimates, if these populations had been diagnosed for diabetes prior to the COVID-19 pandemic, 1.7% (-3.0% to 5.9%) of COVID-19 hospitalisations and 5.0% (-0.9% to 14.1%) of COVID-19 deaths could have been prevented, and 1.8 (-0.3 to 5.0) million quality -adjusted life years gained. Interpretation Our findings suggest that undiagnosed diabetes contributed substantially to COVID-19 hospitalisations and deaths in many LMICs.