Living at High Altitude and COVID-19 Mortality in Peru

Nicolaou, Laura, Anne Steinberg, Rodrigo M. Carrillo-Larco, Stella Hartinger, Andres G. Lescano, and William Checkley. Living at high altitude and COVID-19 mortality in Peru. High Alt Med Biol. 23:146-158, 2022. Previous studies have reported a lower severity of COVID-19 infections at higher altitudes; however, this association may be confounded by various factors. We examined the association between living at altitude and COVID-19 mortality in Peru adjusting for population density, prevalence of comorbidities, indicators of socioeconomic status, and health care access. Utilizing administrative data across 196 provinces located at varying altitudes (sea level to 4,373 m), we conducted a two-stage analysis of COVID-19 deaths between March 19 and December 31, 2020, Peru's first wave. We first calculated cumulative daily mortality rate for each province and fit lognormal cumulative distribution functions to estimate total mortality rate, and start, peak, and duration of the first wave. We then regressed province-level total mortality rate, start, peak, and duration of the first wave as a function of altitude adjusted for confounders. There were 93,528 recorded deaths from COVID-19 (mean age 66.5 years, 64.5% male) for a cumulative mortality of 272.5 per 100,000 population between March 19 and December 31, 2020. We did not find a consistent monotonic trend between living at higher altitudes and estimated total mortality rate for provinces at 500 - 1,000 m (-12.1 deaths per 100,000 population per 100 m, 95% familywise confidence interval -27.7 to 3.5) or > 1,000 m (-0.3, -2.7 to 2.0). We also did not find consistent monotonic trends for the start, peak, and duration of the first wave beyond the first 500 m. Our findings suggest that living at high altitude may not confer a lower risk of death from COVID-19.