ABSTRACT
ObjectivTo explore the link between COVID-19 incidence, socio-economic covariates, and NHL incidence. DesignEcological study design. SettingSardinia, Italy. ParticipantsWe used official reports on the total cases of COVID-19 in 2020, published data on NHL incidence, and socio-economic indicators by administrative unit, covering the whole regional population. Main outcomes and measuresWe used multivariable regression analysis to explore the association between the natural logarithm (ln) of the 2020 cumulative incidence of COVID-19 and the ln-transformed NHL incidence in 1974-2003, weighing by population size and adjusting by socioeconomic deprivation and other covariates. ResultsThe cumulative incidence of COVID-19 increased in relation to past incidence of NHL (p < 0.001), socioeconomic deprivation (p = 0.006), and proportion of elderly residents (p < 0.001) and decreased with urban residency (p = 0.001). Several sensitivity analyses confirmed the finding of an association between COVID-19 and NHL. ConclusionThis ecological study found an ecological association between NHL and COVID-19. If further investigation would confirm our findings, shared susceptibility factors should be investigated among the plausible underlying mechanisms. Strengths and limitations of this studyO_LIThis study exploited the availability of incidence data for non-Hodgkins lymphoma over a 30-year time frame and the 2020 cumulative incidence data for COVID-19 available for all administrative units in the Sardinia region, Italy. C_LIO_LIUsing an ecological study design, we observed that COVID-19 occurrence increased with past incidence of non-Hodgkins lymphoma. C_LIO_LILimitations of the ecological study design require further investigation for confirmation and for identification of susceptibility factors possibly shared between the two diseases. C_LI