Population Health Effects Of Household SARS-CoV-2 Exposure Based On A Retrospective Cohort Design

Background The health impact of the Severe Acute Respiratory Syndrome Coronavirus 2(SARS-Co V-2)can be quantitatively evaluated by measuring changes in population health outcomes,and can be explained from two parts,namely,direct and indirect impact.The direct impact is due to the increase in morbidity,severe illness and death caused or induced by the virus directly acting on the host;the indirect impact is caused by the Coronavirus Disease 2019(COVID-19)outbreak,such as medical runs,exhaustion of medical resources,traffic control,and social distancing policies.People who infected SARS-CoV-2 will not only be affected by the direct impacts caused by the virus infection,but also by the indirect impact caused by the outbreak.Therefore,by comparing the health differences between the infected population after the outbreak and before the outbreak,the total impact of exposure on the health of the population can be obtained.The uninfected SARS-CoV-2 population will only be affected by the indirect impact caused by the outbreak.Therefore,it is possible to get the health impact(indirect impact)caused by the outbreak by comparing the health outcomes before and after the outbreak of COVID-19 in the uninfected SARS-CoV-2 population.Assuming that the indirect health impact is same among the infected and uninfected people,the direct health impact caused by SARS-CoV-2 infection can be obtained.Objective to quantitatively measure the health impact of household SARS-CoV-2 exposure on the health outcomes of out-patient and emergency treatment,hospitalization and death,to prepare medical resources for future COVID-19 response,and to compare the health burden of COVID-19 with other diseases,so as to provide an important basis for the formulation of COVID-19 prevention and control measures and rational allocation of health resources in the future.Method This study is a matched retrospective cohort study.The population of Yichang City(Y city),according to whether there were confirmed SARS-CoV-2 infections in the households during the period from January 1,2020 to February 29,2020,was divided into 2 groups:exposed families(with those who have been diagnosed with SARS-CoV-2 infection)and the control families(without the infection).According to the principle of being in the same community,having the same family size,and similar age structure as the exposed group,the control group was randomly selected from families without cases at a ratio of 1:2.After establishing and determining the research cohort,retrospectively collect the health outcome data of the two groups of people,including outpatient and emergency visits and hospitalizations recorded on the Y city health big data platform from January 1,2017 to December 31,2020,and data on the cause of death monitoring conducted by Y city from January 1,2020 to December 31,2020.Calculate the different annual all-causes and acute respiratory infections(ARI)related outpatient and emergency clinic visit rates,hospitalization rates and mortality in the two groups of cohorts,and calculate the incidence rate difference in annual(IRD)between the two groups.The total impacts,direct impact and indirect impact of household SARS-CoV-2 exposure on the emergency and hospitalization of the population are estimated by Poisson generalized estimation equation.The direct impact of SARS-CoV-2 exposure on the death of the population is estimated by Cox regression equation.The research uses EXCEL 2019 and R 3.6.2 to process and analyze the data.Results 1.3969 subjects were investigated vertically(1323 in the exposure group,2646 in the control group),including 1915 males(48.25%),median age of 48 years(IQR:31-63).There was no statistically significant difference in gender(male 48.07%vs 48.34%,P=0.893)and age(median age:48 vs 47,P=0.379),but the proportion of people with underlying diseases in the exposed group was higher than the control Group(35.45%vs 27.63%,P<0.001).2.From 2017 to 2020,the incidence rates of all-cause outpatient and emergency department visits and acute respiratory infections(Acute Respiratory Infections,ARI)related diseases were 2128.83 vs.167.35,2562.20 vs.211.88,3182.19 vs.286.4,and 3330.06 vs.349.46 times per thousand person-years;the difference in the incidence of outpatient and emergency department visits between the exposure group and the control group,and the difference in the incidence of outpatient and emergency department visits for ARI-related diseases were 544.70 vs 39.97,671.88 vs 87.13,719.63 vs 54.47,and 2804.24 vs 683.30 times per thousand person-years.Within one year after the outbreak of COVID-19,there was no significant difference between the level of all-cause outpatient and emergency visits in households exposed to SARS-CoV-2 and before the outbreak(0.15 times increase,95%CI:-0.02?0.35).The direct effect of households exposed to SARS-CoV-2 increased the risk of all-cause outpatient and emergency visits by 0.48 times(95%CI:0.35?0.63),and the outbreak indirectly led to 0.33 times(95%CI:0.28?0.37)reduction in the risk of all-cause outpatient and emergency visits.Within one year after the outbreak,the level of outpatient and emergency visits for ARI-related diseases among households exposed to SARS-CoV-2 was still higher than before the outbreak of COVID-19(0.80 times increase,95%CI:0.06-2.16),among which the direct effect of households exposed to SARS-CoV-2 increased the risk of outpatient and emergency outpatient visits for ARI-related diseases in the population by 1.44 times(95%CI:0.77?2.70).The outbreak of COVID-19 indirectly reduced the risk of outpatient and emergency outpatient visits for ARI-related diseases by 0.64 times(95%CI:0.54?0.71).The direct impact(0.85 times(95%CI:0.61?1.16)vs.0.36 times(95%CI:0.23?0.51))and indirect impact(0.54 times(95%CI:0.48?0.59)vs.0.26 times(95%CI:0.20?0.31))of households exposure to SARS-CoV-2 on the population's recent all-cause outpatient and emergency visits are greater than the medium and long-term impact.And the direct(2.21 times(95%CI:0.98?4.94)vs.0.43 times(95%CI:-0.26?1.80))and indirect impact(0.73 times(95%CI:0.61?0.81)vs.0.60 times(95%CI:0.46?0.70))of households exposure to SARS-CoV?2 on the population's recent outpatient and emergency visits for ARI-related diseases are greater than the medium and long-term impact.3.From 2017 to 2020,the incidence of all-cause hospitalizations and ARI-related diseases in the survey respondents were 157.14 vs 13.01,207.05 vs 15.48,233.16 vs 18.93,1341.90 vs 160.75 times per thousand person-years;the exposure group and the control group had all the hospitalizations throughout the year.The difference between the incidence of hospitalization and the incidence of ARI-related diseases were-1.05 vs 1.19,46.36 vs 4.24,36.62 vs-9.06,and 625.47 vs 458.42 times per thousand person-years,respectively.Within one year after the outbreak of COVID-19,the incidence of all-cause hospitalizations in households exposed to SARS-CoV-2 was higher than the level of all-cause hospitalizations before the COVID-19 outbreak(increase by 1.39 times,95%CI:0.57?2.71),among which,the direct effect of households exposed to SARS-CoV-2 increased the incidence of all-cause hospitalization in the population by 1.91 times(95%CI:1.17?3.12).The outbreak of COVID-19 also indirectly led to the all-cause population in the whole year.The incidence of hospitalization decreased by 0.52 times(95%CI:0.41?0.60).Within one year after the outbreak,the annual hospitalization level of ARI-related diseases among households exposed to SARS-CoV-2 was higher than before the outbreak of COVID-19(increase by 20.54 times,95%CI:5.84?65.86),among which,the direct effect of SARS-CoV-2 exposure increased the annual hospitalization rate of ARI-related diseases in the population by 21.20 times(95%CI:6.65?66.26),and the COVID-19 outbreak indirectly led to a decrease in the annual hospitalization rate of ARI-related diseases in the population by 0.66 times(95%CI:0.40?0.81).The direct impact(6.75 times(95%CI:3.01?15.37)vs.0.29 times(95%CI:0.05?0.73))and indirect impact(0.78 times(95%CI:0.67?0.85)vs.0.40 times(95%CI:0.26?0.52))of household exposure to SARS-CoV-2 on the population's recent hospitalization for all causes are greater than the medium and long-term impact,and the direct impact on the population's recent hospitalization for ARI-related diseases(58.86 times(95%CI:7.57?466.84)vs.1.59 times(95%CI:0.26?8.00))and indirect impact(0.78 times(95%CI:0.38?0.92)vs.0.61 times(95%CI:0.22?0.80))are larger than the medium and long-term impact.4.From January 1,2020 to December 31,2020,the all-cause mortality rate in the household exposed to SARS-CoV-2 was 3.40%(95%CI:2.42?4.37),and the mortality rate from ARI-related diseases was 2.57%(95%CI:1.71?3.16).The all-cause mortality rate in the control group was 0.64%(95%CI:0.34?0.95),and the mortality rate of ARI-related diseases was 0.08%(95%CI:0?0.18).The risk of death for households exposed to SARS-CoV-2 in the first three months of 2020 is 11.97 times(95%CI:4.07?32.14)that of unexposed people.From April to December 2020,there was no significant increase in the risk of all-cause death in the exposed group compared with the control group(0.63 times increase,95%CI:-0.3?2.78).Conclusion Household SARS-CoV-2 exposure has significantly affected the population's outpatient and emergency visits,hospitalization and death.The total impact of household SARS-CoV-2 exposure on the short-term all-cause and ARI-related diseases of the exposed population is more obvious,and the total impact in the medium and long-term is small.The direct impact on the population of all-cause and ARI-related diseases is to increase the incidence of related outpatients,hospitalizations,and deaths in the exposed population,and the direct impact on ARI-related diseases is far greater than all-cause diseases,and the direct impact in the short term is greater than in the medium and long-term.The indirect impact on the population of all-cause and ARI-related diseases is to reduce the population's related outpatient and emergency visits and hospitalizations,and the short-term indirect impact is greater than the medium and long-term.The health hazards of the COVID-19 outbreak to the population cannot be ignored.In order to effectively reduce the hazards caused by the virus,it is necessary to vigorously promote the establishment of a vaccine-induced population immune barrier through vaccination.