Excess All-Cause Mortality in China After Ending the Zero COVID Policy

Abstract

ImportanceIn China, the implementation of stringent mitigation measures kept COVID-19 incidence and excess mortality low during the first years of the pandemic. However, China’s decision to end its dynamic zero COVID policy (a proactive strategy that deploys mass testing and strict quarantine measures to stamp out any outbreak before it can spread) in December 2022 resulted in a surge in COVID-19 incidence and hospitalizations. Despite worldwide attention given to this event, the actual impact of this sudden shift in policy on population mortality has not been empirically estimated.ObjectiveTo assess the association of the sudden shift in China’s dynamic zero COVID policy with mortality using empirical and syndromic surveillance data.Design, Setting, and ParticipantsThis cohort study analyzed published obituary data from 3 universities in China (2 in Beijing and 1 in Heilongjiang) and search engine data from the Baidu index (BI; weighted frequency of unique searches for a given keyword relative to the total search volume on the Baidu search engine) in each region of China from January 1, 2016, to January 31, 2023. Using an interrupted time-series design, analyses estimated the relative change in mortality among individuals 30 years and older in the universities and the change in BI for mortality-related terms in each region of China from December 2022 to January 2023. Analysis revealed a strong correlation between Baidu searches for mortality-related keywords and actual mortality burden. Using this correlation, the relative increase in mortality in Beijing and Heilongjiang was extrapolated to the rest of China, and region-specific excess mortality was calculated by multiplying the proportional increase in mortality by the number of expected deaths. Data analysis was performed from February 10, 2023, to March 5, 2023.ExposureThe end to the dynamic zero COVID policy in December 2022 in China.Main Outcomes and MeasuresMonthly all-cause mortality by region.ResultsAn estimated 1.87 million (95% CI, 0.71 million-4.43 million; 1.33 per 1000 population) excess deaths occurred among individuals 30 years and older in China during the first 2 months after the end of the zero COVID policy. Excess deaths predominantly occurred among older individuals and were observed across all provinces in mainland China except Tibet.Conclusions and RelevanceIn this cohort study of the population in China, the sudden lifting of the zero COVID policy was associated with significant increases in all-cause mortality. These findings provide valuable insights for policy makers and public health experts and are important for understanding how the sudden propagation of COVID-19 across a population may be associated with population mortality.

Analyses of academician cohorts generate biased pandemic excess death estimates

“…Besides data from academicians, other cohorts related to universities have been used for excess death calculations. Xiao et al 32 used obituaries from 3 Chinese universities.…”

“…Amish and Mennonites. 34,35 Using information from online searches for funeral services and related terms 32,33 expands further the data collection, but the representativeness of collected samples is difficult to gauge. Moreover, online searches are probably affected by both real and perceived crises and it is difficult to separate the two.…”

“…Besides data from academicians, other cohorts related to universities have been used for excess death calculations. Xiao et al 32 used obituaries from 3 Chinese universities. Populations of university professors and staff are also select groups with higher than average socioeconomic status.…”

“…Worse, missingness may be uneven over time, with heightened interest in obituaries (and thus more obituaries written and captured) during a crisis or perceived crisis – as during active pandemic waves. Using obituaries from a wider population 32,33 makes the sample less selective, but missingness (and uneven missingness over time) may become even more prominent. Reliability may be higher in sharply defined populations with focused, exclusive venues for publishing obituaries, e.g.…”

Spatiotemporal distribution of migraine in China: analyses based on baidu index

“…Google Trends is a popular tool for tracking search interests worldwide, but it is not accessible in Mainland China. As of March 2023, China had surpassed 1 billion internet users, with over 90% of web surfers in China preferring Baidu, which dominates China’s search engine market, akin to Google in Western countries [ 9 ]. However, to the best of our knowledge, no study has used Baidu Index (BI) data to explore the spatiotemporal distribution of migraine in China.…”