Siwei Zhang

Supplementary Figure 1 shows the geographic distribution and population coverage of 782 counties included in final analyses, along with the population density of China.

Supplementary Figure 2 was a scatter diagram of the age-standardized esophageal cancer mortality rate in 1973-1975 and the absolute change in mortality rates from 1973–1975 to 2015–2017.

Supplementary Table 1 shows three major measures of data quality of cancer registries included in this study.

Supplementary Table 3 shows the difference in age-standardized esophageal cancer mortality rates between 90th and 10th percentile counties by province and time period.

Supplementary Table 2 shows the change in esophageal cancer mortality rates in counties with and without screening programs.

Background:Geographic variability in esophageal cancer has been reported in China, but data are lacking at the local level. We aimed to investigate changes in disparities in esophageal cancer–related mortality among Chinese counties and whether county-level socioeconomic status was associated with this variation.Methods:We used data from a nationwide survey and population-based cancer registries to calculate esophageal cancer–related mortality rates for 782 Chinese counties for the periods of 1973–1975 and 2015–2017. We performed hotspot analysis to identify spatial clusters. We used a multivariable negative binomial regression model to estimate the associations between county-level socioeconomic factors and mortality.Results:From 1973–1975 to 2015–2017, the age-standardized esophageal cancer–related mortality rate decreased from 27 to 8 per 100,000 person-years in China. By county, 577 (74%) of 782 counties experienced decreasing mortality. Geographic disparities in mortality substantially narrowed, with the gap in mortality rates between 90th and 10th percentile counties decreasing from 55 per 100,000 person-years in 1973–1975 to 16 in 2015–2017. However, clusters of elevated rates persisted across north-central China. Rurality [adjusted mortality rate ratio (MRR) 1.15; 95% confidence interval (CI), 1.10–1.21], per capita gross domestic product (adjusted MRR, 0.95; 95% CI, 0.91–0.98), and percentage of people with a high-school diploma (adjusted MRR, 0.86; 95% CI, 0.84–0.87) in a county were significantly associated esophageal cancer–related mortality rates.Conclusions:China has made substantial progress in reducing esophageal cancer–related mortality and disparities, but the intercounty differences remain large.Impact:Continued efforts are needed to address the geographical and socioeconomic disparities in esophageal cancer.

Supplementary Table 2 shows the change in esophageal cancer mortality rates in counties with and without screening programs.

Supplementary Table 1 shows three major measures of data quality of cancer registries included in this study.

Background: Geographic variability in esophageal cancer has been reported in China, but data are lacking at the local level. We aimed to investigate changes in disparities in esophageal cancer mortality among Chinese counties and whether county-level socioeconomic status was associated with this variation. Methods: We used data from a nationwide survey and population-based cancer registries to calculate esophageal cancer mortality rates for 782 Chinese counties for the periods of 1973-1975 and 2015-2017. We performed hotspot analysis to identify spatial clusters. We used a multivariable negative binomial regression model to estimate the associations between county-level socioeconomic factors and mortality. Results: From 1973-1975 to 2015-2017, the age-standardized esophageal cancer mortality rate decreased from 27 to 8 per 100,000 person-years in China. By county, 577 (74%) of 782 counties experienced decreasing mortality. Geographic disparities in mortality substantially narrowed, with the gap in mortality rates between 90th and 10th percentile counties decreasing from 55 per 100,000 person-years in 1973-1975 to 16 in 2015-2017. However, clusters of elevated rates persisted across north-central China. Rurality (adjusted mortality rate ratio [MRR] 1.15, 95% CI 1.10-1.21), per capita gross domestic product (adjusted MRR 0.95, 0.91-0.98), and percentage of people with a high school diploma (adjusted MRR 0.86, 0.84-0.87) in a county were significantly associated esophageal cancer mortality rates. Conclusions: China has made substantial progress in reducing esophageal cancer mortality and disparities, but the intercounty differences remain large. Impact: Continued efforts are needed to address the geographical and socioeconomic disparities in esophageal cancer.

Supplementary Table 2 shows the change in esophageal cancer mortality rates in counties with and without screening programs.