Spatial clusters and temporal trends of malignant melanoma mortality in Ecuador

Abstract

Objective: The aim of this study is two fold. First, it describes the temporal trends of malignant melanoma mortality from 2000 to 2016 in Ecuador. Second, it analyzes the spatial clusters of high mortality rates due to malignant melanoma in the country, from 2011 to 2016. Methods: This is an ecological study; we included all death certificates of malignant melanoma from the National Institute of Statistics and Census database in Ecuador from 2000 to 2016. We calculated crude mortality rates and age-standardized mortality rates, all rates are expressed as deaths per 100,000 population. In order to assess the trend of malignant melanoma rates, we obtained average annual percent changes through Joinpoint regression analysis. Spatial scan statistics were used to identify high-risk clusters and the spatial autocorrelation was evaluated through a global Moran index. Results: In Ecuador, between 2000 and 2016, malignant melanoma caused a total of 958 deaths. Crude mortality rates increased significantly (annual percent change = 4.8%; 95% confidence interval: 2.6–7.0), the age-standardized mortality rate also increased (annual percent change: 2.9%; 95% confidence interval: 0.5–5.4). The most likely cluster included 19 cantons and the second most likely cluster included 10 cantons, located in the Highlands region. The Global Moran I index for the study period shows a positive spatial autocorrelation (0.32; p = 0.001). Conclusion: Mortality due to malignant melanoma in Ecuador significantly increased over the 17-year study period; the spatial analysis and spatial autocorrelation indicates the presence of high-risk occurrence clusters in the Highlands region of the country.