Estimating completeness of national and subnational death reporting in Brazil: application of record linkage methods

Abstract

Background In Brazil, both the Civil Registry (CR) and Ministry of Health (MoH) Mortality Information System (SIM) are sources of routine mortality data, but neither is 100% complete. Deaths from these two sources can be linked to facilitate estimation of completeness of mortality reporting and measurement of adjusted mortality indicators using generalized linear modeling (GLM). Methods The 2015 and 2016 CR and SIM data were linked using deterministic methods. GLM with covariates of the deceased’s sex, age, state of residence, cause of death and place of death, and municipality-level education decile and population density decile, was used to estimate total deaths and completeness nationally, subnationally and by population sub-group, and to identify the characteristics of unreported deaths. The empirical completeness method and Global Burden of Disease (GBD) 2017 estimates were comparators at the national and state level. Results Completeness was 98% for SIM and 95% for CR. The vast majority of deaths in Brazil were captured by either system and 94% were reported by both sources. For each source, completeness was lowest in the north. SIM completeness was consistently high across all sub-groups while CR completeness was lowest for deaths at younger ages, outside facilities, and in the lowest deciles of municipality education and population density. There was no clear municipality-level relationship in SIM and CR completeness, suggesting minimal dependence between sources. The empirical completeness method model 1 and GBD completeness estimates were each, on average, less than three percentage points different from GLM estimates at the state level. Life expectancy was lowest in the northeast and 7.5 years higher in females than males. Conclusions GLM using socio-economic and demographic covariates is a valuable tool to accurately estimate completeness from linked data sources. Close scrutiny of the quality of variables used to link deaths, targeted identification of unreported deaths in poorer, northern states, and closer coordination of the two systems will help Brazil achieve 100% death reporting completeness. The results also confirm the validity of the empirical completeness method.

Generating age-specific mortality statistics from incomplete death registration data: two applications of the empirical completeness method

“…C-RC study results are themselves subject to limitations which may bias their age-specific accuracy, especially if the assumption of the independence of sources is violated. In the Brazil study, however, the generalised linear models used included several covariates that reduced any bias from source dependency [ 14 ].…”

“…We firstly compare the two approaches using results from a C-RC study in Brazil, because it provides independent and direct source information of mortality indicators and age-specific completeness that do not rely on MLTs [ 14 ]. That C-RC study matched registered deaths to deaths reported in the Ministry of Health (MoH) Mortality Information System (SIM), an independent source.…”

“…In that C-RC study, total deaths, all-age completeness of registration (i.e. the civil registry) and mortality indicators were estimated by state, sex and age using generalised linear modelling with a series of covariates of demographic, geographic and socio-economic factors, as well as cause of death and place of death [ 14 ]. In this study, we compare estimated total deaths, 45 q 15 and 25 q 60 (probability of dying between age 60 and 85 years) of the conventional and equivalent death methods for all 27 states with the results in the C-RC study, as well as age-specific completeness for three states with the lowest levels of all-age completeness (Pará, Amapá and Maranhão).…”

“…C-RC methods, which match individual death data in a death registration (or reporting) system to another data source, can however estimate completeness of death registration for specific age groups and use this to adjust registration data and produce complete life tables [ 3 , 14 ]. Importantly, C-RC studies’ estimates of age-specific completeness of registration (and hence the true age pattern of mortality) do not rely on an assumed age pattern of mortality from a MLT.…”

“…Hence, C-RC studies of mortality registration data are relatively rare. Recent examples of such studies include those conducted in Brazil, Thailand, Vietnam, Brazil, Oman, Kiribati and Bohol, Philippines [14][15][16][17][18][19][20].…”