Record linkage under suboptimal conditions for data-intensive evaluation of primary care in Rio de Janeiro, Brazil.

BACKGROUND: Linking Brazilian databases demands the development of algorithms and processes to deal with various challenges including the large size of the databases, the low number and poor quality of personal identifiers available to be compared (national security number not mandatory), and some characteristics of Brazilian names that make the linkage process prone to errors. This study aims to describe and evaluate the quality of the processes used to create an individual-linked database for data-intensive research on the impacts on health indicators of the expansion of primary care in Rio de Janeiro City, Brazil. METHODS: We created an individual-level dataset linking social benefits recipients, primary health care, hospital admission and mortality data. The databases were pre-processed, and we adopted a multiple approach strategy combining deterministic and probabilistic record linkage techniques, and an extensive clerical review of the potential matches. Relying on manual review as the gold standard, we estimated the false match (false-positive) proportion of each approach (deterministic, probabilistic, clerical review) and the missed match proportion (false-negative) of the clerical review approach. To assess the sensitivity (recall) to identifying social benefits recipients' deaths, we used their vital status registered on the primary care database as the gold standard. RESULTS: In all linkage processes, the deterministic approach identified most of the matches. However, the proportion of matches identified in each approach varied. The false match proportion was around 1% or less in almost all approaches. The missed match proportion in the clerical review approach of all linkage processes were under 3%. We estimated a recall of 93.6% (95% CI 92.8-94.3) for the linkage between social benefits recipients and mortality data. CONCLUSION: The adoption of a linkage strategy combining pre-processing routines, deterministic, and probabilistic strategies, as well as an extensive clerical review approach minimized linkage errors in the context of suboptimal data quality.

Analysis of the application of a deterministic routine for identifying multiple pregnancies on SINASC, Brazil. / Análise da aplicação de uma rotina determinística para a identificação de gestações múltiplas no Sistema de Informações sobre Nascidos Vivos.

OBJECTIVE: to evaluate the application of a deterministic routine for identifying multiple pregnancies on the Brazilian Live Birth Information System (SINASC). METHODS: SINASC data deduplication and linkage with the mortality database (fetal deaths) for Rio de Janeiro state for the period 2007-2008; we used a deterministic routine, using a key based on SINASC maternal and birth information, complemented by manual review. RESULTS: of the 433,874 SINASC records, 9,036 (2.1%) were classified as multiple pregnancy newborns; after implementing the routine, we reclassified 385 records as twins, and 286 as singletons; accuracy of multiple pregnancy information on the SINASC database was high (sensitivity=95.8%; specificity=99.9%); applying the routine without the manual review process increased sensitivity by 4.2%, with no significant change of specificity. CONCLUSION: despite the accuracy of information regarding multiple pregnancy held on SINASC, we suggest the use of this routine as an option for improving classification of twins.