Recovering records on cancer of the larynx from anonymous health information databases

Abstract

Objective: To develop a linkage algorithm to match anonymous death records of cancer of the larynx (ICD-10 C32X), retrieved from the Mortality Information System (SIM) and the Hospital Information System of the Brazilian Unified National Health System (SIH-SUS) in Brazil. Methodology: Death records containing ICD-10 C32X codes were retrieved from SIM and SIH-SUS, limited to individuals aged 30 years and over, between 2002 and 2012, in the state of São Paulo. The databases were linked using a unique key identifier developed with sociodemographic data shared by both systems. Linkage performance was ascertained by applying the same procedure to similar non-anonymous databases. True pairs were those having the same identification variables. Results: A total of 14,311 eligible death records were found. Most records, 10,674 (74.6%), were exclusive to SIM. Only 1,853 (12.9%) deaths were registered in both systems, representing true pairs. A total of 1,784 (12.5%) cases of laryngeal cancer in the SIH-SUS database were tracked in SIM with different causes of death. The linkage failed to match 167 (9.4%) records due to inconsistencies in the key identifier. Conclusion: The authors found that linking anonymous data from mortality and hospital records is a feasible measure to track missing records and may improve cancer statistics.

Sex-Specific Mortality from Asbestos-Related Diseases, Lung and Ovarian Cancer in Municipalities with High Asbestos Consumption, Brazil, 2000–2017

“…The strategy for creating the databases was described elsewhere for mesothelioma/pleural cancer and for laryngeal cancer [ 22 , 23 ]. Briefly, in each HIS database, death records of interest were selected based on ICD-10 codes.…”

“…One of the objectives was to capture all the asbestos-related death records in Health Information System (HISs), linking databases and constituting a single database. The linking process proved to be adequate [ 22 , 23 ] and allowed us to estimate that the number of ARD-T deaths in the Brazilian Mortality Information System increased by an average of 33% [ 24 ].…”

Analysis of Mortality from Asbestos-Related Diseases in Brazil Using Multiple Health Information Systems, 1996–2017

“…Detailed information can be found elsewhere [ 19 ]. This strategy was previously tested and presented feasibility and good performance for mesothelioma [ 20 ] and cancer of the larynx [ 21 ].…”