Information Quality and Epidemiological Surveillance Governance in Brazil: Territorial Disparities and Evidence from Severe Acute Respiratory Syndrome Records (2016–2025)

Epidemiological surveillance depends on reliable information, yet incomplete, inconsistent, and documentarily noncompliant records may compromise public health decisions and obscure territorial inequalities. This study aimed to assess the longitudinal quality of severe acute respiratory syndrome surveillance records in Brazil from 2016 to 2025, examining their implications for information reliability and public governance. A retrospective observational study analyzed 4,577,627 publicly available records from Sinan Web Influenza and SIVEP-Gripe. Informative completeness, documentary conformance, internal consistency, and notification timeliness were evaluated using version-specific eligibility criteria, 20 consistency rules, territorial comparisons, and fixed-effects regression models. Overall informative completeness was 88.91%, declining to 87.32% in 2022 before recovering to 92.98% in 2025. Educational attainment and chest radiography accounted for 37.91% of information gaps. Approximately 711,323 inconsistencies and 1,361,211 documentary nonconformities were identified across their respective evaluation opportunities. Notification delays peaked in 2021, while substantial regional disparities persisted. Regression models revealed no statistically significant associations between notification volume and quality indicators. These findings demonstrate that formal data completion does not necessarily ensure analytical usefulness or documentary coherence, highlighting limitations in surveillance information reliability. Although secondary data and documentary changes restrict causal interpretation, the multidimensional approach provides evidence for differentiated quality monitoring. Strengthening surveillance governance requires greater attention to informational usability, territorial disparities, and systematic validation to support transparent and equitable public health decision-making.