Discrepancies between preliminary and final COVID-19 mortality data—the case of Serbia

PURPOSE: Since the start of the COVID-19 pandemic, countries have scrambled to set up data collection and dissemination pipelines for various online datasets. This study aims to evaluate the reliability of the preliminary COVID-19 mortality data from Serbia, which has been included in major COVID-19 databases and utilized for research purposes worldwide. METHODS: Discrepancies between the preliminary mortality data and the final mortality data in Serbia were analyzed. The preliminary data were reported through an emergency-necessitated system, while the final data were generated by the regular vital statistics pipeline. We identified databases that include these data and conducted a literature review of articles that utilized them. RESULTS: The number of deaths due to COVID-19 in Serbia, as reported preliminarily, does not align with the final death toll, which is more than three times higher. Our literature review identified at least 86 studies that were impacted by these problematic data. CONCLUSIONS: We strongly advise researchers to disregard the preliminary COVID-19 mortality data from Serbia due to the significant discrepancies with the final data. We recommend validating any preliminary data using excess mortality if all-cause mortality data are available.