BACKGROUND
Age misreporting affects population estimates at older ages. In Brazil, every citizen must be registered and show an identity document to vaccinate against COVID-19. This requirement to present proof of age provides a unique opportunity for measuring the oldest-old population using novel administrative data.

OBJECTIVE
To offer critically assessed estimates of the Brazilian population aged 80 and older based on data from the vaccination registration system (VRS). To uncover discrepancies between the number of vaccinated oldest-old people and the projections used to estimate target populations for COVID-19 vaccination.

METHODS
We calculate data quality indicators based on data from the VRS – namely, 100+/80+ and 90+/80+ population proportions, sex ratios, and the Myers blended index – and compare them to those based on data on target populations from Brazilian censuses and demographic projections, and from Sweden – a country with high-quality data. We also estimate vaccination coverage ratios using population projections adjusted to excess deaths as the denominators.

RESULTS
Requiring documentation reduces age heaping, age exaggeration, and sex ratios marginally. However, it cannot solve the problem of the misreporting of birth dates due to the absence of long-standing birth registration systems in Brazil, particularly in the northern and central regions. In addition, we find a mismatch between the projected populations and numbers of vaccinated people across regions.

CONCLUSIONS
Despite improvements in data quality in Brazil, we are still not confident about the accuracy of age reporting among the oldest old in the less advantaged Brazilian regions. The postponement of the 2020 census reduced the ability of authorities to define the target populations for vaccinations against COVID-19 and other diseases.



中文翻译：

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巴西 COVID-19 疫苗接种数据库中最年长者的年龄报告：我们可以从中学到什么？（作者：Cássio M. Turra、Fernando Fernandes、Júlia Almeida Calazans、Marília R. Nepomuceno）

背景
年龄误报会影响老年人的人口估计。在巴西，每个公民都必须进行登记并出示身份证件才能接种 COVID-19 疫苗。这种出示年龄证明的要求为使用新的行政数据来衡量最年长的老年人口提供了独特的机会。

目标
根据疫苗接种登记系统 (VRS) 的数据，对 80 岁及以上的巴西人口进行严格评估估计。发现接种疫苗的最年长老年人的数量与用于估计 COVID-19 疫苗接种目标人群的预测之间的差异。

方法
我们根据 VRS 的数据计算数据质量指标——即 100+/80+ 和 90+/80+ 人口比例、性别比例和 Myers 混合指数——并将它们与基于巴西目标人群数据的指标进行比较人口普查和人口预测，以及来自瑞典——一个拥有高质量数据的国家。我们还使用根据超额死亡人数调整后的人口预测作为分母来估算疫苗接种覆盖率。

结果
要求提供文件可略微减少年龄堆积、年龄夸大和性别比例。但是，它无法解决由于巴西缺乏长期存在的出生登记系统而导致的出生日期误报问题，尤其是在北部和中部地区。此外，我们发现预测人口与各地区接种疫苗的人数之间存在不匹配。

结论
尽管巴西的数据质量有所提高，但我们仍然对巴西贫困地区最年长者年龄报告的准确性没有信心。2020 年人口普查的推迟削弱了当局确定 COVID-19 和其他疾病疫苗接种目标人群的能力。