Knight Matthew J, Yu Yuan, Chen Jiacheng, O'Brien Sheila F, Buckeridge David L, Charlton Carmen, Russell W Alton
Department of Epidemiology, Biostatistics and Occupational Health, School of Population and Global Health, McGill University, Montreal, Canada.
Canadian Blood Services, Ottawa, Canada.
BMC Public Health. 2025 Jun 3;25(1):2057. doi: 10.1186/s12889-025-22975-y.
Serological testing was a key component of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) surveillance. Social distancing interventions, resource limitations, and the need for timely data led to serosurveillance studies using a range of recruitment strategies, which likely influenced study representativeness. Characterizing representativeness in surveillance is crucial to identify gaps in sampling coverage and to assess health inequities.
We retrospectively analyzed three pre-existing longitudinal cohorts, two convenience samples using residual blood, and one de novo probabilistic survey conducted in Canada between April 2020 - November 2023. We calculated study specimen counts by age, sex, urbanicity, race/ethnicity, and neighborhood deprivation quintiles. We derived a 'representation ratio' as a simple metric to assess generalizability to a target population and various sociodemographic strata.
The six studies included 1,327,142 specimens. When stratifying by age group and sex, 67% of racialized minority subgroups were moderately underrepresented (representation ratio < 0.75). Representation was generally higher for older Canadians, urban neighborhoods, and neighborhoods with low material deprivation. Rural representation was highest in a study that used outpatient laboratory blood specimens. Racialized minority representation was highest in a de novo probabilistic survey cohort and an open longitudinal cohort recruited from an online polling panel.
While no study had adequate representation of all subgroups, less traditional recruitment strategies were more representative of some population dimensions. Understanding demographic representativeness and barriers to recruitment are important considerations when designing population health surveillance studies.
血清学检测是严重急性呼吸综合征冠状病毒2（SARS-CoV-2）监测的关键组成部分。社交距离干预措施、资源限制以及对及时数据的需求导致血清学监测研究采用了一系列招募策略，这可能影响了研究的代表性。在监测中描述代表性对于识别抽样覆盖范围的差距和评估健康不平等至关重要。
我们回顾性分析了三个现有的纵向队列、两个使用剩余血液的便利样本以及2020年4月至2023年11月在加拿大进行的一项全新概率调查。我们按年龄、性别、城市化程度、种族/族裔以及邻里贫困五分位数计算了研究样本数量。我们得出了一个“代表性比率”作为一个简单指标，以评估对目标人群和各个社会人口阶层的可推广性。
这六项研究包括1327142个样本。按年龄组和性别分层时，67%的少数族裔亚组代表性中度不足（代表性比率<0.75）。加拿大老年人、城市社区以及物质匮乏程度低的社区的代表性通常更高。在一项使用门诊实验室血液样本的研究中，农村地区的代表性最高。在一项全新概率调查队列和一个从在线投票小组招募的开放纵向队列中，少数族裔的代表性最高。
虽然没有一项研究能充分代表所有亚组，但较少传统的招募策略在某些人群维度上更具代表性。在设计人群健康监测研究时，了解人口代表性和招募障碍是重要的考虑因素。
