Background

Multilevel data can be missing at the individual level or at a nested level, such as family, classroom, or program site. Increased knowledge of higher-level missing data is necessary to develop evaluation design and statistical methods to address it.

Methods

Participants included 9,514 individuals participating in 47 youth and family programs nationwide who completed multiple self-report measures before and after program participation. Data were marked as missing or not missing at the item, scale, and wave levels for both individuals and program sites.

Results

Site-level missing data represented a substantial portion of missing data, ranging from 0–46% of missing data at pre-test and 35–71% of missing data at post-test. Youth were the most likely to be missing data, although site-level data did not differ by the age of participants served. In this dataset youth had the most surveys to complete, so their missing data could be due to survey fatigue.

Conclusions

Much of the missing data for individuals can be explained by the site not administering those questions or scales. These results suggest a need for statistical methods that account for site-level missing data, and for research design methods to reduce the prevalence of site-level missing data or reduce its impact. Researchers can generate buy-in with sites during the community collaboration stage, assessing problematic items for revision or removal and need for ongoing site support, particularly at post-test. We recommend that researchers conducting multilevel data report the amount and mechanism of missing data at each level.

中文翻译：

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青年和家庭项目研究中的数据缺失

背景

个人级别或嵌套级别（例如家庭、教室或项目站点）可能缺少多级数据。增加对更高级别缺失数据的了解对于开发评估设计和统计方法来解决它是必要的。

方法

参与者包括参加全国 47 个青年和家庭项目的 9,514 人，他们在项目参与前后完成了多项自我报告措施。个人和项目站点的数据在项目、规模和波级别上被标记为缺失或不缺失。

结果

站点级别的缺失数据占缺失数据的很大一部分，在测试前缺失数据的 0-46% 和测试后缺失数据的 35-71% 不等。青年人最有可能丢失数据，尽管站点级别的数据并没有因所服务的参与者的年龄而不同。在这个数据集中，年轻人完成的调查最多，因此他们丢失的数据可能是由于调查疲劳。

结论

个人的大部分缺失数据都可以通过没有管理这些问题或量表的网站来解释。这些结果表明需要统计方法来解释站点级缺失数据，并需要研究设计方法来减少站点级缺失数据的普遍性或减少其影响。研究人员可以在社区协作阶段产生对站点的支持，评估有问题的项目以进行修改或删除，以及对持续站点支持的需求，特别是在测试后。我们建议进行多级数据的研究人员报告每个级别缺失数据的数量和机制。