Table 1 Variation Assessment Table for Data Abstraction
Variation Type | Definition | Potential Implication | Example of Assessment Method |
|---|---|---|---|
Institutional variation | Variation in practice patterns, outcomes, and patient sociodemographic characteristics | Inconsistent phenotype definition; unbalanced concept distribution | • Compare clinical guideline, protocol, and definition • Calculate the number of eligible patients divided by screening population • Calculate the ratio of the proportion of the persons with the disease over the proportion with the exposure |
EHR system variation | Variation in data type and format caused by different EHR system infrastructure | Inconsistent data type; different data collection processes | • Compare data type, document structure, and metadata • Conduct a semi-structured interview to obtain information about the context of use |
Documentation variation | Variation in reporting schemes during the processes of generating clinical narratives | Noisy data | • Compare the cosine similarity between two documents represented by vectors • Conduct a sub-language analysis to assess syntactic variation |
Process variation | Variation in data collection and corpus annotation process | Poor data reliability, validity, and reproducibility | • Calculate the degree of agreement among abstractors • Conduct a semi-structured interview to obtain information about the context of use |