Table 1.

Advantages and limitations of EMR cohorts linked to DNA biobanks

Advantages

Limitations

Identify large cohorts for most phenotypes, including many rare diseases; Efficient creation of cohorts compared with prospective studies; Extraction of relevant controls (e.g., subjects referred for RHC found not to have PH); Able to examine multiple phenotypes within one cohort (cost-effective); Multisite EMRs can be combined to generate larger cohorts; EMRs can be linked to external data sources (Medicare, state registries, etc.); Genetic association discovery and replication can be performed in single or multisite cohorts

Phenotype specificity depends on accuracy of case definition; Temporality can be challenging to ascertain (e.g., between risk factors and development of disease); No truly “healthy” control subjects when using hemodynamic diagnosis of PH; Available data limited to clinically relevant testing; Unable to prespecify timing of longitudinal follow-up; Merging genotyping platforms can be challenging; Specific to deidentified cohorts:  subjects lost to follow-up cannot be contacted;  cannot perform family studies;  imaging/hemodynamic strips may not be available for review

^NoteEMR: electronic medical record; PH: pulmonary hypertension; RHC: right heart catheterization.