ABSTRACT
This chapter calls attention to the caveats of EHR data, and although it is one of the shorter chapters in the text, it is perhaps the most important. Despite EHR's great promise for research, investigators must be aware of the many assumptions and limitations implicit and explicit in these data. The chapter begins by framing systemic and structural factors that impact the use and reuse of electronic health record data. This is followed by an exploration into data quality concerns including data accuracy, completeness, and missingness, with accompanying remediation strategies. Finally, the chapter explores the notion of the catchment area of a healthcare system, and how this impacts the representativeness of the patients appearing in the EHR. All perils discussed in this chapter have implications for epidemiological analysis and the resulting inference made from these findings.
