Epidemiology of Patient Record Duplication.

Objectives:  Duplicate patient records can increase costs and medical errors. We assessed the association between demographic factors, comorbidities, health care usage, and duplicate electronic health records.

Methods:  We analyzed the association between duplicate patient records and multiple demographic variables (race, Hispanic ethnicity, sex, and age) as well as the Charlson Comorbidity Index (CCI), number of diagnoses, and number of health care encounters. The study population included 3,018,413 patients seen at a large urban academic medical center with at least one recorded diagnosis. Duplication of patient medical records was determined by using a previously validated enterprise Master Person Index.

Results:  Unknown or missing demographic data, Black race when compared with White race (odds ratio [OR]: 1.35, p < 0.001), Hispanic compared with non-Hispanic ethnicity (OR: 1.48, p < 0.001), older age (OR: 1.01, p < 0.001), and "Other" sex compared with female sex (OR: 4.71, p < 0.001) were associated with higher odds of having a duplicate record. Comorbidities (CCI, OR: 1.10, p < 0.001) and more encounters with the health care system (OR: 1.01, p < 0.001) were also associated with higher odds of having a duplicate record. In contrast, male sex compared with female sex was associated with lower odds of having a duplicate record (OR: 0.88, p < 0.001).

Conclusion:  The odds of duplications in medical records were higher in Black, Hispanic, older, nonmale patients with more health care encounters, more comorbidities, and unknown demographic data. Understanding the epidemiology of duplicate records can help guide prevention and mitigation efforts for high-risk populations. Duplicate records can contribute to disparities in health care outcomes for minority populations.