613 Underrepresentation of Minority Patients in an Observational Cohort Study

Abstract

Background

Underrepresentation of ethnic minorities in lupus clinical trials has been identified as an important disparity. We aimed to compare our longitudinal observational lupus cohort participants to our entire lupus clinic population to see if similar disparities exist.

Methods

All patients seen at our academic centre were entered into a custom database from 1990 until 2015. Diagnoses, demographics, and disease manifestations were recorded. In 2015 this was supplanted by an electronic health record (EHR). In 2002, our centre began enrolling in a longitudinal observational research cohort; all patients meeting 1997 ACR criteria for SLE were eligible. Participation requires formal written consent. All patients with a diagnosis of SLE were abstracted from the database and EHR; only those seen after 2002, when cohort enrolment began, were included in this analysis.

Demographics including ethnicity, age at onset, and disease duration and clinical manifestations of SLE were compared between Cohort (Co) and non-Cohort (non-Co) patients.

Results

1236 patients were identified; 404 patients were excluded as there were no clinic visits after 2002. Of the remaining 832 patients, 349 (42%) were enrolled in the research cohort, 483 (58%) were not. Age at diagnosis was similar; (Co = 34±14 years vs. non-Co = 36±14 years, p=0.11), while disease duration at last follow-up was longer in Co patients (Co = 17±11 years vs. non-Co = 13±10 years, p<0.001). The ethnic distribution differed between the two groups. Co: White, n= 245 (70.2%); Indigenous n= 58 (16.6%); Asian n = 33 (9.5%); Other n= 13 (3.7%) vs non-Co: White, n= 252 (52.2%); Indigenous n= 162 (33.5%); Asian n = 57 (11.8%); Other n= 12 (2.5%); p<0.001. (figure 1A). Sex distribution was similar: (Co n=29 (8.3%); non-Co n=55 (11.4%), p=0.146). The proportion of patients who had died was higher in non-cohort patients, (Co n= 60 (17.2%); non-Co n= 119 (24.6%), p=0.01); and non-cohort patients were more likely to have died before the age of 50 (Co n=14 (23.3%); non-Co n=44 (37.0%), p=0.07) (figure 1A). Clinical manifestations are shown in figure 1B. While minor mucocutaneous manifestations were more frequent in Co patients, (Malar rash: Co n= 210 (60%); non-Co n= 193 (40%), p<0.001; Photosensitivity: Co n=152 (44%); non-Co n= 146 (30%), p<0.001); Mucosal Ulcerations: Co n= 197 (56%); non-Co n= 129 (28%), p<0.001) there was no difference in renal (Co n= 256 (53%); non-Co n=182 (52%), p=0.81), or neurologic involvement (Co n= 46 (10%); non-Co n= 50 (13%), p=0.21).

Conclusions

In this single academic centre study, ethnic minority patients were underrepresented in the observational research cohort, mirroring what is described in clinical trial participation. While disease severity (represented by renal and neurologic involvement) did not appear to differ, the higher death rate, and death rate at an early age among nonparticipants suggests underrepresentation of high-risk vulnerable patients in our observational cohort. Observational cohorts represent an important source of real-world data; without representative participation we are lacking data on those lupus patients with the highest prevalence and worst outcomes. Better engagement of ethnic minority and vulnerable patients in research will be key to improve understanding of lupus.

Abstract 613 Figure 1

A. Demographic differences between Cohort Participants and Non-Participants. B. Differences in Clinical Manifestations between Cohort Participants and Non-Participants

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