Changes in emergency department utilization in vulnerable populations after COVID-19 shelter in place orders

Purpose To compare emergency department (ED) utilization and admission rates for patients with a history of mental health (MH), substance use disorder (SUD) and social determinants of health (SDOH) before and after implementing COVID-19’s shelter-in-place (SIP) orders. Methods This was a retrospective, multicenter study leveraging electronic medical record data from 20 EDs across a large Midwest integrated healthcare system from 5/2/2019 to 12/31/2019 (pre-SIP) and from 5/2/2020 to 12/31/2020 (post-SIP). Diagnoses were documented in the patient’s medical records. Poisson and logistic regression models were used to evaluate ED utilization and admission rate changes. Results 871,020 total ED encounters from 487,028 unique patients were captured. 2,572 (0.53%) patients had a documented Z code for SDOH. Patients with previously diagnosed MH or SUDs were more likely to seek ED care after the SIP orders were implemented (RR: 1.20, 95% CI: 1.18 – 1.22, p<0.001), as were patients with SDOH (RR: 2.37, 95% CI: 2.19 – 2.55, p<0.001). Patients with both previously diagnosed MH or SUD and a documented SDOH had even higher ED utilization (RR: 3.31, 95% CI: 2.83 – 3.88, p<0.001) than those with either condition alone. Patients with MH and SUDs (OR: 0.89, 95% CI: 0.86 – 0.92, p<0.001) or SDOH (OR: 0.67, 95% CI: 0.54, 0.83, p<0.001) were less likely to be admitted post-SIP orders while patients with a history of diseases of physiologic systems were more likely to be admitted. Conclusions Vulnerable populations with a history of MH, SUD, and SDOH experienced increased ED utilization but a lower rate of hospital admissions after the implementation of SIP orders. The findings highlight the importance of addressing these needs to mitigate the impact of public health crises on these populations. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Cleveland Clinic IRB approved as exempt research. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors. * MH : Mental health SUD : Substance use disorder SDOH : Social determinant of health ED : Emergency department SIP : Shelter in place