The early impact of the COVID-19 pandemic on patients with severe mental illness: an interrupted time series study in South-East England

Background: Deterioration in general population mental health since the start of the COVID-19 pandemic has been reported, but the impact of the pandemic on people with severe mental illness (SMI) has received less attention. Aims: Understand the impact of the early stages of the pandemic on the patients with SMI, in terms of provision of mental health care and patient outcomes. Method: We examined records of 34,446 patients with SMI in Oxford Health Foundation Trust between March 2016 and July 2020. We used interrupted time series analysis to estimate the immediate and subsequent changes in weekly rates of the use of community mental health services, hospitalisation, and patient outcomes (as measured by Health of the Nation Outcome Scales, or HoNOS, scores) during the weeks of lockdown between 23rd March and 3rd July, 2020. Results: Mean total HoNOS scores for all patients deteriorated in the weeks subsequent to lockdown (0.060 per week; 95%CI: 0.033, 0.087). Scores for patients with a history of psychosis deteriorated immediately (0.63; 95% CI: 0.26, 1.0). There was an immediate decrease in weekly referrals to community and outpatient services (-196; 95%CI: -300, -91) and no immediate change in weekly inpatient admissions (-4.2; 95%CI: -9.9, 1.5) or weekly total contacts (-26; 95%CI: -475, 423). Conclusions: Patients with SMI were negatively impacted during the early stages of the COVID-19 pandemic. Patients with a history of psychosis experienced distinct and immediate impacts. During the same period, referrals to community and outpatient services fell with no consequent impact on inpatient admissions.