Patterns of utilisation of specialist care after SARS-Cov-2 infection: a retrospective cohort study.

Abstract

To explore the pattern of health services utilisation of people who had had a documented SARS-Cov-2 infection. Retrospective cohort study. The Italian province of Reggio Emilia. 36 036 subjects who recovered from SARS-CoV-2 infection during the period September 2020-May 2021. These were matched for age, sex and Charlson Index with an equal number of subjects never found positive at the SARS-Cov-2 swab test over the study period. Hospital admissions for all medical conditions and for respiratory or cardiovascular conditions only; access to emergency room (for any cause); outpatient specialist visits (pneumology, cardiology, neurology, endocrinology, gastroenterology, rheumatology, dermatology, mental health) and overall cost of care. Within a median follow-up time of 152 days (range 1-180), previous exposure to SARS-Cov-2 infection was always associated with higher probability of needing access to hospital or ambulatory care, except for dermatology, mental health and gastroenterology specialist visits. Post-COVID subjects with Charlson Index≥1 were hospitalised more frequently for heart disease and for non-surgical reasons than subjects with Charlson index=0, whereas the opposite occurred for hospitalisations for respiratory diseases and pneumology visits. A previous SARS-CoV-2 infection was associated with 27% higher cost of care compared with people never infected. The difference in cost was more evident among those with Charlson Index<u>></u>1. Subjects who had anti-SARS-CoV-2 vaccination had lower probability of falling in the highest cost quartile. Our findings reflect the burden of post-COVID sequelae, providing some specific insight on their impact on the extra-use of health services according to patients' characteristics and vaccination status. Vaccination is associated with lower cost of care following SARS-CoV-2 infection, highlighting the favourable impact of vaccines on the use of health services even when they do not prevent infection.