COVID-19 patients followed in Portuguese Primary Care: a retrospective cohort study based on the national case series.

Background: The pandemic state caused by SARS CoV-2 came to overburden all levels of healthcare, including Primary Care. In Portugal, most patients were followed in ambulatory, monitored by phone calls or face-to-face visits by their General Practitioner.

Objective: The aim was to characterize the pathway of COVID-19 outpatients in Primary Care and establish the risk factors that mostly influences the need for hospitalization or death during the follow-up.

Methods: A retrospective cohort study was established, based on the official Portuguese dataset of the first wave between March 2nd and June 30th 2020. The predictive effects of variables, including age, gender, residency and clinical features, were analysed using Cox regression analysis.

Results: A total of 38,545 patients infected with SARS-CoV-2 was included for analysis (56.3% female), with a median age of 47 years old. There were 4,327 hospitalized patients, 253 in intensive care units and 1,153 deaths. Females present lower risk of hospitalization (HR = 0.78; 95% CI: 0.73-0.82; P < 0.001) and age is associated with higher risk (HR = 7.08; 95% CI: 6.68-7.50; P < 0.001), as well as the presence of at least one comorbidity (HR = 7.03; 95% CI: 6.43-7.69; P < 0.001). Multivariate analysis showed that cardiovascular disease, diabetes, smoking, obesity, chronic kidney disease, cancer, chronic obstructive pulmonary disease, HIV and other immunodeficiencies, transplant or immunosuppression, haematological disorders, neurological disorders and liver disease increased the risk of hospitalization.

Conclusion: Male gender, age and the presence of comorbidities are the main determinants for hospitalization and death. These COVID-19 patients should receive a higher attention when they come to primary care for assistance.