Characteristics and factors associated with severity of COVID-19 infections in primary care.

Introduction: Primary care service plays a vital role in early clinical assessment of patients with COVID-19 in Malaysia. This study aimed to evaluate the potential risk factors of COVID-19 severity at presentation to primary care facilities in the post-vaccination period.

Method: Clinical records from the Selangkah system of all patients with COVID-19 aged above 18 years seen at COVID-19 assessment centres located in 10 government health clinics in Gombak district, Selangor, from 1 October to 31 December 2021 with complete documentation and outcomes were retrieved. Demographics, comorbidities, clinical features and vaccination statuses and types were retrospectively evaluated. The variables were compared between mild and severe diseases. Univariate and multivariable logistic regressions were used to identify the factors affecting disease severity.

Results: A total of 4406 patients (median age=37 years, men=51.2%) were analysed. Approximately 97.1% of the cases were mild, while 2.9% were severe. Fever, difficulty breathing, lethargy, throat irritation/runny nose, oxygen saturation of <95%, respiratory rate of >20 breaths per minute, CoronaVac vaccination and hypertension were the determinants of severity (P<0.05).

Conclusion: The high proportion (97.1%) of mild cases in this study compared with an earlier report (81.8%) during the pre-vaccination period may suggest the impact of vaccine, as 84.9% of this cohort was fully vaccinated. Our study also demonstrated a significant difference in COVID-19 severity between the vaccine types. The identified clinical features and comorbidities could assist primary care doctors in stratifying patients with COVID-19 judiciously in terms of hospital referral or home quarantine.