Natural history and clinical course of symptomatic and asymptomatic COVID-19 patients in the Kingdom of Saudi Arabia

Objectives: To analyze symptomatic and asymptomatic COVID-19 patients in Saudi Arabia in terms of initial presentation, risk factors, laboratory findings, clinical outcomes and healthcare utilization. Methods: All laboratory-confirmed reverse transcription-polymerase chain reaction positive COVID-19 patients who had been tested at three governmental hospitals in Saudi Arabia (two in Riyadh and one in Makkah) between March 8 and May 18, 2020 were included. Demographics, COVID-19 variables, clinical characteristics and healthcare utilization variables were extracted and combined, and a descriptive analysis was conducted. Symptomatic and asymptomatic (on presentation) patients' data were compared. Results: Eighty percent of the patients were males (81.4% of symptomatic and 73.2% of asymptomatic patients, P = 0.02). Moreover, 47.6% and 38.4% of symptomatic and asymptomatic patients were aged 40-64 years, respectively. Fever, cough and breathing difficulties were frequent presenting symptoms. Overall, diabetes (16.4%), hypertension (11.7%), chronic respiratory disease (7.1%) were the most frequent comorbidities, with no differences between the two groups. Symptomatic patients had higher C-reactive protein levels (3.55 vs. 0.30 mg/L; P < 0.0001) and lower total lymphocytes (1.41 vs. 1.70; P = 0.02). ICU admission and mortality were 12.1% and 4.1% in symptomatic, compared to 6.0% and 2.9% in asymptomatic patients, respectively. Conclusion: In the studied COVID-19 cohort, symptomatic patients tended to be older, had higher C-reactive protein and more lymphopenia with worse outcome than asymptomatic patients. This granular analysis of COVID-19 cohorts enables identification of at-risk cohorts in future waves, optimizing development of patient pathways and public health interventions.