Factors Associated with Delayed Diagnosis among Patients with COVID-19 in Okinawa, Japan

The delayed presentation and diagnosis of COVID-19 can contribute to spread of the disease to others but can also cause severe conditions. This study examined factors associated with delayed diagnosis among patients with COVID-19 in Okinawa, Japan. We used the data from 7125 reported cases of people living in Okinawa prefecture with symptom onset between September 2020 and March 2021. The outcome variable was the number of days from symptom onset to diagnosis. The predictor variables included age, sex, occupation, residential area, presumed infection route, and the day of the week. Cox regression analysis was used to compare the outcome between categories for each predictor variable. The median number of days from onset to diagnosis was 3 days, with an interquartile range of 1 to 5 days. Significantly more time from onset to diagnosis was observed in patients in their 60s vs. those in their 20s (hazard ratio: 0.88; 95% confidence interval: 0.81-0.96); hospitality workers were compared to office workers (0.90; 0.83-0.97), patients with unknown infection routes to those with known infection routes (0.77; 0.70-0.84), and those with symptom onset on Sundays/national holidays to those with symptom onset on weekdays (0.90; 0.85-0.96).