COVID-19 was a highly infectious emerging disease that had caused a global pandemic.127 The rapid development of the epidemic had exposed the deficiencies in epidemic prevention and control, public health systems, and health care systems of various countries. In some areas, the unequal allocation of medical resources directly led to the delay of patient medical visits and treatment.128
The results of this research showed that the 1st time interval of COVID-19 patients in China was 0 days to 7.52 days, with an estimated value of 3.38 ± 1.55 days, and it was 4.22 ± 1.13 days in Hubei Province and 3.10 ± 1.57 days in non-Hubei provinces. Overseas articles did not involve the time data. The 1st time interval was approximately 1 day longer for COVID-19 patients in Hubei than in non-Hubei areas, whereas the time interval between Wuhan and the rest of Hubei province was relatively similar. This indicated that people in Hubei province had poorer access to health care than other provinces during the outbreak, which had further contributed to the spread of COVID-19 there.
The lack of public awareness of COVID-19 at the beginning of the epidemic, coupled with the fact that most SARS-CoV-2 infected individuals have mild symptoms and the early clinical manifestations of the disease are difficult to distinguish from the common cold, might lead infected individuals to ignore the initial mild symptoms and not pay a timely medical visit. As shown in Fig. 5B, the cordon sanitaire policies implemented from January 23 in Wuhan had strengthened people's attention to COVID-19, and the 1st time interval had been significantly shortened after these cordon sanitaire policies.28 Therefore, timely disclosure of the outbreak and strong preventive and control measures can help raise the awareness of the public.
At the end of January, China implemented the highest level of public health emergency response policies, including quarantine and medical observation for people with an exposure history, case tracing, and screening of close contacts. An article from Shenyang showed that the 1st time interval of patients with an exposure history was shorter than that of those without an exposure history, which was related to these policies.49 Nevertheless, the outbreak of COVID-19 caused a certain degree of social panic, and some suspected patients were afraid of paying a medical visit and handled by themselves through home isolation, which was also a reason leading to the delay of patients’ medical visits and treatment.129, 130 Therefore, during the critical period of epidemic prevention and control, national and local authorities should disclose information in an understandable, timely, transparent and coordinated manner to reduce public panic.131 At the same time, the authorities should strengthen epidemiological investigation, health education, public awareness of medical visits, to urge the patients to pay a medical visit in time.
The 2nd time interval of COVID-19 patients in China was 1 day to 15 days, with an estimated value of 8.35 ± 6.83 days, and it was 12.94 ± 7.43 days in Hubei Province, and 4.17 ± 1.45 days in non-Hubei provinces. The 2nd time interval outside China was 3 days to 8 days, with an estimated value of 4.89 ± 0.89 days. If the regional disparities in the 2nd time interval of COVID-19 patients between China and outside China might be influenced by lifestyle, health systems, and patient treatment,23 then the more obvious differences among multiple regions in China were more likely due to the variances in the supply and demand status of medical resources. The mean of the 2nd time interval in Hubei provinces was obviously longer and the standard deviation was strongly bigger than those non-Hubei provinces of China may indicate that Hubei Province had not only the longest 2nd time interval but also a huge difference in system composition compared with other regions. Figure 5B showed that there was a slight difference in the 1st time interval of patients between Wuhan and non-Hubei provinces, while Fig. 5C showed that the 2nd time interval of patients in Wuhan was significantly longer than that in non-Hubei provinces, and the trend of increasing over time in Fig. 5C could be considered consequently caused by medical overwhelmed in Wuhan with the rapid accumulation of cases.77, 78 Therefore, the length of the 2nd time interval, to some extent, reflected the inadequacy of medical resources in Wuhan during the health emergency. However, as a provincial capital city, the number of tertiary hospitals in Wuhan ranked ahead in China,132 and the proportion of medical staffs (10.19 health technical personnel per thousand, 3.69 licensed physicians per thousand, 5.07 registered nurses per thousand) were much higher than national average level, in which corresponding numbers were 7.26, 2.77 and 3.18.132, 133 If the outbreak is out of control at the initial stage, the shortage of medical resources in a specific period cannot be avoided even in an area with relatively sufficient self-resource reserves and supplements mobilized from other areas.
Of the 107 articles included, 6 articles compared the 1st time interval, and 8 articles compared the 2nd time interval in COVID-19 patients with various disease severities. The results showed that both time intervals were longer in patients with severe disease than in patients with mild disease and common patients. Meta-analysis comparing the length of the 2nd time interval between common patients and severe patients revealed that delayed hospitalization may be an influential factor in the exacerbation of the patient's condition. Although one research from Wuhan reported a shorter the 1st time interval in critically ill patients than in the common patients, this may be related to the fact that the average age of critically ill patients (69yrs old) is higher than that of the common patients (43yrs old),106 and numerous researches have confirmed the strong correlation between age and severity of disease in patients with COVID-19.6 Some research indicated that delayed treatment would also affect virus shedding time,74 resulting in a higher risk of infection among close contacts, easy spread, and the occurrence of cluster outbreaks, which was not conducive to the national epidemic prevention and control.
Advantages and limitations
This research analyzed whether COVID-19 patients receive treatment in time by summarizing the 1st and 2nd time intervals from the 109 articles. In terms of advantages, our research demonstrated the supply and demand status of medical resources in the early stage of the epidemic by comparing the differences in the 1st time interval and the 2nd time interval of patients in different regions and with various disease severities, to analyze whether there is an increase in case fatality rate caused by insufficient medical resources and provide a reference for national or regional medical resource allocation, personnel scheduling, and prevention and control policy decisions.
The research had several limitations. Firstly, only seven articles outside China were included in this research, which may have caused some bias. Secondly, the estimation of time intervals may affect the accuracy of the research results due to the sample size weighting method and the conversion method of median to estimate the mean, as well as missing data in some articles.