Abstract

Objective

This paper investigates the relationship between the positivity rate and numbers of deaths and intensive care unit (ICU) patients. In addition, it explores the use of the positivity rate as an indicator for the spread of COVID-19.

Methods

We used COVID-19 datasets for eight countries – Canada, USA, UK, Italy, Belgium, Ireland, Colombia and South Africa – and considered two correlation cases. The first case considers the correlation of the number of confirmed cases with each of deaths and ICU patients. The second case considers the correlation of the positivity rate with each of deaths and ICU patients. When obtaining the correlation, we considered different lagging periods between the date of confirming a case and the date of its ICU admittance or death. We compared the obtained correlation coefficient values for each of the two considered cases to explore whether the positivity rate is a better indicator for the spread of the disease than confirmed cases. For each of the eight considered countries, we obtained the daily reproduction number using each of confirmed cases and positivity rate. The two obtained sets of reproduction number values for each country were statistically compared to investigate whether they are significantly different.

Results

When considering the daily positivity rate instead of the daily number of confirmed cases, the maximum correlation with deaths is increased by 349.9% for the USA (the country with the highest increase) and 4.5% for the UK (the country with the lowest increase), with an average increase of 60.8% considering the eight countries. Considering the daily positivity rate instead of the daily number of confirmed cases caused the maximum correlation with the number of ICU patients to be increased by 74.7% for the USA (the country with the highest increase) and 2.2% for the UK (the country with the lowest increase), with an average increase of 25% over the considered countries. The results for the daily reproduction number obtained using the positivity rate are statistically different from those obtained using daily confirmed cases.

Conclusion

The results indicate that positivity rate is a better indicator for the spread of the disease than the number of confirmed cases. Therefore, it is highly advised to use measures based on the positivity rate when indicating the spread of the disease and considering responses accordingly because these measures consider the daily number of tests and confirmed cases.

中文翻译：

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阳性率：COVID-19 传播的指标

摘要

客观的

本文研究了阳性率与死亡人数和重症监护病房 (ICU) 患者人数之间的关系。此外，它还探讨了使用阳性率作为 COVID-19 传播的指标。

方法

我们使用了八个国家（加拿大、美国、英国、意大利、比利时、爱尔兰、哥伦比亚和南非）的 COVID-19 数据集，并考虑了两个相关案例。第一个案例考虑了确诊病例数与每个死亡人数和ICU患者的相关性。第二个案例考虑了阳性率与每个死亡和ICU患者的相关性。在获得相关性时，我们考虑了确诊日期与其入住ICU或死亡日期之间的不同滞后期。我们比较了两个考虑的病例中每一个获得的相关系数值，以探讨阳性率是否比确诊病例更好地指示疾病的传播。对于八个考虑的国家中的每一个，我们使用每个确诊病例和阳性率获得了每日再现数。将获得的每个国家的两组再生数值进行统计比较，以研究它们是否有显着差异。

结果

当考虑每日阳性率而不是每日确诊病例数时，美国（增幅最高的国家）与死亡的最大相关性增加了 349.9%，英国（增幅最低的国家）增加了 4.5% ，考虑到八个国家，平均增长 60.8%。考虑到每日阳性率而不是每日确诊病例数导致美国（增幅最大的国家）与 ICU 患者数量的最大相关性增加了 74.7%，英国（增幅最大的国家）增加了 2.2%。增幅最低），比所考虑的国家平均增幅为 25%。使用阳性率获得的每日再现数的结果与使用每日确诊病例获得的结果有统计学差异。

结论

结果表明，阳性率是比确诊病例数更好的疾病传播指标。因此，强烈建议在指示疾病传播并相应考虑应对措施时使用基于阳性率的措施，因为这些措施考虑了每日检测和确诊病例的数量。