陈剑：美国疫情观察（六）：检测不足仍是瓶颈，死亡率接近百分之四

（2020.4.12）

Here are some observations on the COVID-19 metrics in the United States:

1. Latest positive ratios are still high (US 22%, NY 43%)

2. Test adequacy (test:case ratio) and the number of infections per million population are negatively correlated (correlation coefficient -48%), indicating that the more severe the outbreak, the less adequate tests are performed;

3. Test adequacy and mortality are also negatively correlated (correlation coefficient -43%), indicating that the mortality rate is higher in those states where the test is less inadequate;

4. The overall mortality rate in the United States is close to 4% and in Michigan it is close to 6 %;

5. We previously thought that the US entered a plateau period (about 30,000 new cases per day), due to the different peak dates in each state. It does not appear to be accurate. The main reason is probably due to inadequate testing in several severe states (New York, New Jersey, Connecticut and Michigan).

今天关于美国疫情数字的一些观察:

1. 从美国和纽约的最新检测数字来看，阳性比例还是很高（US 22%， NY 43%）

2. 检测充分度（检测：确诊比例）和每百万人口感染数是负相关的（相关系数-48%），说明疫情越严重的地方检测也越不充分；

3. 检测充分度和死亡率也是负相关的（相关系数-43%），说明检测越不充分的地方死亡率也越高；

4. 美国整体死亡率已经接近4%，密歇根州已经接近6%;

5. 我们之前认为美国全国进入平台期（每天新增3万例左右）是由于各州的峰值日期不同，现在看来并不准确。问题主要还是出在检测不够，包括纽约，新泽西，康州，密歇根几个特别严重的地区。