关键是后者，对照组数据16,120 and 16,130是什么？ 研究选择比较的对照组人数是10倍，而不是发病10倍吧？
这1612 例心肌炎和 1613 例心包炎，文章里始终称这部分为case patients；而对照组controls ，文里从来没提到或称他们为patients（心肌/心包炎病患）。
We matched those cases（特指1612 例心肌炎和 1613 例心包炎）to 16,120 and 16,130 control subjects,（对照组） respectively. The characteristics of the cases and their matched controls are shown in Table 1. For both myocarditis and pericarditis, key differences between cases and controls included a higher proportion among cases of a history of myocarditis or pericarditis, of history of SARS-CoV-2 infection, and receipt of an mRNA Covid-19 vaccine. The mean age and proportion of women were lower among patients with myocarditis than those with pericarditis.
见这表，CASES与对照组比较，https://www.nature.com/articles/s41467-022-31401-5/tables/1
关键看表格里最后3行。。这1612 例心肌炎和 1613 心包炎患者中有其病史并过去5年内曾住过院的，有的是感染过新冠的，他们之中打过/没打疫苗大约各50%。
