Table 2. Summary Characteristics of the Data Sources^a.

	Studies with access to individual-level data		Studies without access to individual-level data		Medical claims databasesc: matched COVID-19–negative controls
	Data on health status before COVID-19	No data on health status before COVID-19b	COVID-19–negative control group	No control group
Age, mean (SD), y	53.7 (20.6)	48.6 (18.6)	35.8 (12.8)	47.2 (14.9)	52.6 (21.7)
Sex, %
Male	50.0	53.8	45.8	48.0	44.7
Female	50.0	46.2	54.2	52.0	55.3
Countries with input datad	Austria,19 Iran,15 Italy,18 the Netherlands,16 Russia,17,20 Switzerland14	Faroe Islands,24 Germany,25,26 Sweden,27,28 US29	China,30 Denmark,31 Norway,32 UK,10,33,34 US35	Australia,36 Belgium,37 China,38 France,39,40,41,42 India,43,44 Iran,45 Israel,46,47 Italy,48,49,50,51,52,53 the Netherlands,54 Norway,55 Saudi Arabia,56 South Africa,57 Spain,58,59,60,61,62 Switzerland,63 Turkey,64 UK,11,65,66,67,68,69 US9,70,71,72	US73,74
Hospitalizede	10 198	328	8516	9915	250 928
Not hospitalized	1355	551	34 375	586	846 046

^a Stratified by method of controlling for non–COVID-attributable symptoms. Details of each study appear in eTable 1 in Supplement 1.

^b Data were adjusted by the ratio of excess risk of Long COVID symptoms to total symptoms from the 6 collaborating cohort studies that reported these types of data.

^c Based on a range of demographic and comorbid conditions, 2 US administrative databases were used to match controls to cases with a positive polymerase chain reaction test for COVID-19. The difference between the cases and controls was used as the proportion of symptoms attributable to COVID-19.

^d All extracted data used in the analyses appear in Supplement 3.

^e Received care in general hospital ward or intensive care unit.