Table 1

Study characteristics

StudyDesignCountryPopulation sizeAge
(% female)
COVID-19 confirmation methodFollow-up time (days)Follow-up timepointFollow-up mode
 Hopkins et al58Cross sectionalUK434Median (range): 40 (19–77)75PCR or serological assays (26.3%)6 monthsFirst surveyElectronic survey
 Klein et al47Cohort (P)Israel103Mean (SD): 35 (12)38PCR (RT-PCR)6 monthsOnsetPhone interview
 Petersen et al32Cohort (P)Faroe Islands180Mean (SD; range): 39.9 (19.4; 0–93)54PCR (RT-PCR)Mean (SD) 125 (17)OnsetPhone interview
 Stavem et al68CrosssectionalNorway451Mean (SD): 49.8 (15.2)56PCR (RT-PCR)Median (range): 117 (41–193)OnsetOutpatient visit and survey
Non-hospitalised and hospitalised
 Parente-Arias et al55Cohort (P)Spain151Mean (range): 55.2 (18–88)65PCR (RT-PCR)Mean (SD): 100.5 (3.3)AdmissionPhone interview
 Venturelli et al60Cohort (P)Italy767Mean (SD): 63 (13.6)33PCR (RT-PCR) (94%); serology (5%)
Clinician diagnosis (1.2%)
Median (IQR): 105 (84–127)OnsetOutpatient visit
 Anastasio et al41Cohort (P)Italy379Median (IQR; range): 56 (49–63; 20–80)54PCR (RT-PCR)Median (IQR): 135 (102–175)OnsetOutpatient visit
 Einvik et al67CrosssectionalNorway538Mean (SD)
57.7 (14.2) (hospital)
49.6 (15.3)
42 (hospital)
PCR (RT-PCR)Mean (SD):
112 (30) (hospital)
118 (27)
OnsetOutpatient visit and survey
 Jacobson et al40Cohort (P)USA118Mean (SD): 43.3 (14.4)47PCR (RT-PCR)Mean (SD): 119.3 (33)DiagnosisOutpatient visit
 Logue et al35Cohort (P)USA177
21 (C)
Mean (SD): 48 (15.2)57Lab confirmedMedian (range): 169 (31–300)OnsetElectronic survey
 Mazza et al70Cohort (P)Italy226Mean (SD; range): 58 (12.8; 26–87)34PCR (RT-PCR)Mean (SD): 90 (13.4)DischargePhone interview
 Rass et al50Cohort (P)Austria135Median (IQR; range) 56 (48–68; 19–87)39PCR (RT-PCR)Median (IQR): 102 (91–110)OnsetOutpatient visit
 Sonnweber et al48Cohort (P)Austria145Mean (SD): 57 (14)43PCR (RT-PCR)Mean (SD): 103 (21)DiagnosisOutpatient visit
 Alharthy et al54Cohort (P)Saudi Arabia127Mean (SD): 47 (11.38)21PCR (RT-PCR)4 monthsDischargeOutpatient visit
 Arnold et al37Cohort (P)UK110Median (IQR): 60 (46–73)38PCR or radiological diagnosisMedian (IQR): 90 (80–97)OnsetOutpatient visit
 Baricich et al63CrosssectionalItaly204Mean (SD): 57.9 (12.8)40NRMean (SD): 124.7 (17.5)DischargeOutpatient visit
 Bellan et al42Cohort (P)Italy238Median (IQR): 61 (50–71)40PCR (RT-PCR) (97.5%); bronchoalveolar lavage (0.4%); serology/radiological (2.1%)3–4 monthsDischargeOutpatient visit
 Blanco et al38Cohort (P)Spain100Mean (SD)
TLco<80: 54.98 (10.72)
TLco>80: 54.75 (9.83)
36PCR (RT-PCR)Median (IQR): 104 (89.25–126.75)OnsetOutpatient visit
 Doyle et al66Cohort (P)UK129Mean:
62 (Cambridge)
56 (London)
31 (Cambridge)
27 (London)
PCR (RT-PCR)Median (range): 113 (96–138)DischargeNR
 Garrigues et al65Cohort (P)France120Mean (SD): 63.2 (15.7)38PCR (RT-PCR)Mean (SD): 110.9 (11.1)AdmissionPhone interview
 Gherlone et al57Cohort (P and R)Italy122Median (IQR): 62.5 (53.9–74.1)25PCR (RT-PCR)Median (IQR): 104 (95–132)DischargeOutpatient visit
 Han et al46Cohort (P)China114Mean (SD; range): 54 (12; 24–82)30PCR (RT-PCR)Mean (SD): 175 (20)OnsetOutpatient visit
 Huang et al56Cohort (P and R)China1733Median (IQR): 57 (47–65)48Lab confirmedMedian (IQR): 186 (175–199)OnsetOutpatient visit
 Zhang et al31Cohort (R/S)China527Median (IQR; range): 42.5 (32–54; 0–91)44NR6 monthsDischargeOutpatient visit
 Lerum et al61Cohort (P)Norway103Median (25th–75th percentile): 59 (49–72)48Nasopharyngeal swab3 monthsDischargeOutpatient visit
 Méndez et al49Cohort (R/S)Spain215Median (IQR): 55 (47–66)40Lab confirmedMedian (IQR): 87 (62–109)DischargeOutpatient visit
 Nguyen et al33Cohort (P)France125Median (IQR; range): 36 (27–48; 16–85)55PCR (RT-PCR)Mean (SD): 221.7 (10.9)OnsetPhone interview
 Nugent et al36Cohort (R/S)USA182
1430 (C)
Median (IQR): 67.4 (58.3–80.1)47PCR (RT-PCR)Median (IQR): 92.9 (52.5–127.7)DischargeOutpatient visit
 Qin et al53Cohort (P)China647Mean (SD): 58 (15)56PCR (RT-PCR)90DischargeOutpatient visit
 Qu et al34Cohort (P)China540Median (IQR): 47.50 (37–57)50PCR (RT-PCR)3 monthsDischargeElectronic survey
 Sibila et al51Cohort (P)Spain172Mean (SD): 56.1 (19.8)43NRMean (SD): 101.5 (19.9)DischargeOutpatient visit
 Simani et al59Cohort (P)Iran120Mean (SD): 54.62 (16.94)33PCR or radiological diagnosis6 monthsDischargeOutpatient visit
 Suárez-Robles et al64CrosssectionalSpain134Mean (SD): 58.53 (18.53)54PCR (RT-PCR)90DischargePhone survey
 Sykes et al39Cohort (P)UK134Median (range): 58 (25–89)34PCR (RT-PCR)Median (range): 113 (46–167)DischargeOutpatient visit
 Taboada et al62Cross sectionalSpain183Mean (SD): 65.9 (14.1)40PCR (RT-PCR)6 monthsDischargeUnstructured interview
 Weng et al45Cohort (P)China11745.3%≥60 years44Viral nucleic acid test90DischargePhone interview
 Xiong et al44Cohort (P)China538
184 (C)
Median (IQR; range): 52 (41–62; 22–79)55PCR (RT-PCR)Median (IQR; range): 97.0
(95.0–102.0; 91–116)
DischargePhone interview
 Xu et al43Case–controlChina103
27 (C)
Median (IQR)
M/M: 56 (45–63)
S/C: 61 (55–68)
M/M: 58.8
S/C: 53.6
NR3 monthsDischargeOutpatient visit
 Zhang et al52Cohort (P)China310Median (IQR): 51 (31.8–61)50PCR (RT-PCR)Median (IQR): 92.0 (90–100)DischargeOutpatient visit
  • C, control group; M/M, mild/moderate; NR, not reported; P, prospective; PCR, polymerase chain reaction; R, retrospective; RT, Reverse transcription; S/C, severe/critical; TLco, carbon monoxide transfer factor.