Table 3

Matched samples from clinic versus laboratory

WONDFOMENARINIFORTRESSBIOPANDA iBIOSURE/MOLIGIC I
Matched LFIA results between clinic and laboratory, n7647486844
Days since symptom onset, median (IQR)37 (32–47)41 (33–47)59 (49–69)44 (35–54)40 (32–49)
Sensitivity (%) against reference assays (95% CI)
Sensitivity vs PCR confirmed
 Clinic (fingerprick)21.1 (12.5 to 31.9)91.5 (79.6 to 97.6)79.2 (65.0 to 89.5)64.7 (52.2 to 75.9)56.8 (41.0 to 71.7)
 Laboratory (serum)73.7 (62.3 to 83.1)93.6 (82.5 to 98.7)87.5 (74.8 to 95.3)75.0 (63.0 to 84.7)79.5 (64.7 to 90.2)
p<0.001p=1.000p=0.219p=0.167p=0.006
 Kappa0.13 (0.03 to 0.24)0.54 (0.08 to 1.00)0.56 (0.25 to 0.86)0.34 (0.11 to 0.58)0.41 (0.16 to 0.65)
Sensitivity (%) vs S-ELISA and/or hybrid DABA
 Clinic (finger prick)21.9 (13.1 to 33.1)95.6 (84.9 to 99.5)84.4 (70.5 to 93.5)67.7 (54.9 to 78.8)60.0 (43.3 to 75.1)
 Laboratory (serum)76.7 (65.4 to 85.8)95.6 (84.9 to 99.5)93.3 (81.7 to 98.6)76.9 (64.8 to 86.5)85.0 (70.2 to 94.3)
p<0.001p=1.000p=0.219p=0.238p=0.002
  • Sample is individuals with only matched clinic and laboratory results for the specific LFIAs. 95% CI, 95% binomial exact CI. P value compares clinic and laboratory sensitivity using McNemar's χ2 test. Kappa is the inter-rater agreement between the self-test result and the serum test result.

  • hybrid DABA, hybrid spike protein receptor binding domain double antigen bridging assay; S-ELISA, spike protein ELISA.