Table 1 Results of non-linear regression analysis of ELISA-measured plasma PfHRP2 concentration vs. digital reading, and of interobserver variability assessment for each of four kits

Digital assessment

 Top (reading units)

1867

1796

807.2

1414

 HillSlope

1.408

1.904

7.058

1.453

 EC50 (ng/ml)

63.14

36.25

75.91

66.99

 EC50 (95 % CI)

48.38–82.40

31.69–41.48

49.63–116.1

47.35–94.80

 Goodness of fit (r²)

0.9082

0.9627

0.5661

0.8516

Visual assessment kappa-statistic

 0—no visible band

0.7931

1

0.7785

0.7857

 1—faint line

0.3197

1

0.3262

0.3056

 2—faint band

0.7869

0.7432

0.6019

0.6296

 3—clear band weaker than control

0.7778

0.9187

0.5879

0.6384

 4—band at least as strong as control

1

0.9664

0.5662

0.85

 Combined

0.8602

0.9377

0.5865

0.7198