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Table 5 Prevalence of disease on microscopy (upper part of the table) and qPCR (lower part of the table), N (%, 95% CI) *McNemar to compare sensitivity and specificity present ratio of proportions. All ratios presented as XN-30 relative to HRP-2 and pLDH respectively

From: The XN-30 hematology analyzer for rapid sensitive detection of malaria: a diagnostic accuracy study

XN-30 and RDT (HRP-2 and pLDH) versus corrected microscopy results (n = 837)
  XN-30 HRP-2 Test ratio p value pLDH Test ratio p value
Pos Neg Pos Neg 95% CI   Pos Neg 95% CI  
Microscopy positive 234 3 231 6    208 29   
Microscopy negative 21 579 136 464    9 591   
Sensitivity 98.7%   97.5%   0.99 (0.97–1.01) p = .45 87.8%   0.89 (0.85–0.93) p < .0001
Specificity 96.5%   77.3%   6.47 (4.31–9.73) p < .0001 98.5%   0.43 (0.23–0.81) p = .012
PPV 91.8%   62.9%     95.9%    
NPV 99.5%   98.7%     95.3%    
XN-30 and RDT (HRP-2 and pLDH) versus qPCR results (n = 837)
  XN-30 HRP-2 Test ratio p value pLDH Test ratio p value
Pos Neg Pos Neg 95% CI   Pos Neg 95% CI  
qPCR > 0.05 p/μL 253 104 308 49    215 142   
qPCR < 0.05 p/μL 2 478 59 421    2 478   
Sensitivity 70.9%   86.3%   1.22 (1.15–1.29) < 0.0001 60.2%   0.85 (0.80–0.89) < .0001
Specificity 99.6%   87.7%   0.04 (0.01–0.14) < 0.0001 99.6%   1.0 (0.07–13.8) 1.0
PPV 99.2%   83.9%     99.1%    
NPV 82.1%   89.6%     77.1%    
  1. Pos positive, neg negative, HRP2 histidine-rich protein 2, pLDH pan-Plasmodium lactate dehydrogenase, qPCR qualitative polymerase chain reaction, PPV positive predictive value, NPV negative predictive value