Table 3

Diagnostic performances of GPR, Fibroscan, APRI and Fib-4 in the training set (The Gambia) and in validation sets (France and Senegal)*

 The Gambia (n=135)France (n=63)†Senegal (n=80)‡
F0–1 vs F2–4F0–2 vs F3–4F0–3 vs F4F0–1 vs F2–4F0–2 vs F3–4F0–3 vs F4F0–1 vs F2–4F0–2 vs F3–4
GPR
AUROC (95% CI)0.80 (0.72 to 0.88)0.81 (0.72 to 0.89)0.83 (0.72 to 0.94)0.72 (0.59 to 0.85)0.76 (0.62 to 0.90)0.87 (0.76 to 0.98)0.73 (0.59 to 0.86)0.93 (0.87 to 0.99)
 Cut-off values§0.320.320.560.320.320.560.320.32
 Sensitivity/specificity (%)83/6986/6485/7673/4980/44100/6850/8389/80
 Correctly classified (%)7471776052707381
 PPV/NPV (%)63/8653/9139/9756/6731/8817/10059/7836/98
 Positive/negative LR2.7/0.32.4/0.23.5/0.21.4/0.61.4/0.53.1/0.03.0/0.64.5/0.1
Fibroscan
AUROC (95% CI)0.85 (0.78 to 0.91)0.89 (0.82 to 0.95)0.98 (0.97 to 1.00)0.61 (0.48 to 0.74)0.71 (0.53 to 0.89)
 Cut-off values§7.98.29.57.98.2
 Sensitivity/specificity (%)81/8193/82100/8981/3089/41
 Correctly classified (%)8185904646
 PPV/NPV (%)73/8770/9661/10036/7616/97
 Positive/negative LR4.2/0.25.0/0.18.9/01.1/0.61.5/0.3
APRI
AUROC (95% CI)0.66 (0.57 to 0.76)0.68 (0.58 to 0.78)0.70 (0.55 to 0.86)0.77 (0.65 to 0.89)0.83 (0.72 to 0.93)0.78 (0.57 to 0.98)0.62 (0.48 to 0.76)0.89 (0.80 to 0.98)
 Cut-off values¶0.51.51.02.00.51.51.02.00.51.5
 Sensitivity/specificity (%)64/649/9840/8725/9977/6720/9150/7825/9242/700/96
 Correctly classified (%)64628088715776876165
 PPV/NPV (%)54/7371/6235/8975/8768/7667/5613/9617/9541/720/67
 Positive/negative LR1.8/0.63.8/0.93.0/0.728/0.82.3/0.42.2/0.92.3/0.63.0/0.81.4/0.80.0/1.0
 Indeterminate results (%)4213401431
Fib-4
AUROC (95% CI)0.66 (0.56 to 0.76)0.68 (0.57 to 0.78)0.73 (0.58 to 0.87)0.75 (0.62 to 0.88)0.86 (0.77 to 0.95)0.83 (0.69 to 0.98)0.57 (0.42 to 0.71)0.71 (0.53 to 0.89)
 Cut-off values**1.453.251.453.251.453.25
 Sensitivity/specificity (%)63/6814/9873/7327/9644/830/100
 Correctly classified (%)667173797989
 PPV/NPV (%)48/7975/7046/9067/8125/92NA/89
 Positive/negative LR1.9/0.56.3/0.92.7/0.46.4/0.82.6/0.71.0/NA
 Indeterminate results (%)362920
Comparison of AUROC
 GPR and Fibroscanp=0.2p=0.02p=0.003N/AN/AN/Ap=0.2p=0.04
 GPR and APRIp<0.001p=0.002p=0.03p=0.4p=0.2p=0.3p=0.05P=0.3
 GPR and Fib-4p=0.003p=0.01p=0.03p=0.6p=0.1p=0.6p=0.04P=0.02
 Fibroscan and APRIp<0.001p<0.001p<0.001N/AN/AN/Ap=0.9p=0.1
 Fibroscan and Fib-4p<0.001p<0.001p<0.001N/AN/AN/Ap=0.6p=0.9
 APRI and Fib-4p=0.9p=0.9p=0.6p=0.6p=0.6p=0.6p=0.4p=0.03
  • *The cut-off values for GGT were 58 in The Gambia, 45 in men and 30 in women in France, and 73 in men and 43 in women in Senegal. The cut-off values for AST were 46 in men and 25 in women in The Gambia, 45 in men and 40 in women in France, and 59 in men and 36 in women in Senegal.

  • †In France, Fibroscan was not performed.

  • ‡In Senegal, there was no patient with cirrhosis (F4).

  • §Cut-off values for GPR and Fibroscan were determined to maximise the sum of sensitivity and specificity in the training data set.

  • ¶Predetermined cut-off values of APRI were used (0.5 and 1.5 to distinguish significant fibrosis, and 1.0 and 2.0 to distinguish cirrhosis).

  • **Predetermined cut-off values of Fib-4 were used (1.45 and 3.25 to distinguish extensive fibrosis).

  • APRI, AST-to-platelet ratio index AST; aspartate transaminase; AUROC, area under the receiver operating characteristic curve; GGT, gamma-glutamyl transpeptidase; GPR, gamma-glutamyl transpeptidase to platelet ratio; LR, likelihood ratio; NA, not applicable; NPV, negative predictive value; PPV, positive predictive value.