Globulin and albumin to globulin ratio precisely diagnose periprosthetic joint infection and determine the timing of second-stage reimplantation

Table 3 Diagnostic value of the markers for PJI

Markers	AUC (95% CI)	Youden index	Optimal cutoff value	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	P^a	P^b
CRP (mg/L)	0.848 (0.788–0.907)	0.686	8.15	83.5	85.0	77.6	89.3
ESR (mm/h)	0.865 (0.813–0.918)	0.616	15.70	88.6	75.4	70	91.5
PLT (× 10⁹/L)	0.727 (0.657–0.796)	0.359	241.5	65.8	70.1	57.8	76.7	0.009	0.002
PCT (%)	0.706 (0.633–0.779)	0.321	0.236	68.4	63.8	54.0	76.4	0.003	0.0005
PMR	0.718 (0.648–0.788)	0.353	25.31	62.0	73.2	59.0	75.6	0.006	0.001
GLB	0.784 (0.719–0.849)	0.476	30.65	80.0	71.7	75.9	72.4	0.157	0.049
AGR	0.826 (0.770–0.880)	0.398	1.165	67.1	86.7	67.1	80.3	0.594	0.308
PLT/AGR	0.844 (0.791–0.898)	0.585	188.9	86.1	76.4	86.1	72.4	0.937	0.586

PJI, periprosthetic joint infection; CI, confidence interval; AUC, area under the curve; PPV, positive predictive value; NPV, negative predictive value; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; PLT, platelet count; MPV, mean platelet volume; PCT, plateletcrit; PMR, PLT to MPV ratio; GLB, globulin; AGR, albumin to globulin ratio
^aCompared with the AUC of CRP
^bCompared with the AUC of ESR

ISSN: 1749-799X