Table 3.

Diagnostic test statistics of individual AAPA to discriminate eRA versus SpA: sensitivity, specificity and likelihood ratios.

AAPA	Sensitivity	95% CI	Specificity	95% CI	+LR	95% CI	−LR	95% CI
Ac-lysine	32.50	24.2–41.7	98.00	89.4–99.9	16.25	2.3–115.1	0.69	0.6–0.8
Ac-lysine.inv	42.00	32.2–52.3	82.76	64.2–94.2	2.44	1.1–5.6	0.70	0.6–0.9
Ac-ornithine	39.17	30.4–48.5	96.00	86.3–99.5	9.79	2.5–38.8	0.63	0.5–0.7

AAPA, anti-acetylated peptide antibodies; CI, confidence interval; eRA, early RA; +LR, positive likelihood ratio; –LR, negative likelihood ratio; SpA, spondyloarthritis.