TABLE 2.

Sensitivities and specificities of different diagnostic criteria estimated among patients with invasive pneumococcal disease and healthy controls, respectively

Characteristic of sample tested	Study subsample	Criterion	Patients with IPD			Healthy controls
			No. of subjects	Sensitivity	95% CI	No. of subjects	Specificity	95% CI
Ratio rise in convalescent/acute-phase concentration	All children	>2.0-fold rise	98	0.48	0.38-0.58	97	0.93	0.86-0.97
	All children	>2.7-fold rise	98	0.42	0.32-0.52	97	0.97	0.91-0.99
	Age <2 yr	>2.7-fold rise	46	0.46	0.31-0.61	45	1.00	0.92-1.00
	Age ≥2 yr	>2.7-fold rise	52	0.38	0.25-0.53	52	0.94	0.84-0.99
	Acute-phase serum taken on admission	>2.7-fold rise	48	0.48	0.33-0.63	97	0.97	0.91-0.99
	Acute-phase serum taken after admission	>2.7-fold rise	50	0.36	0.23-0.51	97	0.97	0.91-0.99
	Age <2 yr and acute-phase serum taken on admission	>2.7-fold rise	24	0.50	0.29-0.71	45	1.00	0.92-1.00
Acute-phase concentration alone		>250 ng/ml	98	0.19	0.12-0.29	97	0.96	0.90-0.99
		>290 ng/ml	98	0.18	0.11-0.27	97	0.97	0.91-0.99