Table 3.

Sensitivity, Specificity, and Positive and Negative Predictive Values of the RAMQ Physician Billing Claims Database for Identifying All Acute Respiratory Infections Combined, by Study Physician

Study Physician	RAMQ Physician Billing Claims
	Number of Claims with a Diagnosis of Acute RI	Total Number of Claims	Prevalence per 1,000 (95% CI)	Sensitivity* (95% CI)	Specificity* (95% CI)	PPV† (95% CI)	NPV‡ (95% CI)
1	1,324	16,264	81.4 (77.1, 85.6)	0.85 (0.78, 0.91)	1.00 (0.99, 1.00)	0.96 (0.94, 0.98)	0.99 (0.98, 1.00)
2	2,041	18,319	111.4 (106.9, 116.0)	0.39 (0.33, 0.44)	0.98 (0.98, 0.99)	0.89 (0.86, 0.92)	0.82 (0.78, 0.86)
3	522	4,815	108.4 (99.6, 117.2)	0.42 (0.35, 0.49)	1.00 (0.99, 1.00)	0.97 (0.95, 1.00)	0.84 (0.80, 0.88)
4	356	9,614	37.0 (33.3, 40.8)	0.34 (0.24, 0.47)	1.00 (1.00, 1.00)	0.98 (0.96, 1.00)	0.93 (0.90, 0.96)
5	163	5,553	29.4 (24.9, 33.8)	0.37 (0.22, 0.56)	1.00 (0.99, 1.00)	0.89 (0.81, 0.97)	0.95 (0.92, 0.99)
6	159	6,905	23.0 (19.5, 26.6)	0.57 (0.16, 0.90)	0.99 (0.99, 1.00)	0.77 (0.64, 0.90)	0.99 (0.98, 1.00)
7	752	6,754	111.3 (103.8, 118.8)	0.72 (0.45, 0.89)	0.98 (0.96, 1.00)	0.82 (0.66, 0.98)	0.96 (0.92, 1.00)
8	94	4,815	19.5 (15.6, 23.4)	1.00 (1.00, 1.00)	0.99 (0.99, 1.00)	0.70 (0.53, 0.87)	1.00 (1.00, 1.00)
9	365	18,319	19.9 (17.9, 21.9)	0.19 (0.06, 0.47)	1.00 (0.99, 1.00)	0.97 (0.95, 1.00)	0.92 (0.84, 1.00)

^*Adjusted for over-sampling of respiratory infections relative to other diagnoses (Begg and Greenes 1983; Irwig et al. 1994).

^†Positive predictive value.

^‡Negative predictive value.

RI, respiratory infection.