Table 2.

Sensitivity, Specificity, and Positive and Negative Predictive Values of the RAMQ Physician Billing Claims for Identifying Episodes of Acute Respiratory Infection

	RAMQ Physician Billing Claims
	Prevalence per 1,000 (95% CI)	Sensitivity* (95% CI)	Specificity* (95% CI)	PPV† (95% CI)	NPV‡ (95% CI)
All respiratory infections	67.3 (65.6, 69.0)	0.49 (0.45, 0.53)	0.99 (0.99, 1.00)	0.93 (0.91, 0.94)	0.93 (0.92, 0.94)
All likely viral respiratory infections	16.4 (15.6, 17.3)	0.30 (0.26, 0.34)	1.00 (1.00, 1.00)	0.84 (0.81, 0.88)	0.97 (0.96, 0.97)
Laryngitis/tracheitis	1.2 (0.9, 1.4)	0.20 (0.13, 0.30)	1.00 (1.00, 1.00)	1.00 (1.00, 1.00)	1.00 (0.99, 1.00)
Common cold	1.4 (1.2, 1.7)	0.11 (0.08, 0.15)	1.00 (1.00, 1.00)	0.89 (0.82, 0.96)	0.99 (0.99, 0.99)
Influenza	3.6 (3.2, 4.0)	0.45 (0.30, 0.60)	1.00 (1.00, 1.00)	0.66 (0.58, 0.74)	1.00 (1.00, 1.00)
Unspecified acute URI	10.2 (9.6, 10.9)	0.35 (0.29, 0.42)	1.00 (1.00, 1.00)	0.82 (0.77, 0.88)	0.98 (0.98, 0.99)
All potentially bacterial respiratory infections	50.9 (49.4, 52.3)	0.51 (0.47, 0.56)	0.99 (0.99, 0.99)	0.89 (0.87, 0.92)	0.95 (0.95, 0.96)
Pharyngitis/tonsillitis	5.3 (4.9, 5.8)	0.42 (0.32, 0.53)	1.00 (1.00, 1.00)	0.87 (0.81, 0.93)	0.99 (0.99, 1.00)
Otitis media	8.6 (7.9, 9.2)	0.44 (0.35, 0.53)	1.00 (1.00, 1.00)	0.88 (0.82, 0.93)	0.99 (0.99, 0.99)
Sinusitis	12.5 (11.7, 13.2)	0.46 (0.38, 0.53)	1.00 (1.00, 1.00)	0.90 (0.85, 0.95)	0.99 (0.98, 0.99)
Acute bronchitis	19.5 (18.6, 20.4)	0.52 (0.46, 0.59)	0.99 (0.99, 0.99)	0.72 (0.67, 0.78)	0.99 (0.98, 0.99)
Pneumonia	5.0 (4.5, 5.5)	0.38 (0.28, 0.47)	1.00 (1.00, 1.00)	0.91 (0.85, 0.97)	0.99 (0.99, 1.00)

^*Adjusted for over-sampling of physician billing claims with a diagnosis of acute respiratory infection relative to claims without such a diagnosis (Begg and Greenes 1983; Irwig et al. 1994).

^†Positive predictive value.

^‡Negative predictive value.

URI, upper respiratory infection.