Table 1.

Concordance of Diagnoses in Physician Billing Claims and Patient Medical Records

Number of Physician Billing Claims	Number of Visits in Patient Medical Records
	Laryngitis	Common Cold	Influenza	Unspecified Acute URI	Pharyngitis	Otitis Media	Sinusitis	Acute Bronchitis	Pneumonia	No Respiratory Infection	Total
Laryngitis	63	0	0	0	0	0	0	0	0	0	63
Common cold	1	66	1	0	2	0	0	0	0	4	74
Influenza	2	1	85	7	1	1	6	6	5	15	129
Unspecified acute URI	0	1	1	154	3	0	2	4	0	22	187
Pharyngitis	2	1	1	2	93	1	1	0	0	6	107
Otitis media	0	0	0	5	1	116	1	0	1	8	132
Sinusitis	1	1	1	0	0	0	138	3	0	9	153
Acute bronchitis	6	3	1	11	3	3	15	173	9	15	239
Pneumonia	0	0	0	0	0	0	2	2	81	4	89
No respiratory infection	4	29	5	28	12	28	19	28	11	2,189	2,353
Total	79	102	95	207	115	149	184	216	107	2,272	3,526
Uncorrected sensitivity*	0.80	0.65	0.89	0.74	0.81	0.78	0.75	0.80	0.76

Note: Shaded numbers indicate concordance.

^*The uncorrected sensitivity estimate is inflated due to the purposeful 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).

URI, upper respiratory infection.