Table 3.

2 × 2 table depicting results for Algorithm B^a, optimal for use when medical record review is not possible^a

		MRI Result (Gold standard)
Algorithm B		AVN (+)	AVN (−)	Total
	Algorithm (+) for AVN	48	11	59
	Algorithm (−) for AVN	35	8106	8141
	Total	83	8117	8200

^aAlgorithm B: Defined as ≥2 ICD-9 codes for AVN at least 7 days apart within 6 months of MRI; Sensitivity = 57.8% (95% CI 46.5–68.6), PPV = 81.4% (95% CI 69.1–90.3).