TABLE 3

Summary of the accuracy (AFE) and precision (RMSE and NRMSE) of predicting K_i values for reversible cytochrome P450 inhibition from values of IC₅₀/2 when [S] ≈ K_m

Inhibition Type	n	Ratio of Observed versus Predicted K_i				Correlation coefficient (r)	AFE^{^a}	RMSE^{^b}	NRMSE^{^c}
Inhibition Type	n	Mean	Range	n < 0.5	n > 2.0	Correlation coefficient (r)	AFE^{^a}	RMSE^{^b}	NRMSE^{^c}
									%
Mixed	217	1.13	0.481–2.95	1	9	0.926	1.07	74.2	3.90
Competitive	108	1.19	0.335–3.41	1	9	0.985	1.10	35.8	2.57
Noncompetitive	13	1.90	1.26–2.79	0	6	0.994	1.85	79.2	17.2
Uncompetitive	5	1.35	0.725–2.55	0	1	0.951	1.24	3.85	33.5
Mixed, competitive, and uncompetitive	330	1.15	0.335–3.41	2	19	0.941	1.08	63.5	3.34
Total	343	1.18	0.335–3.41	2	25	0.940	1.10	64.2	3.38

↵^a See eq. 4.
↵^b See eq. 5.
↵^c See eq. 6.