Table 3. Eigenvalues (λ) and loadings for the oblimin-rotated components identified in the principal component analysis (PCA) of the Spearman's rank correlation matrix of MICs to 15 drugs from the NARMS study in 2004 (n₂₀₀₄ = 2097), 2008 (n₂₀₀₈ = 1292), and 2012 (n₂₀₁₂ = 1376).

Variables with loadings > 0.4 were used to interpret the component, and the density of the induced subgraphs containing the variables with loading > 0.4 for each component are provided in ${\overline{m}}_{\lambda }$. The ${\overline{m}}_{\lambda }$ of components consisting of a single variable were undefined (N/D). Resistance results for azithromycin (AZI) was not available in 2004 and 2008, and resistance results for amikacin (AMI) was not available in 2012.

	2004				2008				2012
	λ1	λ2	λ3	λ4	λ1	λ2	λ3	λ4	λ1	λ2	λ3	λ4
	3.31	2.94	1.70	1.20	3.71	3.10	1.57	1.29	3.41	2.72	1.78	1.21
AMC	0.85				0.89				0.83
AMP	0.81				0.85				0.81
AXO	0.77				0.84				0.82
FOX	0.79				0.83				0.79
TIO	0.81				0.85				0.81
AMI				0.91				0.81	-	-	-	-
GEN		0.73				0.83				0.76
KAN		0.67				0.69				0.47
STR		0.63				0.74				0.75
CIP			0.78				0.87					0.94
NAL			0.85				0.80				0.55	0.49
FIS		0.88				0.87				0.85
COT		0.71				0.59				0.65
TET		0.49				0.5				0.46
CHL			0.49					0.61			0.75
AZI	-	-	-	-	-	-	-	-			0.82
${\overline{m}}_{\lambda }$ (%)	100	73.3	66.7	N/D	100	66.7	100	0	100	53.3	100	100