Table 4.

Sensitivity, specificity, positive predictive value and negative predictive value of independent individual factors contributing to the signal selection process, as well as the combination of these factors.

	Sensitivity	Specificity	Positive predictive value	Negative predictive value
Individual factors
ROR full ATC code/preferred term statistically significant	0.55	0.73	0.33	0.87
Index or control report concerns a ‘serious’ ADR	0.50	0.88	0.51	0.88
Critical term present	0.62	0.82	0.46	0.90
ADR unlabelled	0.64	0.60	0.28	0.87
Combined factors
One or more factors present	1	0.29	0.26	1
Two or more factors present	0.72	0.80	0.48	0.92
Three or more factors present	0.52	0.95	0.53	0.89
All four factors present	0.07	0.99	0.6	0.81