Accuracy of using automated methods for detecting adverse events from electronic health record data: a research protocol

Table 2 Sample sizes ^a required for a 95% confidence interval width of 0.10 around the sensitivity estimate adjusted for the over-sampling of adverse event (AE) positive patients induced by the study design

Adverse event (AE) indicator	Estimated incidence rate ^b	Desired specificity	Expected corrected sensitivity (range)	Expected positive predictive value (range)	Optimal sampling test positivity rate	Optimal sample sizes ^c
Adverse event (AE) indicator	Estimated incidence rate ^b	Desired specificity	Expected corrected sensitivity (range)	Expected positive predictive value (range)	Optimal sampling test positivity rate	No. of AE positive patients	No. of AE negative patients	Total no. of patients sampled
Nosocomial pneumonia (NP)	0.05	0.95	0.85	0.80	0.10290	191	1,980	2,171
				0.90	0.10290	94	979	1,073
			0.90	0.80	0.07104	237	3,099	3,336
				0.90	0.07104	117	1,532	1,649
		0.98	0.85	0.80	0.06667	119	1,975	2,094
				0.90	0.06667	59	976	1,035
			0.90	0.80	0.04545	148	3,111	3,259
				0.90	0.04545	73	1,538	1,611
Central venous catheter-associated blood stream infection (CVC-BSI)	0.05	0.95	0.85	0.80	0.10290	191	1,980	2,171
				0.90	0.10290	94	979	1,073
			0.90	0.80	0.07104	237	3,099	3,336
				0.90	0.07104	117	1,532	1,649
		0.98	0.85	0.80	0.06667	119	1,975	2,094
				0.90	0.06667	59	976	1,035
			0.90	0.80	0.04545	148	3,111	3,259
				0.90	0.04545	73	1,538	1,611
In-hospital fall	0.07	0.95	0.85	0.80	0.10290	133	1,379	1,512
				0.90	0.10290	66	682	747
			0.90	0.80	0.07104	165	2,161	2,327
				0.90	0.07104	82	1,068	1,150
		0.98	0.85	0.80	0.06667	83	1,376	1,458
				0.90	0.06667	41	680	721
			0.90	0.80	0.04545	103	2,170	2,273
				0.90	0.04545	51	1,073	1,124

^aSample size calculations are based on [58]. ^bBased on the literature and expert opinion. ^cValues in italics represent the worst case scenario for a given AE indicator.

ISSN: 1748-5908