International prevalence of adverse drug events in hospitals: an analysis of routine data from England, Germany, and the USA

Table 3 Standardized prevalence rates of ADEs for England, Germany and the USA

		England^*	Germany^†	USA^*
Category	Definition	Rate in % [95% CI]
A	Caused by a drug or other substance	0.99 [0.99–1.00]	3.14 [3.10–3.17]	4.43 [4.42–4.45]
B	Poisoning by or harmful use of a drug or other substance	1.21 [1.20–1.22]	0.49 [0.48–0.51]	0.63 [0.63–0.64]
C	ADE very likely	1.07 [1.07–1.08]	1.14 [1.11–1.16]	0.86 [0.85–0.87]
A-C		3.22 [3.20–3.23]	4.78 [4.73–4.83]	5.64 [5.63–5.66]

^*Inpatient stays were counted once within each category. The rates were adjusted for the distribution of the following data elements in the DRG statistic using a direct standardization: operation (yes/no), sex (male/female), emergency (yes/no), age at admission (≤ 53 years/> 53 years). The rates were further adjusted for the mean number of secondary diagnoses in Germany.
^†Inpatients stays were counted twice in categories A and B if the ADE occurred in each of the sub-categories. Otherwise, they were counted once. To aggregate the initial results, which were differentiated according to principal and secondary diagnoses, the total number of inpatient stays for categories A, B, and C was multiplied by a factor of 0.88.

ISSN: 1472-6963