Table 3.

Classification systems for adverse events, with prevalence figures (proportion of total adverse events in given category)

Forster et al. [27]		Brennan et al. [17]		Hoonhout et al. [28]		Yao et al. [14]
Event category	Proportion in category	Event category	Proportion in category	Event category	Proportion in category	Event category	Proportion in category
Death	0	Death	0.136	Death	0.078	Death	0.05
Permanent disability	0.03	Permanent impairment, >50% disability	0.026	Permanent disability	0.047	Permanent impairment, >50% disability	0.02
		Permanent impairment, ≤50% disability	0.039			Permanent impairment, ≤50% disability	0.03
Readmission	0.21	Moderate impairment, recovery >6 months	0.028	Moderate disability	0.617	Moderate impairment, recovery >6 months	0.10
A&E visit	0.11	Moderate impairment, recovery 1–6 months	0.137			Moderate impairment, recovery 1–6 months	0.30
Physician visit	0.14	Minimal impairment, recovery <1 month	0.634	Minimal effect	0.257	Minimal impairment, recovery <1 month	0.50
No extra use of health service	0.51