Systematic review on the recurrence of postoperative nausea and vomiting after a first episode in the recovery room – implications for the treatment of PONV and related clinical trials

Table 2 The pooled estimates and their 95%-confidence intervals of the recurrence of PONV or vomiting.

Observation interval	Number of included studies*	Incidence of recurrence of ...	Pooled incidence (95%-confidence interval) [%]
0–1 hour	4 ^30,34,47,49	PONV	65 (53...75)
	4 ^30,32,33,52	vomiting	67 (59...74)
0–2 hours	7 ^§	PONV	67 (54...78)
	5 ^{29,37–39,45}	PONV	69 (51...83)
	8^{31,38–40,42,44,48,51}	vomiting	65 (44...81)
0–6 hours	9^{28,30,36,38,40,46,50,51,55}	PONV	79 (66...88)
	10 ^{28,30,32,36,38,40,41,46,}	vomiting	70 (58...79)
	^53,54
0–24 hours	13 ^§	PONV	84 (73...91)
	11 ^{26,28,36,37,41,43–45,49,}	PONV	84 (71...92)
	^50,53	vomiting	79 (61...90)
	8 ^{26,28,35,36,41,42,44,53}

* Please note that even if the absolute number of included trials is equal not necessarily the same trials were analyzed for the outcomes "PONV" on the one hand and "vomiting" on the other hand.
§ Pooled results using the random effects model with including the results of the two unpublished trials [5,16].

ISSN: 1471-2253