Table 1.

Overview of studies

Author	Year	Country	Number of patients	Patient days non-ventilated	Patient days ventilated	Daily costs, non-ventilated	Daily costs, ventilated	Base year	Detailed cost figures from the hospital perspective available?
Jacobs	2004	UK	193	910	480a	GBP 455	GBP 587	2000–1	Yes
Moran	2004	Australia	1333	2933	2266	AU$ 1616	AU$ 1911	1991	Yes
Dasta	2005	USA	51 009	117 275	104 104	USD 3250	USD 4772	2002	Nob
Moerer	2007	Germany	453	2154	567a	EUR 680	EUR 946	2003	Yes
Kahn	2008	USA	1778	5879	1469a	USD 2104	USD 2210	2005–6	Yes

PD = Patient days.

^aPatient days derived from the proportion of patients ventilated and mean/median LoS. In two studies (Kahn and Jacobs) it was also assumed that ventilation takes place during 50% of total ICU stay.

^bDaily costs were estimated by multiplying daily hospital charges by hospital specific cost-to-charge ratios.