Objective: To study methods for costing hospital services, specifically in relation to multi-unit studies of activity, case mix, severity of illness, outcome, and resource use in adult intensive care units (ICUs).
Data sources: Twenty published cost studies of adult ICUs. The studies are all published in English and are both European and American.
Study selection: Cost studies of adult ICUs published in international journals (English language).
Data extraction: Literature survey, where the articles were obtained through MEDLINE and other database searches.
Data synthesis: Cost of intensive care therapy was compared across the 20 studies. However, as stressed in the article, to compare costs of intensive care therapy across units is not possible for a number of reasons. One of the reasons for this limitation is that the studies employed different approaches to costing and thereby introduced a methodologic bias. In addition, the costing methodology applied in the majority of the studies was wrongly specified in relation to the purpose and viewpoint of the studies.
Conclusions: The methodologies for costing ICU therapy are flawed and fail to provide correct answers. In most studies, the study question is not adequately specified and the cost concept used in the studies is not tailored to the purposes of the study. Standardizing the cost model would lead to better, faster, and more reliable costing. This standardized cost model should not be rigid, but adaptable to different decision situations. A decision tree or taxonomy is proposed as a way toward better costing of ICU activity.