Page 72 - DECISION-MAKING IN SEVERE TRAUMATIC BRAIN INJURY PATIENT OUTCOME, HOSPITAL COSTS, AND RESEARCH PRACTICE

Chapter 3
Outcome
All relevant data was reported in a descriptive manner. In line with the inclusion criteria, patients were included from three different severity groups as they were reported in the included studies (GCS≤8, AIS≥4, AIS≥5). These subgroups were also used in the text and figures. In one figure, hospital LOS was presented by using black indicators (f) and ICU LOS by white indicators (<cuadrado><cuadrado>). A clear distinction between hospital costs and hospital charges, when known, was made by using black and white indicators respectively. In-text, both the reported hospital charges and hospital costs were presented as in- hospital costs. The Gross Domestic Product (GDP) per capita of the study country was included as reference value, to improve comparability between the reported costs. The reference year that was used, corresponded with the currency year. 31 All costs, including GDP per capita, were converted to US dollars (2015) using the CCEMG – EPPI-Centre Cost Converter. 32 This web-based tool utilizes Gross Domestic Product deflator index values and Purchasing Power Parities conversion rates provided by the International Monetary Fund. 33 In case a reference year was not provided we used the last year in which patients were included or, when unknown, the year of publication. Figures were designed with GraphPad Prism version 7.0.2.
RESULTS
Literature search and study selection
The systematic literature search identified 2372 studies (Fig 1). First, a total of 283 duplicate, non-English or unfindable studies were removed. The remaining 2089 studies were screened on title and abstract, resulting in 204 studies considered eligible for full-text assessment. Studies were excluded because; (1) they did not include a s-TBI cohort defined by a GCS≤8 and/or AIS≥4 (N=134), (2) they did not report hospital costs for patients with s-TBI (N=28) or (3) in-hospital acute care costs were not distinguishable from other costs (N=13). No additional studies were identified through the reference check. Ultimately, 25 articles were included in this systematic review.
Study characteristics
The main study characteristics can be found in Table 1. Twelve studies were published after 2010, nine between 2000 and 2019, and four before 2000. Cohort size ranged from 20 to 7774 patients. 34,35 Nineteen studies were conducted in high income countries of which sixteen in the USA. The majority of studies focused on adult
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