Page 98 - DECISION-MAKING IN SEVERE TRAUMATIC BRAIN INJURY PATIENT OUTCOME, HOSPITAL COSTS, AND RESEARCH PRACTICE
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Chapter 4
First, data on health care consumption were collected from electronic patient records and recorded in a predefined cost assessment database. Units were counted in five main categories: (1) admission; including length of stay (LOS) in (non-)ICU with consultations, (2) surgical interventions, (3) imaging, (4) laboratory; including blood products and (5) other; including transportation and outpatient visits. Since this study focused on in-hospital acute healthcare costs, only post-discharge costs associated with re-admissions and outpatient clinic visits related to the initial trauma were included.
Second, as hospital specific costs prices were not available for external research purposes, units were valued by using external sources in accordance with the guidelines. 24 Some units were valued using the reference prices from the guideline, being cost prices based on large patient cohorts. 24 The use of these prices is recommended for costs research and preferred for cost outcome interpretation and generalization, because prices are non-site-specific. 24,25 Units that were not available in the guidelines were valued using the maximum amount per unit that healthcare providers are allowed to charge according to the -The Netherlands Healthcare Authority (NZa)-, an autonomous administrative authority falling under the Dutch Ministry of Health, Welfare and Sport. 26 The remaining units were valued by using their average national price, based on declared fees including hospital costs and physicians’ fees. 27 A detailed overview of all used unit costs and corresponding sources can be found in supplement 1.
Third, we corrected all unit costs expressed in different base years to 2012 EURO using the national general consumer price index (CBS). This year was chosen because it was the last year of patient inclusion. And finally, to calculate in-hospital costs, all counted units were multiplied with its corresponding price and rounded to the nearest ten euros. No discounting of costs was deemed necessary. In January 2012, one euro equalled $1.28 dollar.
Statistical analysis
Baseline data were presented as absolute numbers and percentages. Continues variables, like costs and LOS, were presented as mean ± standard deviation, unless stated otherwise. Subgroups were made based on age, TBI severity, pupillary abnormalities, surgical intervention and outcome. Comparison between groups was done by using an independent t-test. A p-value of <0.05 was considered statistically significant. All analyses were performed using IBM’s statistical package for social sciences version 23 (SPSS). Figures were designed with GraphPad Prism version 7.02.
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