Traumatic brain injury patient volume and mortality in neurosurgical intensive care units: a Finnish nationwide study.
BACKGROUND
Differences in outcomes after traumatic brain injury (TBI) between neurosurgical centers exist, although the reasons for this are not clear. Thus, our aim was to assess the association between the annual volume of TBI patients and mortality in neurosurgical intensive care units (NICUs).


METHODS
We collected data on all patients treated in the five Finnish university hospitals to examine all patients with TBI treated in NICUs in Finland from 2009 to 2012. We used a random effect logistic regression model to adjust for important prognostic factors to assess the independent effect of ICU volume on 6-month mortality. Subgroup analyses were performed for patients with severe TBI, moderate-to-severe TBI, and those who were undergoing mechanical ventilation or intracranial pressure monitoring.


RESULTS
Altogether 2,328 TBI patients were treated during the study period in five NICUs. The annual TBI patient volume ranged from 61 to 206 patients between the NICUs. Univariate analysis, showed no association between the NICUs' annual TBI patient volume and 6-month mortality (p = 0.063). The random effect model showed no independent association between the NICUs' annual TBI patient volume and 6-month mortality (OR = 1.000, 95% CI = 0.996-1.004, p = 0.876). None of the pre-defined subgroup analyses indicated any association between NICU volume and patient mortality (p > 0.05 for all).


CONCLUSIONS
We did not find any association between annual TBI patient volume and 6-month mortality in NICUs. These findings should be interpreted taking into account that we only included NICUs, which by international standards all treated high volumes of TBI patients, and that we were not able to study the effect of NICU volume on neurological outcome.
Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Topeliuksenkatu 5, PB-266, FI-00029 HUS, Helsinki, Finland. rahul.raj@hus.fi.
Rahul
R
Raj
Division of Intensive Care, Kuopio University Hospital, Puijonlaaksontie 2, PB-100, FI-70029 KYS, Kuopio, Finland.
Stepani
S
Bendel
Division of Intensive Care, North Karelia Central Hospital, Tikkamäentie 16, 80210, Joensuu, Finland.
Matti
M
Reinikainen
Department of Anaesthesiology, Intensive Care and Pain Medicine, Tampere University Hospital, Teiskontie 35, PB-2000, FI-33521, Tampere, Finland.
Sanna
S
Hoppu
Department of Neurosurgery, University of Tampere, Medical School, and Tampere University Hospital, Teiskontie 35, PB-2000, FI-33521, Tampere, Finland.
Teemu
T
Luoto
Division of Intensive Care, Department of Anaesthesiology, Oulu University Hospital and Oulu University, Medical Research Center Oulu, Oulu, Finland.|Research Group of Surgery, Anaesthesia and Intensive Care, Medical Faculty, University of Oulu, PB-22 OUH, FI-90029, Oulu, Finland.
Tero
T
Ala-Kokko
Department of Neurosurgery, Oulu University Hospital, Kajaanintie 50, 90220, Oulu, Finland.
Sami
S
Tetri
Department of Perioperative Services, Intensive Care and Pain Medicine, Turku University Hospital, Turku, Finland.
Ruut
R
Laitio
Department of Neurosurgery, Kuopio University Hospital, Puijonlaaksontie 2, PB-100, FI-70029 KYS, Kuopio, Finland.
Timo
T
Koivisto
Department of Neurosurgery, Turku University Hospital and University of Turku, Hämeentie 11, PB-52, FI-20251, Turku, Finland.
Jaakko
J
Rinne
Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Topeliuksenkatu 5, PB-266, FI-00029 HUS, Helsinki, Finland.
Riku
R
Kivisaari
Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Topeliuksenkatu 5, PB-266, FI-00029 HUS, Helsinki, Finland.
Jari
J
Siironen
Department of Anaesthesiology, Intensive Care and Pain Medicine, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 4, PB-340, FI-00029 HUS, Helsinki, Finland.|Australian and New Zealand Intensive Care Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
Markus B
MB
Skrifvars
D000328:Adult; D000368:Aged; D000070642:Brain Injuries, Traumatic / Q000453:epidemiology* / Q000601:surgery; D003422:Critical Care / Q000379:methods*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends