Out of Hours Discharge from Intensive Care and In-Hospital Mortality: A Meta- Analysis Introduction Patients who are discharged from Intensive Care Units (ICUs) have long been acknowledged as a group of patients requiring special attention on wards. Mortality rates amongst this group of patients have been reported in the literature as anywhere between 3.7% and 13.3% [1, 2]for the UK and 2.9% to 22.6% [3, 4] worldwide, with a national average of 7.4% [5]). Other groups generally widely considered to be high risk have much lower mortality rates, such as upper gastrointestinal surgical patients (2.4%), cardiothoracic surgical patients (2.7%) and patients admitted with acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD) (7.5%) [8]. As early as the 1980s the need to investigate the management of patients following discharge from ICU was acknowledged [9-11], and much work has been done in this area since. Preliminary work in this area has identified as out of hours discharge as a significant risk factor for this excess mortality, however not review to date has collated this evidence. Objective This review aims to determine the effect of out of hours intensive care discharge on post-icu inhospital mortality (PIIHM). Design The design of this search strategy has been guided by a medical librarian, who will assist in the conduct of these searches. Data sources The main databases we plan to search are: medline web of knowledge CINAHL The Cochrane library OpenGrey Limitations Studies will be limited to those including adults aged 16 and over.
Search strategy The search strategy will be adapted according to the database being searched, but will generally include: 1. MORTALITY 2. *DEATH. 3. (mortality OR death* OR die OR died) 4. 1 OR 2 OR 3 5. *INTENSIVE CARE 6. *INTENSIVE CARE UNITS 7. *CRITICAL CARE 8. "intensive care" 9. "intensive treatment" 10 "intensive therapy" 11."critical care" 12."critical* ill*" 13. (ITU OR ICU OR AICU) 14. 5 OR 6 OR 7 OR 8 OR 9 OR 10 OR 11 OR 12 OR 13 15. *PATIENT DISCHARGE 16. discharge* 17. (post OR after OR following) 18. (ward* OR inhospital OR "in hospital") 19. "transfer* from" 20. 15 OR 16 OR 17 OR 18 OR 19 21. out of hours 22. off-hour 23. night-time 24. 21 OR 22 OR 23 25. 4 AND 14 AND 20 AND 24 Managing references After conducting the searches, the results will be exported to an independent database. Subsequently, all the references will be merged in a unique database, and duplicates will be automatically identified and removed. Each team member will receive a copy of this final database. We will use reference manager software for this purpose. Screening Eligibility We will include: Study types: o studies which use quantitative methods of data collection and analysis, Article types: o original articles and review articles including systematic reviews. Participants: o Patients who have been discharged alive from Intensive Care to a lower level of care (HDU or ward). All ages and conditions will be included. Settings:
o Patients discharged from medical, surgical or mixed ICUs will be included. Outcome measures: o In-hospital mortality. Geographical area: o Studies conducted in any country. Date of publication: o Articles published since and including 1990. We will exclude: o Measures of mortality which extend beyond hospital discharge, or for which post- ICU mortality cannot be identified from whole hospital stay mortality. Reviewing results Results will be reviewed in three stages at title, at abstract and at full text. Search results will be screen by title by two researchers, and either rejected as irrelevant or selected for abstract review. Any discrepancies between the two researchers will be discussed and agreed with a third reviewer. Abstracts will be reviewed by two researchers and either rejected as not relevant or selected for full text review. Full text articles will be reviewed by two reviewers and either selected for inclusion or excluded on the following grounds: Not relevant Follow-up extends beyond hospital stay Full hospital stay not included In-ICU mortality included Unable to use data Where eligibility cannot be ascertained, the authors of the study will be contacted to clarify. Further searches Once the initial searches have been performed, we will review backward & forward citation for Web of Knowledge for the studies identified as relevant at the end of the screening process (i.e., those that are chosen to be included in the review). Further searches will be conducted using keywords (using medline) from the initial search papers, and citation searches (using web of knowledge) for each paper. These will again be reviewed initially by title, followed by abstract and full text as above.
Data extraction Data for each study will be extracted by two researchers using data extraction tables. For studies where there is ambiguity in the data or all data is not reported, clarification will be sought from the authors where possible. Data for each study will be extracted by two researchers using data extraction tables which will be piloted prior to use. This will include type of study, setting, numbers of patients, definition of out of hours, main findings, population and cohort data, data to allow analysis of risk of bias. Where there is lack of clarity in the data extracted, clarification will be sought from the authors. Where studies do not report participant level data, this will be sought from the authors. Quality assessment of studies Once all searches have been completed, the final included studies will be assessed for quality using the Newcastle Ottowa scale. This scale examines bias in three areas: Selection Comparability Outcome Studies are given a score out of 9, with a low score indicating areas of concern regarding bias. A further subjective analysis of quality and bias will be made for each study. Two reviewers will independently assess each included study, with any discrepancies resolved with a third researcher. Bias assessment of individual papers will be made available in the final publication. Analysis Based on our current knowledge of the available data, it is anticipated that meta-analysis will be possible for most studies. Data will be aggregated at the level of individual studies. An assessment of heterogeneity will be made (using both the X 2 test and the I 2 statistic) and a decision between a fixed effects or random effects model will be made based on this. We will consider an I2 value greater than 50% indicative of substantial heterogeneity. We will calculate 95% confidence intervals and P values for the outcome of in-hospital mortality. Sub-analysis We anticipate there may be some sub-analysis of different definitions of 'out of hours' and of discharge to different clinical settings (ward or HDU care). If appropriate, sub-analysis of different speciality ICUs may be undertaken, such as ICUs with only cardiac or neurosurgical patients, or with a majority of cardiac and/or neurosurgical patients. In the case of studies reporting post-icu mortality in shorter terms than to hospital discharge, these may also be sub-analysed separately.
References 1. Daly, K., R. Beale, and R.W. Chang, Reduction in mortality after inappropriate early discharge from intensive care unit: logistic regression triage model. BMJ, 2001. 322(7297): p. 1274-6. 2. Goldfrad, C. and K. Rowan, Consequences of discharges from intensive care at night. Lancet, 2000. 355(9210): p. 1138-1142. 3. Al-Subaie, N., et al., CRP as a predictor of outcome after discharge from the intensive care: a prospective observational study. British Journal of Anaesthesia, 2010. 105(3): p. 318-325. 4. Araujo, I., et al., Assessment of risk factors for in-hospital mortality after intensive care unit discharge. Biomarkers, 2012. 17(2): p. 180-5. 5. ICNARC. Intensive Care National Audit and Research Centre. Summary Statistics, 2011-12. https://www.icnarc.org/documents/summary%20statistics%20-%202011-12.pdf. Accessed June 2014. 6. Bridgewater, B., et al., Publishing cardiac surgery mortality rates: lessons for other specialties. Bmj, 2013. 346: p. f1139. 7. Chan, D.S., et al., Influence of a regional centralised upper gastrointestinal cancer service model on patient safety, quality of care and survival. Clin Oncol (R Coll Radiol), 2013. 25(12): p. 719-25. 8. Myint, P.K., et al., U.K. National COPD Resources and Outcomes Project 2008: patients with chronic obstructive pulmonary disease exacerbations who present with radiological pneumonia have worse outcome compared to those with non-pneumonic chronic obstructive pulmonary disease exacerbations. Respiration, 2011. 82(4): p. 320-7. 9. Franklin, C. and D. Jackson, Discharge decision-making in a medical ICU: characteristics of unexpected readmissions. Crit Care Med, 1983. 11(2): p. 61-6. 10. Rubins, H.B. and M.A. Moskowitz, Discharge decision-making in a medical intensive care unit. Identifying patients at high risk of unexpected death or unit readmission. Am J Med, 1988. 84(5): p. 863-9. 11. Snow, N., K.T. Bergin, and T.P. Horrigan, Readmission of patients to the surgical intensive care unit: patient profiles and possibilities for prevention. Crit Care Med, 1985. 13(11): p. 961-4.