Intensive care unit length of stay: Benchmarking based on Acute Physiology and Chronic Health Evaluation (APACHE) IV*

Objective:To revise and update the Acute Physiology and Chronic Health Evaluation (APACHE) model for predicting intensive care unit (ICU) length of stay. Design:Observational cohort study. Setting:One hundred and four ICUs in 45 U.S. hospitals. Patients:Patients included 131,618 consecutive ICU admissions during 2002 and 2003, of which 116,209 met inclusion criteria. Interventions:None. Measurements and Main Results:The APACHE IV model for predicting ICU length of stay was developed using ICU day 1 patient data and a multivariate linear regression procedure to estimate the precise ICU stay for randomly selected patients who comprised 60% of the database. New variables were added to the previous APACHE III model, and advanced statistical modeling techniques were used. Accuracy was assessed by comparing mean observed and mean predicted ICU stay for the excluded 40% of patients. Aggregate mean observed ICU stay was 3.86 days and mean predicted 3.78 days (p < .001), a difference of 1.9 hrs. For 108 (93%) of 116 diagnoses, there was no significant difference between mean observed and mean predicted ICU stay. The model accounted for 21.5% of the variation in ICU stay across individual patients and 62% across ICUs. Correspondence between mean observed and mean predicted length of stay was reduced for patients with a short (≤1.7 days) or long (≥9.4 days) ICU stay and a low (<20%) or high (>80%) risk of death on ICU day 1. Conclusions:The APACHE IV model provides clinically useful ICU length of stay predictions for critically ill patient groups, but its accuracy and utility are limited for individual patients. APACHE IV benchmarks for ICU stay are useful for assessing the efficiency of unit throughput and support examination of structural, managerial, and patient factors that affect ICU stay.

[1]  A S Detsky,et al.  Prognosis, survival, and the expenditure of hospital resources for patients in an intensive-care unit. , 1981, The New England journal of medicine.

[2]  R. Oye,et al.  Patterns of resource consumption in medical intensive care. , 1991, Chest.

[3]  W. Knaus,et al.  The APACHE III prognostic system. Risk prediction of hospital mortality for critically ill hospitalized adults. , 1991, Chest.

[4]  W. Knaus,et al.  Reliability of a measure of severity of illness: acute physiology of chronic health evaluation--II. , 1992, Journal of clinical epidemiology.

[5]  W. Knaus,et al.  Variations in Mortality and Length of Stay in Intensive Care Units , 1993, Annals of Internal Medicine.

[6]  E. Draper,et al.  Improving intensive care: Observations based on organizational case studies in nine intensive care units A prospective, multicenter study , 1993, Critical care medicine.

[7]  C. Sirio,et al.  Cleveland Health Quality Choice (CHQC)--an ongoing collaborative, community-based outcomes assessment program. , 1994, New horizons.

[8]  S Lemeshow,et al.  A method for assessing the clinical performance and cost‐effectiveness of intensive care units: A multicenter inception cohort study , 1994, Critical care medicine.

[9]  E F Haponik,et al.  Effect on the duration of mechanical ventilation of identifying patients capable of breathing spontaneously. , 1996, The New England journal of medicine.

[10]  J DePorter.  UHC operations improvement: adult ICU benchmarking project summary. University HealthSystem Consortium. , 1997, Best practices and benchmarking in healthcare : a practical journal for clinical and management application.

[11]  C Weissman,et al.  Analyzing intensive care unit length of stay data: problems and possible solutions. , 1997, Critical care medicine.

[12]  M. Simoons,et al.  A clinical trial comparing primary coronary angioplasty with tissue plasminogen activator for acute myocardial infarction. , 1997, The New England journal of medicine.

[13]  G. Cooper,et al.  Severity-Adjusted Mortality and Length of Stay in Teaching and Nonteaching Hospitals: Results of a Regional Study , 1997 .

[14]  D. Bates,et al.  Coronary Angiography and Angioplasty after Acute Myocardial Infarction , 1997, Annals of Internal Medicine.

[15]  W. Knaus,et al.  Evaluation of acute physiology and chronic health evaluation III predictions of hospital mortality in an independent database. , 1998, Critical care medicine.

[16]  C. Sprung,et al.  Use of the SOFA score to assess the incidence of organ dysfunction/failure in intensive care units: results of a multicenter, prospective study. Working group on "sepsis-related problems" of the European Society of Intensive Care Medicine. , 1998, Critical care medicine.

[17]  M. Niederman,et al.  A "closed" medical intensive care unit (MICU) improves resource utilization when compared with an "open" MICU. , 1998, American journal of respiratory and critical care medicine.

[18]  A J Rotondi,et al.  Community-wide assessment of intensive care outcomes using a physiologically based prognostic measure: implications for critical care delivery from Cleveland Health Quality Choice. , 1999, Chest.

[19]  B. Kavanagh,et al.  Utilization of intensive care unit days in a Canadian medical-surgical intensive care unit. , 1999, Critical care medicine.

[20]  Douglas Thompson,et al.  The impact of long‐term acute‐care facilities on the outcome and cost of care for patients undergoing prolonged mechanical ventilation , 2000, Critical care medicine.

[21]  J. Norrie,et al.  Evaluation of predicted and actual length of stay in 22 Scottish intensive care units using the APACHE III system , 2000, Anaesthesia.

[22]  C. Weissman.  Factors influencing changes in surgical intensive care unit utilization , 2000, Critical care medicine.

[23]  Todd Dorman,et al.  Intensive care unit telemedicine: Alternate paradigm for providing continuous intensivist care , 2000, Critical care medicine.

[24]  Charles Weissman,et al.  Analyzing the impact of long-term patients on ICU bed utilization , 2000, Intensive Care Medicine.

[25]  Peter J. Pronovost,et al.  ICU nurse-to-patient ratio is associated with complications and resource use after esophagectomy , 2000, Intensive Care Medicine.

[26]  M. F. Mascia,et al.  Pharmacoeconomic impact of rational use guidelines on the provision of analgesia, sedation, and neuromuscular blockade in critical care , 2000, Critical care medicine.

[27]  S. Mackenzie,et al.  Should the pre‐sedation Glasgow Coma Scale value be used when calculating Acute Physiology and Chronic Health Evaluation scores for sedated patients? , 2000, Critical care medicine.

[28]  A. Rosenberg,et al.  Patients readmitted to ICUs* : a systematic review of risk factors and outcomes. , 2000, Chest.

[29]  W. Knaus,et al.  Intensive care unit length of stay: Recent changes and future challenges , 2000, Critical care medicine.

[30]  W J Sibbald,et al.  Sedation in the intensive care unit: a systematic review. , 2000, JAMA.

[31]  P. Marik,et al.  What’s in a day? Determining intensive care unit length of stay , 2000, Critical care medicine.

[32]  Frank E. Harrell,et al.  Regression Modeling Strategies: With Applications to Linear Models, Logistic Regression, and Survival Analysis , 2001 .

[33]  Gordon H Guyatt,et al.  The attributable mortality and length of intensive care unit stay of clinically important gastrointestinal bleeding in critically ill patients , 2001, Critical care.

[34]  Peter J. Pronovost,et al.  Intensive care unit physician staffing is associated with decreased length of stay, hospital cost, and complications after esophageal resection , 2001, Critical care medicine.

[35]  U. Janssens,et al.  Analysis of resource use and cost-generating factors in a German medical intensive care unit employing the Therapeutic Intervention Scoring System (TISS-28) , 2002, Intensive Care Medicine.

[36]  R. Beale,et al.  Reduction in mortality after inappropriate early discharge from intensive care unit: logistic regression triage model , 2001, BMJ : British Medical Journal.

[37]  R Consunji,et al.  Increased resource use associated with catheter-related bloodstream infection in the surgical intensive care unit. , 2001, Archives of surgery.

[38]  Alice Greenwood,et al.  Expanding a performance improvement initiative in critical care from hospital to system. , 2002, The Joint Commission journal on quality improvement.

[39]  Peter J Pronovost,et al.  Physician staffing patterns and clinical outcomes in critically ill patients: a systematic review. , 2002, JAMA.

[40]  Peter J Pronovost,et al.  Qualitative review of intensive care unit quality indicators. , 2002, Journal of critical care.

[41]  S. Fakhry,et al.  Outcomes of and resource consumption by high-cost patients in the intensive care unit. , 2002, American journal of critical care : an official publication, American Association of Critical-Care Nurses.

[42]  Mitchell J Barnett,et al.  Day of the Week of Intensive Care Admission and Patient Outcomes: A Multisite Regional Evaluation , 2002, Medical care.

[43]  S. Lemeshow,et al.  Length of Stay Data as a Guide to Hospital Economic Performance for ICU Patients , 2003, Medical care.

[44]  J. Takala,et al.  Resource use in the ICU: short‐ vs. long‐term patients * , 2003, Acta anaesthesiologica Scandinavica.

[45]  M. Kollef,et al.  Improving family communications at the end of life: implications for length of stay in the intensive care unit and resource use. , 2003, American journal of critical care : an official publication, American Association of Critical-Care Nurses.

[46]  Stanley Lemeshow,et al.  Early indicators of prolonged intensive care unit stay: Impact of illness severity, physician staffing, and pre–intensive care unit length of stay , 2003, Critical care medicine.

[47]  Rodney A Hayward,et al.  Accepting Critically Ill Transfer Patients: Adverse Effect on a Referral Center's Outcome and Benchmark Measures , 2003, Annals of Internal Medicine.

[48]  J. Zimmerman,et al.  The use of benchmarking to identify top performing critical care units: a preliminary assessment of their policies and practices. , 2003, Journal of critical care.

[49]  Corinne Alberti,et al.  Determinants of postintensive care unit mortality: A prospective multicenter study , 2003, Critical care medicine.

[50]  B. Afessa,et al.  Hospital mortality rate and length of stay in patients admitted at night to the intensive care unit* , 2003, Critical care medicine.

[51]  Sharon Einav,et al.  Intensive care outflow limitation--frequency, etiology, and impact. , 2003, Journal of critical care.

[52]  J. Suarez,et al.  Length of stay and mortality in neurocritically ill patients: Impact of a specialized neurocritical care team* , 2004, Critical care medicine.

[53]  M. Keegan,et al.  Mortality rate and length of stay of patients admitted to the intensive care unit in July* , 2004, Critical care medicine.

[54]  T. Williams,et al.  Delayed discharges from an adult intensive care unit. , 2004, Australian health review : a publication of the Australian Hospital Association.

[55]  Karen Burns,et al.  Characteristics and outcomes for critically ill patients with prolonged intensive care unit stays* , 2005, Critical care medicine.

[56]  Sanjay Saint,et al.  Clinical and economic consequences of ventilator-associated pneumonia: A systematic review , 2005, Critical care medicine.

[57]  James Deddens,et al.  Variation in outcomes in Veterans Affairs intensive care units with a computerized severity measure* , 2005, Critical care medicine.

[58]  M. Keegan,et al.  Evaluating the performance of an institution using an intensive care unit benchmark. , 2005, Mayo Clinic proceedings.

[59]  J. Garnacho-Montero,et al.  Effect of critical illness polyneuropathy on the withdrawal from mechanical ventilation and the length of stay in septic patients* , 2005, Critical care medicine.

[60]  A. Combes,et al.  Adverse effect on a referral intensive care unit's performance of accepting patients transferred from another intensive care unit* , 2005, Critical care medicine.

[61]  J. Zimmerman,et al.  Acute Physiology and Chronic Health Evaluation (APACHE) IV: Hospital mortality assessment for today’s critically ill patients* , 2006, Critical care medicine.

[62]  G. Rosenthal,et al.  Is there a July Phenomenon? , 2003, Journal of General Internal Medicine.