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Journal Club Special, March 2008: Live Discussion

Critical Care

ATS Forum Live Discussion

Gajic O, Afessa B, Hanson AC, Krpata T, Yilmax M, Mohamed SF, et al. Effect of 24-hour mandatory versus on-demand critical care specialist presence on quality of care and family and provider satisfaction in the intensive care unit of a teaching hospital. Critical Care Medicine 2008;36:36-44.


Jeremy M. Kahn, MD MSc
Division of Pulmonary, Allergy & Critical Care; Center for Clinical Epidemiology & Biostatistics; Leonard Davis Institute of Health Economics, University of Pennsylvania School of Medicine, Philadelphia PA

Observational evidence suggests that staffing the intensive care unit (ICU) with a trained intensivist is associated with improved outcomes in critical care [1-3]. Under an intensivist staffing model, the intensivist is typically present in the ICU during daylight hours. Whether or not additional benefit can be achieved by extending the intensivist presence to 24 hours is unknown.

Gajic and colleagues performed a prospective cohort study of 24-hour intensivist coverage in the medical ICU of an large academic hospital. During the study period the ICU staffing model changed from a closed model with daytime intensivist coverage and night-time coverage provided by housestaff and fellow-level trainees to a model identical to first but with the addition of an in-house staff intensivist from 7 PM to 7 AM. The researchers compared risk-adjusted mortality, risk-adjusted length of stay, adherence to evidence-based practice, and ICU complications before and after the organizational change. They also used two validated survey instruments to examine the effect of night-time intensivist staffing on patient, family and staff satisfaction.

Patient characteristics were similar before and after addition of night-time intensivist staffing. After the change, there was slightly greater adherence to guidelines for stress ulcer prophylaxis (100% vs. 98%, p=0.002) and deep vein thrombosis prophylaxis (94% vs. 91%, p=0.38). Night-time staffing was also associated with increased use of a standardized order set for severe sepsis (82% vs. 71%) and lung protective ventilation for acute lung injury (81% vs. 72%), although these findings did not achieve statistical significance. ICU complications were rare in both time periods. When taken as a composite, the incidence of complications was reduced after the change (11% vs. 7%, p=0.02). When complications were examined separately, only clinically significant bleeding was significantly reduced (2.2% vs. 0.8%, p=0.05).

After controlling for potential confounders, there was a significant reduction in hospital length of stay (adjusted mean difference -1.4 days, 95% confidence interval -0.3 days to -2.5 days) but no differences ICU length of stay, ICU mortality, or in-hospital mortality. Approximately half of eligible staff members and family members returned the satisfaction survey. Among staff respondents, the addition of a night-time intensivist was associated with increased provider satisfaction, mostly due to perceived benefits to patient care. There was no difference in patient or family satisfaction between time periods.

The addition of a night-time intensivist to an academic medical ICU staffed with day-time intensivists and trainees at night was associated with increased use of select evidence-based practices and a modest reduction in the incidence of ICU complications. There was no measurable effect on patient-centered outcomes such as mortality or family satisfaction. Staff satisfaction increased, primarily due to a perception that the new staffing model was provided more optimal patient care.

This is the first study to formally evaluate 24-hour on-site intensivist staffing in the ICU. Daytime intensivist coverage is associated with improved patient outcomes in most clinical settings. The authors add to this literature by studying the role of in-house intensivist staffing at night. Major strengths of the study include careful determination of ICU complications and guideline adherence, use of a validated risk-adjustment tool to compare mortality and length of stay between study periods, and recognition that staff and family satisfaction are important outcomes in critical care.

There are some limitations of this study, mostly inherent to the study design. The authors used a before-after design, sometimes known as a time-series trial. Time-series trials are frequently used to evaluate organizational change in health care—whenever an major change is planned it is relatively simple to measure outcomes before and after the change. Indeed, the vast majority of studies evaluating intensivist physician staffing employ a before-after design [2]. There are several major threats to the validity of this type of study, including temporal trends and regression towards the mean. Temporal trends in outcomes are common in the ICU—the effects of quality improvement initiatives and new care protocols might be continue for months or years after they are instituted. It is possible that the observed reductions in ICU complications and improvements in evidence-based practice in this study might have occurred regardless of the staffing change. Regression towards the mean is an insidious problem that arises as part of random variation inherent to natural systems. Regression towards the mean dictates that whenever outcomes worsen they are likely to improve in the next observable time period. Because the authors only studied two time periods, it is impossible to say how much of the variation in this study is due to temporal trends or the regression towards the mean. Alternative study designs such as cluster-randomized trials can overcome some of these potential biases but are time-consuming and expensive to conduct.

It is worth noting that this study was performed in a single academic medical ICU with a reputation for high quality care. Consequently, it is difficult to generalize these results outside the academic setting or to other types of ICUs. The “before” arm of the study was already a very high intensity of care—intensivists were present in the ICU during the day, were available by page at night, and residents and fellows were present at all times. Only a small minority of ICUs in the United States have achieved this level of staffing [4]. It is possible that ICUs with less optimal staffing at baseline would observe a different, perhaps stronger, effect. Finally, night-time intensivist staffing could have an impact on adverse drug events or procedural complications, neither of which were measured in this study.

From these data we can conclude that the addition of a night-time intensivist almost certainly does not worsen outcomes and may be associated with improvements in the process of care. However, the improvements were small and inconsistent, possibly due to the high quality of care prior to adopting the night-time staffing model. Other types of hospitals, particularly those with no physicians in the ICU at night, might observe a greater effect. Whether or not 24-hour intensivist staffing represents a cost-effective use of resources remains to be seen. Trained intensivists are expensive, and it is possible that the same effects could be achieved using less expensive hospitalists or non-physician providers. It is also possible that a greater benefit could be achieved by directing these resources elsewhere in the hospital.

It is likely that night-time intensivist staffing is not feasible for most hospitals at this time. Detailed workforce analyses suggest that there are not enough intensivists to meet current demand, and a small minority of ICUs currently have intensivist staffing of any type [5]. Hospitals struggling to adopt a mandatory consult or fully closed model are unlikely to be actively considering 24-hour intensivist converge. Instead, these results apply to a small number of academic hospitals with both sufficient resources and available staff.

The data on physician staffing in the ICU are in a state of continual evolution. Telemedicine, hospitalist-driven care, and non-physician providers all offer ways to extend the benefits of an intensivist to more patients at more times [6-8]. This work contributes to the literature by demonstrating that 24-hours intensivist staffing may be beneficial in some settings. Future work will need to address effectiveness outside academic hospitals, cost-effectiveness, and feasibility given the current workforce.


  1. Kahn JM, Brake H, Steinberg KP: Intensivist physician staffing and the process of care in academic medical centres. Qual Saf Health Care 2007;16:329-33.
  2. Pronovost PJ, Angus DC, Dorman T, et al: Physician staffing patterns and clinical outcomes in critically ill patients: a systematic review. JAMA 2002;288:2151-62.
  3. Treggiari MM, Martin DP, Yanez ND, et al: Effect of intensive care unit organizational model and structure on outcomes in patients with acute lung injury. Am J Respir Crit Care Med 2007;176:685-90.
  4. Angus DC, Shorr AF, White A, et al: Critical care delivery in the United States: Distribution of services and compliance with Leapfrog recommendations. Crit Care Med 2006;34:1016-24.
  5. Angus DC, Kelley MA, Schmitz RJ, et al: Current and projected workforce requirements for care of the critically ill and patients with pulmonary disease: can we meet the requirements of an aging population? JAMA 2000;284:2762-70.
  6. Breslow MJ: Remote ICU care programs: current status. J Crit Care 2007;22:66-76.
  7. Lindenauer PK, Rothberg MB, Pekow PS, et al: Outcomes of care by hospitalists, general internists, and family physicians. N Engl J Med 2007;357:2589-600.
  8. Mathur M, Rampersad A, Howard K, et al: Physician assistants as physician extenders in the pediatric intensive care unit setting-A 5-year experience. Pediatr Crit Care Med 2005;6:14-9.