Nighttime Intensivist Care May Reduce Hospital Deaths

Using a low-intensity physician staffing model (optional consultation with the intensivist) and Hhaving an intensivist working overnight were associated with decreased risk-adjusted in-hospital mortality among intensive care unit (ICU) patients. However, no additional benefit was observed when nighttime intensivist staffing was present in ICUs that used a high-intensity staffing model (consultation with an intensivist was mandatory or primary care responsibility was transferred to the intensivist), according to results published online in the New England Journal of Medicine [doi:10.1056/NEJMsa1201918]. The findings reconcile the results of 2 earlier single-center studies.

The researchers conducted a retrospective study involving patients admitted to ICUs in 34 hospitals that used the APACHE (Acute Physiology and Chronic Health Evaluation) clinical information system from 2009 through 2010. Multivariate models were used to assess the relationship between nighttime intensivist staffing and in-hospital mortality among ICU patients, with adjustment for daytime intensivist staffing, severity of illness, and case mix. Patients >17 years of age who were admitted to an ICU with completed survey data were eligible for inclusion. For patients with multiple ICU admissions, subsequent admissions were included in the analysis. The primary outcome measure was in-hospital mortality.

Data were analyzed based on completed surveys from APACHE coordinators, which included 65,752 patients admitted to 49 ICUs in 25 hospitals. For the study, 12 ICUs with an overnight intensivist contributed data on 14,424 admissions, and 37 ICUs without a nighttime intensivist had data on 51,328 admissions. Among ICUs without nighttime intensivist staffing, the most common nighttime staffing model was resident coverage in 25 ICUs (51% of total), followed by in-house coverage in 6 ICUs (12%), coverage by physicians who were not intensivists in 5 ICUs (10%), and coverage by a nurse practitioner or physician assistant in 1 ICU (1%).

The results showed that in the 22 ICUs with low-intensity daytime staffing, having a nighttime intensivist was associated with a reduction in risk-adjusted in-hospital mortality (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.39-0.97; P=.04). Among the 27 ICUs with high-intensity daytime staffing, nighttime intensivist staffing conferred no benefit (OR, 1.08; 95% CI, 0.63-1.84; P=.78).

To verify the results of the initial analysis, the researchers conducted a second retrospective cohort study (n=10,319) using data from the Pennsylvania Health Care Cost Containment Council. In the verification cohort, there was a similar relationship between daytime staffing, nighttime staffing, and in-hospital mortality. The interaction between nighttime staffing and daytime staffing was not significant (P=.18), yet the direction of the findings was similar to that of the APACHE cohort. In ICUs with high-intensity daytime staffing, nighttime staffing conferred no additional benefit with respect to mortality reduction (OR, 0.97; 95% CI, 0.67-1.39; P=.86). In ICUs that had low-intensity daytime staffing, in-house nighttime intensivists corresponded with reduced in-hospital mortality (OR, 0.83; 95% CI, 0.69-0.99; P=.05).

Limitations of the study included that the hospitals participating in the study were not a random sample, although “still diverse with respect to size, region, and academic status.” Also, the definition of nighttime staffing was based on the job title given to nighttime providers; the researchers did not explicitly measure their clinical behavior.

“Individual hospitals and ICUs will need to weigh the anticipated benefits of expanding intensivist nighttime coverage against those of other quality-improvement efforts in order to best serve their patients, staff, and community,” the researchers concluded.