Quality of Care in Anesthesia

Section One
Summary of Pertinent Quality of Care Studies and Data

In the January/February 2007 issue of Nursing Research, a team of researchers led by Daniel Simonson, CRNA, MHPA, published the results of a retrospective analysis titled “Anesthesia Staffing and Anesthetic Complications During Cesarean Delivery.” Using data from the state of Washington, the researchers set out to identify differences in the rates of anesthetic complications for cesarean section in hospitals where the obstetrical (OB) anesthesia was provided solely by CRNAs compared with hospitals where the OB anesthesia was provided solely by anesthesiologists. 

The study results showed that there is no difference in complication rates or mortality rates between hospitals that use only CRNAs compared with hospitals that use only anesthesiologists.

A. Rationale for Undertaking Study
According to the researchers, the study was undertaken:

• To determine whether there are any differences between hospitals that employ only CRNAs to perform OB anesthesia and hospitals that employ only anesthesiologists to perform OB anesthesia.
• Because research data is needed to assist hospitals and anesthesia groups in making cost-effective staffing choices.

B. Background
For purposes of the study, Washington state hospital admission data for 1993-2004 were obtained from the Comprehensive Abstract and Reporting System database and merged with data from a survey of anesthesia or medical staff at hospitals where OB anesthesia was staffed by CRNAs only and hospitals where OB anesthesia was staffed by anesthesiologists only.  A total of 134,806 patient records were analyzed, including those of 33,236 patients who were cared for by CRNAs only and 101,570 who were cared for by anesthesiologists only.

Regression analysis was used to adjust for independent variables such as hospital characteristics (geographic location, size, and teaching status), patient demographics (age, primary payer, and type of admission), and patient comorbidities.

In the study sample, there were 965 OB anesthesia complications and 17 deaths. According to the researchers, 76 percent of the complications were of a less serious nature per the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM), and only one of the deaths had an ICD-9-CM code associated with an anesthetic complication.  The CRNA-only hospitals had a complication rate of 0.58 percent, while the anesthesiologist-only hospitals had a rate of 0.76 percent.

Significant Findings and Patterns. Several important findings and patterns emerged from the Simonson study:

• Hospitals with CRNA-only staffing had a lower rate of anesthetic complications than those with anesthesiologist-only staffing (0.58 percent vs. 0.76 percent, p = .0006).  However, after regression analysis, this difference was not significant.
• The CRNA-only hospitals had a greater percentage of Medicaid, rural, teaching, urgent admission, and very young (under 17 years old) patients; the anesthesiologist-only hospitals had a greater percentage of emergency admissions and older mothers (over 35 years old).
• A substantially higher percentage of sicker patients were transferred to CRNA-only hospitals, a factor which could, potentially, affect the number of anesthetic complications in a facility.  However, this did not prove to be the case.

C. Conclusions
Simonson et al. concluded the following:

• That OB anesthesia complications are no different between the CRNA-only and anesthesiologist-only staffing models. “As a result, hospitals and anesthesiology groups may safely examine other variables, such as provider availability and costs, when staffing for obstetrical anesthesia.” [page 1]
• That further study is needed to validate the use of ICD-9-CM codes for anesthesia complications as an indicator of quality.

Next: Pine Study

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