[Vila, H, Soto, R, Cantor, AB, Mackey, D. "Comparative Outcomes Analysis of Procedures Performed in Physician Offices and Ambulatory Surgery Centers." Archives of Surgery. 2003; 138:991-995.]
In the September 2003 issue of Archives of Surgery (an American Medical Association publication), a paper titled "Comparative Outcomes Analysis of Procedures Performed in Physician Offices and Ambulatory Surgery Centers" raised questions about patient safety in physician offices. The study was based in Florida.
The researchers, Hector Vila, Jr., MD; Roy Soto, MD; Alan B. Cantor, PhD; and David Mackey, MD, are among the first to compare office surgery outcomes with outcomes in ambulatory surgery centers (ASCs). Because the methodology used for the study was flawed in many ways, the only supportable conclusion one can reach from the results is that more comprehensive studies similar in nature need to be undertaken. However, despite this particular study's flaws, and the fact that the results are of questionable value, research of this nature does have merit.
It is important to note that Vila et al.'s paper:
Does not specifically mention CRNAs.
Does not compare the work of anesthesia providers (specifically, physician anesthesiologists and CRNAs).
Has not been as widely misrepresented by the American Society of Anesthesiologists (ASA) or its state societies in an effort to denigrate CRNAs as the Silber/Pennsylvania study has been misrepresented (see analysis of Silber/Pennsylvania study, pp. 21-28 in this booklet).
Makes the unsupportable assertion that office surgery may not be as safe when an anesthesiologist is not present.
A. Rationale for Undertaking Study
According to the researchers, the study was undertaken to determine whether patient safety is similar in Florida ASCs and off ices.
B. Background
The researchers reviewed: "All adverse incident reports to the Florida Board of Medicine for procedure dates April 1, 2000, to April 1, 2002.... The numbers of office procedures performed during a 4-month period were used to estimate the total number of procedures. Ambulatory surgery death summaries, adverse incident data, and volumes of procedures for 2000 were procured from the Florida Agency for Health Care Administration."
Vila et al. concluded from their review of the two-year period that the risk of adverse incidents and deaths was approximately 10 times greater in the office setting than in ASCS, and that if all office procedures had been performed in ASCS, approximately 43 injuries and six deaths per year could have been prevented.
Vila et al. also concluded, without any solid evidence for support, that the presence of anesthesiologists in ASCs "may be a factor in more favorable outcomes."
C. AANA Comments on Vila Study
The AANA agrees that reasonable regulation of surgery and anesthesia in physicians' offices is warranted. The Association has long been proactive in educating anesthesia providers about and advocating for patient safety in the office setting. In 1999, the AANA developed and disseminated the first national Standards for Office Based Anesthesia Practice. The AANA also believes that surgery and anesthesia safety is based on appropriate patient-selection criteria, staffing, equipment, systems, and procedures, and not on the particular type of facility involved.
It is important that appropriate data on deaths and other adverse incidents related to office surgery be collected. Despite the Vila study's numerous methodological problems, the researchers' finding of significantly greater rates of mortality and adverse events in physicians' offices suggests that further study is needed.
Problems with the Study. Two areas of great concern with the Vila study are the following:
The researchers' analysis largely consists of speculation unsupported by hard data, and
The Vila study has major methodological flaws.
Vila et al. state that "anesthesiologists are present in nearly all ASCs and were present in the study reported by Hoefflin et al. in which there were no deaths in more than 23,000 office procedures [Hoefflin, SM, Bornstein, JB, Gordon, M. "General anesthesia in an office-based plastic surgical facility: a report on more than 23,000 consecutive off ice-based procedures under general anesthesia with no significant anesthetic complications." Plast Reconstr Surge. 2001; 107:243-2571. This suggests that their presence may be a factor in more favorable outcomes."
The assertion that office surgery may be safer when an anesthesiologist is present is indefensible, for all of the reasons cited below.
Anesthesiologist researchers have long made these kinds of assertions with little or no data to support their claims. For instance: Should Vila et al. be taken at their word that "anesthesiologists are present in nearly all (emphasis added) ASCS" simply because they say so? Where is the data to support this claim?
"Presence" does not indicate "involvement." Do CRNAs actually administer (provide the hands-on care) in "nearly all" of Florida's ASCS, and are these facilities safer because this is so? Were CRNAs the main hands-on providers of anesthesia in the Hoefflin study? This pertinent information is not included in the Vila paper.
According to the researchers themselves, "A statistical analysis of the impact of requirements for surgeon credentialing, office accreditation, and the presence of an anesthesiologist (emphasis added) could not be determined because of insufficient data on the patients who did not experience adverse incidents' " Five sentences later, Vila et al. go on to speculate about how the presence of anesthesiologists may be a factor in more favorable outcomes, an assertion they had just acknowledged to be unsubstantiated by data!
In stark contrast to what Vila et al. assert is a statement by George Bitar, MD, et al. in their study titled "Safety and Efficacy of Office-Based Surgery with Monitored Anesthesia Care/Sedation in 4778 Consecutive Plastic Surgery Procedures '" published in the January 2003 issue of Plastic and Reconstructive Surgery. Bitar et al. concluded that "...office-based surgery with intravenous sedation, performed by board-certified plastic surgeons and nurse anesthetists, is safe. Appropriate accreditation, safe anesthesia protocols, and proper patient selection constitute the basis for safe and efficacious office-based plastic surgery."
Also in stark contrast to Vila et al.'s assertion are written state- ments from 13 Florida-based office physicians protesting the study's implication that office surgery and anesthesia are not as safe as in ASCS. Collectively, these surgeons reported more than 35,000 procedures using CRNAs to provide the anesthesia care, without any patient deaths or significant complications. There were no anesthesiologists present for these cases. This begs the question: Is it office surgery in general that isn't safe, or merely surgery in a small number of selected physicians' offices?
Vila et al. cite the adoption of office surgery guidelines by the Federation of State Medical Boards (FSMB) as a step toward improving patient safety. Significantly, the FSMB guidelines do not require anesthesiologist involvement in anesthesia care.
Finally, in November 2000, an administrative law judge in Florida struck down a rule proposed by the Florida Board of Medicine that would have had the effect of preventing surgeons from using nurse anesthetists for procedures performed in certain office settings. In a 45-page opinion, Judge William Pfeiffer wrote: "In summary, there is no reliable data demonstrating that Level III office surgery is safer with an anesthesiologist than with a CRNA." (An appellate court overturned Judge Pfeiffer's decision on purely technical grounds unrelated to his factual finding.)
The Vila Study also suffers from numerous methodological flaws. Following are several examples:
Vila et al.'s comments contain some speculation about possible reasons (e.g., presence of an anesthesiologist or type of facility) for differences in outcomes. These must be regarded as pure speculation because the data analyzed are inadequate to address these issues, as the researchers themselves acknowledge in their paper.
In their current form the databases of procedures performed in ASCs and physicians' offices differ so substantially that an accurate comparison of the two is nearly impossible.
Accurate data on the results of surgical procedures performed in physicians' offices is extremely difficult to obtain and, when avail- able, is not directly comparable with publicly available information from hospitals and ambulatory surgical centers.
The actual number of procedures performed in physicians' offices that would qualify for inclusion in the Vila study is unknown.
The definition of adverse incidents used for ASCs differs from that used for physicians' offices.
Vila et al. do not present any data on the completeness of incident reporting for either practice setting.
The time frames encompassed by the ASC and office databases used by Vila et al. are markedly different.
Vila et al. acknowledge the absence of risk adjustment for patient severity in their analysis.
Summary
5. Silber Study in Anesthesiology
Quality of Care in Anesthesia Table of Contents
Practice Documents