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Armin Ernst, MD, FCCP; Michael Simoff, MD, FCCP; David Ost, MD, FCCP; Felix Herth, MD, FCCP
Author and Funding Information

Correspondence to: Armin Ernst, MD, FCCP, Chief, Interventional Pulmonology, Beth Israel Deaconess Medical Center, Harvard Medical School, One Deaconess Rd, Deaconess 201A, Boston, MA 02215; e-mail: aernst@bidmc.harvard.edu


The authors have reported to the ACCP that no significant conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.

Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/site/misc/reprints.xhtml).


© 2009 American College of Chest Physicians


Chest. 2009;135(5):1402-1403. doi:10.1378/chest.09-0242
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To the Editor:

We appreciate the opportunity to reply to the letter by Dr. Ouellette1 in regard to our article2 on risk-adjusted outcome analysis after interventional bronchoscopic procedures.

We are unclear what Dr. Ouellette means with the title of the letter and the statement that the data reported were “uncontrolled.” In our report,2 the data were collected prospectively, and all data fields were defined before the data-entering process started. The reported outcome data were clearly controlled for quality, patient illness, and intervention performed. This represents an enormous step forward in our field, in which most reported outcomes have been collected retrospectively and generally have been uncontrolled.

By “uncontrolled,” Dr. Ouellette might also mean that there was no sham control arm or nontreatment group. This was not a randomized controlled trial (RCT), but rather a prospective observational study to assess morbidity and mortality. Hence, there are no claims or assertions for the superiority of any particular treatment option. The evidence base in interventional pulmonology does not contain many RCTs, especially for well-established interventions, such as airway stenting and ablative techniques, such as Nd-YAG laser ablation. Most reports in the surgical literature also do not have RCT evidence. However, new interventions, such as bronchoscopic treatments for emphysema, have been designed with sham control arms and are underway.

But are RCTs always necessary for investigating all things? In our opinion, no. Indeed, such a claim misrepresents the evidence-based medicine approach. Evidence-based medicine does not limit itself to one method of investigation in order to draw inferences. Indeed, the American College of Chest Physicians lung cancer guidelines3 state that high-quality evidence includes RCTs without important limitations or overwhelming evidence from observational studies. The techniques used in our study are well-established therapeutic techniques that demonstrate a high level of directly observable effects. Patients in respiratory failure who stop receiving mechanical ventilation immediately after successful ablation and stent placement clearly constitute “overwhelming observational evidence.” This is not to say that all patients can benefit but is merely to state that in certain carefully selected patients there is overwhelming observational evidence that these techniques are of benefit (grade 1A). The majority of cases fall into a gray zone (ie, grade 1B, 1C, or even 2C), and much of the work of evidence-based medicine must therefore revolve around risk/benefit quantification for these groups. This highlights the importance of proper patient selection.

The assertion that this is analogous to prior arguments in favor of the use of pulmonary artery catheters is weak. The interventions described are therapeutic, whereas the pulmonary artery catheter is diagnostic. As such, the nature of the evidence, the reference standards of truth, and the definition of a proper control are different. Pulmonary artery catheters provide information but not treatment. The interventions described produce directly observable effects. While we might agree that the evidence basis for pulmonary artery catheters impacting outcome is weak, that has no bearing on the interventions discussed in this article.2

To argue that all bronchoscopic interventions need to be proven by RCTs is clearly flawed. Certainly, there is a need for RCTs to prove the efficacy of some bronchoscopic interventions, such as those for COPD and asthma. But for other interventions, such as stenting for malignant airway obstruction in carefully selected patients, the observational evidence meets the standard for a 1A evidence grade. To assert that conducting RCTs for all bronchoscopic interventions is warranted is less like the debate over pulmonary artery catheters and more like a debate over whether we should require RCTs for parachutes.4 Of course, brave volunteers are always needed for additional studies, and we can probably get a statistically significant result with a fairly small sample size, although study enrollment may be a bit slow.

We do agree that more outcome data would be helpful. Our collection was not designed to assess functional outcomes of interventions or quality of life. As the title of our article stated, it was a morbidity and/or mortality analysis. In order to establish best practices and to assess the comparative value of interventional procedures, additional data fields would need to be added. Our article showed that diligent data collection is feasible and valuable, a necessary first step in the design of any registries or databases. The next step will be the design and implementation of more advanced and Web-based databases.

Ouellette D. The Emperor wears no clothes. Chest. 2009;135:1402. [PubMed] [CrossRef]
 
Ernst A, Simoff M, Ost D, et al. Prospective risk-adjusted morbidity and mortality outcome analysis after therapeutic bronchoscopic procedures: results of a multi-institutional outcomes database. Chest. 2008;134:514-519. [PubMed]
 
McCrory DC, Lewis SZ, Heitzer J, et al. Methodology for lung cancer evidence review and guideline development. Chest. 2007;132suppl:23S-28S. [PubMed]
 
Smith GC, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ. 2003;327:1459-1461. [PubMed]
 

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References

Ouellette D. The Emperor wears no clothes. Chest. 2009;135:1402. [PubMed] [CrossRef]
 
Ernst A, Simoff M, Ost D, et al. Prospective risk-adjusted morbidity and mortality outcome analysis after therapeutic bronchoscopic procedures: results of a multi-institutional outcomes database. Chest. 2008;134:514-519. [PubMed]
 
McCrory DC, Lewis SZ, Heitzer J, et al. Methodology for lung cancer evidence review and guideline development. Chest. 2007;132suppl:23S-28S. [PubMed]
 
Smith GC, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. BMJ. 2003;327:1459-1461. [PubMed]
 
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