Abstract: Slide Presentations |

A decrease in the maximum concentration of methacholine administered during bronchoprovocation testing does not improve short-term military retention in a United States Marine Corps recruit population FREE TO VIEW

Christopher M. Stafford, MD*; Erik J. Storlie, MD; Travis G. Deaton, MD; Rich T. Mahon, MD; David A. Bradshaw, MD
Author and Funding Information

Naval Medical Center, San Diego, CA


Chest. 2004;126(4_MeetingAbstracts):705S. doi:10.1378/chest.126.4_MeetingAbstracts.705S-b
Text Size: A A A
Published online


PURPOSE:  Bronchoprovocation testing with methacholine is used to determine bronchial hyperresponsiveness in United States Marine Corps (USMC) recruits suspected to have asthma. We recently modified our methacholine challenge testing (MCT) protocol by lowering the maximum final PC20 concentration from 25 to 16 mg/ml to reflect the current American Thoracic Society guidelines. We hypothesized that lowering the maximum concentration would decrease the number of recruits diagnosed with airway hyperresponsiveness and thereby increase recruit graduation rates.

METHODS:  A retrospective chart review was performed on all MCTs completed by USMC recruits referred for possible asthma during a two-year period to compare the percentage of positive methacholine challenge tests. If the initial methacholine challenge was negative, subsequent graduation rates were determined and compared.

RESULTS:  The percentage of positive methacholine challenge tests did not change after switching to a lower dose protocol (48.0% versus 45.1%, p=0.773). The overall graduation rate for recruits who had a negative methacholine challenge was significantly higher in high dose protocol compared to low dose protocol (85.4 % versus 53.3%, p=0.002) although no recruit who had a negative methacholine challenge with the low dose protocol was subsequently diagnosed with asthma during the remainder of recruit training.

CONCLUSION:  Modifying the methacholine challenge protocol to lower the maximum PC20 concentration did not change overall short-term retention as measured by completion of recruit training.

CLINICAL IMPLICATIONS:  This study suggests that a methacholine challenge protocol with a maximum concentration of 16 mg/ml can be safely administered without a significant false negative result. 2001 (HDP)2002 (LDP)DifferenceSubjects referred for asthma who completed MCT10688P = 0.1951Age (years)19.0 +/− 1.4219.4 +/− 1.82P = 0.1043Subjects with positive MCT51 (48.1%)40 (45.5%)P = 0.7731Mean PC20 (mg/ml)11.1 +/− 10.127.1 +/− 5.92P = 0.0743Negative MCT separated for asthma1 (2.1%)0P = 1.001Negative MCT and successful graduation41 (85.4%)16 (53%)P = 0.0021Negative MCT separated for non-asthma conditions6 (12.5%)14 (46%)P = 0.00111 = Calculated with Fisher’s exact test2 = Calculated as mean +/− standard deviation3 = Calculated with rank sum test

DISCLOSURE:  C.M. Stafford, None.

Monday, October 25, 2004

10:30 AM- 12:00 PM




Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

CHEST Journal Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543