Background: The methacholine challenge test (MCT) is a test of bronchial hyperreactivity used as an aid in the diagnosis of asthma. MCT results are reported as the provocation concentration at which the forced expiratory volume in 1 second (FEV1) decreases 20% (PC20). The requirement for a 20% or greater decrease in FEV1 results in precipitous decreases in FEV1 in some patients.
Objective: To improve MCT safety without compromising accuracy.
Methods: We performed a retrospective analysis of 879 consecutive MCTs (derivation cohort). A novel protocol for MCT was developed and validated in a cohort of 564 MCTs performed in a second institution.
Results: In comparison with a PC20 cutoff of less than 8 mg/mL, a provocation concentration at which the FEV1 decreases 10% (PC10) cutoff of 1 mg/mL or less has a sensitivity of 86%, a specificity of 98%, a positive predictive value (PPV) of 97%, and a negative predictive value (NPV) of 91%. We propose a novel 2-tiered protocol for MCT. If the PC10 is 1 mg/mL or less, bronchial hyperreactivity is present; if the PC10 is greater than 1 mg/mL, the test is continued until the provocative concentration is 8 mg/mL or a 20% decrease in FEV1 is achieved. Compared with the standard protocol, the proposed protocol has a sensitivity, specificity, PPV, NPV, and overall accuracy of 100%, 98%, 97.6%, 100%, and 99%, respectively. The modified protocol would have enabled us to avoid 26 of 42 cases (62%) in which a 40% or greater decrease in FEV1 occurred and would save 0.65 dose for every MCT performed. The 2-tiered protocol performed well in the validation cohort; sensitivity, specificity, PPV, NPV, and overall accuracy were 100%, 98%, 87%, 100%, and 98%, respectively.
Conclusion: The proposed 2-tiered protocol is accurate, saves time, and avoids precipitous decreases in FEV1.
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http://dx.doi.org/10.1016/j.anai.2013.03.004 | DOI Listing |
Prim Care Companion CNS Disord
April 2024
New Jersey Institute for Successful Aging, Rowan-Virtua School of Osteopathic Medicine, Stratford, New Jersey.
Current therapies for multiple sclerosis (MS) often have limited efficacy and side effects, necessitating alternative approaches. Noninvasive brain stimulation (NIBS), such as transcranial direct current stimulation and transcranial magnetic stimulation (TMS), offers potential solutions. Among NIBS techniques, theta burst stimulation (TBS) is notable for its ability to modulate cortical activity.
View Article and Find Full Text PDFMol Genet Metab
November 2023
Departments of Pediatrics and Population Health Sciences, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Clinical Sciences Center (K4/948), Madison, WI 53792, USA. Electronic address:
This Commentary summarizes what the author has learned in 46 years of research on newborn screening (NBS) for cystic fibrosis (CF) combined with healthcare and public health practice. The original expectation was that screening for this relatively common, life-threatening genetic disorder would lead to consistently timely diagnoses in the neonatal period and be equitable. Unfortunately, this ambitious goal has not been achieved in the USA despite the availability of an excellent, although imperfect, 2-tiered screening test employing immunoreactive trypsinogen (IRT) and DNA analysis for pathogenic variants in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR).
View Article and Find Full Text PDFJMIR Res Protoc
February 2020
Clinic for Anaesthesiology, University Medicine Greifswald, Greifswald, Germany.
Background: German emergency medical services are a 2-tiered system with paramedic-staffed ambulances as the primary response, supported by prehospital emergency doctors for life-threatening conditions. As in all European health care systems, German medical practitioners are in short supply, whereas the demand for timely emergency medical care is constantly growing. In rural areas, this has led to critical delays in the provision of emergency medical care.
View Article and Find Full Text PDFAnn Diagn Pathol
December 2019
Department of Pathology and Laboratory Medicine, Zucker School of Medicine at Hofstra Northwell, United States of America. Electronic address:
Background: Colorectal carcinomas are one of the most commonly diagnosed malignancies. There are many prognostic factors relating to clinical course and disease progression, including tumor stage, metastasis, and tumor budding. In 2016, the International Tumor Budding Consensus Conference (ITBCC) created a system to uniformly assess tumor budding.
View Article and Find Full Text PDFCan Pharm J (Ott)
August 2019
Graduate School of Health (Pharmacy) (Donovan, Bajorek), The University of Technology Sydney, Broadway, NSW, Australia.
Objectives: To describe primary care pharmacists' current scope of practice in relation to laboratory testing.
Method: A 2-tiered search of key databases (PubMed, EMBASE, MEDLINE) and grey literature with the following MeSH headings: . We focused on Canada, the United States, the United Kingdom, New Zealand and Australia for this review.
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