Trial reportAnnals of the American Thoracic Society2018
The Effect of Defining Chronic Obstructive Pulmonary Disease by the Lower Limit of Normal of FEV
Trial report in Annals of the American Thoracic Society, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01126437 (A Randomized, Active-controlled, Double-blind, Double-dummy, Parallel Group Design, Multi-center Trial to Compare the Efficacy and Safety of 2.5 µg and 5 µg Tiotropium Inhalation Solution Delivered by the Respimat Inhaler With Tiotropium Inhalation Capsules 18 µg Delivered by the HandiHaler), which is not on this map. Cited by 12 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Randomized, Active-controlled, Double-blind, Double-dummy, Parallel Group Design, Multi-center Trial to Compare the Efficacy and Safety of 2.5 µg and 5 µg Tiotropium Inhalation Solution Delivered by the Respimat Inhaler With Tiotropium Inhalation Capsules 18 µg Delivered by the HandiHaler (TIOSPIR)
Who cites it
12 citing papers in PubMed.
- Health status and prognosis of COPD patients in relation to the FEVNPJ primary care respiratory medicine · 2026Article
- Construction and Validation of Active Case-Finding Tool in Community Participants with Chronic Obstructive Pulmonary Disease Using an Interpretable Machine Learning Approach.International journal of chronic obstructive pulmonary disease · 2026Article
- Clinical significance of a flattening index derived from the flow-volume loop.Frontiers in physiology · 2026Article
- Tiotropium in Patients With Airflow Limitation According to the Fixed Ratio But Not the Lower Limit of Normal: A Secondary Analysis of the Tiotropium in Early-COPD Study.Chronic obstructive pulmonary diseases (Miami, Fla.) · 2025Article
- Prevalence of respiratory symptoms and lung function impairments among woodworkers in Gondar City.Scientific reports · 2025Article
- Development of airflow limitation, dyspnoea, and both in the general population: the Nagahama study.Scientific reports · 2022Article
- ACO (Asthma-COPD Overlap) Is Independent from COPD: The Case in Favour.Diagnostics (Basel, Switzerland) · 2021Review
- Defining Airflow Obstruction: More Data, Further Clarity.American journal of respiratory and critical care medicine · 2020Article
- Fixed Ratio versus Lower Limit of Normality for Diagnosing COPD in Primary Care: Long-Term Follow-Up of EGARPOC Study.International journal of chronic obstructive pulmonary disease · 2020Article
- Update in Chronic Obstructive Pulmonary Disease 2018.American journal of respiratory and critical care medicine · 2019Article
- Diagnosis of Chronic Obstructive Pulmonary Disease: Breathing New Life into an Old Debate.Annals of the American Thoracic Society · 2018Article
- Predictors of accelerated FEVChronic respiratory diseaseArticle
Corrections and comments
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Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
rationaleThere is continuing debate about whether to define airflow obstruction by a post-bronchodilator ratio of forced expiratory volume in 1 second (FEV
objectivesTo determine whether using the LLN criterion affects the classification and outcomes of patients previously defined as having chronic obstructive pulmonary disease by the fixed FEV
methodsWe applied the LLN definition to pooled data from the Tiotropium Safety and Performance in Respimat study that used the fixed FEV
resultsA total of 17,072 patients were analyzed; of these, 1,807 (10.6%) patients had a ratio greater than or equal to LLN. Patients with a ratio greater than or equal to LLN had similar risks of death from any cause and fatal major adverse cardiovascular (CV) event as those below LLN. Patients with a ratio below LLN had a significantly lower risk of major adverse CV events (hazard ratio = 0.69; 95% confidence interval [CI] = 0.55-0.86; P = 0.001), and had significantly greater risks of moderate to severe exacerbation (rate ratio = 1.48; 95% CI = 1.36-1.61; P < 0.0001) and severe exacerbation (rate ratio = 2.01; 95% CI = 1.68-2.40; P < 0.0001) when compared with patients greater than or equal to LLN. Study outcomes by treatment arm (5 μg tiotropium Respimat vs. 18 μg HandiHaler) were comparable.
conclusionsUsing the LLN to define airflow obstruction would have excluded patients in the Tiotropium Safety and Performance in Respimat study with a higher risk of nonfatal major adverse CV events and a lower risk of exacerbation; study outcomes by treatment arm (2.5 μg/5 μg tiotropium Respimat vs. 18 μg HandiHaler) remained similar. Clinical trial registered with www.clinicaltrials.gov (NCT01126437).
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28957643What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.