RATIONALE: The lambda-mu-sigma (LMS) method is a novel approach that defines the lower limit of normal (LLN) for the ratio of FEV1/FVC as the fifth percentile of the distribution of Z scores. The clinical validity of this threshold as a basis for establishing chronic obstructive pulmonary disease is unknown. OBJECTIVE: To evaluate the association between the LMS method of determining the LLN for the FEV1/FVC, set at successively higher thresholds, and clinically meaningful outcomes. METHODS: Using data from a nationally representative sample of 3,502 white Americans aged 40-80 years, we stratified the FEV1/FVC according to the LMS-LLN, with thresholds set at the 5th, 10th, 15th, 20th, and 25th percentiles (i.e., LMS-LLN5, LMS-LLN10, etc.). We then evaluated whether these thresholds were associated with an increased risk of death or prevalence of respiratory symptoms. Spirometry was not specifically completed after a bronchodilator. MEASUREMENTS AND MAIN RESULTS: Relative to an FEV1/FVC greater than or equal to LMS-LLN25 (reference group), the risk of death and the odds of having respiratory symptoms were elevated only in participants who had an FEV1/FVC less than LMS-LLN(5), with an adjusted hazard ratio of 1.68 (95% confidence interval, 1.34-2.12) and an adjusted odds ratio of 2.46 (95% confidence interval, 2.01-3.02), respectively, representing 13.8% of the cohort. Results were similar for persons aged 40-64 years and those aged 65-80 years. CONCLUSIONS: In white persons aged 40-80 years, an FEV1/FVC less than LMS-LLN5 identifies persons with an increased risk of death and prevalence of respiratory symptoms. These results support the use of the LMS-LLN5 threshold for establishing chronic obstructive pulmonary disease.
RATIONALE: The lambda-mu-sigma (LMS) method is a novel approach that defines the lower limit of normal (LLN) for the ratio of FEV1/FVC as the fifth percentile of the distribution of Z scores. The clinical validity of this threshold as a basis for establishing chronic obstructive pulmonary disease is unknown. OBJECTIVE: To evaluate the association between the LMS method of determining the LLN for the FEV1/FVC, set at successively higher thresholds, and clinically meaningful outcomes. METHODS: Using data from a nationally representative sample of 3,502 white Americans aged 40-80 years, we stratified the FEV1/FVC according to the LMS-LLN, with thresholds set at the 5th, 10th, 15th, 20th, and 25th percentiles (i.e., LMS-LLN5, LMS-LLN10, etc.). We then evaluated whether these thresholds were associated with an increased risk of death or prevalence of respiratory symptoms. Spirometry was not specifically completed after a bronchodilator. MEASUREMENTS AND MAIN RESULTS: Relative to an FEV1/FVC greater than or equal to LMS-LLN25 (reference group), the risk of death and the odds of having respiratory symptoms were elevated only in participants who had an FEV1/FVC less than LMS-LLN(5), with an adjusted hazard ratio of 1.68 (95% confidence interval, 1.34-2.12) and an adjusted odds ratio of 2.46 (95% confidence interval, 2.01-3.02), respectively, representing 13.8% of the cohort. Results were similar for persons aged 40-64 years and those aged 65-80 years. CONCLUSIONS: In white persons aged 40-80 years, an FEV1/FVC less than LMS-LLN5 identifies persons with an increased risk of death and prevalence of respiratory symptoms. These results support the use of the LMS-LLN5 threshold for establishing chronic obstructive pulmonary disease.
Authors: M R Miller; J Hankinson; V Brusasco; F Burgos; R Casaburi; A Coates; R Crapo; P Enright; C P M van der Grinten; P Gustafsson; R Jensen; D C Johnson; N MacIntyre; R McKay; D Navajas; O F Pedersen; R Pellegrino; G Viegi; J Wanger Journal: Eur Respir J Date: 2005-08 Impact factor: 16.671
Authors: Nicholas R Anthonisen; Melissa A Skeans; Robert A Wise; Jure Manfreda; Richard E Kanner; John E Connett Journal: Ann Intern Med Date: 2005-02-15 Impact factor: 25.391
Authors: Carlos A Vaz Fragoso; John Concato; Gail McAvay; Peter H Van Ness; Carolyn L Rochester; H Klar Yaggi; Thomas M Gill Journal: Respir Med Date: 2009-05-21 Impact factor: 3.415
Authors: Nicholas R Anthonisen; John E Connett; Paul L Enright; Jure Manfreda Journal: Am J Respir Crit Care Med Date: 2002-08-01 Impact factor: 21.405
Authors: Carlos A Vaz Fragoso; Thomas M Gill; Gail McAvay; Henry Klar Yaggi; Peter H Van Ness; John Concato Journal: J Investig Med Date: 2011-10 Impact factor: 2.895
Authors: Carlos A Vaz Fragoso; Thomas M Gill; Gail McAvay; Peter H Van Ness; H Klar Yaggi; John Concato Journal: Respir Care Date: 2011-05-20 Impact factor: 2.258