Simple Fixed Threshold IDs Those at Risk for COPD-Related Events
FEV1:FVC of 0.70 not significantly different from optimal threshold, better than LLN threshold
TUESDAY, July 9, 2019 (HealthDay News) -- Use of a threshold of airflow obstruction of forced expiratory volume in one second:forced vital capacity (FEV1:FVC) of 0.70 discriminates chronic obstructive pulmonary disease (COPD)-related hospitalization and mortality, according to a study published in the June 25 issue of the Journal of the American Medical Association.
Surya P. Bhatt, M.D., from the University of Alabama at Birmingham, and colleagues examined the discriminative accuracy of various FEV1:FVC fixed thresholds for predicting COPD-related hospitalization and mortality using pooled data for 24,207 adults from four U.S. cohorts. Complete data were available for 11,077 individuals at 15 years.
The researchers found that 3,925 participants experienced COPD-related events during 340,757 person-years of follow-up, including 3,563 COPD-related hospitalizations and 447 COPD-related deaths. With respect to discrimination of COPD-related events, the investigators found no significant difference between the optimal fixed threshold (0.71; C-statistic, 0.696) and the 0.70 threshold (difference, 0.001; 95 percent confidence interval, −0.002 to 0.004); however, the optimal fixed threshold was more accurate than the lower limit of normal threshold (difference, 0.034; 95 percent confidence interval, 0.028 to 0.041). In the subgroup analysis of ever smokers and in adjusted models, the 0.70 threshold provided optimal discrimination.
"We were able to show that a simple fixed threshold worked well in our study's very diverse sample, which improves the generalizability of our results," a coauthor said in a statement.
Several authors disclosed financial ties to the pharmaceutical industry.