COPD in 2016: some answers, more questions

WW Labaki, CH Martinez, MLK Han - The Lancet Respiratory …, 2016 - thelancet.com
WW Labaki, CH Martinez, MLK Han
The Lancet Respiratory Medicine, 2016thelancet.com
2016 Research Highlights 942 www. thelancet. com/respiratory Vol 4 December 2016
appealing strategy for the implementation of disease-modifying interventions. In its 2016
update, the US Preventive Services Task Force (USPSTF) maintained its 2008
recommendation against screening for COPD in asymptomatic adults, citing an absence of
net benefit in this patient population. 3 Although this recommendation is based on the best
available evidence, it is worth noting that the key word is asymptomatic. Hence the …
2016 Research Highlights
942 www. thelancet. com/respiratory Vol 4 December 2016 appealing strategy for the implementation of disease-modifying interventions. In its 2016 update, the US Preventive Services Task Force (USPSTF) maintained its 2008 recommendation against screening for COPD in asymptomatic adults, citing an absence of net benefit in this patient population. 3 Although this recommendation is based on the best available evidence, it is worth noting that the key word is asymptomatic. Hence the recommendation should not be interpreted as precluding thorough evaluation of those at increased risk of COPD who are not truly asymptomatic because of self-restriction of activity to minimise symptoms. The best approach for such COPD case-finding strategies needs to be further investigated.
Currently, a diagnosis of COPD is made on the basis of a post-bronchodilator FEV1 to forced vital capacity (FVC) ratio of less than 0· 70 on spirometry. 4 However, many smokers without airflow obstruction (FEV1: FVC> 0· 70) still have dyspnoea, cough, sputum production, and wheezing in the same way as those with airflow obstruction. Woodruff and colleagues5 showed that, among current or former smokers with preserved pulmonary function, those who were symptomatic (as defined by a COPD Assessment Test [CAT] score≥ 10) had a higher rate of respiratory exacerbations, a shorter 6-min walk distance, and greater airway wall thickening on chest CT than those who were asymptomatic. However, whether these patients represent a trans itional pre-COPD phase or a separate clinical entity remains uncertain. Moreover, many individuals studied were already being given bronchodilators, underscoring the need to establish a therapeutic evidence base for this patient population. Although COPD exacerbations substantially contribute to the morbidity and mortality of the disease, the association between exacerbations and decline in lung function has until now been informed by small studies. In a longitudinal analysis of 2000 individuals followed for 5 years, Dransfield and coworkers6 showed that respiratory exacerbations were associated with an accelerated decline in lung function that was most pronounced in individuals with mild disease. This association was not observed in current or former smokers without airflow obstruction. Whether reduc tion in exacerbation frequency through early aggressive therapy results in less rapid decline in lung func tion is unknown.
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