While research has made large strides in the assessment and treatment of patients with COPD in recent years, a number of important questions remain to be answered. The American Thoracic Society and European Respiratory Society have teamed up to publish a joint statement that describes current evidence on the diagnosis, assessment, and management of COPD; identifies gaps in knowledge; and makes recommendations for future research.
Perhaps the biggest need that spans all areas of COPD research is to determine which outcomes matter most to patients and then to ensure that research studies measure these outcomes. “Understanding what patients care about is the basis of patient-centered care,” says Kevin C. Wilson, MD, co-author of the statement, which was published in the American Journal of Respiratory and Critical Care Medicine. Physiological and/or anatomical outcomes are used frequently in studies because they tend to be easier to measure. Such surrogate outcomes, however, should strongly correlate with patient-centered outcomes if they are used in clinical research. Examples of patient-centered outcomes include quality of life, dyspnea, and frequency and severity of exacerbations.
Determining the optimal method for diagnosing COPD based on spirometry is another important research need according to Dr. Wilson. It is undetermined whether the diagnosis of COPD should be based upon a fixed threshold or the lower limit of normal for the FEV1/FVC ratio. A post-bronchodilator FEV1/FVC ratio of less than 0.7 has traditionally been the criterion for airflow limitation. However, this threshold may result in more frequent identification of airflow limitation among the elderly and less frequent diagnoses among patients younger than 45 when compared with a threshold based on the lower limit of normal.
Phenotyping data is another big need in the clinical assessment and management of COPD. “Research is needed to determine which patients respond better to specific therapies,” Dr. Wilson says. “Evidence suggests that patients with certain characteristics might respond better to ‘therapy A,’ whereas patients with different characteristics may respond better to ‘therapy B.’”
Dr. Wilson also notes that a number of indexes are currently used to determine prognosis in patients with COPD. Although the prognostic accuracy of each has been confirmed in separate studies, few studies have directly compared the indexes with one another.
Improving knowledge of the interaction between COPD and the comorbidities that patients with the disease often have is of the utmost importance, according to Dr. Wilson. “Most clinical guidelines and standards are written for the care of patients with COPD only,” He says. “However, less than 10% of patients older than 65 have COPD alone. Little is also known about how therapies for other diseases impact COPD and how COPD therapies affect other diseases.”
Clinicians should know the limits of the evidence on which they base their actions, says Dr. Wilson. “It’s important to know whether a clinical decision is based upon sound evidence and should be carried out, or based upon little evidence and more appropriate for a case-by-case approach.” Overall, Dr. Wilson and colleagues hope their recommendations on COPD research needs will help the fight to alleviate some of the burden caused by COPD, a disease that currently ranks as the third leading cause of mortality in the United States.”
Celli B, Decramer M, Wedzicha J, et al. An official American Thoracic Society/European Respiratory Society Statement: Research Questions in chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2015;191:e4-e27. Available at www.thoracic.org/statements/resources/copd/copd-research-st.pdf.
Thun M, Carter B, Feskanich D, et al. 50-year trends in smoking-related mortality in the United States. N Engl J Med. 2013;368:351-364.
Guarascio A, Ray S, Finch C, Self T. The clinical and economic burden of chronic obstructive pulmonary disease in the USA. Clinicoecon Outcomes Res. 2013;5:235-245.
Vestbo J, Hurd S, Agust´ı A, Jones P, et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Respir Crit Care Med. 2013;187:347-365.