Lessons from the major studies in COPD: problems and pitfalls in translating research evidence into practice

Abstract

SummaryTranslating the growing evidence base on COPD management into practice can be challenging and understanding the strengths and weakness of published studies is crucial. Studies should conform to the standards of CONSORT statement; they should be sufficiently powered, participants should be randomised, there should be assignment concealment, and the outcome measures and analyses should be decided in advance.The interpretation of the results may be affected by age and severity inclusion criteria for the study and the exclusion of patients with co-morbid illnesses. Whether previous medication is continued or stopped can affect the interpretation of the results. Secondary analyses in sub-groups should be viewed with caution unless pre-specified and accommodated in the trial design and power calculations. Real world observational studies may be confounded by non-randomisation of participants but can sometimes yield valuable insights.The way in which the results are presented can influence their interpretation and their magnitude with respect to minimal important differences as well as statistical significance is important.Research studies help formulate management algorithms but often the questions they address are too specific to allow evidence-based sequencing of therapies.

Chronic obstructive pulmonary disease self-management activation research trial (COPD–SMART): Results of recruitment and baseline patient characteristics

“…Study populations for most pharmacological and non-pharmacological trials of patients with COPD are often not representative of patients with COPD [4,5,37,38]. In pharmacological trials patients are often excluded because of co-morbid conditions or current medication use [34].…”

Comparative Causal Analysis of the Effects of Long-Acting Muscarinic Antagonist Versus No Long-Acting Bronchodilator Use on Readmission or Mortality After Hospitalization for Chronic Obstructive Pulmonary Disease

“…However, RCTs are conducted in controlled settings and historically have not included populations that are generally representative of real-world populations. Importantly, older individuals are frequently excluded from COPD RCTs, as are individuals with asthma and many other comorbidities [28]. While there is RCT-based evidence for LAMA effectiveness in reducing exacerbation-associated hospitalization risk, LAMA effectiveness at reducing the risk of readmission or mortality after a COPD-related hospitalization in a real-world population has not been well studied.…”

Is the family physician an accomplice in the development of the ‘primary care gap’? The importance of high quality real-life primary care respiratory research

“…In a recent Scottish study, the median time from the earliest reported symptom to consultation was 99 days, 8 and a questionnaire revealed that 75% of participants had unrecognised symptoms of lung cancer. The presence of COPD, which increases the risk of lung cancer up to five times, 9 often delays diagnosis. Estimates suggest that the causes for delay between first symptom and presentation to specialist care can be split equally between patient-related and primary care-related issues.…”

“…A recent study suggests that a median of only 6% (range 0% -43%) of patients treated for asthma meet the eligibility criteria for major trials cited in evidencebased treatment guidelines. 8 In his excellent article published in the PCRJ in 2010, 9 Halpin outlines many fundamental limitations of landmark COPD trials and how such trial data may be difficult to apply at the primary care level. For example, in relation to trials such as ISOLDE, 10,11 TORCH 12 and UPLIFT, 13 there has been minimal, if any, discussion around the pragmatic implications of high early withdrawal rates from the active treatment arms in these studies -a reality that invariably compounds the difficulty of translating trial information into the most cost-effective care for our primary care patients.…”