Background Despite currently available treatment, 13.9% of patients admitted to hospital for exacerbations of chronic obstructive pulmonary disease (COPD) die within 3 months, and fewer than half survive 5 years. Most of the cost of COPD to the UK health service, which approaches £1bn/year, is associated with the treatment of exacerbations. There is clearly a need to improve outcomes of patients admitted to hospital for exacerbations, and yet relatively few research studies attempt to recruit patients specifically during this phase of their illness.
Methods During 2010–2011, two studies were conducted within our institution recruiting patients hospitalised for COPD exacerbations. One was an observational study with relatively broad entry criteria; the other was a randomised, controlled, interventional trial with more stringent entry criteria (ISRCTN66148745). We analysed the screening logs to identify eligibility rates and potential barriers to recruitment, and to provide a guide for researchers on the feasibility of proposed studies in similar populations elsewhere.
Results In the 12-month period commencing March 2010, 172 patients were screened for entry to the observational study. In the period January to June 2011, a further 72 patients, not included in the first study, were screened for entry into the clinical trial. Significant exclusion criteria for each study protocol for were identified; for comparison, these are represented across organ systems (Abstract P216 table 1). 29% of those screened for the observational study were eligible for inclusion and 11% for the clinical trial. The clinical trial identified more renal and metabolic conditions, reflecting their particular relevance to experimental drug administration. The observational study identified more physical factors, such as frailty, which may limit patients' ability to engage with observational research tasks.
Conclusion Patients hospitalised for COPD exacerbations are heterogeneous and have significant and diverse co-morbidities which may limit their eligibility for research studies. In view of this, broad entry criteria are necessary to ensure that studies in this population are feasible. With careful design, such studies will be pivotal in driving improved treatment and outcomes among these patients who, despite their poor prognosis, presently receive disproportionately little research attention.