Objective: COPD patients have challenges for effective use of inhalers due to advanced age, fixed airflow obstruction and comorbid medical conditions. Published clinical trials investigate drug efficacy but rarely consider the inhaler device. This trial investigates device efficacy, comparing clinical outcomes for the same medication via two different devices. Our intention was to communicate the results and to critically appraise the study protocol to inform planning of future device comparison research. Subjects with spirometry confirming at least moderate COPD were randomly assigned to inhaler sequence; starting with Accuhaler or metered dose inhaler and spacer (MDI/s). After baseline testing, subjects were assigned to fluticasone propionate/salmeterol xinafoate (SFC) 500/50 mcg twice daily via the first device for 6 weeks' duration, then changed to the alternate device for the following 6 weeks. Subjects were reassessed in terms of health-related quality of life (HRQL), exercise endurance and lung function after each exposure period.
Results: The recruitment target was not achieved due to unanticipated developments within the pharmaceutical industry, potentially compromising the study's power. Study outcomes did not differ significantly according to the allocated inhaler device even after adjusting for baseline lung function or inhaler technique. Recommendations for future device comparison protocols are offered. Trial registration Australia and New Zealand Clinical Trials Registry, Current Controlled Trials ACTRN12618000075280, date of registration: 18.01.2018. Retrospectively registered.
Keywords: Assessor-blind method; Chronic obstructive; Cross over; Inhalation devices; Pulmonary disease; Quality of life.