Introduction COPD and Asthma affect more than 10% of the population. Most patients use their inhaler incorrectly, mainly the elderly, thereby becoming more susceptible to poor clinical control and exacerbations. Placebo device training is regarded as one of the best teaching methods, but there is scarce evidence to support it as the most effective one to improve major clinical outcomes. Our objective is to perform a single-blinded RCT to assess the impact of this education tool in these patients.

Methods and Analysis A multicentre single-blinded RCT will be set, comparing a placebo-device training programme versus usual care, with a one-year follow-up, in elderly patients with Asthma or COPD. Intervention will be provided at baseline, and after 3 and 6 months, with interim analysis at an intermediate time point. Exacerbation rates were set as primary outcomes, and quality of life, adherence rates, clinical control and respiratory function were chosen as secondary outcomes. A sample size of 146 participants (73 in each arm) was estimated as adequate to detect a 50% reduction in event rates. Two-sample proportions Chi-squared test will be used to study primary outcome and subgroup analysis will be carried out according to major baseline characteristics.

Discussion The investigators expect to confirm that inhaler performance education will significantly reduce exacerbation rate and improve clinical and functional control.

Ethics and dissemination:

Every participant will sign a consent form. A Data Safety Monitoring Board will be set up to evaluate data throughout the study and to monitor stop earlier criteria. Identity of all participants will be protected. Results will be presented in scientific meeting and published in peer-reviewed journals.

Inclusion Criteria:

• Patients with a diagnosis of COPD or Asthma, medicated with any kind of inhaler device (pressurized Metered Dose Inhaler (pMDI) with or without Spacer, Dry Powder Inhaler (DPI) or Soft Mist), aged ≥65 years and being a regular user of primary health care services (defined as having at least one consultation performed in the last two years with his/her own Family Doctor). In order to minimize diagnostic inaccuracy, Asthma and COPD diagnosis will be reviewed in every participant at baseline prior to enrolment and according to GINA and GOLD strategies.

Exclusion Criteria:

• Severe or acute illness (such as unstable cardiovascular status, unstable angina, recent myocardial infarction (within one month) or pulmonary embolism, haemoptysis of unknown origin, recent pneumothorax (within one month), recent thoracic, abdominal or eye surgery (within one month), acute nausea or vomiting, severe respiratory distress, dementia). Patients with intermittent asthma, as well as COPD patients with mild obstruction (GOLD class I) will be excluded, since these patients do not need to take inhaler medication on a daily basis, and tend to have a low frequency of disease exacerbations.

Elderly patients

All data from the trial will be kept in a safe place of the principal investigator's institutional facilities and by the Data Safety Monitoring Board, in accordance with the national and international clinical research policies.

Blinding for the investigator that acess outcomes, that will not be involved in the intervention process.