Factors Influencing on Correctness of Inhalation Technique.

Asthma and chronic obstructive pulmonary disease (COPD) are common chronic diseases of respiratory system. Asthma affects about 5% of adults in Poland. The inhaling therapy is the cornerstone of asthma treatment, especially inhaled glucocorticosteroids (ICS). The correct use of inhalers is crucial for efficiency of the therapy and reduction of undesirable side effects of medications. COPD is also a common chronic respiratory disease that affects about 10% of adults above 40 years old. The most important action to prevent and to treat COPD is to stop smoking. The main medications used by COPD patients are inhaled bronchodilators. Both asthma and COPD patients misuse the inhalers.

The objective of this study is to determine the factors influencing the number of inhalation errors committed by asthma and COPD patients when using the inhalers.

Patients:

Patients with asthma or COPD treated in hospital or in out-patient clinic will be asked for participating in the study. Power analysis and sample size calculations indicated that a sample size of 215 subjects (with either asthma or COPD) would provide statistical power to detect even weak correlation (r=0.2) assuming error alpha = 0.05, beta = 0.20 and 10% drop out.

Study design

In included patients inhalation technique will be evaluated (by both list of inhalation errors and 4 point scale of proper inhaling) by two observers and the below information will be gathered:

• general demographic information and education level
• information concerning time of diagnosis, the previous course of disease, smoking history, number of previous inhalation techniques training, the sources of information about the inhalation technique and adherence to therapy
• Asthma Control Test and COPD Assessment Test respectively for asthma and COPD
• assessment of quality of life with the disease (St. George's Questionnaire for COPD and Asthma Quality of Life Questionnaire for asthma)
• cognitive functions assessment using Mini-Mental State Examination
• the simplified assessment of vision impairments
• the results of spirometry The main outcome will be correlation between inhalation technique and other above mentioned factors.

Identification of factors influencing the inhaling errors in patients with asthma or COPD will enable to plan the actions to improve the efficiency of inhaler medications use. At the end of the study all patients will be taught how to use their inhalers properly.

Inclusion criteria

• Informed consent for participating in the study
• Age 18 -85 years
• COPD or asthma diagnosed at least 3 months prior to enrolment
• using of at least one inhaler regularly every day
• using one of the inhalers: Metered Dose Inhalers (MDI), Dry Powder Inhalers (DPI) or Metered Dose Liquid Inhalers (MDLI)

Exclusion criteria

• Lack of informed consent
• Age <18 years or > 85 years old
• Diagnosis of asthma or COPD shorter than 3 months before enrollment
• Using inhalers unregularly.
• Symptoms of infection 5 days prior to beginning of the study