Repeated instruction on inhalation technique improves adherence to the therapeutic regimen in asthma.
BACKGROUND
Adherence to inhalation therapy is a critical determinant of the success of asthma management. Reasons for nonadherence have been well studied, but reasons for good adherence are poorly understood. Understanding the mechanisms of adherence to inhalation therapy is important in developing strategies to promote adherence. The objective of this study was to assess the factors and mechanisms that contribute to and the clinical outcomes relating to adherence to inhalation therapy.


METHODS
The factors and outcomes related to adherence to inhalation therapy were examined cross-sectionally in 176 adults with asthma using a self-reported adherence questionnaire that consisted of four items dealing with the use of inhaled controller medications. A 5-point Likert scale was used for the responses to each item. Adherence was assessed based on the overall mean adherence score.


RESULTS
Of the 176 patients who were potential participants, 146 (83%) responded with usable information. Significant factors associated with the overall mean adherence score were older age (r = .18, p = .032) and receiving repeated instruction on inhalation techniques (p = .0016). Of the 146 respondents, 25 (17.1%) patients were given repeated verbal instruction or demonstrations of inhalation technique by a respiratory physician. On logistic regression analysis, good adherence to inhalation therapy was significantly related to the receiving of repeated instruction on inhalation technique, with an odds ratio of 2.90 (95% confidence interval 1.07-7.88; p = .037). Furthermore, less intentional nonadherent behavior was reported in patients with repeated instruction on inhalation technique compared to those without it. A significant correlation was found between the overall mean adherence score and the frequency of asthma exacerbations (r = -.19, p = .021), emergency room visits (r = -.19, p = .042), and the health-related quality of life score (St. George's Respiratory Questionnaire: Total, r = -.22, p = .024; Symptoms, r = -.21, p = .022; Impacts, r = -.20, p = .035).


CONCLUSIONS
Repeated instruction on inhalation techniques may contribute to adherence to inhalation therapy through decreasing intentional nonadherence. Furthermore, good adherence to the therapeutic regimen may offer good asthma-related outcomes.
Takemura
Masaya
M
Division of Respiratory Medicine, Kitano Hospital, Tazuke Kofukai, Medical Research Institute, Osaka, Japan. YHY01454@nifty.com
Kobayashi
Michiru
M
Kimura
Kiyomi
K
Mitsui
Katsumi
K
Masui
Hiroko
H
Koyama
Misuzu
M
Itotani
Ryo
R
Ishitoko
Manabu
M
Suzuki
Shinko
S
Aihara
Kensaku
K
Matsumoto
Masataka
M
Oguma
Tsuyoshi
T
Ueda
Tetsuya
T
Kagioka
Hitoshi
H
Fukui
Motonari
M
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use; D000328:Adult; D000367:Age Factors; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy*; D003430:Cross-Sectional Studies; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D055118:Medication Adherence / Q000523:psychology; D036501:Metered Dose Inhalers / Q000706:statistics & numerical data; D008875:Middle Aged; D009330:Nebulizers and Vaporizers / Q000706:statistics & numerical data*; D016017:Odds Ratio; D010353:Patient Education as Topic / Q000379:methods / Q000706:statistics & numerical data*; D011788:Quality of Life; D012737:Sex Factors; D011795:Surveys and Questionnaires; D016903:Drug Monitoring
D000305:Adrenal Cortex Hormones