Personality and unachieved treatment goals related to poor adherence to asthma medication in a newly developed adherence questionnaire - a population-based study.

BACKGROUND: Health-care professionals have a responsibility to be attentive to patients' adherence behavior but it could be difficult to identify poor adherence in the context of clinical practice. Assessment of personality could be used to identify individuals who are in need for support with their adherence behavior. To our knowledge, existing adherence questionnaires are not based on individuals reflecting asthmatics in the general population and there is limited research describing adherence with asthma medication in relation to personal goals with the treatment. The aim was to develop and validate an adherence questionnaire in adult individuals with asthma from the general population and to assess adherence in relation to personality traits and goals with the asthma medication using the developed questionnaire.

METHODS: The study was conducted in three phases: 1. A preliminary postal 46-item questionnaire was refined after psychometric testing (n = 157). 2. The questionnaire was validated (n = 104). 3. The developed adherence questionnaire was analyzed in relation to personality traits and achieved goals with the asthma medication. Adult respondents with physician diagnosed asthma using asthma medications were selected from the population-based West Sweden Asthma Study. The respondents completed the Neuroticism, Extraversion and Openness to Experience Five-Factor Inventory and the Medication Adherence Report Scale and stated their goals with the asthma medication. Data were analyzed using t-tests, correlations, multiple regression and principal component analysis.

RESULTS: A final questionnaire was developed consisting of ten items organized in three subscales - "medication routines", "self-adjusting the medication" and "concerns about side-effects". Two of the subscales - "medication routines" and "self-adjusting the medication" - were associated with the Medication Adherence Report Scale. The subscale "medication routines" was associated with the personality traits - Conscientiousness and Neuroticism and unachieved goals with the asthma medication.

CONCLUSIONS: The developed questionnaire appears to be useful for measuring adherence to asthma medication in adult individuals with asthma. The study suggests that both individual differences and personal treatment goals need to be addressed in efforts to promote adherence to asthma medication treatment.