Development and preliminary validation of the Adult Asthma Adherence Questionnaire™.

BACKGROUND

Asthma medication adherence is related to better asthma outcomes, but identification of suboptimal patient adherence behavior is not standardized in clinical settings.

OBJECTIVE

[corrected] The purpose of this study was to develop a practical questionnaire that reflects nonadherence risk and identifies potential adherence barriers.

METHODS

A questionnaire that included 20 potential adherence questions was completed by 420 adult patients with asthma who filled a prescription for an inhaled corticosteroid (ICS) and a short-acting beta agonist (SABA) in the previous 6 months. Questions without substantial floor or ceiling effects that were significantly related to self-reported low adherence or previous ICS canister dispensings were identified. Internal consistency reliability was tested by Cronbach α. Relationships of these questions to Asthma Control Test scores, future percent of days covered for ICS dispensings, and future asthma exacerbations and SABA dispensings were determined.

RESULTS

Five final questions were identified: following "my medication plan," forgetting, not "needing" the medications, side effects, and cost. Low internal consistency reliability (<0.50) suggested items should not be summarized by a single score. All five questions were related to Asthma Control Test scores. Following the medication plan, forgetting, and not needing medication were significantly related to prospective percent of days covered. Side effects were related to subsequent SABA and oral corticosteroid dispensings, and cost was significantly related to oral corticosteroid dispensings.

CONCLUSIONS

We identified five questions related to other measures of adherence and to asthma control that can be used clinically to identify patients at risk of nonadherence and the specific adherence barriers involved.