Adherence to prophylactic asthma medication: habit strength and cognitions

To explain adherence to prophylactic asthma medication (PAM, inhaled corticosteroids) by the attitude, social influence, and self-efficacy (ASE) model added with the concept of habit strength and to study whether habit moderates or mediates relationships between ASE factors and adherence.

A mail-out survey was conducted among 139 asthmatic adults. Multiple regression analysis was conducted, with self-reported adherence as the outcome and ASE factors and habit as the independent variables. Simple slope analyses and bootstrapping mediation analyses were also conducted.

Having more severe asthma, taking PAM habitually, and perceiving few negative consequences of taking PAM were associated with better adherence. Self-efficacy influenced adherence indirectly through habit. The relationship between social norms and adherence was moderated by habit: In the case of weak habits, a supportive norm in a patient's environment toward taking PAM was positively related to PAM adherence; in the case of strong habits, a supportive norm led to less adherence.

Interventions to increase adherence should enhance the formation of habits by stimulating patients to perform the behavior frequently in similar situations by increasing self-efficacy and providing environmental cues, such as reminder devices and pill organizers. In addition, the disadvantages of PAM use should be negated.