Background: Patients' perception of their ability to influence their asthma symptoms has not been sufficiently addressed.
Objective: To study the relationship between patients' perceived ability to self-care, as approached by internal locus of control (LOC) orientation, and concomitant level of asthma control.
Methods: A cross-sectional study was conducted from May 19, 2004, through July 7, 2005. Asthma patients receiving inhaled corticosteroids and supervised in primary care were identified. Asthma control was measured with the Asthma Control Test. Patients reported their LOC orientation on a 100-mm visual analog scale (0%, "I have absolutely no influence on asthma change," to 100%, "this change only depends on me"). Asthma therapy was obtained from a prescription database. The risk of an internal LOC of less than 50% was studied.
Results: Among the 163 patients with documented LOC (mean age, 52 years; 58% female), 72 (44.2%) had an internal LOC of less than 50%. Asthma control was inadequate for 65 of the 157 patients with available data on the global score of the Asthma Control Test (41.4%). Patients with inadequately controlled asthma had a higher risk of a LOC of less than 50% (odds ratio, 2.68; 95% confidence interval, 1.23-5.81). A 3-fold increased risk also appeared for patients older than 65 years compared with those younger than 45 years. Conversely, no association was identified with sex, asthma severity markers, or therapy.
Conclusions: Asthma control was related to internal LOC orientation (ie, perceived ability to self-care). Improved self-care efficiency is a target for adequate disease management.