Methods: Subject eligibility criteria included (1) age between 12-20 years; (2) diagnosed asthma that has required health service use (preventive or acute) within 12 months prior to enrollment; (3) persistent asthma; (4) no other chronic medical conditions requiring daily medication; (5) primary residence located in inner cities; and (6) ability to understand spoken and written English. Participants were recruited from Buffalo NY (n=123), Baltimore MD (n=100), and Memphis TN (n=66). Modified asthma expectancy scale measures the cognitive constructs of SCT.9 The scale consists of three subscales, outcome expectancy (α=.76), self-efficacy (α=.69) and impediment perception (α=.70). For medication adherence, Horne’s Medication adherence report scale (MARS, α=.76),10 was used in combination with the self-reported number of days preventive medication were used in the past 4 weeks. To assess asthma control, four impairment-based criteria (symptoms, nocturnal awakening, activity limitations and rescue inhaler use) were measured on a 4-point scale. Pearson correlations were computed to examine the relationships among the three cognitive concepts. Multiple regression analyses were conducted to examine the extent to which the cognitive factors predicted adolescents’ medication adherence and asthma control. The regression models included sociodemographic factors (gender, age and household income) and age at the first asthma diagnosis as covariates.
Results: Of 289 inner-city adolescents (mean age=14.591.92) who participated in the study, 51% were female, most (>83%) were black, and 71% had public health insurance. The majority reported either not well controlled (51%) or very poorly controlled asthma (35%), and 71% (n=204) were on at least one preventive medication. The most common reason for not taking preventive medication was forgetfulness (42%) followed by “don’t need it” (36%). Self-efficacy was positively associated with outcome expectancy (r=0.52, p<.001) and negatively with impediment perception (r=-0.18, p=.002). No significant relationship was found between outcome expectancy and impediment perception. In regression models where each cognitive factor was considered separately, after controlling for covariates, medication adherence scale was predicted by impediment perception (B=-0.427, p=.004), and actual number of adherence days in the past month was predicted by outcome expectancy (B=0.185, p=.027) and self-efficacy (B=0.178, p=.03). Symptom control was also predicted by self-efficacy (B=-0.031, p=.017) and impediment perception (B=-0.024, p=.022). In a full model where all three cognitive factors were considered simultaneously along with the covariates, self-efficacy and outcome expectancy were no longer significant predictors of medication adherence or asthma control. However, impediment perception remained a significant predictor of medication adherence (B=0.08, p=.006), suggesting that as impediments increase adherence decreases. Medication adherence was higher in males (B=1.32, p=.013), and the number of preventive medication uses in the past month was greater in those from higher household income (B=0.13, p=.042) and lower in those whose asthma was diagnosed later in life (B=-0.08, p=.003). Symptom control was greater in those who were older (B=-0.02, p=.04), who were from higher income families (B=-0.03, p=.004), and whose asthma was diagnosed later in life (B=-0.01, p=.021).
Conclusion: Three cognitive factors including outcome expectancy, self-efficacy and impediment perceptions are associated with each other and influence medication adherence and/or symptom control in adolescents with asthma. The relationships, to some extent, appear to be accounted for by sociodemographic factors and age at diagnosis, suggesting the importance of understanding cognitive factors in the context of the circumstantial factors. These findings support the SCT’s major assertion that individuals’ behaviors are influenced by cognitive factors and their complex interplay with other inter- and intra-personnel factors. This study underscores the need for tailored interventions taking into account individuals’ gender, age and SES as well as chronicity of asthma, which can modify cognitive factors to promote medication adherence and asthma outcomes in inner-city adolescents.