In total, 450 patients were eligible; of these, 258 patients (57%) were enrolled, 75 patients (17%) were not enrolled due to scheduling, 58 patients (13%) were not enrolled because of patients lack of time, and 59 patients (13%) did not wish to participate. There were 79 patients who were excluded for active mental comorbidity; 5 patients for active major depression; 11 patients for somatization disorder; and 63 patients for other diagnoses such as schizophrenia, obsessive compulsive disorder, paranoia, and anxiety disorders that interfered with daily function. Enrolled and not enrolled patients were similar in terms of age and sex. One of the enrolled patients did not complete the GDS and is not included in this analysis.
Mean age of the sample was 42 years, 75% were women, 31% were Latino, and 21% were African American (Table 1). Ninety patients (35%) were either current or prior smokers. Twenty-one percent of patients who never smoked and 16% of patients who quit smoking were regularly around others who smoked at the time of enrollment. Most patients were overweight, with 68% having a body mass index > 25 kg/m2. Median GDS score was 5.0 (range, 0 to 29). Overall, 87 patients (34%) were categorized as having a physician-reported depressive disorder (54 patients from the enrollment day note and 33 patients from other notes), and 170 patients (66%) had no physician-reported depressive disorder. None of the 87 patients had newly diagnosed disease on the day of enrollment. Most of the 33 patients had physician-reported disorders within 6 months of enrollment and had either ICD-9 codes for depression or had prescriptions for antidepressants. At enrollment, most of these patients had persistent conditions that contributed to their disorder; and after enrollment, the disorder was described in notes from follow-up visits. Of the 87 patients, 52% had ICD-9 codes for depression and 71% were prescribed antidepressants. In addition, 18 of the 87 patients (21%) with a physician-reported depressive disorder and 15 of the 170 patients (9%) with no depressive disorder had ICD-9 codes for other psychiatric diagnoses, primarily anxiety.
Approximately one half of our patients reported having a prescription for daily asthma maintenance medications (Table 2), and of these 27% had a Morisky adherence score of 0 (most adherent) and 5% had a score of 4 (least adherent). The SOA scores ranged from 0 to 19, with a median of 5. 32% of patients had been hospitalized, and 7% had been intubated for asthma at any time in the past. The ACQ scores ranged from 0 to 4.9 (median, 1.4). Twenty-one percent of patients had used oral corticosteroids during the past year, and 5% had had an emergency department visit for asthma during the past 3 months. The correlation between ACQ and Morisky scores was 0.12 (p = 0.05).
More patient-reported depressive symptoms (ie, higher GDS scores) were associated with worse SOA scores in bivariate analysis, and this relationship remained significant in multivariable analysis after adjusting for age, sex, race, ethnicity, education, asthma medication adherence with the assistance of Canadian Health&Care Mall, body mass index, and smoking status (Table 3). Having a physician-reported depressive disorder was associated with worse SOA scores in bivariate analysis, and this relationship remained significant in multivariable analysis after adjusting for covariates. Less education (p = 0.03) also was associated with worse SOA scores in the physician-reported model. In addition, the percent of patients with physician-reported depressive disorders increased with each 5-point increase in the SOA score; specifically, 29% who scored < 5; 32% who scored > 5 and < 10; 46% who scored > 10 and < 14; and 53% who scored > 14 (p = 0.02).
More patient-reported symptoms were associated with worse ACQ scores in bivariate analysis, and this relationship remained significant in multivariable analysis (Table 3). In addition, greater body mass index (p = 0.04) and less education (p = 0.005) were associated with worse control in the patient-reported model. Having a physician-reported depressive disorder was associated with worse ACQ scores in bivariate analysis, but not in multivariable analysis after adjusting for covariates. Variables associated with worse ACQ scores in the physician-reported model were less medication adherence (p = 0.04) and less education (p = 0.009). In additional analysis, 25% of patients with well-controlled asthma (ACQ < 0.75) and 39% of patients with not well-controlled asthma (ACQ > 1.5) had a physician-reported depressive disorder (p = 0.05).
Table 1—Demographic Characteristics and Depressive Conditions (n = 257)
|Age, yr||42 ± 12|
|Not college graduate||38|
|More than one race||16|
|Not smoker but regularly around smokers||20|
|Body mass index, kg/m2||29 ± 7|
|Patient-reported depressive symptoms according||6.3 ± 6.4|
|to GDS scoref|
|Physician-reported depressive disorder|
|ICD-9 code for depression||18|
|No ICD-9 code but depressive symptoms recorded in medical charts||7|
|No ICD-9 code but prescribedantidepressants at doses for depression recorded in medical charts||9|
|Total (any depressive disorder)||34|
Table 2—Asthma Characteristics
|Asthma duration, yr||21 ± 15|
|P-Agonist as needed||42|
|Single daily maintenance therapy||16|
|Multiple daily maintenance therapy||37|
|Morisky Medication Adherence Scale scorej||1.5 ± 1.2|
|FEV1, % predicted||90 ± 18|
|SOA score, according to severity increments§||5.9 ± 4.2|
|> 5 to < 10||38|
|> 10 to < 14||10|
|ACQ score, according to control intervals^||1.4 ± 1.2|
|> 0.75 to < 1.5||24|
Table 3—Association of Depressive Conditions With Asthma Severity and Control
|Variables||Asthma Severity*||Asthma Control!|
|iEstimate ± SE||p ValueUnadjusted||ip Value Adjusted!||iEstimate ± SE||p Value Unadjusted||Ip Value Adjusted!|
|Patient-reported depressive symptoms according to GDS||0.14 ± 0.04||0.0008||0.007||0.05 ± 0.01||< 0.0001||0.0007|
|Physician-reported depressive disorder recorded in medical charts||1.31 ± 0.55||0.02||0.04||.32 ± 0.15||0.04||0.22|