Controlled and uncontrolled allergic asthma in routine respiratory specialist care - a clinical-epidemiological study...

Studies in the last decade showed high rates of poorly treated and poorly controlled asthma in the community. Extending these findings we describe the more recent situation in specialist respiratory care as the most frequent source of treatment provision using comprehensive clinical and patient assessments and exploring predictors for poor control.

This is a German cross-sectional, clinical epidemiological study in a nationally representative stratified treatment prevalence sample of N = 572 outpatients diagnosed with allergic asthma (AA; females 58.2%, aged 47.5 ± 16.3 (16-81 years). Treating physicians completed standardized clinical assessments (lung function, laboratory, clinical findings, severity, illness and treatment history, asthma control [GINA]), supplemented by patients' self-report measures (EQ5-D, AQLQ, ACT) and mental health module (CIDI-SF).

A total of 65.4% of patients were rated (GINA) as controlled, 30.3% partially controlled, and 4.4% uncontrolled; the patient-rated ACT showed lower rates of control (19.9% controlled, 44.2% partial, 35.8% uncontrolled, kappa: 0.2). Consistent with findings of clinical measures, controlled asthma was highest among patients with pre-treatment stage I severity (83.6%) and decreased by pre-treatment severity (stage IV patients: 29.3%). Poorer control was associated with pre-treatment severity, nocturnal attacks, diminished adherence and comorbid anxiety/depression. Patients received complex multiple drug and non-drug interventions, largely consistent with guidelines. Degree of asthma control was associated with improved and even normalized quality of life findings.

In this representative sample of longterm treated AA patients in specialist respiratory care we find better control rates and better adherence to guidelines as previous studies. Despite remarkable differences in clinician- vs patient-rated control ratings even the initially most severe stage IV patients (12.9% of patients) showed remarkable control rates and close to normal quality of life. Intensified treatment (e.g. omalizumab) was associated with improved control. Poorer control was associated with higher initial severity, diminished adherence, comorbid anxiety/depression and old age.

Findings apply to AA patients in respiratory specialist care sector which is likely to treat the more severely affected patients. Thus, findings cannot be generalized to the general population, other treatment settings or asthma types.