Impact of Adult Asthma
Impact of Adult Asthma
To assess the separate and interactive effects of asthma severity, subspecialty practice
 variation, asthma-related psychosocial variables, and other factors on asthma outcomes,
 including asthma-specific quality of life and activity limitations, health care utilization
 for asthma, and direct and indirect costs of asthma.
BACKGROUND:

 Asthma is both common and costly. Neither the risk factors of poor outcome nor the predictors
 of better outcome are well understood. Illness severity is clearly an important predictive
 factor in asthma, but may explain less variability in outcome than other determinants, such
 as patient-perceived asthma control, other asthma-related psychosocial measures, and the kind
 and extent of subspecialty care for asthma. By quantifying predictors of asthma-specific
 quality of life, functional status, services utilization, and the direct and indirect illness
 costs of asthma, this study addressed a major research gap in secondary and tertiary
 prevention efforts.

 DESIGN NARRATIVE:

 A random sample of pulmonary and allergy subspecialists initially enrolled 600 persons with
 asthma identified in patient visit logs. This established panel completed 45 minute baseline
 and follow-up computer-assisted telephone interviews (CATI); 539 (90%) were successfully
 re-interviewed after 18 months of follow-up. A supplemental sampling frame of persons with
 asthma identified from family practitioners was completed as was a group with rhinitis but
 without asthma. Interviews assessed disease severity and other covariables using validated
 survey instruments. Pulmonary function and medical records were used to validate severity in
 a sub-sample of subjects. The study extended longitudinal follow-up study of this initial
 cohort. Its analysis tested predictive models for the asthma outcomes of interest.

 The study completion date listed in this record was obtained from the "End Date" entered in
 the Protocol Registration and Results System (PRS) record.
No eligibility criteria