Perceived control of asthma and quality of life among adults with asthma.
BACKGROUND
Perceived control of certain chronic conditions influences health status outcomes.


OBJECTIVE
To explore the impact of perceived control of asthma on asthma-specific and generic health status outcomes among adults with asthma. Perceived control was defined as individuals' perceptions of their ability to deal with asthma and its exacerbations.


METHODS
Data were drawn from the baseline and first two followups of a longitudinal study of adults with asthma surveyed by telephone at 18-month intervals. An 11-item questionnaire (Perceived Control of Asthma Questionnaire [PCAQ]) was developed and validated.


RESULTS
The PCAQ demonstrated high internal consistency (Cronbach's alpha = 0.79). Greater perceived control was associated with less severe asthma, greater asthma self-efficacy, lower perceived asthma severity, lower perceived danger from asthma, and greater perceived usefulness of asthma medicines. Greater perceived control was significantly associated with better asthma-specific quality of life concurrently and 18 and 36 months later, after controlling for demographics, smoking, and severity of asthma. Greater perceived control as also significantly associated with generic mental health outcomes concurrently and 18 and 36 months later, after controlling for covariates. Perceived control was associated with physical function concurrently and 18 months later, but not 36 months later.


CONCLUSIONS
The PCAQ is a reliable and valid measure of perceived control of asthma. Perceived control of asthma was associated with both asthma-specific and generic health status outcomes, concurrently and predictively. If perceived control could be modified, better outcomes, particularly better psychologic outcomes, might be achieved for individuals with asthma.
Katz
Patricia P
PP
Department of Medicine, University of California, San Francisco 94143-0920, USA. pkatz@itsa.ucsf.edu
Yelin
Edward H
EH
Eisner
Mark D
MD
Blanc
Paul D
PD
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy; D003430:Cross-Sectional Studies; D003710:Demography; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010465:Perception; D011594:Psychometrics; D011788:Quality of Life; D011795:Surveys and Questionnaires