Quantification of asthma control: validation of the Asthma Control Scoring System

We developed an instrument for quantifying asthma control, the Asthma Control Scoring System (ACSS), based on the criteria proposed by the Canadian Asthma Consensus Guidelines.

To assess the measurement properties of the ACSS.

The ACSS and two other questionnaires were completed by 44 asthmatic patients on a first visit and 2 weeks later. The ACSS evaluates three types of parameters: clinical, physiologic, and inflammatory. These parameters are each quantified to obtain a maximal score of 100% and a global score is calculated as the mean of these scores.

The analysis showed sufficient internal consistency for every section of the ACSS (Cronbach's-alpha ranging from 0.72 to 0.88). Pearson's correlations indicated good test-retest reliability for the clinical score (r = 0.59, P = 0.005), the physiologic score (r = 0.86, P < 0.0001), the inflammatory score (r = 0.71, P = 0.049), and the global score (r = 0.65, P = 0.001). Cross-sectional and longitudinal construct validity were supported by moderate correlations between the ACSS scores and corresponding instruments.

The ACSS is a valid tool for quantifying asthma control parameters, using a percent score. Further research should determine the usefulness of such an instrument as a means to improve asthma management and reduce related morbidity.