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Characteristics of subjective symptomatology of asthma were examined within a group of 132 adult asthma patients receiving medical care in a university-based, ambulatory clinic setting. Patients responded to 36 symptom descriptions or adjectives associated with asthma which were included in a modified version of the Asthma Symptoms Checklist (ASC). A principal components exploratory factor analysis was conducted and five factors were identified. The five factors measured 1) panic-fear, 2) airways obstruction, 3) hyperventilation, 4) fatigue, and 5) irritability. Psychometric properties of the factor scores were satisfactory. The reliabilities were high, standard deviations were large, and differences in factor mean scores conformed to clinical experience. Correlational analyses support the construct validity of the ASC, especially the panic-fear factor. An important outcome of this study was to verify the ASC factor structure in an outpatient setting. The ASC was confirmed as a valuable instrument for use in self-management programs for adults with asthma. The five ASC factors represent highly stable components of subjective symptomatology of asthma among diverse adult patient populations and geographical settings.

The purpose of this study was to demonstrate that a simple submaximal "step-test" could be used as an exercise challenge to identify elementary school students with suspected but undiagnosed asthma. This article also describes a protocol for exercise testing that can be used in epidemiological evaluations. School age children grades 1-4 with suspected but undiagnosed asthma were identified by a 12-item questionnaire completed by a parent or guardian. Only students identified with suspected asthma by questionnaire were exercise challenged on a step-test it baseline spirometry was normal and there was no contraindication for intense aerobic activity. Possible asthma was defined as a 15% or greater decrease in FEV1 or a 25% or greater decrease in FEF25-75 from baseline at either 3 or 10 minutes. The exercise protocol included spirometry before and after stepping continuously for 5 minutes at an exercise intensity sufficient to maintain a heart rate between 150 and 200 beats per minute. Heart rate was continuously monitored throughout the exercise period. Testing was completed at school. No complications occurred during the exercise testing. Exercise testing was completed on 548 students with suspected undiagnosed asthma. Thirty students (6%) had exercise test changes in pulmonary function that met established criteria for suspecting asthma. A board-certified pediatric allergist/immunologist or private physician examined 26 of the 30 students with positive exercise testing. Asthma was diagnosed in 23 (88.89%) of these students. All students with impaired pulmonary function after exercise were able to return to class after a short period of observation. In conclusion, a simple, reproducible school-based exercise protocol can be used to identify students with suspected undiagnosed asthma.

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Several reviewers have recently identified a need for systematic efforts to improve the quality of questionnaires and other measures used in asthma research. This article applies standard psychometric techniques to scales developed to help meet this need. These scales assess asthma symptoms, respiratory diseases, the extent to which asthma inconveniences patients, medication regimens, and medication side effects. Scale quality was assessed by using data from 262 adult asthma patients. The results in general support the usefulness of these scales. The reliabilities indicate an acceptable to good level of internal consistency; the spread of scores is good; and correlations with external variables support validity.