SUBJECTIVE SYMPTOMATOLOGY OF ASTHMA - VALIDATION OF THE ASTHMA SYMPTOM CHECKLIST IN AN OUTPATIENT SPANISH POPULATION

The objective of this study was to validate the Asthma Symptom Checkli st (ASC) so that it could be reliably used to assess the subjective sy mptomatology of asthma attacks in our context. Subjective symptomatolo gy of asthma was examined in a group of 100 adult Spanish outpatients (57 women, 43 men; 17-69 years of age) with asthma. All of them comple ted the modified version of the ASC as well as questionnaires of depre ssion, anxiety, and self-management of asthma (self-efficacy expectanc ies and health care utilization). Data about duration and severity of asthma, as well as dyspnea and %FEV1, were also recorded. The highest reliability Cronbach alpha indexes were for the panic-fear and fatigue scales. The oblique rotation of the ASC revealed five correlated fact ors (53% of the total variance explained): 1) panic-fear, 2) airways o bstruction, 3) airways obstruction and panic-fear, 4) fatigue and irri tability, 5) hyperventilation. The structure of factors was revalidate d using orthogonal (varimax) rotation. Construct validity was examined by Pearson product-moment coefficient correlations, ANOVAs (asthma se verity x ASC scores), and t-tests (sex by ASC scores). Panic-fear show ed the best construct validity, as it was related to the severity of t he asthma and the use of high-cost health care resources. There were n o differences in ASC scores either on the basis of the asthma severity or on the sex of patients. The ASC factors represent stable component s of subjective symptomatology of asthma attacks, especially with rega rd to the panic-fear and the hyperventilation subscales; however, the structure of the checklist as a whole was not identical to those repor ted in other studies. Correlations of the ASC with clinical variables related to asthma severity support the construct validity of the instr ument and confirm its utility to evaluate the subjective symptomatolog y of asthma attacks in outpatients.