Development, validation, and initial results of the Angioedema Activity Score.

BACKGROUND: Recurrent angioedema (RecA) is a frequent clinical problem characterized by suddenly occurring cutaneous and/or mucosal swellings. Depending on their location, RecA may be painful, hindering, disfiguring, or even life-threatening. The assessment of disease activity in affected patients is important to guide treatment decisions. Currently, however, there is no standardized and validated outcome measure available to do so. OBJECTIVE: To develop and validate the first specific patient-reported outcome instrument to assess disease activity in RecA patients, the Angioedema Activity Score (AAS). METHODS: After a set of potential AAS items was developed, item evaluation and reduction were performed by means of impact analysis, factor analysis, regression analysis, and by checking for face validity. In addition, the items of the final AAS questionnaire were tested for their validity and reliability during a 12-week validation study. RESULTS: In total, data from 110 and 80 RecA patients were used during the AAS item evaluation and validation phase, respectively. The resulting AAS consisted of five items and was found to have a one-dimensional structure and excellent internal consistency. It correlated well with other measures of disease activity and quality-of-life impairment, thus demonstrating its convergent validity. In addition, the known-groups validity and test-retest reliability of the AAS were found to be good. CONCLUSIONS: The AAS is the first validated and reliable tool to determine disease activity in RecA patients, and it may serve as a valuable instrument in future clinical studies and routine patient care.

Development and construct validation of the angioedema quality of life questionnaire.

BACKGROUND: Recurrent angioedema is a frequent clinical problem characterized by unpredictably and rapidly occurring cutaneous and mucosal swellings. These swellings may be painful and/or disfiguring. Upper airway involvement can also lead to dyspnea and suffocation. Although the disease burden is high, there is currently no specific instrument to measure health-related quality of life (QoL) impairment. OBJECTIVE: To develop and validate the first symptom-specific tool to assess QoL impairment in recurrent angioedema patients, adhering to established methodological recommendations. METHODS: During the development phase, 29 questions (items) were generated. Subsequently, item reduction was performed by means of impact analysis and factor analysis as well as by checking for content and face validity. As a result, 17 items were selected and included in the final instrument, the Angioedema QoL Questionnaire (AE-QoL). AE-QoL was then tested for its validity, reliability, and influence factors. RESULTS: One hundred and ten angioedema patients took part in the validation of AE-QoL. AE-QoL was found to have a four-dimensional structure as well as a valid total score. All of its four domains (functioning, fatigue/mood, fears/shame, food) showed good levels of internal consistency with Cronbach's alpha > 0.8. Test-retesting revealed a good reliability of the instruments total score and domain scores. Gender as well as the patients' self-rated disease activity was found to be predictors of the AE-QoL total score. CONCLUSIONS: Angioedema Quality of Life Questionnaire is the first angioedema-specific QoL questionnaire. It is a short, valid and reliable instrument that may serve as a valuable tool in future clinical studies and in routine patient care.

Formation of a cyclic adenine adduct with a 4-nitroquinoline N-oxide metabolite model.

Pentacyclic adducts are obtained in the reaction of adenine derivatives with the diacetyl ester of 4-hydroxyamino quinoline oxide, the postulated metabolite of the potent carcinogen, 4-nitroquinoline N-oxide (4-NQO).