Development and validation of the Cholinergic Urticaria Quality-of-Life Questionnaire (CholU-QoL)

Cholinergic urticaria (CholU), a common form of chronic inducible urticaria, is characterized by itchy weals that occur in response to physical exercise or passive warming. CholU patients frequently exhibit a high burden of disease. As of yet, no specific instrument is available to assess their disease-related quality-of-life (QoL) impairment.

The aim of this study was to develop and validate the first disease-specific QoL instrument for CholU patients, the Cholinergic Urticaria Quality-of-Life Questionnaire (CholU-QoL).

Using a combined approach of the literature search, semistructured patient interviews and expert opinion, we developed 96 potential CholU-QoL items. Subsequent item selection was performed by means of impact analysis complemented by an expert review for face validity. The resulting final CholU-QoL was then tested for levels of validity, reliability and influence factors in 88 CholU patients. In parallel, an US American-Canadian English version of the CholU-QoL was developed.

The final 28-item CholU-QoL was found to have a 5-domain structure ("symptoms," "functional life," "social interaction," "therapy," "emotions") with excellent internal consistency. The CholU-QoL also showed a valid total score, and good levels of convergent validity, known-groups validity, as well as test-retest reliability. Multiple regression analysis found no significant drivers of the CholU-QoL total score.

The CholU-QoL is the first disease-specific QoL instrument for CholU and also the first specific QoL measure in the field of chronic inducible urticarias. It may serve as a valuable tool for clinical trials and improve routine patient management.