The development and validation of an acne self-regulation inventory.

BACKGROUND: Acne, an inflammatory disease of the pilosebaceous unit, is now recognized and investigated as a chronic disease. Since the physiological and psychosocial impact of acne may be long-lasting, the treatment of acne vulgaris poses a formidable challenge for dermatologists.

OBJECTIVE: The present study aims at investigating the validity and reliability of a self-developed instrument "acne self-regulation inventory" (ASRI) based on self-regulation theory in assessing the selfregulation ability of acne patients as part of the therapeutic strategy.

METHODS: All proposed items to be included in ASRI, which consisted of four subscales (i.e., self-monitoring, self-judgment, self-reaction, and self-motivation), were first reviewed by 5 experts in the field. Pilot testing of scale reliability and validity of ASRI were then performed by recruiting 144 acne patients, followed by conduction of formal questionnaire survey by enrolling other 90 acne patients to complete a questionnaire comprising the refined ASRI, Cardiff Acne Disability Index (CADI), and Dermatology Life Quality Index (DLQI) to obtain constructive validity to evaluate the associations of ASRI with clinical acne grading scores, CADI, and DLQI.

RESULTS: Expert review resulted in the inclusion of totally 31 items for pilot testing (i.e., self-monitoring 6 items, self-judgment 6 items, self-reaction 12 items, and self-motivation 7 items). The differentiating ability of each item was confirmed by significant difference between the higher third scorers and those of the lower third using t-test for independent means (all p<0.001). Moreover, Cronbach's α indicated that deletion of a single item in ASRI did not elevate mean value above 0.958 and removal of each item in the four subscales did not increase the mean value of the set Cronbach's α value for each subscale (i.e., 0.886; 0.860; 0.895; 0.907, respectively), suggesting suitability of the 31 items. A high Cronbach's α coefficient of the whole scale as well as the four subscales (i.e., 0.958; 0.886, 0.860, 0.895, and 0.907) demonstrated a high reliability of the ASRI. Pearson's correlation demonstrated moderate to high discriminant validity of ASRI with coefficients between each pair of the four subscales ranging from 0.637-0.798. Formal questionnaire survey demonstrated significant difference between the higher third ASRI scorers and those of the lower third in comparison with clinical acne grading scores, CADI, and DLQI, using t-test for independent means (both p=0.001).

CONCLUSION: The results of the present study demonstrated the usefulness of a self-developed ASRI as an assessment tool to be included in the treatment strategy for acne patients.