Development and Validation of the Japanese Version of the Hyperhidrosis Quality of Life Index

Hyperhidrosis decreases an individual's quality of life (QOL). The Hyperhidrosis Quality of Life Index (HidroQoL) measures the impact of hyperhidrosis on QOL and has established reliability and validity. However, a Japanese version does not exist. Hence, this study aimed to develop the Japanese version of the HidroQoL (HidroQoL-J) and verify its reliability and validity. The first survey included 528 participants (272 males, 256 females, mean age ± standard deviation 41.89 ± 15.24 years) who met the criteria for hyperhidrosis and scored ≥ 2 on the Hyperhidrosis Disease Severity Scale (HDSS). The second survey was conducted for reliability and included 210 participants (105 males, 105 females, mean age ± standard deviation 43.56 ± 14.60 years). The main survey items were (1) HidroQoL-J, (2) Dermatology Life Quality Index (DLQI), (3) Skindex-16, and (4) Anxiety Scale Specific to Hyperhidrosis Symptoms (ASSHS). Confirmatory factor analysis revealed the HidroQoL-J had a two-factor structure: a "daily life activities domain" with six items and a "psychosocial life domain" with 12 items, as in the original English version of the instrument. Cronbach's alphas (α) for the HidroQoL-J were 0.93, 0.85, and 0.91 for overall, daily life activities, and psychosocial life, respectively. Test-retest reliability was r = 0.70, 0.67, and 0.69 for overall, daily life activities, and psychosocial life (all p < 0.001), respectively. Furthermore, the intraclass correlation coefficients were 0.70, 0.67, and 0.69, respectively. Moderate positive correlations were observed between the overall HidroQoL-J score and the DLQI (r = 0.56) and Skindex-16 (r = 0.43) scores (all p < 0.001). There was also a moderate positive correlation between the overall score of the HidroQoL-J and HDSS (r = 0.42) and a weak positive correlation with ASSHS (r = 0.39) (all p < 0.001). Therefore, the HidroQoL-J exhibited sufficient reliability and validity to measure the impact of hyperhidrosis symptoms on QOL.