Skin conditions affect the quality of life (QoL) of patients and their family members. To assess family members' life quality, a quality-of-life questionnaire uniquely designed for family members is necessary. We translated the Family Dermatology Life Quality Index (FDLQI), originally created and validated by Basra et al., into Japanese, and evaluated its reliability and validity. For psychometric evaluations, 150 dermatology patients and their family members were included. The Japanese version of FDLQI showed high test-retest reliability (intraclass correlation coefficient=0.95) and internal consistency reliability (Cronbach's alpha=0.86). FDLQI scores significantly correlated with DLQI scores (r=0.58, p < 0.01, Spearman's rho) and global question (GQ) which measured the patients' skin condition on a visual analogue scale (r = 0.36, p < 0.01). Family members of patients with inflammatory skin diseases showed higher FDLQI scores than those with isolated lesions, but the difference was not statistically significant (5.98 ± 4.61, 4.22 ± 3.52, respectively,
p=0.062, Mann-Whitney U-test). Responsiveness to change was demonstrated in a groupin which patients' skin condition was assessed as improved (n = 37, r = 0.46, p < 0.01) but not in that in which patient's skin condition became worse. The difference of the change between the two groups was statistically significant (p<0.01). Additionally, the change in FDLQI scores and GQ were significantly correlated (r = 0.40, p<0.01). Exploratory factor analysis suggested essential unidimensionality of the instrument. We showed acceptable validity and responsiveness of this Japanese version of FDLQI. Further clinical epidemiological studies are required to confirm this.Key words: Family, FDLQI, Psychometric evaluations, QoL, Validation, Skin disease
INTRODUCTIONMany skin diseases influence patients' life quality in various aspects of their lives. The disability of patients can also influence the life quality of patients' family members. The influence can be serious for partners or other family members, as well as the caregivers of children. [1][2][3] This secondary impact on the quality of life (QoL) of close family members has been shown to be serious in emotional aspects but may also be seen in the physical wellbeing, social, and financial aspects of their lives. 1,2 Understanding the disability experienced by family members is essential to create educational and supportive programs to improve their life quality. 4 To evaluate their QoL accurately, a comprehensive questionnaire specific for family members is necessary. The Family Dermatology Life Quality Index (FDLQI) is a unique QoL measure designed for family members of 3 dermatology patients, developed and validated by Basra et al. 5,6 It has been shown to be a practical and useful tool to assess the life quality of family members.In this study, we translated the FDLQI into Japanese and carried out a psychometric study in Japanese patients and their family members or partners.
METHODSThe study was approved by the...