Validation of a new tool to assess health-related quality of life in psoriasis: the PSO-LIFE questionnaire

Abstract

BackgroundSeveral questionnaires have been used to measure health related quality of life (HRQoL) in patients with psoriasis, few have been adapted for use in Spain; none of them was developed specifically for the Spanish population. The purpose of the study was to validate and assess the sensitivity to change of a new questionnaire to measure HRQOL in patients with psoriasis (PSO-LIFE).MethodsObservational, prospective, multicenter study performed in centers around Spain. Patients with active or inactive psoriasis completed the PSO-LIFE together with other Dermatology Quality of Life Index (DLQI) and Psoriasis Disability Index (PDI). A control group of patients with urticaria or atopic dermatitis was also included. Internal consistency and test-retest reliability of the PSO-LIFE were assessed by calculating Cronbach’s alpha and Intraclass Correlation Coefficient (ICC). Validity was assessed by examining factorial structure, the capacity to discriminate between groups, and correlations with other measures. Sensitivity to change was measured using effect sizes.ResultsThe final sample included for analysis consisted of 304 patients and 56 controls. Mean (SD) age of psoriasis patients was 45.3 (14.5) years compared to 38.8 (14) years for controls (p < 0.01). Cronbach’s alpha for the PSO-LIFE was 0.95 and test-retest reliability using the ICC was 0.98. Factor analysis showed the questionnaire to be unidimensional. Mean (SD) PSO-LIFE scores differed between patients with psoriasis and controls (64.9 [22.5] vs 69.4 [17.3]; p < 0.05), between those with active and inactive disease (57.4 [20.4] vs 76.4 [20.6]; p < 0.01), and between those with visible and non-visible lesions (63.0 [21.9] vs. 74.8 [23.9]; p < 0.01). The correlation between PSO-LIFE and PASI scores was moderate (r = −0.43) while correlations with DLQI and PDI dimensions ranged from moderate to high (between 0.4 and 0.8). Effect size on the PSO-LIFE in patients reporting ‘much improved’ health status at study completion was 1.01 (large effect size).ConclusionsThe present results provide substantial support for the reliability, validity, and responsiveness of the PSO-LIFE questionnaire in the population for which it was designed.

Patient reported health outcomes and non-adherence in psoriasis patients receiving adalimumab or ustekinumab for moderate to severe plaque psoriasis

“…The DLQI is a 10-item skin disease-specific instrument with lower scores indicating better dermatology-related outcomes (17,18). A DLQI score of 0 or 1 indicates no negative effect of skin disease on a patient's life, with 30 indicating maximum impact on quality of life.…”

Genetics of Psoriasis and Pharmacogenetics of Biological Drugs

“…The prevalence of psoriasis is 2-3% worldwide [2]. Psoriasis has a negative impact on the patient's health and quality of life, is associated with serious medical comorbidities, and affects the quality of life of family members [3, 4]. …”

Quality of Life is More Affected in Psoriasis than Vitiligo: A Study of 40 Moroccan Patients

“…On the contrary, besides suffering from physical discomfort, impaired emotional functioning and a negative body self-image, psoriatic patients suffer from limitations in daily activities, social contacts and work. 3 Indeed, the DLQI's questions focus on physical limitations and few items address the frequent psychological impact of skin diseases. This implies that the DLQI is better at assessing the impact of severe (inflammatory) diseases than that of diseases with a relatively mild impact or with few physical symptoms but high psychological impact such as vitiligo.…”

“…These are all factors affecting quality of life, as well as having a chronic disease with treatment side effects. 3,4 Therefore, it is important to consider psoriasis as a serious disease and resist the tendency to underestimate its impact on the overall patient well-being. 2 Several quality of life scales were used in this dermatosis known for its negative impact on the patient's health related life quality.…”