The PsoTeenQOL - Preliminary Reliability and Validity

Study Overview
=================
Brief Summary
-----------------
This study aims to develop and provide preliminary reliability and validity of a questionnaire to measure Health-related Quality of Life (HRQOL) in adolescents with psoriasis. To the best of our knowledge, this will be the first psoriasis-specific HRQOL instrument for use in adolescent patients. Data will be collected from a Danish population of adolescents with psoriasis (12-17 years), as well as from parents of adolescents with psoriasis, and a group of adolescents without psoriasis.

Detailed Description
-----------------
The present study will examine the psychometric properties of a preliminary 41-item version of the PsoTeenQOL. The preliminary PsoTeenQOL has been developed based on qualitative interviews of adolescents (12-17 years) with psoriasis, their parents, and health professionals working within the field, as well as literature reviews and existing questionnaires. Face and content validity has been established through subsequent cognitive interviews with the target group. Exploratory factor analysis (EFA) and analysis of differential item functioning (DIF) will be used to further refine the PsoTeenQOL questionnaire by selecting the most appropriate items. In addition, indicators of reliability (internal consistency; test-retest reliability), validity (construct validity, criterion validity; discriminant validity), and responsiveness will be evaluated.

Official Title
-----------------
The PsoTeenQOL - Preliminary Reliability and Validity of a Health-related Quality of Life Questionnaire for Adolescents With Psoriasis

Conditions
-----------------
Psoriasis

Intervention / Treatment
-----------------
* Other: No intervention


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Either a) Subjects with psoriasis, b) Parents of adolescents 12-17 years with psoriasis, or c) Subjects without psoriasis Ability to read Danish and complete electronic survey Exclusion Criteria: Inability to read Danish and complete electronic survey

Ages Eligible for Study
-----------------
Minimum Age: 12 Years
Maximum Age: 17 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Adolescents with psoriasis<br>No assigned intervention: completion of PsoTeenQOL and other instruments for assessment of psychometric properties and further refinement of the PsoTeenQOL. | Other: No intervention<br>* Completion of surveys<br>|
| Parents of adolescents with psoriasis<br>No assigned intervention: completion of proxy-version of the PsoTeenQOL for validation purposes | Other: No intervention<br>* Completion of surveys<br>|
| Adolescents without psoriasis<br>No assigned intervention: completion of non-psoriasis control-version of the PsoTeenQOL for validation purposes | Other: No intervention<br>* Completion of surveys<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Examine the psychometric properties of the PsoTeenQOL | Analyses will include exploratory factor analysis, examination of differential item functioning (DIF) and evaluation of indicators of reliability and validity of the instrument | Baseline and up to 3 months after first completion of questionnaire package | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Indicators of validity | Correlations and comparisons between PsoTeenQOL and similar non-psoriasis-specific instruments (Children's Dermatology Life Quality Index (CDLQI); Pediatric Quality of Life Inventory (PedsQL); WHO-5, proxy- and non-psoriasis control version of the PsoTeenQOL) as well as measures of disease severity (Self-assessed Simplified Psoriasis Index (saSPI), and Psoriasis Area Severity Index (PASI)). | Baseline | 
| Indicators of reliability | Internal consistencies (Cronbach's alpha), test-retest reliability and responsiveness of the PsoTeenQOL (change scores on the PsoTeenQOL as compared to the CDLQI and disease severity indicators) | Test-retest: 2 weeks (+/-3 days) after baseline; Responsiveness: 3 months after baseline | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
psoriasis, adolescents, quality of life, PRO (patient-reported outcome), validation