Further refinement of the Patient-Reported Impact of Dermatological Diseases (PRIDD) measure using classical test theory and item response theory

Background: Existing dermatology-specific patient-reported outcome measures (PROMs) do not fully capture the substantial physical, psychological, and social impact of dermatological conditions on patients’ lives and are not recommended for use according to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) criteria. Most were developed with insufficient patient involvement and relied on classical psychometric methods. We are developing the new Patient-Reported Impact of Dermatological diseases (PRIDD) measure for use in research and clinical practice in partnership with patients. Objectives: To examine the factor structure of PRIDD, determine the definitive selection of items for each subscale, and establish structural validity and internal consistency through classical and modern psychometric methods. Methods: Two cross-sectional online surveys. Adults (≥ 18 years) worldwide living with a dermatological condition were recruited through the International Alliance of Dermatology Patient Organizations’ (GlobalSkin) membership network. They completed PRIDD and a demographics questionnaire via an online survey. We examined missing data and distribution of scores for each item. The factor structure was assessed using confirmatory and exploratory factor analysis (Survey 1). Internal consistency was examined using Cronbach’s alpha. Rasch measurement theory analyses were conducted, including iterative assessment of rating scale function, fit to the Rasch model, unidimensionality, reliability, local dependence, targeting and differential item functioning (DIF)(Survey 1 and 2). Results: 483 and 504 people participated in Survey 1 and 2, respectively. All items had ≤3% missing scores and all five response options were used. A four-factor model showed best fit. PRIDD and all four subscales were internally consistent but showed some misfit to the Rasch measurement model. Adjustments were made to rectify disordered thresholds, remove misfitting items, local dependency and DIF, and improve targeting. The resultant 16-item version and subscales fit the Rasch model, showed no local dependency or DIF at the test level, and were well-targeted. Conclusions: This field test study produced the final PRIDD consisting of 16 items across four domains. The data triangulated and refined the conceptual framework of impact and provide evidence of PRIDD’s structural validity and internal consistency. The final step in PRIDD’s development and validation is to test the remaining measurement properties

Development of a conceptual framework for a patient-reported impact of dermatological diseases (PRIDD) measure: A qualitative concept elicitation study

Existing patient-reported outcome measures cannot comprehensively capture the full impact of living with a dermatological condition. The aim of this study was to develop a conceptual framework on which to build a new Patient-Reported Impact of Dermatological Diseases (PRIDD) measure. Adults (≥ 18 years of age) living with a dermatological condition, worldwide and/or representatives from a patient organization recruited via a global patient organization network, were invited to an individual or group interview. Data were analyzed thematically. Sixty-five people from 29 countries, representing 29 dermatological conditions, participated. Key themes were: (i) impacts at the individual, organizational and societal levels; (ii) impacts were point-in-time and cumulative; and (iii) impact is a multifaceted construct, with two subthemes (iiia) common impacts and (iiib) psychological and social impacts are most significant. The conceptual framework shows that impact is a multifaceted concept presenting across physical, psychological, social, financial, daily functioning and healthcare, and provides the basis for co-constructing the PRIDD with patients

Patient prioritisation of items to develop the Patient‐Reported Impact of Dermatological Diseases measure: A global Delphi study

Background: The Global Research on the Impact of Dermatological Diseases (GRIDD) project is developing the new Patient‐Reported Impact of Dermatological Diseases (PRIDD) measure. PRIDD measures the impact of dermatological conditions on the patient's life. Objectives: This study aimed to seek consensus from patients on which items to prioritize for inclusion in PRIDD. Methods: A modified, two‐round Delphi study was conducted. Adults (≥18 years) with dermatological conditions were recruited. The survey consisted of a demographic's questionnaire and 263 potential impact items in six languages. Quantitative data used Likert‐type ranking scales and analysed against consensus criteria. Qualitative data collected free text responses for additional feedback and a framework analysis was conducted. Results: 1154 people representing 90 dermatological conditions from 66 countries participated. Items were either removed (n = 79), edited (n = 179) or added (n = 2), based on consensus thresholds and qualitative feedback. Results generated the first draft of PRIDD with 27 items across five impact domains. Conclusion: This Delphi study resulted in the draft version of PRIDD, ready for psychometric testing. The triangulated data helped refine the existing conceptual framework of impact. PRIDD has since been pilot tested with patients and is currently undergoing psychometric testing

Evidence of the content validity, acceptability, and feasibility of a new patient-reported impact of dermatological diseases (PRIDD) measure

Background: The Global Research on the Impact of Dermatological Diseases (GRIDD) team is developing the new Patient-Reported Impact of Dermatological Diseases (PRIDD) measure of the impact of dermatological conditions on the patient’s life, in partnership with patients. To develop PRIDD, we conducted a systematic review, followed by a qualitative interview study with 68 patients worldwide and subsequently a global Delphi survey of 1,154 patients to ensure PRIDD items were meaningful and important to patients. Objective: To pilot test PRIDD with patients with dermatological conditions, focusing on its content validity (comprehensiveness, comprehensibility, and relevance), acceptability, and feasibility. Methods: We conducted a theory-led qualitative study using the Three-Step Test-Interview method of cognitive interviewing. Three rounds of semi-structured interviews were conducted online. Adults (≥ 18 years) living with a dermatological condition and who spoke English sufficiently to take part in the interview were recruited through the International Alliance of Dermatology Patient Organizations’ (GlobalSkin) global membership network. The topic guide met the gold-standard COSMIN (Consensus-based Standards for the Selection of Health Measurement Instruments) standards for cognitive interviewing. Analysis followed the thematic analytical model of cognitive interviewing. Results: Twelve people (58% male) representing six dermatological conditions from four countries participated. Overall, patients found PRIDD to be comprehensible, comprehensive, relevant, acceptable, and feasible. Participants were able to discern the conceptual framework domains from the items. Feedback resulted in: the recall period being extended from 1 week to 1 month; removal of the ‘not relevant’ response option; and changes to the instructions and item ordering and wording to improve clarity and increase respondents’ confidence in their ability to respond. These evidence-based adjustments resulted in a 26-item version of PRIDD. Conclusion: This study met the gold-standard COSMIN criteria for the pilot testing of health measurement instruments. The data triangulated our previous findings, in particular the conceptual framework of impact. Our findings illuminate how patients understand and respond to PRIDD and other patient-reported measurement instruments. The results of comprehensibility, comprehensiveness, relevance, acceptability, and feasibility of PRIDD provide evidence of content validity from the target population. The next step in the development and validation of PRIDD is psychometric testing

Patient-reported outcome measures in dermatology: a systematic review

By relying on data from existing patient-reported outcome measures of quality of life, the true impact of skin conditions on patients’ lives may be underestimated. This study systematically reviewed all dermatology-specific (used across skin conditions) patient-reported outcome measures and makes evidence-based recommendations for their use. The study protocol is registered on PROSPERO (CRD42018108829). PubMed, PsycInfo and CINAHL were searched from inception to 25 June 2018. The Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) criteria were used to assess the measurement properties and methodological quality of studies. A total of 12,925 abstracts were identified. Zero patient-reported outcome measures were assigned to category A (ready for use without further validation), 31 to category B (recommended for use, but only with further validation) and 5 to category C (not recommended for use). There is no gold-standard dermatology-specific patient-reported outcome measure that can be recommended or used without caution. A new measure that can comprehensively capture the impact of dermatological conditions on the patient’s life is needed

Analysis of the methodology of skin cancer incidence registration in German cancer registries

Skin cancer is one of the most common cancers in the world but non-melanoma skin cancer (NMSC) has been included for the first time in the Global Cancer Incidence, Mortality and Prevalence (GLOBOCAN). Germany is one of the countries with high-quality data collected by 16 population-based cancer registries, yet NMSC always faced completion issues because of out-patient based treatment. The purpose of this study is to analyze the methodology of skin cancer incidence registration, assess the quality of data on skin cancer, and suggest improvements. The information was extracted from annual reports of all German cancer registries, the Robert Koch Institute (RKI), the Manual of cancer registration, through a questionnaire sent to all the registries and relevant articles. Comparison of the methodology with that of Nordic countries was done to suggest improvements. Legislative laws for remuneration, changing ICD codes, no multiple tumors counting, all affect skin cancer registration and its reported incidence rate. Use of mortality/incidence (M/I) ratio as an assessment of completeness, national skin cancer screening (SCS) project, the incomplete Tumor Node Metastasis (TNM) staging, determine the quality of skin cancer data. This data is definitely more complete for malignant melanoma (MM) as compared to NMSC. Nordic countries have achieved higher completion even for skin cancer data. Reporting basal cell cancer (BCC) in a separate file, recording the tumor stage and site specifications will improve the quality of data. Remuneration laws and rules for multiple tumors need to be reformed and standardized across all the federal states. Upcoming clinical cancer registries would complement the epidemiological registries and help improve the situation in the future in Germany