Title: Cross-Cultural Validation and Calibration of the PROMIS
Funder: The Academy of Medical Sciences

Abstract: This study aims to provide evidence supporting the use of state-of-the-art measurement approaches to physical function and pain outcomes in the UK. Specific objectives include 1) to cross-culturally adapt the National Institute of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and pain interference item banks and 2) to obtain UK-specific bank calibrations. Patient-Reported Outcome Measures (PROMs) aim to assess a patient’s health status. Utilising Item Response Theory (IRT) and Computer Adaptive Testing (CAT) methodologies on USA reference populations, the PROMIS system was conceived as the most advanced approach to PROMs measurement for minimising patient burden and increasing interpretability whilst maintain strict psychometric standards. The PROMIS instruments are increasingly recognised worldwide as a reference standard in musculoskeletal research, including in the UK. It is accepted that for PROMs to be used across cultures, the items must be translated linguistically and adapted to maintain content validity. Furthermore, assessment of the IRT model fit, calibration to the local population, and assessment of measurement invariance is required before deployment. A state-of-the-art translation approach will be used; forward and backward translation, expert review and cognitive debriefing will be undertaken to ensure content equivalence. The cross-culturally translated items will be administered to a representative UK reference population of 1000 participants. Item parameters will be derived through IRT analysis. Differential Item Functioning (DIF) between original US data and UK data will be quantified. The feasibility of this methodology has been discussed with our PPI group who have assisted in the study design.

Lay abstract: Patient-Reported Outcome Measures (PROMs) are questionnaires that aim to measure a patient’s viewpoint of their health. Thousands of PROMs are available, normally measuring the impact of a certain condition like arthritis, or a symptom such as pain. The PROMIS (Patient-Reported Outcomes Measurement Information System) is a new way of collecting this information. It was designed to be quick and simple to use. When delivered electronically, it uses collections of hundreds of potential questions. The computer picks the most relevant questions to answer. The final score is more focused on that particular person. Because of the way it is administered, the scores can be compared between conditions, treatments and populations. The PROMIS system was developed in the USA and the questions are written in American English. Often there are words such as ‘yard’, ‘trash’ or ‘faucet’. These questions need to be changed to be valid in the UK. We also need to know the scores of a representative population of UK residents, as the average response may be different from the USA population. We have worked with members of the public to design a study. First, we will translate these questions. Then we will ask 1000 participants to complete the questionnaires. We will then calculate a UK-specific calibration. By doing this, we will be able to administer PROMIS with confidence that it is relevant to UK individuals. We will also be able to interpret the scores more clearly and compare them internationally to other study populations.

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS;8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: GENERIC HEALTH RELEVANCE