A Guide to Understanding and Analysing PROMs Scores in Wales

This perspective article outlines the recommendations for the analysis and presentation of data collected via patient-reported outcome measures (PROMs), to promote good practice across Wales. We do not present detailed instructions or repeat what can be easily found in statistics texts, but rather focus on the overall approach that should be adopted when dealing with such data. Throughout the article, we introduce the importance of patient-reported outcome data within the National Health Service (NHS) Wales. We then briefly describe how PROM questionnaires are validated. We then introduce the different data types and describe how PROM questionnaires are structured. Following this, we highlight how the way that patient-reported outcome data is collected can affect appropriate analysis and what should be kept in mind when comparing different items within a questionnaire. We then provide some recommendations as to how to present such data and how to go about choosing appropriate inferential statistics tests for further analysis. Finally, we go over some of the potential consequences of not analysing the data appropriately. Additionally, we also include a simplified version of these recommendations that can be shared with a wider audience.