Developing survey instruments for low back and neck pain to improve disease severity estimates for burden of disease assessment

Abstract Two people living with the same disease can have very different experiences; one has little consequence, whilst the other struggles with much more debilitating consequences that impacts how they live their lives day-to-day. A growing body of research highlights the need for better estimates of disease severity to facilitate better estimation of the non-fatal burden of disease (BOD). Routine data does not always offer solutions because it’s often not coded at a granular enough level to map to individual health states. Data offering solutions are scarce and therefore not available across time or space. Most commentators have quantified the problem of assuming the same proportional severity splits to fill data gaps; a problem common to the Global Burden of Disease (GBD) study and independent BOD studies. However, whilst the need for highlighting the problems associated with this assumption remains, there are other positive steps that can be taken to overcome it. We propose how reproducible approaches can be developed, and present how they can be used to develop disease severity estimates. This involves developing a survey instrument to estimate the overall and health state prevalence of back pain and neck pain, basing health state definitions from the GBD non-fatal disease models, where the classification of cases by severity is based on the combination of respondent’s answers. Furthermore, we discuss how self-assessed severity estimates allow for internal validity checks, but also more widely offer opportunities to appraise the appropriateness of GBD non-fatal disease models. The development, and publication, of survey instruments can assist both independent studies and the GBD study to improve estimates of disease severity, as well as retaining important opportunities for cross-country comparability. Understanding the spectrum of severity is important for understanding how disease impacts populations and can inform healthcare provision and expenditure strategies.