Trajectories of physical, mental health and health satisfaction before and after arthritis diagnosis: a UK population-based study

BackgroundFew longitudinal studies have explored changes in physical and mental health in individuals prior to and after arthritis diagnosis. This is important for understanding timing of diagnosis in relation to symptoms and their broader health impacts.MethodsAdults (>= 16 years) reporting new diagnoses of arthritis between 2010 and 2023 in the UK Household Longitudinal Study (UKHLS) were included in the study (N = 5,258), along with a 1:1 matched sample of arthritis-free individuals. Trajectories of physical health (assessed using the SF-12 physical component summary), mental health (General Health Questionnaire (GHQ-12)) and satisfaction with health were constructed from 8 years prior to 8 years after diagnosis using growth curve models with linear splines. Difference in difference analysis was used to test whether changes in health measures following diagnosis were attributable to arthritis diagnosis.ResultsPhysical health decreased from 8 years prior to diagnosis, but began to show a steeper decline from 4 years before diagnosis. There was a small recovery in the year following diagnosis, followed by a continued decline from 4 years post diagnosis. Mental health worsened at 2 years prior to diagnosis and then remained relatively stable. Health satisfaction also decreased around 2 years prior to diagnosis, showing a gradual increase in the 3 years following diagnosis and then remaining stable. Patterns of change were similar by sex, neighbourhood deprivation and living situation. There was some evidence that changes in mental health and health satisfaction were larger and occurred earlier in individuals diagnosed at younger ages (16-49 year olds). Difference in difference models showed consistent findings, with deteriorations across all three outcomes in the arthritis group relative to their matched controls.ConclusionsDetectable changes in physical and mental health several years prior to diagnosis suggest the need to improve pathways to diagnosis. Persistence of worse mental health, particularly amongst younger people, highlights the importance of considering both physical and mental health in the years following diagnosis.