The change of pain classes over time: a latent transition analysis

Background Pain is common in older adults, and associated with increased morbidity and reduced quality of life. Recent research has highlighted different classes of older adults with pain, each with differing impacts on their life. It has not yet been investigated if, and how, such classes change over time and what influences individuals to prospectively transition to a profile of either improved or worsened pain impact. Methods Latent transition analysis (LTA) is a longitudinal model-based approach to identifying underlying subgroups in a population. LTA was used to model the change in pain of people aged 50 and above, from The Irish Longitudinal Study on Ageing, across three waves (n = 5,925). The LTA model was extended to include biopsychosocial covariates to predict transition probabilities between classes over time. Results Three latent classes were identified based on three pain indicators (pain presence; pain affects daily life; pain requires medication) and were characterized as "No Pain", "Low-Moderate Impact Pain" and "High Impact Pain". Results indicate that the pain class of many changes over time. However, poor physical or mental health increased the risk of transitioning to a more severe pain class, from Wave 1 to Wave 2 and Wave 2 to Wave 3. Conclusions These findings show the change in pain of older adults over time, with both marked improvement and deterioration being observed. Critically, the predictors of individuals transitioning between classes reflect the breadth of biopsychosocial factors involved in pain. Significant Statement This article identified differing classes of pain in older adults, using latent transition analysis. The analysis demonstrated how the pain classes of older adults are broadly consistent over time, however both improvement and deterioration in pain impact were observed. Transitions between classes were associated with several biopsychosocial factors. These results have important implications for the health and quality of life of older adults. Consideration of health, lifestyle and socio-demographic factors may enhance assessment and management of pain in older adults.