Identifying phenotypes and long term course of hand problems in older people using a latent transition approach

Abstract

Musculoskeletal conditions of the hand are frequent causes of pain and disability in older people, yet knowledge regarding the characteristics and patterns of hand pain and problems over time is lacking. The objectives of this project were to identify sub-groups of older individuals with distinct presentations (phenotypes) of hand pain and function, investigate how these phenotypes changed over a 6 year period, and explore what characteristics and factors were associated with long-term outcomes. In addition to this, an exploration of the longitudinal association between hand phenotypes and mental health was performed.
The study population stemmed from the North Staffordshire Osteoarthritis Project (NorStOP); a large, general population-based, prospective cohort study of adults aged 50 years and over. Information on hand pain and problems was collected using questionnaires at baseline, 3 and 6 years. A total of 5,617 participants responded at all time points and were included in the analysis. Five phenotypes were identified using Latent Transition Analysis (‘least affected’, ‘high pain’, ‘poor gross function’, ‘high pain and poor gross function’ and ‘severely affected’) based on eight hand pain and function items. The most common transition between phenotypes was from ‘high pain’ at baseline to ‘least affected’ at 3 years. Individuals classified in the ‘least affected’ or ‘severely affected’ groups at baseline were the most stable. Individuals with nodes, chronic hand pain, sleep problems and bilateral hand pain at baseline were more likely to be in a more severe hand phenotype at 6 years. In addition to this, those in more severe hand phenotypes were more likely to have poor symptoms of mental health. The results provide clinically relevant information regarding the pattern of hand pain and problems over time, and the characteristics of those more likely to have an unfavourable outcome over a 6 year period.