Association Between Motor Difficulties and Osteoarthritis in Ageing Adults: Evidence From Propensity Score Matching

Objective
To examine whether self-reported motor difficulties (walking, stair climbing and rising from a chair) are independently associated with self-reported osteoarthritis (OA) risk among older European adults, utilising propensity score matching (PSM).

Methods
This work utilised data from Waves 1, 2 and 4–9 of the large cross-national Survey of Health, Ageing and Retirement in Europe (SHARE) dataset representing 127,372 adults aged 50 years and older. Osteoarthritis and motor difficulties were self-reported based on participants' reports of physician diagnosis and functional limitations. Propensity score matching was applied to balance covariates and try to improve causal inference.

Results
Individuals with motor difficulties had extensively higher OA prevalence (28.4% vs. 10.8%), with prevalence increasing in a dose-dependent manner. PSM score-adjusted analysis showed motor difficulty was associated with a 17.1 percentage points (OR = 3.1) higher prevalence of OA, a stronger association than traditional models. We also confirmed higher OA and motor difficulties in women, older age and people with obesity, low handgrip strength, chronic conditions and reduced quality of life.

Conclusions
Self-reported motor difficulties are strongly associated with self-reported OA in older European adults. These findings highlight the close link between lower-limb functional limitations and OA reporting in population-based surveys. Given the cross-sectional and self-reported nature of the measures, the results should be interpreted as associations rather than evidence of temporality or causality.