# Non-linear threshold effects of kinesiophobia on exercise adherence in older adults with COPD: a segmented regression analysis

## TL;DR

Older adults with COPD who fear movement (kinesiophobia) show reduced exercise adherence, especially when their fear exceeds a threshold score of 20.

## Contribution

This study identifies a specific threshold score for kinesiophobia that significantly impacts exercise adherence in COPD patients.

## Key findings

- A TSK score of 20 is a critical threshold for kinesiophobia affecting exercise adherence in COPD patients.
- Patients with TSK scores above 20 showed a sharp decline in exercise adherence as fear increased.
- Kinesiophobia, hospitalization frequency, COPD severity, and anxiety were significant predictors of poor adherence.

## Abstract

To explore the threshold effect of kinesiophobia on exercise adherence in older adult patients with chronic obstructive pulmonary disease (COPD).

A cross-sectional survey was conducted on 357 older adults with COPD were assessed using standardized questionnaires for general information, exercise adherence, and kinesiophobia (Tampa Scale for Kinesiophobia, TSK). Multiple linear regression identified independent factors affecting adherence. A restricted cubic spline model analyzed the non-linear relationship between kinesiophobia and adherence.

The mean scores for exercise adherence and kinesiophobia were 30.9 ± 7.7 and 35.8 ± 10.7, respectively, with 59.9% of patients scoring above the clinical cutoff (>37) for significant kinesiophobia. Kinesiophobia (β = −0.51, p < 0.001), frequent hospitalizations (β = −0.25, p < 0.001), severe GOLD stage (β = −0.18, p < 0.001), and anxiety symptoms (β = −0.13, p = 0.001) were independent predictors of poorer adherence. A significant threshold effect was identified at a TSK score of 20. Below this threshold, kinesiophobia had no significant impact on adherence (β = −0.15, p = 0.312); above it, adherence declined sharply with increasing fear (β = −0.89, p < 0.001).

Exercise adherence was suboptimal in older adults with COPD, who demonstrated substantial kinesiophobia. A TSK score of 20 points serves as a critical threshold, recommending its use for early identification of high-risk patients. Clinical management should prioritize patients with TSK scores ≥20, frequent exacerbations, and comorbid anxiety for targeted interventions.