The Mediating Role of Physical Function on the Self-Reported Pain and Cognitive Function Association.

Abstract

Background/objectives: Studies that have investigated the relationship between pain intensity and interference and cognitive function have failed to fully consider the role physical function may play in this relationship. Therefore, the purpose of this study was to examine the mediating role of physical function in the relationship between self-reported pain intensity and interference and cognitive function in middle-to-older aged adults with knee pain.

Methods: Middle-to-older aged participants with knee pain (n = 202) completed the Graded Chronic Pain Scale to assess pain intensity and interference, the Short Performance Physical Battery to assess lower-extremity physical function, and the Montreal Cognitive Assessment to assess global cognitive function. Linear regression-based mediation analyses were used to assess associations between pain intensity and interference and cognitive function, with lower-extremity physical function as the mediator.

Results: The direct relationship between pain intensity and cognitive function was significant (β = -0.269, p < .001) and remained significant when physical function was included as a mediator (c'=-0.0854, p = .003). The direct relationship between pain interference and cognitive function was also significant (β = -0.149, p = .023) but was attenuated when physical function was included as a mediator (c'=-0.0100, p = .09).

Conclusion: Physical function partially mediated the relationship between pain intensity and cognitive function and fully mediated the relationship between pain interference and cognitive function. Significance/Implications: Higher levels of pain intensity and interference may lead to worse cognitive function when physical function is also impaired. Improving physical function may improve cognitive function in those with pain.