Objective:

To investigate whether early changes in fear of movement (kinesiophobia), self-efficacy, and catastrophising were mediators of the relationship between allocation to the pre-habilition intervention and later changes in health outcomes.

Methods:

The original prehabilitation trial (PREPARE, ISRCTN17115599) recruited 118 participants awaiting lumbar fusion surgery, half of whom received a prehabilitation intervention designed based on the modified fear-avoidance model and half of whom received usual care. Mediation analysis was performed to test each mediator separately. Analysis was performed on each outcome of interest separately (Oswestry Disability Index; Patient-Specific function; EQ General health; and Moderate/vigorous physical activity). Mediation analysis was carried out using PROCESS. Beta coefficients and bootstrapped 95% CIs were used to interpret the results.

Results:

None of the potential mediators were found to mediate the relationship between allocation to the intervention and three-month scores on any of the health outcomes tested.

Conclusions:

Screening patients for higher levels of catastrophising and fear-avoidance, and lower levels of self-efficacy, could help ensure only the patients who are most likely to benefit from the intervention are included.