Sex Differences in the Mediating Effect of Kinesiophobia on Chronic Pain, Dysesthesia, and Health-Related Quality of Life in Japanese Individuals Aged 65 Years Old and Older Treated with Surgery for Lumbar Spinal Stenosis

PURPOSE: This study aimed to determine whether kinesiophobia mediates the relationship between low back pain (LBP), leg pain (LP), and leg dysesthesia (LD) and health-related quality of life (HRQOL) among Japanese individuals aged 65 years old and older treated with surgery for lumbar spinal stenosis (LSS). PATIENTS AND METHODS: Data collection for this study took place between October 2019 and August 2020 at two Japanese medical facilities. Eligibility criteria for participants in this study were individuals aged 65 years or older and those who had undergone surgery for LSS at least more than one year ago. A self-administered questionnaire assessed the intensity of LBP, LP, and LD (numerical rating scale: NRS), HRQOL (EuroQol-5 Dimension-5 Levels: EQ-5D-5L), and kinesiophobia (Tampa Scale for Kinesiophobia-17 items: TSK-17). Mediation analysis using sex as a control variable was conducted. RESULTS: Complete responses were obtained from 238 of 431 individuals (73.1 ± 5.1 years; 135 males and 103 females). The mediating effect of NRS scores for LBP, LP, and LD to EQ-5D-5L index on TSK-17 score was significant, respectively (LBP: −0.007 [95% confidence interval −0.012, −0.004], p = 0.000; LP and LD: −0.007 [−0.011, −0.004], p = 0.000). The strength of the association between NRS scores and EQ-5D-5L index decreased when the mediating effect of TSK-17 score (LBP: β = −0.698 [−0.792, −0.603], p = 0.000 to β = −0.616 [−0.707, −0.524], p = 0.000; LP: β = −0.629 [−0.729, −0.529], p = 0.000 to β = −0.539 [−0.638, −0.440], p = 0.000; LD: β = −0.568 [−0.675, −0.460], p = 0.000 to β = −0.482 [−0.586, −0.378], p = 0.000). The mediating effect of TSK score was greater in females than males. CONCLUSION: Kinophobia partially mediated the relationship between LBP, LP and LD, and HRQOL in Japanese aged 65 years and older after lumbar surgery. The mediating effect differed by sex.