How Do Functional Comorbidities Affect PROMIS-PF Scores Following Lumbar Fusion Surgery?

Area of Science:

• Orthopedics
• Neurosurgery
• Rehabilitation Medicine

Background:

• The National Institutes of Health's Patient-reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) domain is validated for spine surgery.
• Limited data exists on how functional comorbidities impact PROMIS-PF scores and recovery post-lumbar fusion.
• This study hypothesizes that functional comorbidities negatively affect patient recovery outcomes.

Purpose of the Study:

• To analyze PROMIS-PF score trends after lumbar fusion surgery.
• To determine the effect of functional comorbidities on PROMIS-PF scores.
• To compare PROMIS-PF score trends with Oswestry Disability Index (ODI) and PROMIS Pain Interference (PI) scores.

Main Methods:

• Retrospective review of 1893 patients undergoing lumbar fusion for degenerative conditions (2014-2022).
• Comparison of PF scores at 3-month intervals for 2 years between patients with and without defined functional comorbidities (CHF, COPD, CVD, paraplegia).
• Mixed-effects multivariable regressions and MCID (5+ point improvement) analysis.

Main Results:

• The functional comorbidity group (35%) had lower absolute PF scores (2.5 points) and less improvement (1.3 points) at 24 months post-surgery.
• Only 19.3% of patients with functional comorbidities achieved MCID compared to 80.9% without (P <0.001).
• Groups were similar in age, surgical invasiveness, and diagnosis, but comorbidity group had higher Charlson index (3.8 vs 1.0).

Conclusions:

• Patients with functional comorbidities exhibit diminished recovery and are less likely to achieve MCID after lumbar fusion.
• PROMIS-PF scores effectively benchmark recovery but may require complementary metrics for patients with comorbidities.
• Functional comorbidities significantly impact long-term physical function outcomes following lumbar fusion surgery.