Long-term quality of life and functional outcomes after management of spinal epidural abscess.

BACKGROUND/CONTEXT: In recent years, the incidence of spinal epidural abscesses (SEA) has tripled in number and nonoperative management has risen in popularity. While there has been a shift towards reserving surgical intervention for patients with focal neurologic deficits, a third of patients will still fail medical management and require surgical intervention. Failure to understand long-term quality of life and functional outcomes hinders effective decision making and prognostication.

PURPOSE: To describe patterns and associated factors impacting long-term quality of life following treatment of spinal epidural abscess.

STUDY DESIGN/SETTING: Multicenter cohort study at two urban academic tertiary referral centers and two community centers.

PATIENT SAMPLE: Adult patients treated for a spinal epidural abscess.

OUTCOME MEASURES: EuroQoL 5-Dimension 5L (EQ5D), Neuro-Quality of Life Lower Extremity - Mobility (Short Form; NeuroQoL-LE), Patient-Reported Outcomes Measurement Information System Physical Function (short form 4a; PROMIS PF), and PROMIS Global Mental Health score (PROMIS Mental).

METHODS: Eligible patients were enrolled and administered questionnaires. Multivariable analysis assessed the influence of ambulatory status on HRQL, adjusting for covariates including age, biologic sex, Charlson comorbidity index, intravenous drug use, management approach, and ASIA grade on presentation.

RESULTS: Sixty-one patients were enrolled (mean age 60.5 years, 46% male). Thirty-four patients (58%) underwent operative management. Mean standard deviation (SD) results for HRQL measures were: EQ5D 0.51 (0.37), EQ5D visual analogue scale 60.34 (25.11), NeuroQoL Lower extremity 41.47 (10.64), PROMIS physical function 39.49 (10.07), and PROMIS Global Mental Health 44.23 (10.36). Adjusted analysis demonstrated ambulatory status at presentation, and at 1 year, to be important drivers of HRQL, irrespective of other factors including IVDU and ASIA grade. Patients with independent ambulatory function at 1 year had mean EQ5D utility of 0.65 (95% CI 0.55, 0.75), whereas those requiring assistive devices saw a 49% decrease with mean EQ5D utility of 0.32 (0.14, 0.51). Ambulatory status was associated with global and physical function but did not impact overall health self-assessment or mental health scores.

CONCLUSIONS: We found that ambulatory status was the most important factor associated with long-term HRQL regardless of other factors such as ASIA grade or IVDU. Given prior literature demonstrating the protective effect of operative intervention on ambulatory function, this highlights ambulatory dysfunction as a potential indication for surgery and a marker of poor long-term prognosis, even in the absence of focal neurologic deficits. Our work also highlights the importance of optimized long-term rehabilitation strategies aimed to preserve ambulatory function in this high-risk population.

LEVEL OF EVIDENCE: Level III, cohort study.