5. the Clinical Course of Patients with Lumbar Spinal Stenosis Initiating Nonoperative Care

BACKGROUND CONTEXT Most patients with symptomatic lumbar spinal stenosis (LSS) initially receive nonoperative care before considering surgery, but there is limited high-quality evidence on the overall prognosis of patients seeking nonsurgical care to guide decision making. PURPOSE 1) Describe the clinical course of outcomes over 12 months among patients with LSS who are initiating nonoperative care and 2) examine if patients’ trajectories differ by age, sex, and duration of symptoms. STUDY DESIGN/SETTING Inception cohort study over 12 months at 2 sites. PATIENT SAMPLE We enrolled patients ≥50 years with symptomatic LSS who were initiating nonoperative care in secondary settings. We excluded patients: 1) with serious medical conditions that may produce back-related symptoms or limit walking, 2) who had prior lumbar spine surgeries, and 3) who were planning on lumbar surgery. OUTCOME MEASURES We collected the Oswestry Disability Index (ODI), leg pain intensity using an 11-point numerical rating scale, and the Swiss Spinal Stenosis Questionnaire (SSSQ) symptoms and function subscales via electronic survey or telephone at baseline and 3, 6, and 12 months. METHODS We collected demographics and health characteristics at baseline, including age, sex, and duration of LSS symptoms. We described outcomes at all time points and used linear mixed-effects models to test if the trajectory of each outcome differed by age group (50-59, 60-69, 70-79, and ≥80), sex, and duration of LSS symptoms (<3 months, 3-6 months, 6-12 months, 1-5 years, and > 5 years). We included an interaction term with time to determine if change over time differed by group. Models were adjusted for age, sex, duration, study site, race, education, marital status, and employment status accordingly. RESULTS This analysis included 519 participants who reached their 12-month follow-up. The mean age was 67 (SD=9), and 61% were female. A plurality of participants (37%) had symptoms for > 5 years, and 6% reported lumbar spine surgery over 12 months. On average, the ODI decreased at each time point from 34 (SD=16) at baseline to 26 (SD=18) at 12 months. Mean leg pain scores decreased from 5.4 (SD=4.4) at baseline to 3.8 (SD=2.6) at 6 months and then remained stable to 12 months. The SSSQ symptoms and function subscales also decreased from baseline (3.2 [SD=0.7] and 2.2 [SD=0.7], respectively) to 6 months (2.3 [SD=0.7] and 1.8 [SD=0.6], respectively) and then remained stable. The mixed-effects models showed age was not associated with ODI, leg pain, SSSQ function scores at any timepoint. However, those ≥80 years had higher SSSQ symptom scores at 6 months vs those 50-59, and there was a significant age by time interaction (p=0.0001). There was no difference by sex for ODI scores, leg pain intensity, and SSSQ subscale scores at all timepoints and no significant sex by time interactions. Patients with symptoms < 3 months and 3-6 months had significantly lower ODI, leg pain, and SSSQ subscale scores at 3, 6, and 12-months vs those with > 5 years of symptoms. The duration by time interaction term was significant (p<0.0001) for each outcome. CONCLUSIONS This large cohort of patients seeking non-operative care for LSS showed, on average, patients improved over 12 months. Back-related disability steadily declined over 12 months. Leg pain, stenosis symptoms, and stenosis-related function improved most over the first 6 months. Patients with symptoms lasting ≤6 months had substantially greater improvement over time compared to those with > 5 years of symptoms. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.