P49. Physical activity measures in lumbar laminectomy patients: a prospective comparison of fitness tracker measures versus patient-reported outcome measures

BACKGROUND CONTEXT Assessing spine surgery patients\u0027 disability and mobility levels allows clinicians to evaluate the efficacy of surgical procedures and track postoperative recovery. While the current standard, patient-reported outcome measures (PROMs), provides a cross-sectional subjective assessment of functional levels, wearable fitness trackers can continuously and objectively track physical activity even outside of the clinic. PURPOSE The present study aims to assess how a wearable fitness tracker and two PROMs compare in tracking patients\u0027 recoveries from lumbar laminectomy. STUDY DESIGN/SETTING This is a prospective observational clinical study conducted within an urban academic health system. PATIENT SAMPLE The sample is composed of patients with lumbar stenosis who have undergone non-revision lumbar laminectomy with or without single level fusion. Patients who have had spine surgery within the past 5 years or have medical conditions that significantly inhibit mobility (including cardiovascular conditions and other orthopedic conditions) were excluded. OUTCOME MEASURES Patient median steps taken per day were continuously collected using the Fitbit Flex 2 fitness tracker. The Oswestry Disability Index (ODI) and Physical and Mental Components of the 12-Item Short Form Health Survey (SF-12 PCS/MCS) PROMs were assessed using standardized questionnaires throughout the study period. METHODS Each patient was provided with a fitness tracker at least 2 weeks prior to surgery until 6 months postoperatively to record median steps taken per day during the preoperative (baseline) and 2 week, 1, 3, and 6 month postoperative intervals. ODI and SF-12 PCS/MCS scores were calculated at enrollment and at the end of each interval. Two-tailed Student\u0027s t-tests were used to evaluate changes from baseline. Associations between the change in median steps per day and PROMs throughout the study were evaluated using Pearson\u0027s correlation coefficient. RESULTS Twelve of 18 enrolled subjects have thus far completed the study. Average compliance for wearing the fitness tracker, which was defined as the percentage of days the device was worn relative to the number of days the subject was enrolled in the study, was 91%. Average median steps per day and PROM scores normalized to preoperative levels decline immediately after surgery but recover after 1-3 months. Median steps per day were not significantly different from baseline at 6 months postoperatively (2.45% increase; p = 0.60). Average SF-12 PCS and ODI scores surpassed baseline scores by 1 month postoperatively and improved from baseline by 38% and 45% respectively at 6 months postoperatively (p = 0.004 and 0.05). No significant correlations were found between the change in median steps per day and corresponding change in PROM scores at any study time points. CONCLUSIONS Though enrollment is still ongoing, we can conclude that lumbar laminectomy patients had significantly improved SF-12 PCS and ODI scores by 6 months postoperatively while median steps per day only returned to baseline. Patients therefore perceive that their conditions have improved after lumbar laminectomy more quickly than their mobilities objectively increase. The lack of significant correlations between the change in median steps per day and corresponding change in PROM scores throughout the study also suggests that these outcome measurements describe distinct patient experiences. Though patients\u0027 self-reported pain-free mobility increases, lifestyle and other factors may be important in explaining the lack of difference between preoperative and 6-month postoperative median steps taken per day. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.