Wednesday, September 26, 2018 9:00 AM – 10:00 AM Best Papers: 2. Do cervical spine surgery patients recall their preoperative status? A cohort study of recall bias in patient-reported outcomes

BACKGROUND CONTEXT Surgery for cervical degenerative myelopathy or radiculopathy focuses on addressing pain and disability while improving the patients’ quality of life. Although patient-reported outcomes (PROs) are being widely adopted, their ability to be interpreted may be limited by the accuracy of a patientu0027s ability to recall preintervention impairment. PURPOSE Recall bias has been previously investigated in multiple orthopedic and lumbar spine studies, but recall accuracy in cervical spine patients remains unknown. We sought to characterize the accuracy of patient recall as a function of time on validated outcomes after cervical spine surgery. STUDY DESIGN/SETTING Retrospective review of prospectively collected outcomes. PATIENT SAMPLE Consecutive series of patients undergoing cervical spine surgery for myelopathy or radiculopathy. OUTCOME MEASURES Numeric pain scale, neck disability index. METHODS We analyzed a consecutive series of patients undergoing cervical spine surgery for degenerative myelopathy or radiculopathy at a single institution. Using standardized questionnaires, we recorded preoperative neck and arm numeric pain scores (NPS), neck disability indices (NDI) and 36-Item Short Form Health Survey (SF-36). Patients were asked to recall their preoperative status through a standardized phone call script and were subsequently stratified based on the timing of their recall into short-term ( 1 year) follow-up sub-groups. Actual and recalled scores were compared using McNemaru0027s or paired t tests, and relations were quantified using Pearson correlation coefficients. Characteristics between the subgroups were compared using Wilcoxon rank sum tests, t -tests, chi-square tests, or Fisheru0027s exact tests as appropriate. RESULTS Seventy-three patients with a mean age of 58.2 years (range 22 to 83 years) were included, with 34 and 39 patients in the short-term and long-term follow-up subgroups patients respectively. The mean period of recall from surgery was 4.6 months and 22.2 months for the short-term and long-term follow-up subgroups respectively. Compared to the preoperative scores, patients showed significant improvement in neck NPS (mean difference [MD]=−2.9, 95% CI −3.5 to −2.3), arm NPS (MD −3.4, 95% CI −4.0 to −2.8), and NDI (MD −12.4%, 95% CI −16.9 to −7.9). Patient recollection of preoperative status was more severe than actual for neck NPS (MD +1.5, p CONCLUSIONS Relying on retrospectively recalled data for outcome assessment does not provide an accurate measure of preoperative status. Prospective collection of PROs remains the gold standard to measure outcomes following cervical spine surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.