Do Cervical Spine Surgery Patients Recall Their Preoperative Status?: A Cohort Study of Recall Bias in Patient-reported Outcomes.

STUDY DESIGN: This is a prospective cohort study.

OBJECTIVE: To characterize the accuracy of patient recollection of preoperative symptoms after cervical spine surgery.

SUMMARY OF BACKGROUND DATA: Recall bias is a well-known source of systematic error. The accuracy of patient recall after cervical spine surgery remains unknown.

METHODS: Consecutive patients undergoing cervical spine surgery for myelopathy or radiculopathy were enrolled. Neck and arm numeric pain scores and Neck Disability Indices were recorded preoperatively. Patients were asked to recall their preoperative status at either short (<1 y) or long-term (≥1 y) follow-up. Actual and recalled scores were compared using paired t tests and relations were quantified using the Pearson correlation coefficients. Multivariable linear regression was used to identify factors impacting recollection.

RESULTS: In total, 73 patients with a mean age of 58.2 years were included. Compared with their preoperative scores, patients showed significant improvement in neck pain [mean difference (MD)=-2.9; 95% confidence intervals (CIs), -3.5 to -2.3], arm pain (MD, -3.4; 95% CI, -4.0 to -2.8), and disability (MD, -12.4%; 95% CI, -16.9 to -7.9). Patient recollection of preoperative status was significantly more severe than actual for neck pain (MD, +1.5; 95% CI, 0.8-2.2), arm pain (MD, +2.3; 95% CI, 1.6-3.0), and disability (MD, +5.8%; 95% CI, 2.4-9.2). Moderate correlation between actual and recalled scores with regard to neck (r=0.41), arm (r=0.50) pain, and disability (r=0.67) was seen. This was maintained across age, sex, and time between date of surgery and recollection. Over 30% of patients switched their predominant symptom from neck-to-arm pain or vice versa on recall of their preoperative symptoms.

CONCLUSIONS: Relying on patient recollection does not provide an accurate measure of preoperative status after cervical spine surgery. Prospective and not retrospective collection of patient-reported outcomes remain the gold standard to measure and interpret outcomes after cervical spine surgery. Recall bias has the potential to affect patient satisfaction and requires further study.