Accurate identification of adverse outcomes after cervical spine surgery

Background: Retrospective clinical studies frequently utilize surgeon records as a source of outcomes data. The accuracy of data derived from surgeon records, however, is unknown. The purpose of the present study was to evaluate the accuracy of surgeon records in documenting the prevalence of subjective adverse outcomes. Methods: Consecutive patients who had undergone anterior cervical arthrodesis by four spine surgeons during a ten-month period were included. Surgeon records from the routine six-week, three-month, and six-month postoperative visits were examined for documentation of persistent dysphagia and dysphonia. Patients completed surveys inquiring about the presence and magnitude of symptoms at these three time-points. Agreement between the surgeon records and the patient surveys was analyzed with use of the kappa coefficient. Results: One hundred and sixty-six patients had 342 postoperative visits. Dysphagia was documented twenty-six times in the surgeon records, compared with 107 times on the patient surveys. Dysphagia was thus underreported in 80% of cases. Similarly, dysphonia was documented ten times in the surgeon records, compared with seventy-two times on the patient surveys. Poor correlation between the surgeon records and the patient surveys was observed regardless of symptom severity, previous anterior cervical surgery, anterior arthrodesis of three motion segments or more, arthrodesis cephalad to the fifth cervical level, and anterior cervical plate use. Poor correlation between the surgeon records and the patient surveys also was observed for each surgeon, regardless of subspecialty or institution. Conclusions: Correlation between the surgeon records and the patient surveys was consistently poor, regardless of the specific patient and surgeon factor analyzed. While we chose to study dysphonia and dysphagia, it is conceivable that the results may be generalizable to many situations in which office notes are utilized to ascertain the prevalence of subjective adverse outcomes. These results suggest that the prevalence of such outcomes may be seriously underreported in studies that rely on the retrospective analysis of surgeon records.