Independent predictors of reliability between full time employee-dependent acquisition of functional outcomes...

The prospective acquisition of reliable patient-reported outcomes (PROs) measures demonstrating the effectiveness of spine surgery, or lack thereof, remains a challenge. The aims of this study are to compare the reliability of functional outcomes metrics obtained using full time employee (FTE) vs. non-FTE-dependent methodologies and to determine the independent predictors of response reliability using non FTE-dependent methodologies.

One hundred and nineteen adult patients (male: 65, female: 54) undergoing one- and two-level lumbar fusions at Duke University Medical Center were enrolled in this prospective study. Enrollment criteria included available demographic, clinical and baseline functional outcomes data. All patients were administered two similar sets of baseline questionnaires-(I) phone interviews (FTE-dependent) and (II) hardcopy in clinic (patient self-survey, non-FTE-dependent). All patients had at least a two-week washout period between phone interviews and in-clinic self-surveys to minimize effect of recall. Questionnaires included Oswestry disability index (ODI) and Visual Analog Back and Leg Pain Scale (VAS-BP/LP). Reliability was assessed by the degree to which patient responses to baseline questionnaires differed between both time points.

About 26.89% had a history an anxiety disorder and 28.57% reported a history of depression. At least 97.47% of patients had a High School Diploma or GED, with 49.57% attaining a 4-year college degree or post-graduate degree. 29.94% reported full-time employment and 14.28% were on disability. There was a very high correlation between baseline PRO's data captured between FTE-dependent compared to non-FTE-dependent methodologies (r=0.89). In a multivariate logistic regression model, the absence of anxiety and depression, higher levels of education (college or greater) and full-time employment, were independently associated with high response reliability using non-FTE-dependent methodologies.

Our study suggests that capturing health-related quality of life data using non-FTE-dependent methodologies is highly reliable and maybe a more cost-effective alternative. Well-educated patients who are employed full-time appear to be the most reliable.