Patient Outcome Questionnaires in the British Spine Registry: Why are Response Rates Low and Which Patients Groups are responding?

Abstract
Objective: The British Spinal Registry (BSR) is fast becoming an integral part of recording spinal surgical activity and its outcomes.The most recent report from the BSR identified a complete data set collection of only 30% of recruited patients. We aimed to evaluate feedback rates and to identify which groups of patients were most
likely to respond.

Methods: We analysed a single surgeon’s BSR database identifying response rates for patients recruited from 2016-2018.The subset analysis considered response rates according to patient age, gender, prior responses and date of surgery.

Results: Overall 297 patients were analysed, of these 58% completed the preoperative baseline questionnaire, 33% at 6 weeks, 25% at 6 months and 1 year and 28% at 2 years. Those who responded at 6 weeks were far more likely to respond to subsequent questionnaires OR 29.9 (95% CI=9.3-95.7 p<0.0001). Women, and the millennial generation were more likely to respond OR 2.0 (95% CI 1.2-3.4 p=0.012) and OR 1.79 (95% CI 1.2-2.6 p=0.003) respectively. Analysis of the Oswestry Disability Index (ODI) scores showed patients at the extremes were more likely to respond. The response rate has progressively declined each year.

Conclusion: Overall response rates are low and continuing to decline. Those who respond are most likely to be female millennials with either very high or very low ODI scores. These results should stimulate discussion around improving patient engagement and instil caution when using this registry to guide future practice and funding distribution.