Does country of origin influence research outcomes in operative interventions for lumbar spinal stenosis?

Introduction: Bias undermines evidence-based decision making. To counter this, surgeons must be aware of biases that may influence studies' reported outcomes. Lumbar spinal stenosis often requires operative intervention, with multiple available surgical strategies. Our aim was to assess the role that country of origin plays in published surgical outcomes for lumbar spinal stenosis.

Methods: We performed a search strategy of MEDLINE and EMBASE for all English language primary research papers evaluating operative interventions for lumbar spinal stenosis during the years 2010-2019 inclusive. Small case series and meta-analyses were excluded. Papers were assessed for outcome positivity and country of origin. Data analysis was conducted using GraphPad Prism statistical software.

Results: A total of 487 papers met the inclusion criteria. Of these, 419 (86%) reported positive outcomes. Asian studies were the most likely to report positive outcomes, at 93% (220 of 236), followed by US studies at 89% (98 of 110). European studies had the lowest positive publication rate at 69% (84 of 121). Region of origin was an independent predictor of positive study outcome on multivariable analysis when controlling for different study designs and healthcare systems.

Conclusion: There is an association between country of origin and positive reported outcome in studies evaluating interventions for lumbar spinal stenosis. Clinicians should consider this when making management decisions based on published evidence.

Level Of Evidence I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.