title: Comparative effectiveness research across two spine registries.
abstract: BACKGROUND
  Comparative effectiveness research in spine surgery is still a rarity. In this study, pain alleviation and quality of life (QoL) improvement after lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) were anonymously compared by surgeon and implant.
  
  
  METHODS
  A total of 534 monosegmental TDAs from the SWISSspine registry were analyzed. Mean age was 42 years (19-65 years), 59% were females. Fifty cases with ALIF were documented in the international Spine Tango registry and used as concurrent comparator group for the pain analysis. Mean age was 46 years (21-69 years), 78% were females. The average follow-up time in both samples was 1 year. Comparison of back/leg pain alleviation and QoL improvement was performed. Unadjusted and adjusted probabilities for achievement of minimum clinically relevant improvements of 18 VAS points or 0.25 EQ-5D points were calculated for each surgeon.
  
  
  RESULTS
  Mean preoperative back pain decreased from 69 to 30 points at 1 year (ØΔ 39pts) after TDA, and from 66 to 27 points after ALIF (ØΔ 39pts). Mean preoperative QoL improved from 0.34 to 0.74 points at 1 year (ØΔ 0.40pts). There were surgeons with better patient selection, indicated by lower adjusted probabilities reflecting worsening of outcomes if they had treated an average patient sample. ALIF had similar pain alleviation than TDA.
  
  
  CONCLUSIONS
  Pain alleviation after TDA and ALIF was similar. Differences in surgeon's patient selection based on pain and QoL were revealed. Some surgeons seem to miss the full therapeutic potential of TDA by selecting patients with lower symptom severity.
authors.affiliation: Institute for Evaluative Research in Medicine, University of Bern, Bern, Switzerland. emin.aghayev@memcenter.unibe.ch
authors.forename: Emin
authors.initials: E
authors.lastname: Aghayev
authors.forename: Julia
authors.initials: J
authors.lastname: Henning
authors.forename: Everard
authors.initials: E
authors.lastname: Munting
authors.forename: Peter
authors.initials: P
authors.lastname: Diel
authors.forename: Patrick
authors.initials: P
authors.lastname: Moulin
authors.forename: Christoph
authors.initials: C
authors.lastname: Röder
mesh_terms: D000328:Adult; D000368:Aged; D001416:Back Pain / Q000601:surgery*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011788:Quality of Life; D012042:Registries; D013123:Spinal Fusion; D059145:Total Disc Replacement; D016896:Treatment Outcome