title: Surgical clipping versus endovascular coiling for elderly patients presenting with subarachnoid hemorrhage.
abstract: BACKGROUND
  The comparative effectiveness of the two treatment options (surgical clipping and endovascular coiling) for ruptured cerebral aneurysms has not been studied in real-world practice in the USA. We investigated the association between the treatment method for ruptured cerebral aneurysms and outcomes.
  
  
  METHODS
  We performed a retrospective cohort study of elderly patients who underwent treatment for ruptured cerebral aneurysms from 2007 to 2012 using a 100% sample of Medicare fee-for-service claims data. An instrumental variable analysis was used to control for unmeasured confounding and to create pseudo-randomization on the treatment method. In sensitivity analysis, controlling only for measured confounding, we used propensity score conditioning and inverse probability weighting with mixed effects to account for clustering at the Hospital Referral Region (HRR) level.
  
  
  RESULTS
  During the study period 3210 patients underwent treatment for ruptured cerebral aneurysms and met the inclusion criteria. Of these, 1206 (37.6%) had surgical clipping and 2004 (62.4%) had endovascular coiling. Instrumental variable analysis demonstrated no difference between coiling and clipping in 1-year postoperative mortality (OR 1.04; 95% CI 0.70 to 1.54), likelihood of discharge to rehabilitation (OR 1.07; 95% CI 0.72 to 1.58), or 30-day readmission rate (OR 1.44; 95% CI 0.70 to 1.87). However, clipping was associated with 2.7 days longer length of stay (LOS) (95% CI 0.45 to 4.99). The same associations were present in propensity score adjusted and inverse probability weighted models.
  
  
  CONCLUSIONS
  In a cohort of Medicare patients, we did not demonstrate a difference in mortality, rate of discharge to rehabilitation, and readmissions between clipping and coiling of ruptured cerebral aneurysms. Clipping was associated with a slightly longer LOS.
authors: Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
authors: Kimon
authors: K
authors: Bekelis
authors: The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA.
authors: Dan
authors: D
authors: Gottlieb
authors: The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA.
authors: Yin
authors: Y
authors: Su
authors: The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors: Alistair J
authors: AJ
authors: O'Malley
authors: Department of Radiology, Stony Brook University Medical Center, Stony Brook, New York, USA.
authors: Nicos
authors: N
authors: Labropoulos
authors: Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
authors: Phillip
authors: P
authors: Goodney
authors: The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA Department of Community and Family Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA.
authors: Todd A
authors: TA
authors: MacKenzie
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000628:therapy*; D015331:Cohort Studies; D057186:Comparative Effectiveness Research; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000628:therapy*; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000628:therapy*; D013525:Surgical Instruments; D016896:Treatment Outcome
keywords: Aneurysm; Subarachnoid