title: Likelihood of reaching minimal clinically important difference in adult spinal deformity: a comparison of operative and nonoperative treatment.
abstract: BACKGROUND
  Few studies have examined threshold improvements in health-related quality of life (HRQOL) by measuring minimal clinically important differences (MCIDs) in treatment of adult spinal deformity. We hypothesized that patients undergoing operative treatment would be more likely to achieve MCID threshold improvement compared with those receiving nonoperative care, although a subset of nonoperative patients may still reach threshold.
  
  
  METHODS
  We analyzed a multicenter, prospective, consecutive case series of 464 patients: 225 nonoperative and 239 operative. To be included in the study, patients had to have adult spinal deformity, be older than 18 years, and have both baseline and 1-year follow-up HRQOL measures (Oswestry Disability Index [ODI], Short Form-36 [SF-36] health survey, and Scoliosis Research Society-22 [SRS-22] questionnaire). We compared the percentages of patients achieving established MCID thresholds between operative and nonoperative groups using risk ratios (RR) with a 95% confidence interval (CI).
  
  
  RESULTS
  Compared to nonoperative patients, surgical patients demonstrated significant mean improvement (P<0.01) and were more likely to achieve threshold MCID improvement across all HRQOL scores (ODI RR = 7.37 [CI 4.45, 12.21], SF-36 physical component score RR = 2.96 [CI 2.11, 4.15], SRS Activity RR = 3.16 [CI 2.32, 4.31]). Furthermore, operative patients were more likely to reach threshold MCID improvement in 2 or more HRQOL measures simultaneously and were less likely to deteriorate.
  
  
  CONCLUSIONS
  Patients in both the operative and nonoperative treatment groups demonstrated improvement in at least one HRQOL measure at 1 year. However, surgical treatment was more likely to result in threshold improvement and more likely to lead to simultaneous improvement across multiple measures of ODI, SF-36, and SRS-22. Although a subset of nonoperative patients achieved threshold improvement, nonoperative patients were significantly less likely to improve in multiple HRQOL measures and more likely to sustain MCID deterioration or no change.
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY.
authors.forename: Shian
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.affiliation: Department of Orthopaedic Surgery, University of California-Davis, Sacramento, CA.
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.affiliation: San Diego Center for Spinal Disorders, La Jolla, CA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Mundis
authors.affiliation: Department of Orthopedic Surgery, Baylor Scoliosis Center, Dallas, TX.
authors.forename: Richard
authors.initials: R
authors.lastname: Hostin
authors.affiliation: Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, MD.
authors.forename: Khaled
authors.initials: K
authors.lastname: Kebaish
authors.affiliation: Department of Orthopaedic Surgery, University of California-San Francisco Medical Center, San Francisco, CA.
authors.forename: Vedat
authors.initials: V
authors.lastname: Deviren
authors.affiliation: Department of Orthopaedic Surgery, University of California-Davis, Sacramento, CA.
authors.forename: Munish
authors.initials: M
authors.lastname: Gupta
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY.
authors.forename: Oheneba
authors.initials: O
authors.lastname: Boachie-Adjei
authors.affiliation: Department of Orthopaedic Surgery, Oregon Health & Science University, Portland, OR.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hart
authors.affiliation: Department of Orthopaedic Surgery, Rocky Mountain Hospital for Children, Denver, CO.
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.affiliation: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
keywords: Disability evaluation; pain management; quality of life; spinal cord diseases; surgical procedures–operative