Browsing by Author "Jain, Amit"

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    ItemOpen Access
    A New Piece of the Puzzle to Understand Cervical Sagittal Alignment: Utilizing a Novel Angle δ to Describe the Relationship among T1 Vertebral Body Slope, Cervical Lordosis, and Cervical Sagittal Alignment.
    (Neurosurgery, 2020-03) Goldschmidt, Ezequiel; Angriman, Federico; Agarwal, Nitin; Trevisan, Marcos; Zhou, James; Chen, Katherine; Gerszten, Peter C; Kanter, Adam S; Okonkwo, David O; Passias, Peter; Scheer, Justin; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Schwab, Frank; Bess, Shay; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Miller, Emily; Jain, Amit; Neuman, Brian; Sciubba, Daniel M; Burton, Douglas; Hamilton, D Kojo; International Spine Study Group (ISSG)
    Cervical alignment has become increasingly important in the planning of spine surgery. A relationship between the slope of T1 (T1S), the cervical lordosis (CL), and the overall cervical sagittal vertical axis (cSVA) has previously been demonstrated, but the exact nature of this relationship is poorly understood. In this study, we derive theoretical and empirical equations to better understand how T1S and CL affect cSVA. The first equation was developed on a theoretical basis using inherent trigonometric relationships of the cervical spine. By treating the cervical spine as the arc of a circumference, and by taking into account the cervical height (CH), the geometric relationship between theT1S, CL, and cSVA was described via a trigonometric identity utilizing a novel angle δ subtended by the CH and cSVA (δ = T1S-CL/2). The second equation was developed on an empiric basis by performing a multiple linear regression on data obtained from a retrospective review of a large multicenter deformity database. The theoretical equation determined that the value of cSVA could be expressed as: $cSVA\ = \ CH*{\rm{tan}}( {\pi /180*( {T1S - CL/2} )} )$. The empirical equation determined that value of cSVA could be expressed as: $cSVA=({1.1*T1} )\ - ( {0.43*CL} ) + 6.69$. In both, the sagittal alignment of the head over the shoulders is directly proportional to the T1S and inversely proportional to CL/2. These 2 equations may allow surgeons to better understand how the CL compensates for the T1S, to accurately predict the postoperative cSVA, and to customize cervical interbody grafts by taking into consideration each individual patient's specific cervical spine parameters.
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    ItemOpen Access
    A Novel Tool for Deformity Surgery Planning: Determining the Magnitude of Lordotic Correction Required to Achieve a Desired Sagittal Vertical Axis.
    (World neurosurgery, 2017-08) Goldschmidt, Ezequiel; Angriman, Federico; Agarwal, Nitin; Zhou, James; Chen, Katherine; Tempel, Zachary J; Gerszten, Peter C; Kanter, Adam S; Okonkwo, David O; Passias, Peter; Scheer, Justin; Protopsaltis, Themistocles; Lafage, Virginie; Lafage, Renaud; Schwab, Frank; Bess, Shay; Ames, Christopher; Smith, Justin S; Shaffrey, Christopher I; Miller, Emily; Jain, Amit; Neuman, Brian; Sciubba, Daniel M; Burton, Douglas; Hamilton, D Kojo; International Spine Study Group

    Objective

    We sought to create a model capable of predicting the magnitude of pelvic incidence-lumbar lordosis (PI-LL) correction necessary to achieve a desired change in sagittal vertical axis (SVA).

    Methods

    A retrospective review was conducted of a prospectively maintained multicenter adult spinal deformity database collected by the International Spine Study Group between 2009 and 2014. The independent variable of interest was the degree of correction achieved in the PI-LL mismatch 6 weeks after surgery. Primary outcome was the change in global sagittal alignment 6 weeks and 1 year after surgery. We used a linear mixed-effects model to determine the extent to which corrections in the PI-LL relationship affected postoperative changes in SVA.

    Results

    A total of 1053 adult patients were identified. Of these patients, 590 were managed surgically. Eighty-seven surgically managed patients were excluded because of incomplete or missing PI-LL measurements on follow-up; the remaining 503 patients were selected for inclusion. For each degree of improvement in the PI-LL mismatch at 6 weeks, the SVA decreased by 2.18 mm (95% confidence interval, -2.56, -1.79; P < 0.01) and 1.67 mm (95% confidence interval, -2.07, -1.27; P < 0.01) at 6 weeks and 12 months, respectively. A high SVA measurement (>50 mm) 1 year after surgery was negatively associated with health-related quality of life as measured by the Scoliosis Research Society 22 outcomes assessment.

    Conclusions

    We describe a novel model that shows how surgical correction of the PI-LL relationship affects postoperative changes in SVA. This model may enable surgeons to determine preoperatively the amount of LL necessary to achieve a desired change in SVA.
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    ItemOpen Access
    An assessment of frailty as a tool for risk stratification in adult spinal deformity surgery.
    (Neurosurgical focus, 2017-12) Miller, Emily K; Neuman, Brian J; Jain, Amit; Daniels, Alan H; Ailon, Tamir; Sciubba, Daniel M; Kebaish, Khaled M; Lafage, Virginie; Scheer, Justin K; Smith, Justin S; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    OBJECTIVE The goal of this study was to analyze the value of an adult spinal deformity frailty index (ASD-FI) in preoperative risk stratification. Preoperative risk assessment is imperative before procedures known to have high complication rates, such as ASD surgery. Frailty has been associated with risk of complications in trauma surgery, and preoperative frailty assessments could improve the accuracy of risk stratification by providing a comprehensive analysis of patient factors that contribute to an increased risk of complications. METHODS Using 40 variables, the authors calculated frailty scores with a validated method for 417 patients (enrolled between 2010 and 2014) with a minimum 2-year follow-up in an ASD database. On the basis of these scores, the authors categorized patients as not frail (NF) (< 0.3 points), frail (0.3-0.5 points), or severely frail (SF) (> 0.5 points). The correlation between frailty category and incidence of complications was analyzed. RESULTS The overall mean ASD-FI score was 0.33 (range 0.0-0.8). Compared with NF patients (n = 183), frail patients (n = 158) and SF patients (n = 109) had longer mean hospital stays (1.2 and 1.6 times longer, respectively; p < 0.001). The adjusted odds of experiencing a major intraoperative or postoperative complication were higher for frail patients (OR 2.8) and SF patients ( 4.1) compared with NF patients (p < 0.01). For frail and SF patients, respectively, the adjusted odds of developing proximal junctional kyphosis (OR 2.8 and 3.1) were higher than those for NF patients. The SF patients had higher odds of developing pseudarthrosis (OR 13.0), deep wound infection (OR 8.0), and wound dehiscence (OR 13.4) than NF patients (p < 0.05), and they had 2.1 times greater odds of reoperation (p < 0.05). CONCLUSIONS Greater patient frailty, as measured by the ASD-FI, was associated with worse outcome in many common quality and value metrics, including greater risk of major complications, proximal junctional kyphosis, pseudarthrosis, deep wound infection, wound dehiscence, reoperation, and longer hospital stay.
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    Cost-utility analysis of cervical deformity surgeries using 1-year outcome.
    (The spine journal : official journal of the North American Spine Society, 2018-09) Poorman, Gregory W; Passias, Peter G; Qureshi, Rabia; Hassanzadeh, Hamid; Horn, Samantha; Bortz, Cole; Segreto, Frank; Jain, Amit; Kelly, Michael; Hostin, Richard; Ames, Christopher; Smith, Justin; LaFage, Virginie; Burton, Douglas; Bess, Shay; Shaffrey, Chris; Schwab, Frank; Gupta, Munish

    Background context

    Cost-utility analysis, a special case of cost-effectiveness analysis, estimates the ratio between the cost of an intervention to the benefit it produces in number of quality-adjusted life years. Cervical deformity correction has not been evaluated in terms of cost-utility and in the context of value-based health care. Our objective, therefore, was to determine the cost-utility ratio of cervical deformity correction.

    Study design

    This is a retrospective review of a prospective, multicenter cervical deformity database. Patients with 1-year follow-up after surgical correction for cervical deformity were included. Cervical deformity was defined as the presence of at least one of the following: kyphosis (C2-C7 Cobb angle >10°), cervical scoliosis (coronal Cobb angle >10°), positive cervical sagittal malalignment (C2-C7 sagittal vertical axis >4 cm or T1-C6 >10°), or horizontal gaze impairment (chin-brow vertical angle >25°). Quality-adjusted life years were calculated by both EuroQol 5D (EQ5D) quality of life and Neck Disability Index (NDI) mapped to short form six dimensions (SF6D) index. Costs were assigned using Medicare 1-year average reimbursement for: 9+ level posterior fusions (PF), 4-8 level PF, 4-8 level PF with anterior fusion (AF), 2-3 level PF with AF, 4-8 level AF, and 4-8 level posterior refusion. Reoperations and deaths were added to cost and subtracted from utility, respectively. Quality-adjusted life year per dollar spent was calculated using standardized methodology at 1-year time point and subsequent time points relying on maintenance of 1-year utility.

    Results

    Eighty-four patients (average age: 61.2 years, 60% female, body mass index [BMI]: 30.1) were analyzed after cervical deformity correction (average levels fused: 7.2, osteotomy used: 50%). Costs associated with index procedures were 9+ level PF ($76,617), 4-8 level PF ($40,596), 4-8 level PF with AF ($67,098), 4-8 level AF ($31,392), and 4-8 level posterior refusion ($35,371). Average 1-year reimbursement of surgery was $55,097 at 1 year with eight revisions and three deaths accounted for. Cost per quality-adjusted life year (QALY) gained to 1-year follow-up was $646,958 by EQ5D and $477,316 by NDI SF6D. If 1-year benefit is sustained, upper threshold of cost-effectiveness is reached 3-4.5 years after intervention.

    Conclusions

    Medicare 1-year average reimbursement compared with 1-year QALYdescribed $646,958 by EQ5D and $477,316 by NDI SF6D. Cervical deformity surgeries reach accepted cost-effectiveness thresholds when benefit is sustained 3-4.5 years. Longer follow-up is needed for a more definitive cost-analysis, but these data are an important first step in justifying cost-utility ratio for cervical deformity correction.
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    ItemOpen Access
    Cost-Utility Analysis of rhBMP-2 Use in Adult Spinal Deformity Surgery.
    (Spine, 2020-07) Jain, Amit; Yeramaneni, Samrat; Kebaish, Khaled M; Raad, Micheal; Gum, Jeffrey L; Klineberg, Eric O; Hassanzadeh, Hamid; Kelly, Michael P; Passias, Peter G; Ames, Christopher P; Smith, Justin S; Shaffrey, Christopher I; Bess, Shay; Lafage, Virginie; Glassman, Steve; Carreon, Leah Y; Hostin, Richard A; International Spine Study Group

    Study design

    Economic modeling of data from a multicenter, prospective registry.

    Objective

    The aim of this study was to analyze the cost utility of recombinant human bone morphogenetic protein-2 (BMP) in adult spinal deformity (ASD) surgery.

    Summary of background data

    ASD surgery is expensive and presents risk of major complications. BMP is frequently used off-label to reduce the risk of pseudarthrosis.

    Methods

    Of 522 ASD patients with fusion of five or more spinal levels, 367 (70%) had at least 2-year follow-up. Total direct cost was calculated by adding direct costs of the index surgery and any subsequent reoperations or readmissions. Cumulative quality-adjusted life years (QALYs) gained were calculated from the change in preoperative to final follow-up SF-6D health utility score. A decision-analysis model comparing BMP versus no-BMP was developed with pseudarthrosis as the primary outcome. Costs and benefits were discounted at 3%. Probabilistic sensitivity analysis was performed using mixed first-order and second-order Monte Carlo simulations. One-way sensitivity analyses were performed by varying cost, probability, and QALY estimates (Alpha = 0.05).

    Results

    BMP was used in the index surgery for 267 patients (73%). The mean (±standard deviation) direct cost of BMP for the index surgery was $14,000 ± $6400. Forty patients (11%) underwent revision surgery for symptomatic pseudarthrosis (BMP group, 8.6%; no-BMP group, 17%; P = 0.022). The mean 2-year direct cost was significantly higher for patients with pseudarthrosis ($138,000 ± $17,000) than for patients without pseudarthrosis ($61,000 ± $25,000) (P < 0.001). Simulation analysis revealed that BMP was associated with positive incremental utility in 67% of patients and considered favorable at a willingness-to-pay threshold of $150,000/QALY in >52% of patients.

    Conclusion

    BMP use was associated with reduction in revisions for symptomatic pseudarthrosis in ASD surgery. Cost-utility analysis suggests that BMP use may be favored in ASD surgery; however, this determination requires further research.

    Level of evidence

    2.
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    ItemOpen Access
    Development of a Preoperative Predictive Model for Reaching the Oswestry Disability Index Minimal Clinically Important Difference for Adult Spinal Deformity Patients
    (Spine Deformity, 2018-09-01) Scheer, Justin K; Osorio, Joseph A; Smith, Justin S; Schwab, Frank; Hart, Robert A; Hostin, Richard; Lafage, Virginie; Jain, Amit; Burton, Douglas C; Bess, Shay; Ailon, Tamir; Protopsaltis, Themistocles S; Klineberg, Eric O; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group
    © 2018 Scoliosis Research Society Study Design: Retrospective review of prospective multicenter adult spinal deformity (ASD) database. Objective: To create a model based on baseline demographic, radiographic, health-related quality of life (HRQOL), and surgical factors that can predict patients meeting the Oswestry Disability Index (ODI) minimal clinically important difference (MCID) at the two-year postoperative follow-up. Summary of Background Data: Surgical correction of ASD can result in significant improvement in disability as measured by ODI, with the goal of reaching at least one MCID. However, a predictive model for reaching MCID following ASD correction does not exist. Methods: ASD patients ≥18 years and baseline ODI ≥ 30 were included. Initial training of the model comprised forty-three variables including demographic data, comorbidities, modifiable surgical variables, baseline HRQOL, and coronal/sagittal radiographic parameters. Patients were grouped by whether or not they reached at least one ODI MCID at two-year follow-up. Decision trees were constructed using the C5.0 algorithm with five different bootstrapped models. Internal validation was accomplished via a 70:30 data split for training and testing each model, respectively. Final predictions from the models were chosen by voting with random selection for tied votes. Overall accuracy, and the area under a receiver operating characteristic curve (AUC) were calculated. Results: 198 patients were included (MCID: 109, No-MCID: 89). Overall model accuracy was 86.0%, with an AUC of 0.94. The top 11 predictors of reaching MCID were gender, Scoliosis Research Society (SRS) activity subscore, back pain, sagittal vertical axis (SVA), pelvic incidence–lumbar lordosis mismatch (PI-LL), primary version revision, T1 spinopelvic inclination angle (T1SPI), American Society of Anesthesiologists (ASA) grade, T1 pelvic angle (T1PA), SRS pain, SRS total. Conclusions: A successful model was built predicting ODI MCID. Most important predictors were not modifiable surgical parameters, indicating that baseline clinical and radiographic status is a critical factor for reaching ODI MCID. Level of Evidence: Level II.
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    ItemOpen Access
    Development of Validated Computer-based Preoperative Predictive Model for Proximal Junction Failure (PJF) or Clinically Significant PJK With 86% Accuracy Based on 510 ASD Patients With 2-year Follow-up.
    (Spine, 2016-11) Scheer, Justin K; Osorio, Joseph A; Smith, Justin S; Schwab, Frank; Lafage, Virginie; Hart, Robert A; Bess, Shay; Line, Breton; Diebo, Bassel G; Protopsaltis, Themistocles S; Jain, Amit; Ailon, Tamir; Burton, Douglas C; Shaffrey, Christopher I; Klineberg, Eric; Ames, Christopher P; International Spine Study Group

    Study design

    A retrospective review of large, multicenter adult spinal deformity (ASD) database.

    Objective

    The aim of this study was to build a model based on baseline demographic, radiographic, and surgical factors that can predict clinically significant proximal junctional kyphosis (PJK) and proximal junctional failure (PJF).

    Summary of background data

    PJF and PJK are significant complications and it remains unclear what are the specific drivers behind the development of either. There exists no predictive model that could potentially aid in the clinical decision making for adult patients undergoing deformity correction.

    Methods

    Inclusion criteria: age ≥18 years, ASD, at least four levels fused. Variables included in the model were demographics, primary/revision, use of three-column osteotomy, upper-most instrumented vertebra (UIV)/lower-most instrumented vertebra (LIV) levels and UIV implant type (screw, hooks), number of levels fused, and baseline sagittal radiographs [pelvic tilt (PT), pelvic incidence and lumbar lordosis (PI-LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA)]. PJK was defined as an increase from baseline of proximal junctional angle ≥20° with concomitant deterioration of at least one SRS-Schwab sagittal modifier grade from 6 weeks postop. PJF was defined as requiring revision for PJK. An ensemble of decision trees were constructed using the C5.0 algorithm with five different bootstrapped models, and internally validated via a 70 : 30 data split for training and testing. Accuracy and the area under a receiver operator characteristic curve (AUC) were calculated.

    Results

    Five hundred ten patients were included, with 357 for model training and 153 as testing targets (PJF: 37, PJK: 102). The overall model accuracy was 86.3% with an AUC of 0.89 indicating a good model fit. The seven strongest (importance ≥0.95) predictors were age, LIV, pre-operative SVA, UIV implant type, UIV, pre-operative PT, and pre-operative PI-LL.

    Conclusion

    A successful model (86% accuracy, 0.89 AUC) was built predicting either PJF or clinically significant PJK. This model can set the groundwork for preop point of care decision making, risk stratification, and need for prophylactic strategies for patients undergoing ASD surgery.

    Level of evidence

    3.
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    Diagnosis-Related Group-Based Payments for Adult Spine Deformity Surgery Significantly Vary across Centers: Results from a Multicenter Prospective Cohort Study.
    (World neurosurgery, 2023-03) Yeramaneni, Samrat; Wang, Kevin; Gum, Jeffrey; Line, Breton; Jain, Amit; Kebaish, Khaled; Shaffrey, Christopher; Smith, Justin S; Lafage, Virginie; Schwab, Frank; Passias, Peter; Hamilton, D Kojo; Klineberg, Eric; Ames, Christopher; Burton, Douglas; Bess, Shay; Hostin, Richard

    Background

    To investigate the variation in total episode-of-care (EOC) payment and quality-adjusted life-year (QALY) gain for complex adult spine deformity surgeries in the United States, adjusting for case type and surgeon preferences.

    Methods

    Patients aged >18 years with adult spine deformity with Medicare Severity-Diagnosis-Related Groups (DRGs) 453-460 and a minimum of 2 years of follow-up from index surgery were included. Index and total payments were calculated using Medicare's Inpatient Prospective Payment System. All costs were adjusted for inflation to 2020 U.S. dollar values. QALYs gained were calculated using baseline, 1-year, and 2-year Short-Form 6D scores. Mixed-effect models were used to estimate the proportion of variation in total EOC payment and QALY gain.

    Results

    A total of 330/543 patients from 6 sites were included. Mean age was 62.4 ± 11.9 years, 79% were women, and 92% were white. The mean index and total EOC payment were $77,302 and $93,182, respectively. Patients gained on average 0.15 QALY (P < 0.0001) 2 years after surgery. In unadjusted analysis, 39% of the variation in total EOC payment across the 6 centers was attributable to relative weight of DRG and base rate. Adjusting for patient and procedural factors increased the proportion of variation in total EOC payments across the centers to 56%. Less than 2% of the variation in QALY gain was observed across the 6 centers.

    Conclusions

    Medicare-based payments for complex spine deformity fusions are primarily driven by relative weight of the DRG and the hospital's base rate. Patient and procedural factors are unaccounted for in the DRG-based payments made to the providers.
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    ItemOpen Access
    Early Patient-Reported Outcomes Predict 3-Year Outcomes in Operatively Treated Patients with Adult Spinal Deformity.
    (World neurosurgery, 2017-06) Jain, Amit; Kebaish, Khaled M; Sciubba, Daniel M; Hassanzadeh, Hamid; Scheer, Justin K; Neuman, Brian J; Lafage, Virginie; Bess, Shay; Protopsaltis, Themistocles S; Burton, Douglas C; Smith, Justin S; Shaffrey, Christopher I; Hostin, Richard A; Ames, Christopher P; International Spine Study Group

    Background

    For patients with adult spinal deformity (ASD), surgical treatment may improve their health-related quality of life. This study investigates when the greatest improvement in outcomes occurs and whether incremental improvements in patient-reported outcomes during the first postoperative year predict outcomes at 3 years.

    Methods

    Using a multicenter registry, we identified 84 adults with ASD treated surgically from 2008 to 2012 with complete 3-year follow-up. Pairwise t tests and multivariate regression were used for analysis. Significance was set at P < 0.01.

    Results

    Mean Oswestry Disability Index (ODI) and Scoliosis Research Society-22r total (SRS-22r) scores improved by 13 and 0.8 points, respectively, from preoperatively to 3 years (both P < 0.001). From preoperatively to 6 weeks postoperatively, ODI scores worsened by 5 points (P = 0.049) and SRS-22r scores improved by 0.3 points (P < 0.001). Between 6 weeks and 1 year, ODI and SRS-22r scores improved by 19 and 0.5 points, respectively (both P < 0.001). Incremental improvements during the first postoperative year predicted 3-year outcomes in ODI and SRS-22r scores (adjusted R2 = 0.52 and 0.42, respectively). There were no significant differences in the measured or predicted 3-year ODI (P = 0.991) or SRS-22r scores (P = 0.986).

    Conclusions

    In surgically treated patients with ASD, the greatest improvements in outcomes occurred between 6 weeks and 1 year postoperatively. A model with incremental improvements from baseline to 6 weeks and from 6 weeks to 1 year can be used to predict ODI and SRS-22r scores at 3 years.
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    ItemOpen Access
    Examination of the Economic Burden of Frailty in Patients With Adult Spinal Deformity Undergoing Surgical Intervention.
    (Neurosurgery, 2022-01) Passias, Peter G; Ahmad, Waleed; Kummer, Nicholas; Lafage, Renaud; Lafage, Virginie; Kebaish, Khaled; Daniels, Alan; Klineberg, Eric; Soroceanu, Alex; Gum, Jeffrey; Line, Breton; Hart, Robert; Burton, Douglas; Eastlack, Robert; Jain, Amit; Smith, Justin S; Ames, Christopher P; Shaffrey, Christopher; Schwab, Frank; Hostin, Richard; Bess, Shay; International Spine Study Group***

    Background

    With increasing interest in cost optimization, costs of adult spinal deformity (ASD) surgery intersections with frailty merit investigation.

    Objective

    To investigate costs associated with ASD and frailty.

    Methods

    Patients with ASD (scoliosis ≥20°, sagittal vertical axis [SVA] ≥5 cm, pelvic tilt ≥ 25°, or thoracic kyphosis ≥ 60°) with baseline and 2-yr radiographic data were included. Patients were severely frail (SF), frail (F), or not frail (NF). Utility data were converted from Oswestry Disability Index to Short-Form Six-Dimension. Quality-adjusted life years (QALYs) used 3% rate for decline to life expectancy. Costs were calculated using PearlDiver. Loss of work costs were based on SRS-22rQ9 and US Bureau of Labor Statistics. Accounting for complications, length of stay, revisions, and death, cost per QALY at 2 yr and life expectancy were calculated.

    Results

    Five hundred ninety-two patients with ASD were included (59.8 ± 14.0 yr, 80% F, body mass index: 27.7 ± 6.0 kg/m2, Adult Spinal Deformity-Frailty Index: 3.3 ± 1.6, and Charlson Comorbidity Index: 1.8 ± 1.7). The average blood loss was 1569.3 mL, and the operative time was 376.6 min, with 63% undergoing osteotomy and 54% decompression. 69.3% had a posterior-only approach, 30% combined, and 0.7% anterior-only. 4.7% were SF, 22.3% F, and 73.0% NF. At baseline, 104 were unemployed losing $971.38 weekly. After 1 yr, 62 remained unemployed losing $50 508.64 yearly. With propensity score matching for baseline SVA, cost of ASD surgery at 2 yr for F/SF was greater than that for NF ($81 347 vs $69 722). Cost per QALY was higher for F/SF at 2 yr than that for NF ($436 473 vs $430 437). At life expectancy, cost per QALY differences became comparable ($58 965 vs $58 149).

    Conclusion

    Despite greater initial cost, F and SF patients show greater improvement. Cost per QALY for NF and F patients becomes similar at life expectancy.
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    ItemOpen Access
    Importance of patient-reported individualized goals when assessing outcomes for adult spinal deformity (ASD): initial experience with a Patient Generated Index (PGI).
    (The spine journal : official journal of the North American Spine Society, 2017-10) Scheer, Justin K; Keefe, Malla; Lafage, Virginie; Kelly, Michael P; Bess, Shay; Burton, Douglas C; Hart, Robert A; Jain, Amit; Lonner, Baron S; Protopsaltis, Themistocles S; Hostin, Richard; Shaffrey, Christopher I; Smith, Justin S; Schwab, Frank; Ames, Christopher P

    Background context

    Current metrics to assess patients' health-related quality of life (HRQOL) may not reflect a true change in the patients' specific perception of what is most important to them.

    Purpose

    This study aimed to describe the initial experience of a Patient Generated Index (PGI) in which patients create their own outcome domains.

    Study design

    This is a single-center prospective study.

    Patient sample

    Patients with adult spinal deformity (ASD) comprise the study sample.

    Outcome measures

    Oswestry Disability Index (ODI), Short Form-36 (SF-36 Physical Component Score [PCS] and Mental Component Score [MCS]), Scoliosis Research Society-22r (SRS-22r), and PGI.

    Methods

    Oswestry Disability Index, SF-36, SRS-22r, and PGI were administered preoperatively and postoperatively at 6 weeks, 3 months, 6 months, and 1 and 2 years. PGI correlations with ODI, SF-36, SRS total score, free-text frequency analysis of PGI exact response with text in ODI and SRS-22r questionnaires, and the responsiveness (effect size [ES]) of the HRQOL metrics were analyzed. No funding was used for this study and there are no conflicts of interest.

    Results

    A total of 59 patients with 209 clinical encounters produced 370 PGI written response topics that included affect or emotions, relationships, activities of daily life, personal care, work, and hobbies. Mean preoperative PGI score was 18.6±13.5 (0-71.7 out of 100 [best]), and mean scores significantly improved at every postoperative time point (p<.05). Preoperative PGI scores significantly correlated with preoperative ODI (r=-0.28, p=.03), MCS (r=0.48, p<.01), and SRS total (r=0.57, p<.01). Postoperative PGI scores correlated with all HRQOL measures (p<.0001): ODI (r=-0.65), PCS (r=0.50), MCS (r=0.55), and SRS total (r=0.63). PGI responses exactly matched ODI and SRS-22r text at 47.8% and 35.4%, respectively, and at 63.2% and 58.9%, respectively, for categories. Patient Generated Index ES at a minimum of 1-year follow-up was -2.39, indicating substantial responsiveness (|ES|>0.8). Effect sizes for ODI, SRS-22r total, SF-36 PCS, and SF-36 MCS were 2.16, -2.06, -2.05, and -0.80, respectively.

    Conclusions

    The PGI is easy to administer and offers additional information about the patients' perspective not captured in standard HRQOL metrics. Patient Generated Index scores correlated with all of the standard HRQOL scores and were more responsive than ODI, SF-36, and SRS-22r, suggesting that the PGI may be a step closer to one HRQOL measure that better encompasses concerns and goals of the individual patients.
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    Improvements in Outcomes and Cost After Adult Spinal Deformity Corrective Surgery Between 2008 and 2019.
    (Spine, 2023-02) Passias, Peter G; Kummer, Nicholas; Imbo, Bailey; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton; Vira, Shaleen; Schoenfeld, Andrew J; Gum, Jeffrey L; Daniels, Alan H; Klineberg, Eric O; Gupta, Munish C; Kebaish, Khaled M; Jain, Amit; Neuman, Brian J; Chou, Dean; Carreon, Leah Y; Hart, Robert A; Burton, Douglas C; Shaffrey, Christopher I; Ames, Christopher P; Schwab, Frank J; Hostin, Richard A; Bess, Shay; , on behalf of the International Spine Study Group

    Study design

    A retrospective cohort study.

    Objective

    To assess whether patient outcomes and cost-effectiveness of adult spinal deformity (ASD) surgery have improved over the past decade.

    Background

    Surgery for ASD is an effective intervention, but one that is also associated with large initial healthcare expenditures. Changes in the cost profile for ASD surgery over the last decade has not been evaluated previously.

    Materials and methods

    ASD patients who received surgery between 2008 and 2019 were included. Analysis of covariance was used to establish estimated marginal means for outcome measures [complication rates, reoperations, health-related quality of life, total cost, utility gained, quality adjusted life years (QALYs), cost-efficiency (cost per QALY)] by year of initial surgery. Cost was calculated using the PearlDiver database and represented national averages of Medicare reimbursement for services within a 30-day window including length of stay and death differentiated by complication/comorbidity, revision, and surgical approach. Internal cost data was based on individual patient diagnosis-related group codes, limiting revisions to those within two years (2Y) of the initial surgery. Cost per QALY over the course of 2008-2019 were then calculated.

    Results

    There were 1236 patients included. There was an overall decrease in rates of any complication (0.78 vs . 0.61), any reoperation (0.25 vs . 0.10), and minor complication (0.54 vs . 0.37) between 2009 and 2018 (all P <0.05). National average 2Y cost decreased at an annual rate of $3194 ( R2 =0.6602), 2Y utility gained increased at an annual rate of 0.0041 ( R2 =0.57), 2Y QALYs gained increased annually by 0.008 ( R2 =0.57), and 2Y cost per QALY decreased per year by $39,953 ( R2 =0.6778).

    Conclusion

    Between 2008 and 2019, rates of complications have decreased concurrently with improvements in patient reported outcomes, resulting in improved cost effectiveness according to national Medicare average and individual patient cost data. The value of ASD surgery has improved substantially over the course of the last decade.
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    ItemOpen Access
    Incidence of perioperative medical complications and mortality among elderly patients undergoing surgery for spinal deformity: analysis of 3519 patients.
    (Journal of neurosurgery. Spine, 2017-11) Jain, Amit; Hassanzadeh, Hamid; Puvanesarajah, Varun; Klineberg, Eric O; Sciubba, Daniel M; Kelly, Michael P; Hamilton, D Kojo; Lafage, Virginie; Buckland, Aaron J; Passias, Peter G; Protopsaltis, Themistocles S; Lafage, Renaud; Smith, Justin S; Shaffrey, Christopher I; Kebaish, Khaled M; International Spine Study Group
    OBJECTIVE Using 2 complication-reporting methods, the authors investigated the incidence of major medical complications and mortality in elderly patients after surgery for adult spinal deformity (ASD) during a 2-year follow-up period. METHODS The authors queried a multicenter, prospective, surgeon-maintained database (SMD) to identify patients 65 years or older who underwent surgical correction of ASD from 2008 through 2014 and had a minimum 2 years of follow-up (n = 153). They also queried a Centers for Medicare & Medicaid Services claims database (MCD) for patients 65 years or older who underwent fusion of 8 or more vertebral levels from 2005 through 2012 (n = 3366). They calculated cumulative rates of the following complications during the first 6 weeks after surgery: cerebrovascular accident, congestive heart failure, deep venous thrombosis, myocardial infarction, pneumonia, and pulmonary embolism. Significance was set at p < 0.05. RESULTS During the perioperative period, rates of major medical complications were 5.9% for pneumonia, 4.1% for deep venous thrombosis, 3.2% for pulmonary embolism, 2.1% for cerebrovascular accident, 1.8% for myocardial infarction, and 1.0% for congestive heart failure. Mortality rates were 0.9% at 6 weeks and 1.8% at 2 years. When comparing the SMD with the MCD, there were no significant differences in the perioperative rates of major medical complications except pneumonia. Furthermore, there were no significant intergroup differences in the mortality rates at 6 weeks or 2 years. The SMD provided greater detail with respect to deformity characteristics and surgical variables than the MCD. CONCLUSIONS The incidence of most major medical complications in the elderly after surgery for ASD was similar between the SMD and the MCD and ranged from 1% for congestive heart failure to 5.9% for pneumonia. These complications data can be valuable for preoperative patient counseling and informed consent.
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    Minimum Detectable Measurement Difference for Health-Related Quality of Life Measures Varies With Age and Disability in Adult Spinal Deformity
    (SPINE, 2018-07) Kelly, Michael P; Kim, Han Jo; Ames, Christopher P; Burton, Douglas C; Carreon, Leah Yacat; Polly, David W; Hostin, Richard; Jain, Amit; Gum, Jeffrey L; Lafage, Virginie; Schwab, Frank J; Shaffrey, Christopher I; Smith, Justin S; Bess, Shay; International Spine Study Group
    Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. Study Design. Retrospective cohort. Objective. To investigate the minimum detectable measurement difference (MDMD) in the Scoliosis Research Society-22r (SRS-22r) outcomes instrument in adult spinal deformity (ASD) and to evaluate the effect of baseline data on measurable difference. Summary of Background Data. The minimum clinically important difference (MCID) is the smallest, clinically relevant change observed and has been proposed for the SRS-22r instrument in ASD as 0.4. The MCID must be greater than the MDMD to be useful. The MDMD for the SRS-22r has not been calculated, nor have the effect of patient baseline values on MDMD. Methods. A prospective observation cohort was queried for patients treated both operatively and nonoperatively for ASD. Patients with baseline and 1-year, 2-year follow-up SRS-22r data were included in the analysis. The MDMD was calculated using classical test theory and item-response theory methods. Effect size and standardized response means were calculated. The effect of baseline data values was evaluated for MDMD. Results. A total 839 Patients were eligible for cohort inclusion with 428 (51%) eligible for analysis with complete data. MDMD for Pain (0.6) and Self-Image (0.5) were greater than 0.4. MDMD varied with age (highest for the youngest patients) and with disability (highest for SF-36 Physical Component Summary <28.6). MDMD was less than 0.4 for Activity (0.3), Mental Health (0.3), and Total Score (0.2). Gender and mental health did not affect MDMD for the SRS-22r instrument. Conclusion. An MCID of 0.4 for the SRS-22r total score and domain scores may not be an appropriate value as the calculated MDMD is greater than 0.4 for both the Pain and Self-Image subscores. The MDMD for the SRS-22r instrument varied with age and baseline disability, making the assessment of clinically significant change more difficult using this tool. The MCID must be considered in the setting of the MDMD for instruments used to assess outcomes in ASD.
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    Poor Nutrition Status and Lumbar Spine Fusion Surgery in the Elderly: Readmissions, Complications, and Mortality.
    (Spine, 2017-07) Puvanesarajah, Varun; Jain, Amit; Kebaish, Khaled; Shaffrey, Christopher I; Sciubba, Daniel M; De la Garza-Ramos, Rafael; Khanna, Akhil Jay; Hassanzadeh, Hamid

    Study design

    Retrospective database review.

    Objective

    To quantify the medical and surgical risks associated with elective lumbar spine fusion surgery in patients with poor preoperative nutritional status and to assess how nutritional status alters length of stay and readmission rates.

    Summary of background data

    There has been recent interest in quantifying the increased risk of complications caused by frailty, an important consideration in elderly patients that is directly related to comorbidity burden. Preoperative nutritional status is an important contributor to both sarcopenia and frailty and is poorly studied in the elderly spine surgery population.

    Methods

    The full 100% sample of Medicare data from 2005 to 2012 were utilized to select all patients 65 to 84 years old who underwent elective 1 to 2 level posterior lumbar fusion for degenerative pathology. Patients with diagnoses of poor nutritional status within the 3 months preceding surgery were selected and compared with a control cohort. Outcomes that were assessed included major medical complications, infection, wound dehiscence, and mortality. In addition, readmission rates and length of stay were evaluated.

    Results

    When adjusting for demographics and comorbidities, malnutrition was determined to result in significantly increased odds of both 90-day major medical complications (adjusted odds ratio, OR: 4.24) and 1-year mortality (adjusted OR: 6.16). Multivariate analysis also demonstrated that malnutrition was a significant predictor of increased infection (adjusted OR: 2.27) and wound dehiscence (adjusted OR: 2.52) risk. Length of stay was higher in malnourished patients, though 30-day readmission rates were similar to controls.

    Conclusion

    Malnutrition significantly increases complication and mortality rates, whereas also significantly increasing length of stay. Nutritional supplementation before surgery should be considered to optimize postoperative outcomes in malnourished individuals.

    Level of evidence

    3.
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    The Fate of Patients with Adult Spinal Deformity Incurring Rod Fracture After Thoracolumbar Fusion.
    (World neurosurgery, 2017-10) Hamilton, D Kojo; Buza, John A; Passias, Peter; Jalai, Cyrus; Kim, Han Jo; Ailon, Tamir; Gupta, Munish; Sciubba, Daniel; Jain, Amit; Ames, Christopher P; Deviren, Vedat; Daniels, Alan; Lafage, Virginie; Bess, Shay; Klineberg, Eric; Shaffrey, Christopher I; Smith, Justin S; Hart, Robert; International Spine Study Group

    Objective

    To report the outcome of adult spinal deformity (ASD) in patients with rod fracture (RF) after thoracolumbar fusion.

    Methods

    Retrospective review of prospective, multicenter database. Operative patients with ASD ≥18 years old with RF after ASD surgery and with a minimum 6-month follow-up after RF were included. Health-related quality of life scores and radiographic alignment were compared with nonparametric paired and independent testing (P < 0.05).

    Results

    A total of 51 of 343 patients with ASD (14.9%) sustained a RF, of whom 44 (86.3%) had at least 6-month follow up after RF (mean age = 61.2 years, mean body mass index = 29.6 kg/m2). Mean total follow-up was 37.8 months (range 24.5-66.7 months). Interbody fusion was used in 26 cases of RF (59.1%) (transforaminal lumbar interbody fusion, n = 17 [65.4%], anterior lumbar interbody fusion, n = 5 [19.2%]). RF was symptomatic in 26 of 44 (59.1%) of patients and discovered incidentally in 18 of 44 patients (40.9%). Overall, 28 RFs were revised (63.6%); 12 of 23 (52.2%) unilateral RF and 16 of 21 (76.2%) bilateral RF at last follow-up. Revision patients were significantly more likely to be symptomatic at the time of RF detection (78.6% vs. 25.0%, P = 0.0006), and had significantly worse Oswestry Disability Index and Scoliosis Research Society-22r pain scores.

    Conclusions

    RFs were detected in 14.9% of patients with ASD and were most common at the L4-L5 and L5-S1 levels. Approximately 63.6% of patients underwent revision surgery. The decision to perform revision surgery may be based predominantly on symptoms referable to the RF, pain, and perceived disability, as radiographic parameters at the time of RF did not differ significantly between patients who did and did not undergo revision.
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    Validity, Reliability, and Responsiveness of SRS-7 as an Outcomes Assessment Instrument for Operatively Treated Patients With Adult Spinal Deformity.
    (Spine, 2016-09) Jain, Amit; Lafage, Virginie; Kelly, Michael P; Hassanzadeh, Hamid; Neuman, Brian J; Sciubba, Daniel M; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; Scheer, Justin K; Burton, Douglas; Gupta, Munish C; Hart, Robert; Hostin, Richard A; Kebaish, Khaled M; International Spine Study Group

    Study design

    A retrospective analysis.

    Objective

    The aim of our study was to compare the normality, concurrent validity, internal consistency, responsiveness, and dimensionality of an item response theory-derived seven-question instrument (SRS-7), against the Scoliosis Research Society-22r (SRS-22r) questionnaire in operatively treated patients with adult spinal deformity (ASD).

    Summary of background data

    Compared with SRS-22r, SRS-7 (which has been validated in operatively treated patients with adolescent idiopathic scoliosis) has advantages of being short, unidimensional, and linear.

    Methods

    A prospective database of ASD patients was queried for patients 18 years or older who were operatively treated, and who answered pre- and postoperative (at 2-year follow-up) SRS-22r questions (n = 276). Corresponding SRS-7 scores were calculated using answers to SRS-22r items 1, 4, 6, 10, 18, 19, and 20. Significance was set at a P value less than 0.01.

    Results

    SRS-7 and SRS-22r were normally distributed preoperatively but not postoperatively. SRS-7 and SRS-22r scores had high correlation both preoperatively (r = 0.76, P < 0.01) and postoperatively (r = 0.83, P < 0.01). The internal consistency reliability Cronbach α values were 0.61 (SRS-7) and 0.83 (SRS-22r) preoperatively and 0.91 (SRS-7) and 0.95 (SRS-22r) postoperatively. SRS-7 was found to be more responsive than SRS-22r with measures of effect size: Cohen d = 1.21 versus 1.13, Hedge g = 1.21 versus 1.13, and effect size correlation r = 0.52 versus 0.49. Iterative principal factor analysis of pre- and postoperative scores showed the presence of one dominant latent factor in SRS-7 (unidimensionality) and four latent factors in SRS-22r (multidimensionality).

    Conclusion

    SRS-7 is a valid, reliable, responsive, and unidimensional instrument, which can be used as a short-form alternative to the SRS-22r for assessing global changes in patient-reported outcomes over time in patients with ASD.

    Level of evidence

    3.