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Correlation of PROMIS Physical Function and Pain CAT Instruments with Oswestry Disability Index and Neck Disability Index in Spine Patients
Proceedings of the NASS 30th Annual Meeting / The Spine Journal 15 (2015) 87S–267S and negative binomial regression was employed for continuous variables. RESULTS: The rates of surgical intervention remained unchanged preand post-reform (p50.25). Hospital length of stay (RC -0.18, 95% CI -0.22, -0.14) and the FTR rate following surveillance insensitive complications (OR 0.49, 95% CI 0.25, 0.94) were significantly reduced following health reform. Post-reform, academic centers experienced a 22% reduction in mortality (95% CI 0.61, 0.99) a 40% decrease in FTR (95% CI 0.40, 0.89), a 30% decrease in surveillance insensitive complications (95% CI 0.51, 0.96) and a 67% reduction in FTR after surveillance insensitive morbidity (95% CI 0.11, 0.94). CONCLUSIONS: In the period following Massachusetts health care reform, significant improvements were noted in hospital process and quality measures around the care of patients with cervical spine fractures. Such findings were particularly robust among academic centers. These results may forecast changes in the delivery of spine surgical care following other health reform initiatives. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.068 50. Risk Factors for 30-Day Readmission following Spine Fusion Surgery in Adults: A Review of the National Surgical Quality Improvement Program (NSQIP) Database Alvin Su, MD, PhD1, Ahmad N. Nassr, MD2, Elizabeth Habermann, PhD, MPH1, Kristine Thomsen, BA1, Todd Milbrandt, Annalise N. Larson, MD1; 1 Mayo Clinic, Rochester, MN, US; 2Mayo Clinic Department of Orthopedic Surgery, Rochester, MN, US BACKGROUND CONTEXT: Reducing readmissions is one potential area to improve quality and save costs in medicine. Payers such as CMS are implementing penalties for 30-day readmissions following surgical procedures. However, data regarding rates and risk factors for readmission after spine surgery are limited. We evaluated 30-day readmission rates following spine surgery using the NSQIP database to test the hypothesis that certain patient and procedure factors are independently associated with increased 30-day readmission rates after index surgery. PURPOSE: Populations that carry high risk of readmission should be targeted for special interventions to assure high quality care. These data may help plan targeted perioperative interventions and provide valuable information for negotiations with payers. STUDY DESIGN/SETTING: Population-based cohort study with prospectively-enrolled multicenter database. PATIENT SAMPLE: Obtained from NSQIP database for year 20122013. METHODS: In 2012 and 2013, 18,602 adult spinal surgery procedures were entered prospectively in the NSQIP database. Readmissions were recorded and categorized based on procedure type, postoperative diagnosis and patient characteristics. Chi-square tests, Fisher’s exact tests and t-tests were used to evaluate univariate associations with readmission, followed by multivariable logistic regression to identify independent risk factors. RESULTS: On univariate analysis, readmission rate was associated with procedure type (highest with combined anterior posterior spinal fusion and posterior fusion O 6 levels) as well as diagnosis (highest with disseminated tumor and infection) (both p!0.001). Increased readmission rate was strongly associated with age, ASA slass and perioperative blood transfusion (all p!0.001). Medical comorbidities associated with increased readmissions included dyspnea, severe COPD, CHF, HTN, insulin-dependent DM, steroid use, bleeding disorders, disseminated cancer, O 10% body weight loss, and preoperative renal dialysis. Readmission rate was not associated with BMI, race/ethnicity, smoking or gender. On multivariate analysis, independent risk factors included procedure type, increased age, severe COPD, insulin-dependent DM, steroid use, preoperative renal dialysis and increased ASA class (all p!0.05).
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CONCLUSIONS: This study provides benchmark figures of expected 30readmission rates by using a large high-quality database. Readmission rates for scoliosis and spondylolisthesis surgeries were slightly higher than the overall rate, but less than that of disseminated tumor, solitary tumor, infection and fracture management. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.069
51. Correlation of PROMIS Physical Function and Pain CAT Instruments with Oswestry Disability Index and Neck Disability Index in Spine Patients Mark O. Papuga, PhD1, Addisu Mesfin, MD2, Robert W. Molinari, MD2, Paul T. Rubery, Jr., MD3; 1Seneca Falls, NY, US; 2University of Rochester, Rochester, NY, US; 3Rochester, NY, US BACKGROUND CONTEXT: Spinal surgery outcomes are highly variable, and substantial debate continues regarding the role of surgery in some spinal pathology. The routine collection of patient-based outcomes instruments in spine surgery patients may help inform this debate. Traditionally, the inefficiency associated with the standard validated instruments has been a barrier to routine collection in outpatient clinics. PURPOSE: To overcome the inefficiency associated with the standard validated instruments that has been a barrier to routine collection in outpatient clinics. STUDY DESIGN/SETTING: All measurements were collected crosssectionally at a routine clinical visit. Prospective subjects gave informed consent prior to enrollment in the study, while retrospective data was collected as part of standard of care for one of the treating physicians. PATIENT SAMPLE: IRB approved protocols were used to assess 182 (101 males, 81 females; 53.5 615.8 [mean 6SD] years) patients retrospectively and 96 (53males, 43 females; 58 615.9 years) patients prospectively seen in the orthopedic spine clinic. OUTCOME MEASURES: We utilized several computer adaptive testing (CAT) instruments available through Patient-Reported Outcomes Measurement Information System (PROMIS) to correlate patient reported clinical outcomes with the results obtained using traditional static questionnaire outcomes measurement instruments ODI/NDI. METHODS: PROMIS CAT instruments used included physical function (versions 1.0 and 1.2) pain behavior (version 1.0), and pain interference (version 1.1) to assess both pain and function. The Oswestry Disability Index (ODI) and the Neck Disability Index (NDI) assessments were used as ‘‘gold standard’’ comparisons for patient reported outcomes. RESULTS: Each PROMIS instrument required 4.56 1.8 questions and took 35616 seconds, compared to ODI/NDI which is a static 10 questions taking 188 6 85 seconds when administered electronically. Linear regression analysis of retrospective scores involving a primary back complaint revealed moderate to strong correlations between ODI and PROMIS physical function with R2 values of 0.672 and 0.572 for versions 1.0 and 1.2 respectively. Moderate correlations were also found between ODI and PROMIS Pain measures in this population with R2 values of 0.578 and 0.571 for pain behavior and pain interference respectively. Analysis of retrospective scores involving a primary neck complaint found moderate to strong correlations between NDI and PROMIS physical function measures with R2 values of 0.589 and 0.766 for version 1.0 and 1.2 respectively. Moderate to weak correlations were also found between NDI and PROMIS pain measures in this population with R2 values of 0.342 and 0.456 for pain behavior and pain interference respectively. Prospective data revealed similar correlations to ODI, with R2 values of 0.630 and 0.552 for PROMIS physical function and pain interference respectively. Prospective data also pointed toward strong correlation to NDI with R2 values of 0.822 and 0.706 for PROMIS Physical function and pain interference respectively.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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Proceedings of the NASS 30th Annual Meeting / The Spine Journal 15 (2015) 87S–267S
CONCLUSIONS: Efficiently administered physical function outcome measures in clinical practice offer the ability to inform and improve patient care. We have shown that several PROMIS CAT instruments can provide a low burden means by which to evaluate the outcome of spine treatment when administered during routine clinical visits. The moderate to strong correlations found validate the utility of computer adaptive testing when compared to the gold standard ‘‘static’’ assessments previously employed. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.070
52. Validation of Patient Reported Outcomes Measurement Information System (PROMIS) in Surgically Managed Lumbar Spinal Stenosis Patients Alpesh A. Patel, MD, FACS1, Shah-Nawaz M. Dodwad, MD2, Surabhi Bhatt, BS2, Wellington K. Hsu, MD3, Jason W. Savage, MD1, Nan Rothrock, PhD2; 1Northwestern University Department of Orthopaedics, Chicago, IL, US; 2Northwestern University Feinberg School of Medicine, Chicago, IL, US; 3Northwestern University, Chicago, IL, US BACKGROUND CONTEXT: PROMIS is an adaptive, responsive assessment tool that measures patient-reported health status funded by the National Institutes of Health (NIH). Lumbar spinal stenosis is a common, debilitating condition in patients over the age of 50 that is often treated surgically. The objective of this project is to validate PROMIS measures pain behavior, pain interference and physical function in surgically treated patients with lumbar spinal stenosis against historical outcomes including Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI) and the Short-Form 12 (SF-12). PURPOSE: To accurately assess and compare results of PROMIS physical function and pain interference, pain behavior and pain intensity assessment tools against various standardized legacy measures for patients with lumbar stenosis. STUDY DESIGN/SETTING: Prospective, cohort study. PATIENT SAMPLE: Ninety two consecutive patients treated for lumbar spinal stenosis. OUTCOME MEASURES: PROMIS (pain behavior, pain interference and physical function), ODI, ZCQ and SF-12. METHODS: PROMIS (pain behavior, pain interference, and physical function), ODI, ZCQ and SF-12 outcome measures were administered to 92 consecutive tertiary hospital patients treated surgically for lumbar spinal stenosis. Assessments were done at baseline (preoperatively) and postoperatively at 6 weeks and 3 months. We excluded patients presenting for a revision surgery, tumor, infection or trauma. Each patient prospectively completed the PROMIS assessments and legacy measures custom built into the assessment center by using a secure login and password on a tablet. RESULTS: Of the 92 patients enrolled (mean age of 62.2, 58 male, 34 female), 60 patients (65%) completed assessments up to 3 months. PROMIS measures showed statistically significant improvement in outcome scores similar to ODI, ZCQ, and SF-12 at all-time points with Pearson correlation coefficients ranging from absolute values of .27-.73 at baseline and .27-.70 between 6 weeks and 3 months. Compared to their preoperative condition, at the 6 weeks’ time point, 29 out of 33 (87.9%) patients reported improvement. Compared to their prior visit at 6 weeks, at 3 months postoperatively, 27 patients of 35 patients (77.1%) reported additional improvement in their preoperative condition. At baseline and throughout the assessment, both ZCQ (0-25%) and SF-12 (0-45%) had more patients in the floor and ceiling areas compared to PROMIS (01%) and ODI (0). Nine percent, 8% and 7% of patients had preoperative PROMIS pain behavior, pain interference and physical function, respectively, within 5 points of the general population; at 3 months, 42%, 48%
and 38% of patients had PROMIS pain behavior, pain interference and physical function, respectively, within 5 points of the general population. Concurrent medical conditions that contributed to responses were present in 30% of patients. When this subset of patients was compared to patients who did not identify concurrent medical conditions, there were no significant statistical differences in mean PROMIS, ODI, Zurich, SF-12 scores at baseline nor at 3 months postoperatively other than the baseline MCS of SF-12 at baseline (43.8 in patients with other conditions vs 49.1 in patients with no other related conditions, p5.019). CONCLUSIONS: PROMIS is a valid and responsive measure of surgically treated patients with lumbar spinal stenosis when compared to legacy ODI, SF-12 and Zurich patient outcomes. PROMIS may be preferable to legacy instruments because of the efficacy in measuring treatment effect, ability to accurately evaluate multiple parameters, and avoidance of floor/ceiling effects. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.071
53. National Trends in the Surgical Management of Adult Lumbar Isthmic Spondylolisthesis: 1998 to 2011 Addisu Mesfin, MD1, Brandon L. Raudenbush, DO2, Caroline Thirukumaran, MBBS, MHA3, Paul T. Rubery, Jr., MD3; 1 University of Rochester, Rochester, NY, US; 2Strong Memorial Hospital, University of Rochester, Rochester, NY, US; 3Rochester, NY, US BACKGROUND CONTEXT: Isthmic spondylolisthesis (ISY) is present in up to 6% of the North American population and is usually asymptomatic. The clinical presentation includes varying degrees of axial back pain, with or without radiculopathy. The L5-S1 level is the most common site of ISY and the L5 nerve root is usually affected. PURPOSE: National trends in the surgical management of ISY are not known. Our objective was to identify trends in the surgical management of adult ISY in the United States and to evaluate trends in the surgical techniques. STUDY DESIGN/SETTING: Retrospective evaluation of an administrative database. PATIENT SAMPLE: We used the Healthcare Cost and Utilization Project’s (HCUP) Nationwide Inpatient Sample (NIS) database for the years 1998 to 2011. We used the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) to identify inpatient stays for ISY (diagnosis codes 756.11 and 756.12) that were treated surgically using any of three fusion approaches: (i) anterior only (procedure codes 81.04, 81.06); (ii) posterior only (81.05, 81.07, and 81.08) and; (iii) both anterior and posterior spinal fusion approaches. OUTCOME MEASURES: Our primary outcome was the national trend for the three approaches to fusion surgeries for ISY patients. Additionally, we examined the following outcomes for each of the three surgical groups: (i) postoperative complications, (ii) discharge disposition, (iii) length of stay (LOS) and (iv) hospitalization charges. METHODS: Using the Nationwide Inpatient Sample (NIS), 223,126 adult patients ($18 years) with ISY undergoing lumbar spine fusion from 1998 to 2011 were identified. Poisson regressions, modified Wald tests and linear and logistic regression analyses with p!50.05 were used for statistical analysis. RESULTS: The annual rate of fusion for ISY has increased 4.33 times— from 28.31 surgeries in 1998 to 122.69 surgeries per million US adults per year in 2011. The relative increase in annual rate of posterior fusion (4.31 times increase from 24.30 surgeries in 1998 to 104.76 surgeries per million US adults per year in 2011, p!0.001) was 3.32 times that of anterior fusion (2 times increase from 3.32 surgeries in 1998 to 6.63 surgeries per million US adults per year in 2011; p!0.001). In the same duration, the annual rates of combined surgeries have increased 16.26 times (from 0.70
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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CONCLUSIONS: This study provides benchmark figures of expected 30readmission rates by using a large high-quality database. Readmission rates for scoliosis and spondylolisthesis surgeries were slightly higher than the overall rate, but less than that of disseminated tumor, solitary tumor, infection and fracture management. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.069
51. Correlation of PROMIS Physical Function and Pain CAT Instruments with Oswestry Disability Index and Neck Disability Index in Spine Patients Mark O. Papuga, PhD1, Addisu Mesfin, MD2, Robert W. Molinari, MD2, Paul T. Rubery, Jr., MD3; 1Seneca Falls, NY, US; 2University of Rochester, Rochester, NY, US; 3Rochester, NY, US BACKGROUND CONTEXT: Spinal surgery outcomes are highly variable, and substantial debate continues regarding the role of surgery in some spinal pathology. The routine collection of patient-based outcomes instruments in spine surgery patients may help inform this debate. Traditionally, the inefficiency associated with the standard validated instruments has been a barrier to routine collection in outpatient clinics. PURPOSE: To overcome the inefficiency associated with the standard validated instruments that has been a barrier to routine collection in outpatient clinics. STUDY DESIGN/SETTING: All measurements were collected crosssectionally at a routine clinical visit. Prospective subjects gave informed consent prior to enrollment in the study, while retrospective data was collected as part of standard of care for one of the treating physicians. PATIENT SAMPLE: IRB approved protocols were used to assess 182 (101 males, 81 females; 53.5 615.8 [mean 6SD] years) patients retrospectively and 96 (53males, 43 females; 58 615.9 years) patients prospectively seen in the orthopedic spine clinic. OUTCOME MEASURES: We utilized several computer adaptive testing (CAT) instruments available through Patient-Reported Outcomes Measurement Information System (PROMIS) to correlate patient reported clinical outcomes with the results obtained using traditional static questionnaire outcomes measurement instruments ODI/NDI. METHODS: PROMIS CAT instruments used included physical function (versions 1.0 and 1.2) pain behavior (version 1.0), and pain interference (version 1.1) to assess both pain and function. The Oswestry Disability Index (ODI) and the Neck Disability Index (NDI) assessments were used as ‘‘gold standard’’ comparisons for patient reported outcomes. RESULTS: Each PROMIS instrument required 4.56 1.8 questions and took 35616 seconds, compared to ODI/NDI which is a static 10 questions taking 188 6 85 seconds when administered electronically. Linear regression analysis of retrospective scores involving a primary back complaint revealed moderate to strong correlations between ODI and PROMIS physical function with R2 values of 0.672 and 0.572 for versions 1.0 and 1.2 respectively. Moderate correlations were also found between ODI and PROMIS Pain measures in this population with R2 values of 0.578 and 0.571 for pain behavior and pain interference respectively. Analysis of retrospective scores involving a primary neck complaint found moderate to strong correlations between NDI and PROMIS physical function measures with R2 values of 0.589 and 0.766 for version 1.0 and 1.2 respectively. Moderate to weak correlations were also found between NDI and PROMIS pain measures in this population with R2 values of 0.342 and 0.456 for pain behavior and pain interference respectively. Prospective data revealed similar correlations to ODI, with R2 values of 0.630 and 0.552 for PROMIS physical function and pain interference respectively. Prospective data also pointed toward strong correlation to NDI with R2 values of 0.822 and 0.706 for PROMIS Physical function and pain interference respectively.
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.
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Proceedings of the NASS 30th Annual Meeting / The Spine Journal 15 (2015) 87S–267S
CONCLUSIONS: Efficiently administered physical function outcome measures in clinical practice offer the ability to inform and improve patient care. We have shown that several PROMIS CAT instruments can provide a low burden means by which to evaluate the outcome of spine treatment when administered during routine clinical visits. The moderate to strong correlations found validate the utility of computer adaptive testing when compared to the gold standard ‘‘static’’ assessments previously employed. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.070
52. Validation of Patient Reported Outcomes Measurement Information System (PROMIS) in Surgically Managed Lumbar Spinal Stenosis Patients Alpesh A. Patel, MD, FACS1, Shah-Nawaz M. Dodwad, MD2, Surabhi Bhatt, BS2, Wellington K. Hsu, MD3, Jason W. Savage, MD1, Nan Rothrock, PhD2; 1Northwestern University Department of Orthopaedics, Chicago, IL, US; 2Northwestern University Feinberg School of Medicine, Chicago, IL, US; 3Northwestern University, Chicago, IL, US BACKGROUND CONTEXT: PROMIS is an adaptive, responsive assessment tool that measures patient-reported health status funded by the National Institutes of Health (NIH). Lumbar spinal stenosis is a common, debilitating condition in patients over the age of 50 that is often treated surgically. The objective of this project is to validate PROMIS measures pain behavior, pain interference and physical function in surgically treated patients with lumbar spinal stenosis against historical outcomes including Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI) and the Short-Form 12 (SF-12). PURPOSE: To accurately assess and compare results of PROMIS physical function and pain interference, pain behavior and pain intensity assessment tools against various standardized legacy measures for patients with lumbar stenosis. STUDY DESIGN/SETTING: Prospective, cohort study. PATIENT SAMPLE: Ninety two consecutive patients treated for lumbar spinal stenosis. OUTCOME MEASURES: PROMIS (pain behavior, pain interference and physical function), ODI, ZCQ and SF-12. METHODS: PROMIS (pain behavior, pain interference, and physical function), ODI, ZCQ and SF-12 outcome measures were administered to 92 consecutive tertiary hospital patients treated surgically for lumbar spinal stenosis. Assessments were done at baseline (preoperatively) and postoperatively at 6 weeks and 3 months. We excluded patients presenting for a revision surgery, tumor, infection or trauma. Each patient prospectively completed the PROMIS assessments and legacy measures custom built into the assessment center by using a secure login and password on a tablet. RESULTS: Of the 92 patients enrolled (mean age of 62.2, 58 male, 34 female), 60 patients (65%) completed assessments up to 3 months. PROMIS measures showed statistically significant improvement in outcome scores similar to ODI, ZCQ, and SF-12 at all-time points with Pearson correlation coefficients ranging from absolute values of .27-.73 at baseline and .27-.70 between 6 weeks and 3 months. Compared to their preoperative condition, at the 6 weeks’ time point, 29 out of 33 (87.9%) patients reported improvement. Compared to their prior visit at 6 weeks, at 3 months postoperatively, 27 patients of 35 patients (77.1%) reported additional improvement in their preoperative condition. At baseline and throughout the assessment, both ZCQ (0-25%) and SF-12 (0-45%) had more patients in the floor and ceiling areas compared to PROMIS (01%) and ODI (0). Nine percent, 8% and 7% of patients had preoperative PROMIS pain behavior, pain interference and physical function, respectively, within 5 points of the general population; at 3 months, 42%, 48%
and 38% of patients had PROMIS pain behavior, pain interference and physical function, respectively, within 5 points of the general population. Concurrent medical conditions that contributed to responses were present in 30% of patients. When this subset of patients was compared to patients who did not identify concurrent medical conditions, there were no significant statistical differences in mean PROMIS, ODI, Zurich, SF-12 scores at baseline nor at 3 months postoperatively other than the baseline MCS of SF-12 at baseline (43.8 in patients with other conditions vs 49.1 in patients with no other related conditions, p5.019). CONCLUSIONS: PROMIS is a valid and responsive measure of surgically treated patients with lumbar spinal stenosis when compared to legacy ODI, SF-12 and Zurich patient outcomes. PROMIS may be preferable to legacy instruments because of the efficacy in measuring treatment effect, ability to accurately evaluate multiple parameters, and avoidance of floor/ceiling effects. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. http://dx.doi.org/10.1016/j.spinee.2015.07.071
53. National Trends in the Surgical Management of Adult Lumbar Isthmic Spondylolisthesis: 1998 to 2011 Addisu Mesfin, MD1, Brandon L. Raudenbush, DO2, Caroline Thirukumaran, MBBS, MHA3, Paul T. Rubery, Jr., MD3; 1 University of Rochester, Rochester, NY, US; 2Strong Memorial Hospital, University of Rochester, Rochester, NY, US; 3Rochester, NY, US BACKGROUND CONTEXT: Isthmic spondylolisthesis (ISY) is present in up to 6% of the North American population and is usually asymptomatic. The clinical presentation includes varying degrees of axial back pain, with or without radiculopathy. The L5-S1 level is the most common site of ISY and the L5 nerve root is usually affected. PURPOSE: National trends in the surgical management of ISY are not known. Our objective was to identify trends in the surgical management of adult ISY in the United States and to evaluate trends in the surgical techniques. STUDY DESIGN/SETTING: Retrospective evaluation of an administrative database. PATIENT SAMPLE: We used the Healthcare Cost and Utilization Project’s (HCUP) Nationwide Inpatient Sample (NIS) database for the years 1998 to 2011. We used the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) to identify inpatient stays for ISY (diagnosis codes 756.11 and 756.12) that were treated surgically using any of three fusion approaches: (i) anterior only (procedure codes 81.04, 81.06); (ii) posterior only (81.05, 81.07, and 81.08) and; (iii) both anterior and posterior spinal fusion approaches. OUTCOME MEASURES: Our primary outcome was the national trend for the three approaches to fusion surgeries for ISY patients. Additionally, we examined the following outcomes for each of the three surgical groups: (i) postoperative complications, (ii) discharge disposition, (iii) length of stay (LOS) and (iv) hospitalization charges. METHODS: Using the Nationwide Inpatient Sample (NIS), 223,126 adult patients ($18 years) with ISY undergoing lumbar spine fusion from 1998 to 2011 were identified. Poisson regressions, modified Wald tests and linear and logistic regression analyses with p!50.05 were used for statistical analysis. RESULTS: The annual rate of fusion for ISY has increased 4.33 times— from 28.31 surgeries in 1998 to 122.69 surgeries per million US adults per year in 2011. The relative increase in annual rate of posterior fusion (4.31 times increase from 24.30 surgeries in 1998 to 104.76 surgeries per million US adults per year in 2011, p!0.001) was 3.32 times that of anterior fusion (2 times increase from 3.32 surgeries in 1998 to 6.63 surgeries per million US adults per year in 2011; p!0.001). In the same duration, the annual rates of combined surgeries have increased 16.26 times (from 0.70
Refer to onsite Annual Meeting presentations and postmeeting proceedings for possible referenced figures and tables. Authors are responsible for accurately reporting disclosures and FDA device/drug status at time of abstract submission.