- Email: [email protected]
125. Defining Substantial Clinical Benefit for Lumbar Fusion
60S
Proceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S
surgery we believe the outcomes data will be more evenly distributed. Several limitations are detected in the accurate determination of the MCID: the multiplicity of MCID determinations, conflicting patient self-report, individual perception, wide variation among patient’s scores, and the relationship between pre-treatment baseline and post-treatment change scores. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.146
124. The Minimum Clinically Important Difference in Lumbar Spine Surgery Patients: A Choice of Methods Using the Oswestry Disability Index, MOS Short Form-36, and Pain Scales Anne Copay, PhD1, Steven Glassman, MD2, Brian Subach, MD3, Sigurd Berven, MD4, Thomas Schuler, MD3, Leah Carreon, MD, MSc5; 1 Spinal Research Foundation, Reston, VA, USA; 2University of Louisville, Louisville, KY, USA; 3The Virginia Spine Institute, Reston, VA, USA; 4 University of California, San Francisco, San Francisco, CA, USA; 5 Leatherman Spine Center, Louisville, KY, USA BACKGROUND CONTEXT: A minimum clinically important difference (MCID) is a threshold used to measure the effect of clinical treatments. The impact of lumbar spinal surgery is commonly evaluated with 3 patient-reported outcome measures: Oswestry Disability Index (ODI), the physical component summary (PCS) of the SF-36, and pain scales. Variable threshold values have been proposed as MCID for those instruments despite a lack of agreement on the optimal MCID calculation method. PURPOSE: This study has three purposes. First, to illustrate the range of values obtained by common anchor-based and distribution-based methods to calculate MCID. Second, to determine a statistically sound and clinically meaningful MCID for ODI, PCS, back pain scale, and leg pain scale in lumbar spine surgery patients. Third, to compare the discriminative ability of two anchors: a global health assessment and a rating of satisfaction with the results of the surgery. STUDY DESIGN/SETTING: This study is a review of prospectively collected patient reported outcomes data. PATIENT SAMPLE: 454 patients from a large database of surgeries performed by the Lumbar Spine Study Group with a 1- year follow-up on either ODI or PCS were included in the study. OUTCOME MEASURES: Preoperative and 1-year postoperative scores for ODI, PCS, back pain scale, leg pain scale, health transition item of the SF-36, and satisfaction with results scales. METHODS: ODI, SF-36, and pain scales were administered before and 1 year after spinal surgery. Several candidate MCID calculation methods were applied to the data and the resulting values were compared. The Health Transition Item of the SF-36 was used as the anchor and compared to a second anchor (Satisfaction with Results scale). RESULTS: Potential MCID calculations yielded a range of values: 5-fold for ODI, PCS, and leg pain, 10-fold for back pain. Threshold values obtained with the two anchors were very similar. CONCLUSIONS: The minimum detectable change (MDC) appears as a statistically and clinically appropriate MCID value. MCID values in this sample were 12.8 points for ODI, 4.9 points for PCS, 1.2 points for back pain, and 1.6 points for leg pain. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.147
125. Defining Substantial Clinical Benefit for Lumbar Fusion Steven Glassman, MD1, Anne Copay, PhD2, Sigurd Berven, MD3, David Polly, Jr., MD4, Brian Subach, MD5, Leah Carreon, MD, MSc1; 1 Leatherman Spine Center, Louisville, KY, USA; 2Spinal Research Foundation, Reston, VA, USA; 3University of California, San Francisco,
San Francisco, CA, USA; 4University of Minnesota, Minneapolis, MN, USA; 5The Virginia Spine Institute, Reston, VA, USA BACKGROUND CONTEXT: Health related quality of life (HRQOL) measures, particularly the Oswestry Disability Index (ODI) and MOS SF-36, have become an important standard to evaluate lumbar spine surgery outcomes. Despite their widespread use, there are few well defined criteria for clinical success based on these measures. One key threshold, the minimum clinically important difference(MCID), has been defined and is being utilized with increasing frequency. Although MCID represents a meaningful demarcation, it is more of a floor value than a goal in terms of defining clinical success. Therefore, we have sought to establish thresholds of substantial clinical benefit (SCB) for commonly used HRQOL measures in lumbar spine surgery. PURPOSE: To define thresholds of clinical improvement which represent a substantial clinical benefit (SCB) for commonly used HRQOL measures in lumbar spine surgery. STUDY DESIGN/SETTING: Prospective, multi-center cohort. PATIENT SAMPLE: 454 patients who underwent lumbar spine surgery for degenerative conditions with pre-operative and one-year HRQOL measures. OUTCOME MEASURES: Prospectively collected pre-operative and one-year post-operative SF-36 PCS, ODI, and back pain and leg pain Numeric Rating Scores (NRS). METHODS: Candidate SCB thresholds for SF-36 PCS, ODI and back and leg pain NRS were developed using receiver operating characteristic (ROC) curve analysis. ROC curves assess each potential threshold value in order to optimize sensitivity and specificity in differentiating between cohorts. ROC curves were used to discriminate between two subgroups of patients: the ‘‘Much Better’’ and ‘‘About the Same’’ patients on the SF-36 Health Transition Item, and the ‘‘Most Satisfied’’ and ‘‘Unsure’’ patients on the Satisfaction with Results Scale. Three response parameters were used: net change, percent change, and raw score at one-year followup, for each HRQOL measure. RESULTS: Thresholds of SCB for SF-36 PCS are 6.1 points net improvement, 19.5% improvement, or a final raw score greater than 35.2 points. SCB thresholds for ODI are a 19.0 point net improvement, a 37.6% improvement, or a final raw score less than 30.6 points. SCB thresholds for numeric back pain and leg pain are 2.5 points net improvement or a final raw score less than 3.5 points. SCB thresholds for percent change are 41.4% for back pain NRS and 47.2% for leg pain NRS. CONCLUSIONS: Identification of an SCB threshold for commonly used HRQOL measures in lumbar spine surgery is important, as it describes a magnitude of improvement which the patient recognizes as a substantial benefit. These thresholds are not necessarily intended as a benchmark defining a satisfactory intervention, but rather as a tool for patient discussion and shared decision making. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.148
Friday, October 26, 2007 3:29–4:15 PM Concurrent Session 2: Surgical - Fusion 126. Prospective, Randomized, Double Blind Study of the Efficacy of Post-operative Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site after Posterior Spinal Fusion: Four-year Follow-up Kern Singh, MD1, Frank Phillips, MD1, Eugene Kuo, MD2, Marion Campbell-Hupp, MSN3, Dino Samartzis, DSC4; 1Rush University Medical Center, Chicago, IL, USA; 2TX, USA; 3Department of
Proceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S
surgery we believe the outcomes data will be more evenly distributed. Several limitations are detected in the accurate determination of the MCID: the multiplicity of MCID determinations, conflicting patient self-report, individual perception, wide variation among patient’s scores, and the relationship between pre-treatment baseline and post-treatment change scores. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.146
124. The Minimum Clinically Important Difference in Lumbar Spine Surgery Patients: A Choice of Methods Using the Oswestry Disability Index, MOS Short Form-36, and Pain Scales Anne Copay, PhD1, Steven Glassman, MD2, Brian Subach, MD3, Sigurd Berven, MD4, Thomas Schuler, MD3, Leah Carreon, MD, MSc5; 1 Spinal Research Foundation, Reston, VA, USA; 2University of Louisville, Louisville, KY, USA; 3The Virginia Spine Institute, Reston, VA, USA; 4 University of California, San Francisco, San Francisco, CA, USA; 5 Leatherman Spine Center, Louisville, KY, USA BACKGROUND CONTEXT: A minimum clinically important difference (MCID) is a threshold used to measure the effect of clinical treatments. The impact of lumbar spinal surgery is commonly evaluated with 3 patient-reported outcome measures: Oswestry Disability Index (ODI), the physical component summary (PCS) of the SF-36, and pain scales. Variable threshold values have been proposed as MCID for those instruments despite a lack of agreement on the optimal MCID calculation method. PURPOSE: This study has three purposes. First, to illustrate the range of values obtained by common anchor-based and distribution-based methods to calculate MCID. Second, to determine a statistically sound and clinically meaningful MCID for ODI, PCS, back pain scale, and leg pain scale in lumbar spine surgery patients. Third, to compare the discriminative ability of two anchors: a global health assessment and a rating of satisfaction with the results of the surgery. STUDY DESIGN/SETTING: This study is a review of prospectively collected patient reported outcomes data. PATIENT SAMPLE: 454 patients from a large database of surgeries performed by the Lumbar Spine Study Group with a 1- year follow-up on either ODI or PCS were included in the study. OUTCOME MEASURES: Preoperative and 1-year postoperative scores for ODI, PCS, back pain scale, leg pain scale, health transition item of the SF-36, and satisfaction with results scales. METHODS: ODI, SF-36, and pain scales were administered before and 1 year after spinal surgery. Several candidate MCID calculation methods were applied to the data and the resulting values were compared. The Health Transition Item of the SF-36 was used as the anchor and compared to a second anchor (Satisfaction with Results scale). RESULTS: Potential MCID calculations yielded a range of values: 5-fold for ODI, PCS, and leg pain, 10-fold for back pain. Threshold values obtained with the two anchors were very similar. CONCLUSIONS: The minimum detectable change (MDC) appears as a statistically and clinically appropriate MCID value. MCID values in this sample were 12.8 points for ODI, 4.9 points for PCS, 1.2 points for back pain, and 1.6 points for leg pain. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.147
125. Defining Substantial Clinical Benefit for Lumbar Fusion Steven Glassman, MD1, Anne Copay, PhD2, Sigurd Berven, MD3, David Polly, Jr., MD4, Brian Subach, MD5, Leah Carreon, MD, MSc1; 1 Leatherman Spine Center, Louisville, KY, USA; 2Spinal Research Foundation, Reston, VA, USA; 3University of California, San Francisco,
San Francisco, CA, USA; 4University of Minnesota, Minneapolis, MN, USA; 5The Virginia Spine Institute, Reston, VA, USA BACKGROUND CONTEXT: Health related quality of life (HRQOL) measures, particularly the Oswestry Disability Index (ODI) and MOS SF-36, have become an important standard to evaluate lumbar spine surgery outcomes. Despite their widespread use, there are few well defined criteria for clinical success based on these measures. One key threshold, the minimum clinically important difference(MCID), has been defined and is being utilized with increasing frequency. Although MCID represents a meaningful demarcation, it is more of a floor value than a goal in terms of defining clinical success. Therefore, we have sought to establish thresholds of substantial clinical benefit (SCB) for commonly used HRQOL measures in lumbar spine surgery. PURPOSE: To define thresholds of clinical improvement which represent a substantial clinical benefit (SCB) for commonly used HRQOL measures in lumbar spine surgery. STUDY DESIGN/SETTING: Prospective, multi-center cohort. PATIENT SAMPLE: 454 patients who underwent lumbar spine surgery for degenerative conditions with pre-operative and one-year HRQOL measures. OUTCOME MEASURES: Prospectively collected pre-operative and one-year post-operative SF-36 PCS, ODI, and back pain and leg pain Numeric Rating Scores (NRS). METHODS: Candidate SCB thresholds for SF-36 PCS, ODI and back and leg pain NRS were developed using receiver operating characteristic (ROC) curve analysis. ROC curves assess each potential threshold value in order to optimize sensitivity and specificity in differentiating between cohorts. ROC curves were used to discriminate between two subgroups of patients: the ‘‘Much Better’’ and ‘‘About the Same’’ patients on the SF-36 Health Transition Item, and the ‘‘Most Satisfied’’ and ‘‘Unsure’’ patients on the Satisfaction with Results Scale. Three response parameters were used: net change, percent change, and raw score at one-year followup, for each HRQOL measure. RESULTS: Thresholds of SCB for SF-36 PCS are 6.1 points net improvement, 19.5% improvement, or a final raw score greater than 35.2 points. SCB thresholds for ODI are a 19.0 point net improvement, a 37.6% improvement, or a final raw score less than 30.6 points. SCB thresholds for numeric back pain and leg pain are 2.5 points net improvement or a final raw score less than 3.5 points. SCB thresholds for percent change are 41.4% for back pain NRS and 47.2% for leg pain NRS. CONCLUSIONS: Identification of an SCB threshold for commonly used HRQOL measures in lumbar spine surgery is important, as it describes a magnitude of improvement which the patient recognizes as a substantial benefit. These thresholds are not necessarily intended as a benchmark defining a satisfactory intervention, but rather as a tool for patient discussion and shared decision making. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.148
Friday, October 26, 2007 3:29–4:15 PM Concurrent Session 2: Surgical - Fusion 126. Prospective, Randomized, Double Blind Study of the Efficacy of Post-operative Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site after Posterior Spinal Fusion: Four-year Follow-up Kern Singh, MD1, Frank Phillips, MD1, Eugene Kuo, MD2, Marion Campbell-Hupp, MSN3, Dino Samartzis, DSC4; 1Rush University Medical Center, Chicago, IL, USA; 2TX, USA; 3Department of