Tracking patient-reported outcomes in spinal disorders

The Use of Osteobiologics in Single versus Multi-Level Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic literature review.

OBJECTIVES

In this study we assessed evidence for the use of osteobiologics in single vs multi-level anterior cervical discectomy and fusion (ACDF) in patients with cervical spine degeneration. The primary objective was to compare fusion rates after single and multi-level surgery with different osteobiologics. Secondary objectives were to compare differences in patient reported outcome measures (PROMs) and complications.

METHODS

After a global team of reviewers was selected, a systematic review using different repositories was performed, confirming to PRISMA and GRADE guidelines. In total 1206 articles were identified and after applying inclusion and exclusion criteria, 11 articles were eligible for analysis. Extracted data included fusion rates, definition of fusion, patient reported outcome measures, types of osteobiologics used, complications, adverse events and revisions.

RESULTS

Fusion rates ranged from 87.7% to 100% for bone morphogenetic protein 2 (BMP-2) and 88.6% to 94.7% for demineralized bone matrix, while fusion rates reported for other osteobiologics were lower. All included studies showed PROMs improved significantly for each osteobiologic. However, no differences were reported when comparing osteobiologics, or when comparing single vs multi-level surgery specifically.

CONCLUSION

The highest fusion rates after 2-level ACDF for cervical spine degeneration were reported when BMP-2 was used. However, PROMs did not differ between the different osteobiologics. Further blinded randomized trials should be performed to compare the use of BMP-2 in single vs multi-level ACDF specifically.

Cross-cultural adaptation, validation and establishment of the minimal clinically important change score of the European Portuguese core outcome measures index in patients with lumbar degenerative spine disease

PURPOSE

The core outcome measures index (COMI) for the back is a questionnaire that evaluates five domains and has been translated into several languages and validated for different populations. We aimed to translate, cross-culturally adapt and validate it in European Portuguese for use in patients with degenerative lumbar disease. Additionally, we aimed to establish the minimal clinically important change score (MCIC).

METHODS

The translation and cultural adaptation were done according to published guidelines. Patients awaiting surgery at a neurosurgical center completed the COMI, Oswestry Disability Index (ODI), EQ-5D questionnaires and a pain visual analog scale (VAS). To evaluate COMI's reproducibility, patients completed the questionnaire twice within two weeks, preoperatively, in addition to answering a transition question. The MCIC was determined by analysis of postoperative changes in total COMI score, using the anchor method, with a question ascertaining surgical outcome as perceived by the patient.

RESULTS

The first set of questionnaires was answered by 108 patients and the second, by 98 patients. COMI's construct validity was confirmed by demonstrating the hypothesized correlation between each domain's score (Spearman Rho > 0.4) and the corresponding questionnaire score (ODI, EQ-5D and VAS) and through adequate correlation (Spearman > 0.6) between COMI's total score and ODI and EQ-5D total scores. Intraclass correlation coefficients between each domain and COMI's total score were > 0.8. The MCIC was calculated as 2.1.

CONCLUSION

The cross-culturally adapted COMI questionnaire is a valid clinical assessment tool for European Portuguese-speaking patients with degenerative lumbar disease, with an MCIC of 2.1 points.

Patient-reported outcomes after posterior surgical stabilization for thoracolumbar junction fractures: A pilot study with combined patient-reported outcome measure methodology

Background

Thoracolumbar junction fractures (TLJFs) attract controversy for several parameters, including surgery versus conservative treatment, fusion versus stabilization, open versus percutaneous surgery, construct length, and downstream metalwork extraction.

Aims and Objectives

The aim of this pilot study was to assess the effectiveness of surgical treatment in patients with burst (AO Classification Type A4) TLJFs using patient-reported outcome measures (PROMs) and evaluate and compare different PROMs in this clinical scenario.

Materials and Methods

Patient records of consecutive patients who underwent posterior stabilization surgery for TLJFs were retrospectively reviewed. Data were collected on demographics, medical and social history, neurological examination, and postoperative complications. Telephone interviews and a combined PROM methodology (Numerical Rating Scale [NRS], EuroQol [EQ]-5D-5L, and Oswestry Disability Index [ODI]) were utilized to assess the effectiveness of intervention. Descriptive statistics were used to analyze exposure variables and outcome measures. Spearman's rank correlation was used for the outcome measures.

Results

Thirteen patients were included. The mean age was 42 ± 16 years; the male: female ratio was 8:5; the mean follow-up was 18.9 ± 6.4 months. The mean NRS score was 3.3 ± 2.5, in line with a median score of 2 (2) on EQ-5D-5L pain/discomfort scale. Statistically significant correlations were found between several PROMs: pain-EQ-5D-5L and NRS (rs = 0.8, P = 0.002), pain-EQ-5D-5L and ODI (rs = 0.8, P = 0.001), usual anxiety/depression-EQ-5D-5L, and ODI (rs = 0.7, P = 0.008).

Conclusion

A combined PROM methodology showed supportive evidence for safety and efficacy in the surgical stabilization of burst TLJFs. This alleviated significant pain and prevented neurological deficit and major disability. The preliminary widespread correlation between these PROMs supports further larger studies of their combined use in clinical practice, to measure the outcomes of spine trauma patients.

ALIF Versus TLIF for L5-S1 Isthmic Spondylolisthesis: ALIF Demonstrates Superior Segmental and Regional Radiographic Outcomes and Clinical Improvements Across More Patient-reported Outcome Measures Domains

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study was to compare segmental and regional radiographic parameters between anterior interbody fusion (ALIF) and posterior interbody fusion (TLIF) for treatment of L5-S1 isthmic spondylolisthesis, and to assess for changes in these parameters over time. Secondarily, we sought to compare clinical outcomes via patient-reported outcome measures (PROMs) between techniques and within groups over time.

SUMMARY OF BACKGROUND DATA

Isthmic spondylolistheses are frequently treated with interbody fusion via ALIF or TLIF approaches. Robust comparisons of radiographic and clinical outcomes are lacking.

METHODS

We reviewed pre- and postoperative radiographs as well as Patient-Reported Outcomes Measurement Information System (PROMIS) elements for patients who received L5-S1 interbody fusions for isthmic spondylolisthesis in the Mass General Brigham (MGB) health system (2016-2020). Intraclass correlation testing was used for reliability assessments; Mann-Whitney U tests and Sign tests were employed for intercohort and intracohort comparative analyses, respectively.

RESULTS

ALIFs generated greater segmental and L4-S1 lordosis than TLIF, both at first postoperative visit (mean 26 days [SE = 4]; 11.3° vs. 1.3°, P  < 0.001; 6.2° vs. 0.3°, P  = 0.005) and at final follow-up (mean 410days [SE = 45]; 9.6° vs. 0.2°, P < 0.001; 7.9° vs. 2.1°, P = 0.005). ALIF also demonstrated greater increase in disc height than TLIF at first (9.6 vs. 5.5 mm, P < 0.001) and final follow-up (8.7 vs. 3.6 mm, P < 0.001). Disc height was maintained in the ALIF group but decreased over time in the TLIF cohort (ALIF 9.6 vs. 8.7 mm, P = 0.1; TLIF 5.5 vs. 3.6 mm, P < 0.001). Both groups demonstrated improvements in Pain Intensity and Pain Interference scores; ALIF patients also improved in Physical Function and Global Health - Physical domains.

CONCLUSION

ALIF generates greater segmental lordosis, regional lordosis, and restoration of disc height compared to TLIF for treatment of isthmic spondylolisthesis. Additionally, ALIF patients demonstrate significant improvements across more PROMs domains relative to TLIF patients.Level of Evidence: 3.

Two-year validation and minimal clinically important difference of the Veterans RAND 12 Item Health Survey Physical Component Score in patients undergoing minimally invasive transforaminal lumbar interbody fusion

OBJECTIVE

The Physical Component Score of the Veterans RAND 12 Item Health Survey (VR-12 PCS) has been assessed for use at short-term and intermediate-term time points for lumbar fusion populations. This study assesses the long-term validity and establishes minimal clinically important difference (MCID) values of VR-12 PCS in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

METHODS

A surgical registry was retrospectively reviewed for primary, elective, single-level MIS TLIF procedures with posterior instrumentation. Patients missing preoperative and 2-year postoperative VR-12 PCS survey data were excluded. VR-12 PCS, SF-12 Health Survey Physical Component Summary (SF-12 PCS), Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF), and Oswestry Disability Index (ODI) patient-reported outcome measures (PROMs) were recorded preoperatively and postoperatively. Responsiveness of the VR-12 measure was assessed in two ways. First, the mean postoperative PROM scores were compared with preoperative baseline values using a paired Student t-test. Second, MCID values were calculated using both distribution-based and anchor-based methods and used to assess improvement in VR-12 score at the 2-year time point. Discriminant validity of the VR-12 was assessed using cross-sectional and longitudinal anchors. Convergent validity of the VR-12 measure was assessed using Pearson's correlation coefficient and partial time-independent correlation. Floor and ceiling effects were assessed.

RESULTS

A total of 74 patients who underwent MIS TLIF were included. The VR-12 PCS demonstrated significant improvements at all time points from 12 weeks to 2 years (p < 0.001 for all). VR-12 PCSs were significantly different for patients classified using cross-sectional anchors (p < 0.001) and longitudinal anchors (p ≤ 0.005). Calculated MCID values ranged from 4.1 to 8.5, and 4.1 was selected as the optimal MCID, which 87.8% of patients achieved. Strong, significant correlations of the VR-12 PCS with SF-12 PCS and PROMIS PF were demonstrated at all time points (p < 0.001 for all). No significant floor or ceiling effects were detected.

CONCLUSIONS

The VR-12 PCS demonstrated excellent responsiveness, discriminant and convergent validity, and no significant floor or ceiling effects up to 2 years after MIS TLIF. Therefore, VR-12 PCS may serve as a valid measure of long-term physical function.

Data-driven phenotyping of preoperative functional decline patterns in patients undergoing lumbar decompression and lumbar fusion using smartphone accelerometry

OBJECTIVE

Treatment of degenerative lumbar spine pathologies typically escalates to surgical intervention when symptoms begin to significantly impair patients’ functional status. Currently, surgeons rely on subjective patient assessments through patient-reported outcome measures to estimate the decline in patient wellness and quality of life. In this analysis, the authors sought to use smartphone-based accelerometry data to provide an objective, continuous measurement of physical activity that might aid in effective characterization of preoperative functional decline in different lumbar spine surgical indications.

METHODS

Up to 1 year of preoperative activity data (steps taken per day) from 14 patients who underwent lumbar decompression and 15 patients who underwent endoscopic lumbar fusion were retrospectively extracted from patient smartphones. A data-driven algorithm was constructed based on 10,585 unique activity data points to identify and characterize the functional decline of patients preceding surgical intervention. Algorithmic estimation of functional decline onset was compared with reported symptom onset in clinical documentation across patients who presented acutely (≤ 5 months of symptoms) or chronically (> 5 months of symptoms).

RESULTS

The newly created algorithm identified a statistically significant decrease in physical activity during measured periods of functional decline (p = 0.0020). To account for the distinct clinical presentation phenotypes of patients requiring lumbar decompression (71.4% acute and 28.6% chronic) and those requiring lumbar fusion (6.7% acute and 93.3% chronic), a variable threshold for detecting clinically significant reduced physical activity was implemented. The algorithm characterized functional decline (i.e., acute or chronic presentation) in patients who underwent lumbar decompression with 100% accuracy (sensitivity 100% and specificity 100%), while characterization of patients who underwent lumbar fusion was less effective (accuracy 26.7%, sensitivity 21.4%, and specificity 100%). Adopting a less-permissive detection threshold in patients who underwent lumbar fusion, which rendered the algorithm robust to minor fluctuations above or below the chronically decreased level of preoperative activity in most of those patients, increased functional decline classification accuracy of patients who underwent lumbar fusion to 66.7% (sensitivity 64.3% and specificity 100%).

CONCLUSIONS

In this study, the authors found that smartphone-based accelerometer data successfully characterized functional decline in patients with degenerative lumbar spine pathologies. The accuracy and sensitivity of functional decline detection were much lower when using non–surgery-specific detection thresholds, indicating the effectiveness of smartphone-based mobility analysis in characterizing the unique physical activity fingerprints of different lumbar surgical indications. The results of this study highlight the potential of using activity data to detect symptom onset and functional decline in patients, enabling earlier diagnosis and improved prognostication.

Cross-Cultural Adaptation and Psychometric Validation of the Dutch Version of the Core Outcome Measures Index for the Neck in Patients Undergoing Surgery for Degenerative Disease of the Cervical Spine

OBJECTIVE

To perform the psychometric validation of the Dutch version of the Core Outcome Measures Index (COMI) for the neck.

METHODS

A total of 178 patients, who had an indication for surgery due to degenerative cervical spinal disease, were enrolled in the study. They filled in a baseline booklet containing the Dutch version of the COMI-neck, Likert-scales for neck and arm/shoulder pain, the Neck Disability Index (NDI), the EuroQol-5 dimensions (EQ-5D) and the 12-item Short Form health survey (SF-12). Aside from analyzing construct validity using the Spearman correlation test, test-retest reliability, and responsiveness at 3 months were assessed using the intraclass correlation coefficient (ICC) and the receiver-operating characteristic (ROC) curve, respectively.

RESULTS

The COMI-neck showed good acceptability with missing data ranging from 0% to 4.5% and some floor/ceiling effects for 3 of the domains at baseline. The COMI-summary score showed good to very good correlation with the EQ5D (ρ = -0.43), the physical component summary of the SF-12 (ρ = -0.47) and the NDI (ρ = 0.73). Individual domains showed correlations of -0.28 to 0.85 with the reference questionnaires. Test-retest reliability analysis showed an ICC of 0.91 with a minimal detectable change of 1.7. Responsiveness analysis of the COMI-neck showed an area under 0.79 under the ROC-curve. The standardized response mean for a good outcome was 1.24 and for a poor outcome 0.37.

CONCLUSION

The current study shows that the Dutch version of the COMI-neck is a valid, reliable and responsive Patient-Reported Outcome Measure, among patients undergoing surgery for degenerative cervical spinal disorders.

Objective Outcomes in Lateral Osteotomy Through Anterior-to-Psoas for Severe Adult Degenerative Spine Deformity Correction

Multilevel lateral interbody fusion is an acceptable surgical technique in patients with severe degenerative adult spinal deformity (ASD). The current standard-of-care in spine surgery includes the use of patient reported outcome measures (PROMs) to assess post-operative improvement. Objective activity data during the peri-operative period may provide supplementary information for patients recovering from ASD surgery. In this report, we use smartphone-based activity data as an objective outcome measure for a patient who underwent a two-stage operation for ASD corrective surgery: lateral osteotomy and lumbar interbody fusion with posterior column release. An 82-year-old male presented with intractable back pain secondary to severe thoracolumbar scoliotic deformity (Lenke 5BN). Pre-operative images demonstrated the presence of bridging osteophytes over the left lateral aspect of L2-5 disc spaces and over the apex of the lumbar curvature, with significant neuroforaminal stenosis. Surgical correction was completed in two stages: (1) left-sided lateral osteotomy using anterior-to-psoas approach (ATP) in a right lateral decubitus position, and (2) multilevel Ponte osteotomies and instrumented fusion from T10-pelvis. Post-operative radiography showed correction to scoliotic deformity and sagittal misalignment. The patient had developed seroma and wound dehiscence, which was evacuated on post-operative day 11. At 14-month follow-up, the patient reported significant improvement in pain symptoms, corroborated by patient reported outcome measures. To further quantify and assess patient recovery, smartphone-based patient activity data was collected and analyzed to serve as a proxy for the patient's functional improvement. The patient's walking steps-per-day was compared pre- and post-operatively. The patient's pre-operative baseline was 223 steps/day; the patient's activity during immediate post-operative recovery dropped to 179 steps/day; the patient returned to baseline activity levels approximately 3 months after surgery, reaching an average of 216 steps/day. In conclusion, we found that lateral osteotomy through an ATP approach is a powerful tool to restore normal spine alignment and can be successfully performed using anatomic landmarks. Additionally, smartphone-based mobility data can assess pre-operative activity level and allow for remote patient monitoring beyond routine follow-up schedule.

Patient-Reported Outcomes Following Lumbar Decompression Surgery: A Review of 2699 Cases

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Despite numerous advances in the technology and techniques available to spinal surgeons, lumbar decompression remains the mainstay of degenerative lumbar spine surgery. It has proven efficacy in trials, but only limited evidence of advantage over conservative management in large scale systematic reviews. We collated data from a large surgically managed cohort to evaluate the patient-reported outcomes.

METHODS

We performed a retrospective analysis of a prospectively populated database. Patient demographics, surgical details, and patient outcomes (Spine Tango core outcome measures index [COMI]-Low Back) were collected for 2699 lumbar decompression surgeries.

RESULTS

Lumbar decompression was shown to be successful at improving leg pain (mean improvement in visual analogue scale [VAS] at 3 months = 4) and to a lesser extent, back pain (mean improvement in VAS at 3 months = 2.61). Mean improvement in COMI score was 3.15 for all-comers. Minimal clinically important improvement (MCID) in COMI score (-2 points) was achieved in 73% of patients by 2-year follow-up. Primary surgery was more effective than redo surgery: odds ratio 0.547 (95% CI 0.408-0.733, P < .001). The benefits across all outcomes were maintained for the 2-year follow-up period. Patients can be classified according to their outcome as "early responders"; achieving MCID by 3 months (61% primary vs 41% redo), "late responders"; achieving MCID by 2 years (15% vs 20%) or nonresponders (24% vs 39%).

CONCLUSIONS

Lumbar decompression is effective in improving quality of life in appropriately selected patients. Patient-reported outcome measures collected routinely and collated within a registry are a powerful tool for assessing the efficacy of lumbar spine interventions and allow accurate counseling of patients perioperatively.

A Simpler, Modified Frailty Index Weighted by Complication Occurrence Correlates to Pain and Disability for Adult Spinal Deformity Patients

BACKGROUND

The Miller et al adult spinal deformity frailty index (ASD-FI) correlates with complication risk; however, its development was not rooted in clinical outcomes, and the 40 factors needed for its calculation limit the index's clinical utility. The present study aimed to develop a simplified, weighted frailty index for ASD patients METHODS: This study is a retrospective review of a single-center database. Component ASD-FI parameters contributing to overall ASD-FI score were assessed via Pearson correlation. Top significant, clinically relevant factors were regressed against ASD-FI score to generate the modified ASD-FI (mASD-FI). Component mASD-FI factors were regressed against incidence of medical complications, and factor weights were calculated from regression of these coefficients. Total mASD-FI score ranged from 0 to 21, and was calculated by summing weights of expressed parameters. Linear regression and published ASD-FI cutoffs generated corresponding mASD-FI frailty cutoffs: not frail (NF, <7), frail (7-12), severely frail (SF, >12). Analysis of variance assessed the relationship between frailty category and validated baseline measures of pain and disability at baseline.

RESULTS

The study included 50 ASD patients. Eight factors were included in the mASD-FI. Overall mean mASD-FI score was 5.7 ± 5.2. Combined, factors comprising the mASD-FI showed a trend of predicting the incidence of medical complications (Nagelkerke R ² = 0.558; Cox & Snell R ² = 0.399; P = .065). Breakdown by frailty category is NF (70%), frail (12%), and SF (18%). Increasing frailty category was associated with significant impairments in measures of pain and disability: Oswestry Disability Index (NF: 23.4; frail: 45.0; SF: 49.3; P < .001), SRS-22r (NF: 3.5; frail: 2.6; SF: 2.4; P = .001), Pain Catastrophizing Scale (NF: 41.9; frail: 32.4; SF: 27.6; P < .001), and NRS Leg Pain (NF: 2.3; frail: 7.2; SF: 5.6; P = .001).

CONCLUSIONS

This study modifies an existing ASD frailty index and proposes a weighted, shorter mASD-FI. The mASD-FI relies less on patient-reported variables, and it weights component factors by their contribution to adverse outcomes. Because increasing mASD-FI score is associated with inferior clinical measures of pain and disability, the mASD-FI may serve as a valuable tool for preoperative risk assessment.

Cone of economy classification: evolution, concept of stability, severity level, and correlation to patient-reported outcome scores

STUDY DESIGN

A prospective cohort study OBJECTIVE: To determine a classification system for cone of economy (CoE) measurements that defines clinically significant changes in altered balance and to assess if the CoE measurements directly impacts patients reported outcome measures (PROMs). Preoperative functional data is a crucial component of determining patient disability and prognosis. The CoE has been theorized to be the foundation of biomechanical changes that leads to increased energy expenditure and disability in spine patients. PROMs have been developed to quantify the level of debilitation in spine patients but have various limitations.

METHODS

A total of 423 symptomatic adult patients with spine pathology completed a series of PROMs preoperatively including VAS, ODI, Tampa Scale for Kinesiophobia (TSK), Fear and Avoidance Beliefs Questionnaire (FABQ), and Demoralization (DS). Functional balance was tested in this group using a full-body reflective marker set to measure head and center of mass (CoM) sway.

RESULTS

PROMs scores were correlated with the magnitude of the CoE measurements. Patients were separated by the following proposed classification: CoM coronal sway > 1.5 cm, CoM sagittal sway > 3.0 cm, CoM total sway > 30.0 cm, head coronal sway > 3.0 cm, head sagittal sway > 6.0 cm, and head total sway > 60.0 cm. Significant differences were noted in the ODI (< 0.001), FABQ physical activity (< 0.001-0.009), DS (< 0.001-0.023), and TSK (< 0.001-0.032) across almost all planes of motion for both CoM and head sway. The ODI was most sensitive to the difference between groups across CoM and head sway planes with a mean ODI of 47.5-49.5 (p < 0.001) in the severe group versus 36.6-39.3 (p < 0.001) in the moderate group.

CONCLUSIONS

By classifying CoE measurements by the cutoffs proposed, clinically significant alterations in balance can be quantified. Furthermore, this study demonstrates that across spinal pathology, higher magnitude CoE and range of sway measurements correlate with worsening PROMs. The Haddas' CoE classification system in this study helps to identify patients that may benefit from surgery and guide their postoperative prognosis.

Structural Allograft Versus PEEK Implants in Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

Our primary objective was to compare reported fusion rates after anterior cervical discectomy and fusion (ACDF) using structural allograft versus polyetheretherketone (PEEK) interbody devices in patients with cervical spine degeneration. Our secondary objectives were to compare differences in rates of subsidence and reoperation and in patient-reported outcomes between the 2 groups.

METHODS

Through a systematic review of the English-language literature using various databases, we identified 4702 articles. After we applied inclusion and exclusion criteria, 14 articles (7 randomized controlled trials, 4 prospective studies, and 3 retrospective studies) reporting fusion rates of structural allograft or PEEK interbody devices were eligible for our analysis. No randomized controlled trials compared outcomes of structural allograft versus PEEK interbody devices. Extracted data included authors, study years, study designs, sample sizes, patient ages, duration of follow-up, types of interbody devices used, fusion rates, definition of fusion, reoperation rates, subsidence rates, and patient-reported outcomes.

RESULTS

Fusion rates were 82% to 100% for allograft and 88% to 98% for PEEK interbody devices. The reported data were insufficient to perform meta-analysis. Structural allograft had the highest reported rate of reoperation (14%), and PEEK interbody devices had the highest reported subsidence rate (18%). Patient-reported outcomes improved in both groups. There was insufficient high-quality evidence to compare the associations of various PEEK modifications with fusion rates.

CONCLUSION

Fusion rates were similar between structural allograft and PEEK interbody devices when used for ACDF for cervical spine degeneration. Currently, there is insufficient high-quality evidence to assess associations of PEEK modifications with fusion rates.

LEVEL OF EVIDENCE

II.

Psychometric Evaluation of Patient-reported Outcomes Measurement Information System Physical Function Computer Adaptive Testing in Minimally Invasive Lumbar Spine Surgery: An Analysis of Responsiveness, Coverage, Discriminant Validity, and Concurrent Validity

INTRODUCTION

Although the Patient-reported Outcomes Measurement Information System (PROMIS) is increasingly being used, there are few studies assessing the psychometric properties of PROMIS in minimally invasive spine (MIS) surgery. Thus, the purpose of this study was to perform a psychometric evaluation of PROMIS Physical Function Computer Adaptive Testing (PROMIS-PF CAT) in MIS lumbar surgery.

METHODS

The patient-reported outcome measures collected preoperatively and postoperatively of patients undergoing MIS lumbar surgery were retrospectively analyzed to assess responsiveness, coverage, discriminant validity, and concurrent validity of PROMIS-PF CAT.

RESULTS

Four hundred twenty-one patients were included. The responsiveness of PROMIS Physical Function (PROMIS-PF) was lower than that of the Oswestry Disability Index (ODI) in the decompression subgroup. Although the ODI had a ceiling effect of 16.7% at 1 year, the Short-Form 12 physical health score and PROMIS-PF did not show floor or ceiling effects. PROMIS-PF demonstrated discriminant validity preoperatively and postoperatively and convergent validity with the ODI, as evidenced by a significant strong negative correlation but not with the Short-Form 12 Physical Health Score, as evidenced by the variability in strength of correlation.

CONCLUSIONS

Although the PROMIS-PF showed lower responsiveness than the ODI, particularly in the decompression subgroup, it demonstrated discriminant validity preoperatively and postoperatively, convergent validity with ODI, and better coverage than ODI. These findings suggest that the PROMIS-PF CAT demonstrates reasonable psychometric properties and may be a good surrogate for the ODI.

Cost-effectiveness Applications of Patient-reported Outcome Measures (PROMs) in Spine Surgery

Because of the rising health care costs in the United States, there has been a focus on value-based care and improving the cost-effectiveness of surgical procedures. Patient-reported outcome measures (PROMs) can not only give physicians and health care providers immediate feedback on the well-being of the patients but also be used to assess health and determine outcomes for surgical research purposes. Recently, PROMs have become a prominent tool to assess the cost-effectiveness of spine surgery by calculating the improvement in quality-adjusted life years (QALY). The cost of a procedure per QALY gained is an essential metric to determine cost-effectiveness in universal health care systems. Common patient-reported outcome questionnaires to calculate QALY include the EuroQol-5 dimensions, the SF-36, and the SF-12. On the basis of the health-related quality of life outcomes, the cost-effectiveness of various spine surgeries can be determined, such as cervical fusions, lumbar fusions, microdiscectomies. As the United States attempts to reduce costs and emphasize value-based care, PROMs may serve a critical role in spine surgery moving forward. In addition, PROM-driven QALYs may be used to analyze novel spine surgical techniques for value-based improvements.

Risk Factors Associated With Failure to Reach Minimal Clinically Important Difference in Patient-Reported Outcomes Following Anterior Cervical Discectomy and Fusion

Background

The minimum clinically importance difference (MCID) represents a threshold for improvements in patient-reported outcomes (PROs) that patients deem important. No previous study has comprehensively examined risk factors for failure to achieve MCID after anterior cervical discectomy and fusion (ACDF) procedures for radiculopathic symptomatology. The purpose of this study is to determine risk factors for failure to reach MCID for Neck Disability Index (NDI), Visual Analog Scale (VAS) neck pain, and VAS arm pain in patients undergoing 1- or 2-level ACDF procedures.

Methods

A surgical registry of patients who underwent primary, 1- or 2-level ACDF from 2014 to 2016 was reviewed. Rates of MCID achievement for NDI, VAS neck pain, and VAS arm pain at final follow-up were calculated based on published MCID values. Patients were then categorized into demographic and procedural categories. Bivariate regression was used to test for association of demographic and procedural characteristics with failure to reach MCID for each PRO. The final multivariate model including all demographic and procedural categories as controls was created using backward stepwise regression.

Results

Eighty-three, 84, and 77 patients were included in the analysis for VAS neck, VAS arm, and NDI, respectively. Rates of MCID achievement for VAS neck, VAS arm, and NDI were 55.4%, 36.9%, and 76.6%, respectively. On bivariate analysis, patients with Charlson Comorbidity Index (CCI) ≥ 2 were less likely to achieve MCID for NDI than patients with CCI < 2 (P = .025). On multivariate analysis, CCI ≥ 2 (P = .025) was further associated with failure to reach MCID for NDI.

Conclusions

The results of this study suggest that the majority of patients do not reach MCID for arm pain. Additionally, higher comorbidity burden as evidenced by higher CCI scores is a negative predictive factor for the achievement of MCID in neck disability following ACDF.

Level of Evidence

3.

Digital Phenotyping in Patients with Spine Disease: A Novel Approach to Quantifying Mobility and Quality of Life

OBJECTIVE

To identify trends in mobility and daily pain levels among a cohort of patients with clinically diagnosed spine disease.

METHODS

Participants with spine disease were enrolled from a general neurosurgical clinic and installed a smartphone application (Beiwe) designed for digital phenotyping to their personal smartphone. This application collected passive meta-data on a minute-to-minute basis, including global positioning system (GPS), WiFi, accelerometer, text and telephone logs, and screen on and off time. The application also administered daily visual analog scale pain surveys. A linear mixed model framework was used to test for associations between self-reported pain and mobility and sociability from the passively collected data.

RESULTS

A total of 105 patients were enrolled, with a median follow-up time of 94.5 days; 55 patients underwent a surgical intervention during the follow-up period. The weekly pain survey response rate was 73.2%. By the end of follow-up, the mean change in pain for all patients was -1.3 points (4.96 at the start of follow-up to 3.66 by the end of follow-up). Increased pain was significantly associated with reduced patient mobility as measured using 3 daily GPS summary statistics (i.e., average flight length, maximum diameter travelled, total distance travelled).

CONCLUSIONS

Patients with spine disease who reported greater pain had reduced mobility, as measured by the passively collected smartphone GPS data. Smartphone-based digital phenotyping appears to be a promising and scalable approach to assess mobility and quality of life of patients with spine disease.

Patient-Reported Outcome Measures in Neurosurgery: A Review of the Current Literature

BACKGROUND

Patient-reported outcome measures (PROMs) play an important role in the evaluation of health outcomes, quality of life, and satisfaction, and have been successfully utilized in many areas of clinical medicine and surgical practice. The prevalence of PROMs in neurosurgery is not known.

OBJECTIVE

To review the PROMs that have been utilized in the published neurosurgery literature to date.

METHODS

Articles were searched in MEDLINE, EMBASE, HMIC Health Management Information Consortium, PsycARTICLES, and PsycINFO using search terms related to neurosurgery and PROMs, published from 1806 to August 2016. A total of 268 articles were identified that were stratified by the inclusion and exclusion criteria leading to a total of 137 articles. Twenty-six PROMs, involving both adult and pediatric populations, were identified.

RESULTS

A large number of generic and disease-specific PROMs are used in the neurosurgical literature. Generic PROMs are usually nonspecific measures of health status. Disease-specific PROMs may not address issues relevant to neurosurgical procedures. There are very few neurosurgery-specific PROMs that take into account the impact of a neurosurgical procedure on a specific condition.

CONCLUSION

PROMs that currently feature in the neurosurgical literature may not address the specific outcomes relevant to neurosurgical practice. There is an emergent need for generic and disease-specific PROMs to be validated in neurosurgical patients and neurosurgery-specific PROMs developed to address unmet needs of patients undergoing neurosurgical procedures.

Trends in the use of patient-reported outcome instruments in neurosurgical adult thoracolumbar deformity and degenerative disease literature

Objective:

Shifting national healthcare trends place increased emphasis on patient-centered care and value-based outcomes, and thus, patient-reported outcome instruments (PROIs) are often used. We sought to characterize the trends in PROI use over the past decade with regard to thoracolumbar degenerative spine disease and spinal deformity in major neurosurgical journals.

Methods:

Articles were screened for PROI use through a PubMed search among five major neurosurgical journals from 2006 to 2016. Articles focusing on adult thoracolumbar deformity and degenerative disease were selected with stringent criteria to further characterize PROI use.

Results:

A total of 29 different PROIs were used among 102 articles identified from 2006 to 2016 using our search strategy. Journal of Neurosurgery: Spine contained the most articles utilizing PROIs with 35.3% of all articles meeting search criteria. The most frequently used PROIs were Oswestry Disability Index, visual analog scale, and the European Quality of Life Five-dimension questionnaire used in 79.4%, 59.8%, and 29.4% of articles, respectively. Linear regression identified a significant increase in the number of articles employing PROIs from 2006 to 2016 (Y = 1.85, R²= 0.77, P < 0.01). The total number of PROIs per article was relatively stagnant over time and did not significantly change (Y = 0.03, R²= 0.05, P = 0.51).

Conclusions:

PROI use as an outcome tool in the adult thoracolumbar disease literature has increased during the past decade, which may be an indicative of PROI use to define patient expectations. This may also represent a trend toward PROI use as a surrogate measure of value-based care.