Negative effects of smoking, workers' compensation, and litigation on pain/disability scores for spine patients

Litigation involving sports-related spinal injuries: a comprehensive review of reported legal claims in the United States in the past 70 years

BACKGROUND CONTEXT

Sports-related spinal injuries can be catastrophic in nature. Athletes competing in collision sports (eg, football) may be particularly prone to injury given the high-impact nature of these activities. Due to the oftentimes profound impact of sports-related spinal injuries on health and quality-of-life, they are also associated with a substantial risk of litigation. However, no study to date has assessed litigation risks associated with sports-related spinal injuries. A better understanding of the risk factors surrounding these legal claims may provide insights into injury prevention and other strategies to minimize litigation risks. In addition, it may allow the spine surgeon to better recognize the health, socioeconomic, and legal challenges faced by this patient population.

PURPOSE

To provide a comprehensive assessment of reported legal claims involving sports-related spinal injuries, including a comparative analysis of legal outcomes between collision and non-collision sports. To discuss strategies to prevent sports-related spinal injuries and minimize litigation risks.

STUDY DESIGN/SETTING

Retrospective review.

PATIENT SAMPLE

Athletes experiencing spinal injuries during sports.

OUTCOME MEASURES

Outcomes included verdict outcome (defendant vs. plaintiff), legal claims, injuries sustained, clinical symptoms, and award payouts.

METHODS

The legal research database Westlaw Edge (Thomson Reuters) was queried for legal claims brought in the United States from 1950 to 2021 involving sports-related spinal injuries. Verdict or settlement outcomes were collected as well as award payouts, time to case closure, case year, and case location. Demographic data, including type of sport (ie collision vs. non-collision sport) and level of play were obtained. Legal claims, spinal injuries sustained, and clinical symptoms were also extracted. Furthermore, the nature of injury, injured spinal region, and treatment pursued were collected. Descriptive statistics were reported for all cases and independent-samples t-tests and chi-square tests were used to compare differences between collision and non-collision sports.

RESULTS

Of the 840 cases identified on initial search, 78 met our criteria for in-depth analysis. This yielded 62% (n=48) defendant verdicts, 32% (n=25) plaintiff verdicts, and 6% (n=5) settlements, with a median inflation-adjusted award of $780,000 (range: $5,480-$21,585,000) for all cases. The most common legal claim was negligent supervision (n=38, 46%), followed by premises liability (n=23, 28%), and workers' compensation/no fault litigation (n=10, 12%). The most common injuries sustained were vertebral fractures (n=34, 44%) followed by disc herniation (n=14, 18%). Most cases resulted in catastrophic neurological injury (n=37, 49%), either paraplegia (n=6, 8%) or quadriplegia (n=31, 41%), followed by chronic/refractory pain (n=32, 43%). Non-collision sport cases had a higher percentage of premises liability claims (41% vs. 11%, p=.006) and alleged chronic/refractory pain (53% vs. 28%, p=.04). Conversely, collision sport cases had a higher proportion of workers' compensation/no fault litigation (23% vs. 4%, p=.03) and cases involving disc herniation (29% vs. 9%, respectively; p=.04).

CONCLUSION

Sports-related spinal injuries are associated with multiple and complex health, socioeconomic, and legal consequences, with median inflation-adjusted award payouts nearing $800,000 per case. In our cohort, the most commonly cited legal claims were negligent supervision and premises liability, emphasizing the need for prevention guidelines for safe sports practice, especially in non-professional settings. Cases involving athletes participating in non-collision sports were significantly associated with claims citing chronic/refractory pain, highlighting the importance of long-term care in severely injured athletes.

How does preoperative opioid use impact postoperative health-related quality of life scores for patients undergoing lumbar microdiscectomy?

BACKGROUND CONTEXT

Narcotic use amongst patients suffering from lumbar radiculopathy is common, but the clinical benefit of narcotics for lumbar radiculopathy is likely minimal. It is unknown what the impact of preoperative use of narcotics has on outcomes related to lumbar microdiscectomy.

PURPOSE

Determine the impact that preoperative opioid use has on postoperative outcomes after lumbar microdisectomy.

STUDY DESIGN

Retrospective analysis of a prospectively collected database.

PATIENT SAMPLE

One hundred and twenty-six patients undergoing a microdiscectomy for a lumbar disc herniation.

OUTCOME MEASURES

Patient-reported outcomes measurement information system mental health scores (PROMIS MHS), patient-reported outcomes measurement information system physical health scores (PROMIS PHS) and oswestry disability index (ODI).

METHODS

We analyzed a prospectively collected database of patients undergoing a lumbar microdiscectomy for preoperative opioid use. We measured the severity of lumbar pathology on MRI based on degree of facet/disc degeneration and cross-sectional area of the dural tube at the disc herniation. We tracked PROMIS MHS, PROMIS PHS and ODI for patients both preoperatively and postoperatively. A Mann-Whitney test was used to compare HRQOL scores and time to MCID for the opioid using cohort (OC) and the nonopioid using cohort (non-OC). We performed a linear regression analysis to determine correlation between preoperative opioid use and postoperative HRQOLs.

RESULTS

There were 44 of 126 microdiscectomy patients in the OC (32.5%). There was no difference in the dural cross-sectional area (p=.91), degree of facet degeneration (p=.38), or disc degeneration (p=.5) between OC and non-OC. There were no differences in PROMIS PHS, PROMIS MHS or ODI between the OC and non-OC at the preoperative visit and all postoperative time points. There were no differences in time to reach MCID between the OC and non-OC for ODI (p=.9), PROMIS PHS (p=.64) or PROMIS MHS (p=.90). At three months out from surgery there was a statistically significant correlation between pre-op opioid use and ODI (p=.02), PROMIS MHS (p=.02) and PROMIS PHS (p=.049).

CONCLUSIONS

Our results demonstrate that patients that use opioids prior to lumbar microdiscectomy have equivalent postoperative outcomes as those that do not use opioids. Use of higher doses of opioids is associated with worse short-term outcomes.

Tobacco use predicts poorer clinical outcomes and higher post-operative complication rates after open elbow arthrolysis

INTRODUCTION

Tobacco use is a worldwide public health problem, and has been found to be a predisposing factor for adverse functional outcomes and increased postoperative complication rates after various orthopedic operations. The purpose of this study was to determine the potential impact of tobacco use on open arthrolysis for post-traumatic elbow stiffness.

MATERIALS AND METHODS

A database search identified 145 patients with open arthrolysis performed for post-traumatic elbow stiffness; these were divided into three groups: current tobacco users (37), former users (28), and nonusers (80). All surgeries were performed using the same technique by the same doctor. General patient data, functional performance, and complications were documented and analyzed.

RESULTS

Demographic data and disease characteristics were comparable at baseline. Postoperatively, significant differences were found among the three groups in terms of range of motion (P < 0.001), Mayo Elbow Performance Score (P = 0.006), visual analog scale score for pain (P = 0.015), Dellon classification for ulnar nerve symptoms (P = 0.013), and total complication rates (P < 0.001). The current tobacco users group had the poorest clinical outcomes and highest complication rates, while no significant differences were found between former users and nonusers.

CONCLUSIONS

Current tobacco users reported increased risk of poorer clinical outcomes and higher postoperative complication rates after open arthrolysis. Former users were found to have outcomes similar to those of nonusers. This study underlines the importance of discontinuing tobacco use for patients with post-traumatic elbow stiffness who are considering open arthrolysis.

LEVEL OF EVIDENCE

Level III; Retrospective Cohort Design; Therapeutic Study.

Leveraging healthcare utilization to explore outcomes from musculoskeletal disorders: methodology for defining relevant variables from a health services data repository

Background

Large healthcare databases, with their ability to collect many variables from daily medical practice, greatly enable health services research. These longitudinal databases provide large cohorts and longitudinal time frames, allowing for highly pragmatic assessment of healthcare delivery. The purpose of this paper is to discuss the methodology related to the use of the United States Military Health System Data Repository (MDR) for longitudinal assessment of musculoskeletal clinical outcomes, as well as address challenges of using this data for outcomes research.

Methods

The Military Health System manages care for approximately 10 million beneficiaries worldwide. Multiple data sources pour into the MDR from multiple levels of care (inpatient, outpatient, military or civilian facility, combat theater, etc.) at the individual patient level. To provide meaningful and descriptive coding for longitudinal analysis, specific coding for timing and type of care, procedures, medications, and provider type must be performed. Assumptions often made in clinical trials do not apply to these cohorts, requiring additional steps in data preparation to reduce risk of bias. The MDR has a robust system in place to validate the quality and accuracy of its data, reducing risk of analytic error. Details for making this data suitable for analysis of longitudinal orthopaedic outcomes are provided.

Results

Although some limitations exist, proper preparation and understanding of the data can limit bias, and allow for robust and meaningful analyses. There is the potential for strong precision, as well as the ability to collect a wide range of variables in very large groups of patients otherwise not captured in traditional clinical trials. This approach contributes to the improved understanding of the accessibility, quality, and cost of care for those with orthopaedic conditions.

Conclusion

The MDR provides a robust pool of longitudinal healthcare data at the person-level. The benefits of using the MDR database appear to outweigh the limitations.

Spine Surgery Outcomes in Workers' Compensation Patients

Occupational spine injuries place a substantial burden on employees, employers, and the workers' compensation system. Both temporary and permanent spinal conditions contribute substantially to disability and lost wages. Numerous investigations have revealed that workers' compensation status is a negative risk factor for outcomes after spine injuries and spine surgery. However, positive patient outcomes and return to work are possible in spine-related workers' compensation cases with proper patient selection, appropriate surgical indications, and realistic postoperative expectations. Quality improvement measures aimed at optimizing outcomes and minimizing permanent disability are crucial to mitigating the burden of disability claims.

Comparison of Two Injection Techniques for Intra-articular Hip Injections

OBJECTIVES

Intra-articular hip joint injections have traditionally relied on the use of image guidance to confirm intra-articular needle placement. Musculoskeletal ultrasound (US) has emerged as a popular tool to aid the clinician in performing intra-articular hip injections. Modern automated injection delivery systems are commercially available and may offer the potential to optimize clinical efficiency while limiting procedural morbidity. The purpose of this study was to compare patient-reported outcomes and clinical efficiency between two US-guided intra-articular hip injection techniques. The hypothesis was that the use of an automated delivery system for US-guided intra-articular hip joint injections would show superiority in clinical efficiency over traditional syringe injections.

METHODS

This study was a level 1 randomized prospective postmarket clinical evaluation. Forty patients were randomly assigned to undergo a single intra-articular corticosteroid injection of the hip using either an automated delivery system (Navigator Delivery System; Carticept Medical, Inc, Alpharetta, GA) or a traditional syringe injection. Enrolled patients were prospectively followed at 1, 6, and 12 weeks after injection. A battery of patient-reported outcomes were collected at baseline and again at 1, 6, and 12 weeks after injection. Preparation times were documented for all injections.

RESULTS

Forty patients met inclusion criteria and were enrolled. Twenty patients were randomly assigned to receive US guided intra-articular hip injections using the automated system (group A), and 20 patients were treated with standard syringe injections (group B). Body mass index, smoking history, symptom duration, baseline patient-reported outcomes, and demographic data were similar between groups. Improvements from baseline scores were noted at all time points for all patient-reported outcomes regardless of the injection technique used. However, no significant differences were noted at any time point for any of the patient-reported outcomes based on which injection delivery system was used. Statistically significant differences were noted at 6 and 12 weeks for the subjective global assessment score, which favored the use of the automated delivery system over the standard injection technique (6 weeks, P = .029; 12 weeks, P = .028). Between the two injection procedures, there was no difference in pain experienced by the patient (mean Visual Analog Scale pain score ± SEM: group A, 34.9 ± 6.49; group B, 34.5 ± 5.99; P = .960). Body mass index did not influence pain associated with an intra-articular hip injection (P = .870); however, younger patient age was found to be an independent predictor of increased pain associated with injection (P = .011). Although there were no differences among male or female patients in hip injection pain based on the delivery method, statistically significant differences were encountered between male and female patients, irrespective of treatment assignment (male/female: group A, 25.1/41.4; group B, 26.7/46.1; P= .049). Among patients with a smoking history, large differences were noted for injection pain when data for both groups were pooled, regardless of the delivery method (no history, 30.0 ± 4.86; smoking history, 40.8 ± 9.94). Clinical efficiency (as measured by injection preparation time) was found to be inferior for the automated system compared to traditional syringe injection (P < .0001).

CONCLUSIONS

Use of an automated delivery system for US-guided intra-articular hip injections did not show superior efficiency or patient comfort over traditional syringe injections. Intra-articular corticosteroid injections led to clinically and statistically significant improvements in pain and function for patients with intra-articular hip pain, irrespective of the delivery method. Smoking history and female sex were independent predictors of increased pain associated with intra-articular hip joint injections.

A comparison of opioid use between WCB recipients and other Manitobans for knee, shoulder, back and carpal tunnel release procedures

BACKGROUND

This study's objectives were to evaluate whether WCB claimants with conditions requiring certain surgical procedures are more likely to be prescribed outpatient opioids than other Manitobans and whether those prescribed opioids are more likely to still be on opioid medications 6 months post procedure.

METHODS

We compared 7,246 WCB claims for a number of surgical procedures to 65,032 similar procedures performed in other Manitobans. Logistic regression was used to explore the association between being a WCB claimant and being prescribed opioids, while controlling for type of surgical procedure and other potential confounders.

RESULTS

WCB claimants were more likely than other Manitobans to be prescribed opioids (adjusted OR 1.38; 95%CI 1.30-1.47). Amongst those prescribed opioids, the odds of being still on opioids 6 months post-procedure were not significantly elevated for WCB claimants (adjusted OR 1.09 95%CI 0.97-1.23).

CONCLUSIONS

WCB claimants are prescribed opioids more often than non-claimants for similar procedures.

What Risk Factors Are Associated With Musculoskeletal Injury in US Army Rangers? A Prospective Prognostic Study

BACKGROUND

Musculoskeletal injury is the most common reason that soldiers are medically not ready to deploy. Understanding intrinsic risk factors that may place an elite soldier at risk of musculoskeletal injury may be beneficial in preventing musculoskeletal injury and maintaining operational military readiness. Findings from this population may also be useful as hypothesis-generating work for particular civilian settings such as law enforcement officers (SWAT teams), firefighters (smoke jumpers), or others in physically demanding professions.

QUESTIONS/PURPOSES

The purposes of this study were (1) to examine whether using baseline measures of self-report and physical performance can identify musculoskeletal injury risk; and (2) to determine whether a combination of predictors would enhance the accuracy for determining future musculoskeletal injury risk in US Army Rangers.

METHODS

Our study was a planned secondary analysis from a prospective cohort examining how baseline factors predict musculoskeletal injury. Baseline predictors associated with musculoskeletal injury were collected using surveys and physical performance measures. Survey data included demographic variables, injury history, and biopsychosocial questions. Physical performance measures included ankle dorsiflexion, Functional Movement Screen, lower and upper quarter Y-balance test, hop testing, pain provocation, and the Army Physical Fitness Test (consisting of a 2-mile run and 2 minutes of sit-ups and push-ups). A total of 320 Rangers were invited to enroll and 211 participated (66%). Occurrence of musculoskeletal injury was tracked for 1 year using monthly injury surveillance surveys, medical record reviews, and a query of the Department of Defense healthcare utilization database. Injury surveillance data were available on 100% of the subjects. Receiver operator characteristic curves and accuracy statistics were calculated to identify predictors of interest. A logistic regression equation was then calculated to find the most pertinent set of predictors. Of the 188 Rangers (age, 23.3 ± 3.7 years; body mass index, 26.0 ± 2.4 kg/m(2)) remaining in the cohort, 85 (45.2%) sustained a musculoskeletal injury of interest.

RESULTS

Smoking, prior surgery, recurrent prior musculoskeletal injury, limited-duty days in the prior year for musculoskeletal injury, asymmetrical ankle dorsiflexion, pain with Functional Movement Screen clearing tests, and decreased performance on the 2-mile run and 2-minute sit-up test were associated with increased injury risk. Presenting with one or fewer predictors resulted in a sensitivity of 0.90 (95% confidence interval [CI], 0.83-0.95), and having three or more predictors resulted in a specificity of 0.98 (95% CI, 0.93-0.99). The combined factors that contribute to the final multivariable logistic regression equation yielded an odds ratio of 4.3 (95% CI, 2.0-9.2), relative risk of 1.9 (95% CI, 1.4-2.6), and an area under the curve of 0.64.

CONCLUSIONS

Multiple factors (musculoskeletal injury history, smoking, pain provocation, movement tests, and lower scores on physical performance measures) were associated with individuals at risk for musculoskeletal injury. The summation of the number of risk factors produced a highly sensitive (one or less factor) and specific (three or more factors) model that could potentially be used to effectively identify and intervene in those persons with elevated risk for musculoskeletal injury. Future research should establish if screening and intervening can improve musculoskeletal health and if our findings among US Army Rangers translate to other occupations or athletes.

LEVEL OF EVIDENCE

Level II, prognostic study.

The Influence of No Fault Compensation on Functional Outcomes After Lumbar Spine Fusion

STUDY DESIGN

Prospective cohort study and systematic literature review.

OBJECTIVE

To compare the functional outcomes for lumbar spinal fusion in both compensation and noncompensation patients in an environment of universal no fault compensation and then to compare these outcomes with those in worker's compensation and nonworkers compensation cohorts from other countries.

SUMMARY OF BACKGROUND DATA

Compensation has an adverse effect on outcomes in spine fusion possibly based on adversarial environment, delayed resolution of claims and care, and increased compensation associated with prolonged disability. It is unclear whether a universal no fault compensation system would provide different outcomes for these patients. New Zealand's Accident Compensation Corporation (ACC) provides universal no fault compensation for personal injury secondary to accident and offers an opportunity to compare results with differing provision of compensation.

METHODS

A total of 169 patients undergoing lumbar spinal fusion were assessed preoperatively, at 1 year, and at long-term follow-up out to 14 years, using functional outcome measures and health-related quality-of-life measures. Comparison was made between those covered and not covered by ACC for 3 distinct diagnostic categories. A systematic literature review comparing outcomes in Worker's Compensation and non-Compensation cohorts was also performed.

RESULTS

The functional outcomes for both ACC and non-ACC cohorts were similar, with significant and comparable improvements over the first year that were then sustained out to long-term follow-up for both cohorts. At long-term follow-up, the health-related quality-of-life measures were the same between the 2 cohorts.The literature review revealed a marked difference in outcomes between worker's compensation and non-worker's compensation cohorts with a near universal inferior outcome for the compensation group.

CONCLUSION

The similarities in outcomes of patients undergoing lumbar spine fusion under New Zealand's universal no fault compensation system, when compared with the dramatically inferior outcomes for these patients under other worker's compensation systems, suggest that the system of compensation has a major influence on patient outcomes, and that change of compensation to a universal no fault system is beneficial for patients undergoing lumbar fusion surgery.

LEVEL OF EVIDENCE

2.

The Impact of Worker's Compensation Claims on Outcomes and Costs Following an Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective matched pair cohort analysis using a prospectively maintained registry.

OBJECTIVE

To describe the findings associated with workers' compensation (WC) claimants in regard to surgical outcomes, costs, and reimbursement after a 1- or 2- level anterior cervical discectomy and fusion.

SUMMARY OF BACKGROUND DATA

WC patients are perceived to demonstrate poor surgical outcomes and greater health care expenditure than more traditional patients. This study aims to evaluate the perceived differences in financial costs between patients with and without WC insurance.

METHODS

A retrospective analysis of 352 patients who underwent a primary 1- or 2- level anterior cervical discectomy and fusion for degenerative spinal etiologies between 2007 and 2013 by a single surgeon was performed. Patients were stratified on the basis of the payer status (WC vs. non-WC). Demographics, Charlson Comorbidity Index scores, smoking status, pre- and postoperative Visual Analogue Scale (VAS) scores, procedural time, estimated blood loss, hospital length of stay, complications, and revisions/reoperations were assessed between cohorts. The 1-year arthrodesis rate was also evaluated via computed tomography. Two cohorts of 30 patients were then matched for the number of fusion levels, smoking, and Charlson Comorbidity Index scores to compare hospital costs and reimbursements. All financial data were reported as a ratio of non-WC to WC payment/charges to protect hospital-sensitive financial data. Statistical analysis was performed using the independent sample t test for continuous variables and χ analysis for categorical data. An α level of less than 0.05 denoted statistical significance.

RESULTS

A total of 352 patients were included in this study of which 132 (37.5%) carried WC as the primary payer. The WC cohort was significantly younger (45.2 ± 8.5 vs. 52.9 ± 11.9, P < 0.001) and demonstrated a reduced comorbidity burden (2.3 ± 1.2 vs. 3.4 ± 1.7, P < 0.001) compared with non-WC patients. In addition, the WC cohort consisted of a significantly greater proportion of males, non-Caucasians, and active tobacco users. The preoperative VAS score, number of fusion levels, procedural time, and hospital length of stay did not significantly vary between cohorts. The 6-month VAS scores (3.2 ± 2.9 vs. 2.3 ± 2.4, P < 0.05), pseudarthrosis rates (7.6% vs. 0.9%, P < 0.001), revision/reoperations (12.9% vs. 2.7%, P < 0.001), and smoking rates (29.8% vs. 20.5%, P < 0.05) were significantly increased among WC payers. The difference in the total charges for anterior cervical discectomy and fusion between the WC cohort and the non-WC cohort was not statistically significant. The costs associated with implants, anesthesia, operating room, and in-hospital therapy were comparable between cohorts. The WC cohort was associated with a 282% higher reimbursement rate than the non-WC cohort (P < 0.001).

CONCLUSION

The WC cohort demonstrated lower clinical improvement, reduced 1-year arthrodesis rate, and an increased incidence of revision/reoperations when compared with non-WC patients. The greater proportion of smokers and increased occupational demands within the WC cohort may help explain these findings. Reimbursement rates were significantly higher in the WC patients. However, costs to the health care system during the acute hospitalization period (implants, operating room resources, postoperative care, and therapy) were similar between cohorts.

LEVEL OF EVIDENCE

3.

Proportion of opioid use due to compensated workers' compensation claims in Manitoba, Canada

Background

This study identifies the percentage of opioids prescribed for compensated workplace conditions in Manitoba, Canada and whether Workers Compensation Board (WCB) status is associated with higher prescription opioid doses.

Methods

Opioid prescriptions for WCB recipients were linked with databases housed at the Manitoba Center for Health Policy. Duration of continuous opioid prescription and morphine equivalents (ME) per day (ME/D) were calculated for individuals age 18–65.

Results

Over the period from 1998 to 2010, 3.8% of the total opioid dosage of medication prescribed in the study population were prescribed to WCB recipients. WCB recipients accounted for 2.1% of the individuals prescribed opioids. In adjusted analyses WCB recipients were more likely to be prescribed over 120 ME/D (OR 2.06 95% CI, 1.58–2.69).

Conclusions

WCB recipients account for a small, but significant amount of the total opioid prescribed in Manitoba. Manitoba's WCB population is a group at increased risk of being prescribed over 120 ME/day. Am. J. Ind. Med. 58:33–39, 2015. © 2014 The Authors. American Journal of Industrial Medicine Published by Wiley Periodicals, Inc.

Pain and carpal tunnel syndrome

PURPOSE

Pain is not a classical symptom of carpal tunnel syndrome (CTS), with the exception of numbness that is so intense that it is described by patients as painful. The primary aim of our study was to determine which factors correlated with pain for patients diagnosed with CTS.

METHODS

We prospectively assessed all patients diagnosed with CTS in our unit over a 1-year period. We recorded demographic details for all patients, including past medical history, body mass index, smoking, and occupation. The diagnosis and severity of carpal tunnel syndrome were established through a combination of history, clinical assessment, and nerve conduction studies. Of 275 patients diagnosed and treated for CTS, 183 were women (67%), the mean age was 55 years (range, 22-87 y), and 166 cases were bilateral (60%). The mean body mass index was 29.5 kg/m2 (range, 17-48 kg/m2), and 81 patients smoked (30%). Patients completed a Short Form-McGill pain questionnaire (SF-MPQ) as a measure of pain at initial presentation. We assessed outcome 1 year after intervention using the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score.

RESULTS

We found no association between pain according to the SF-MPQ and the positive clinical signs of CTS or positive nerve conduction studies. Multivariate analysis demonstrated that smoking and bilateral disease independently correlated with the overall SF-MPQ, with similar findings on subanalysis. Independent factors associated with an increased improvement in the QuickDASH at 1 year were the presentation QuickDASH score, positive nerve conduction studies, and smoking.

CONCLUSIONS

The only independent factors that correlated with pain at presentation of CTS were smoking and bilateral disease. Pain according to the SF-MPQ was not associated with classical clinical findings of the disease or with positive findings on nerve conduction testing.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.