Chondroitin sulfate proteoglycan 4 expression in chondrosarcoma: A potential target for antibody-based immunotherapy

Chondrosarcoma is a common primary bone malignancy whose phenotype increases with its histologic grade. They are relatively resistant to chemotherapy and radiation therapy limiting curative options for disseminated disease. Chondroitin sulfate proteoglycan 4 (CSPG4) is a cell surface proteoglycan that is highly expressed across various human cancers, including chondrosarcoma, and has restricted distribution in healthy tissues, making it an attractive target for the antibody-based therapy. CSPG4 specific chimeric antigen receptor (CAR) T cell therapies have been shown to be effective in treating other cancers such as melanoma and triple negative breast cancer. The goal of this study was to assess the prevalence of CSPG4 in human chondrosarcoma and to assess the efficacy of CSPG4 specific CAR T cells in lysing chondrosarcoma cells in vitro. Using immunohistochemistry (IHC), we stained a tissue microarray containing primary conventional and dedifferentiated chondrosarcoma from 76 patients with CSPG4 specific monoclonal antibodies (mAbs). In addition, we incubated 2 chondrosarcoma cell lines with CSPG4-targeting CAR T cells and subsequently evaluated cell survival. Our results showed medium to high expression of CSPG4 in 29 of 41 (71%) conventional chondrosarcoma tumors and in 3 of 20 (15%) dedifferentiated chondrosarcoma tumors. CSPG4 expression showed a positive association with time to metastasis and survival in both subtypes. CSPG4 CAR T treated cell lines showed a lysis of respectively >80% and 70% demonstrating CSPG4-targeted CAR T cells effective in killing CSPG4-positive chondrosarcoma tumors.

High TIL, HLA, and Immune Checkpoint Expression in Conventional High-Grade and Dedifferentiated Chondrosarcoma and Poor Clinical Course of the Disease

Purpose

The aim of this study was to characterize chondrosarcoma tumor infiltration by immune cells and the expression of immunologically relevant molecules. This information may contribute to our understanding of the role of immunological events in the pathogenesis of chondrosarcoma and to the rational design of immunotherapeutic strategies.

Patients and Methods

A tissue microarray (TMA) containing 52 conventional and 24 dedifferentiated chondrosarcoma specimens was analyzed by immunohistochemical staining for the expression of parameters associated with tumor antigen-specific immune responses, namely, CD4⁺ and CD8⁺ tumor infiltrating lymphocytes (TILs) and the expression of HLA class I heavy chain, beta-2 microglobulin (β2m), HLA class II and immune checkpoint molecules, B7-H3 and PD-1/PD-L1. The results were correlated with histopathological characteristics and the clinical course of the disease.

Results

CD8⁺ TILs were present in 21% of the conventional and 90% of the dedifferentiated chondrosarcoma tumors tested. B7-H3 was expressed in 69% of the conventional and 96% of the dedifferentiated chondrosarcoma tumors tested. PD-1 and PD-L1 were expressed 53% and 33% respectively of the dedifferentiated tumors tested. PD-L1 expression was associated with shorter time to metastasis.

Conclusion

The tumor infiltration by lymphocytes suggests that chondrosarcoma is immunogenic. Defects in HLA class I antigen and expression of the checkpoint molecules B7-H3 and PD-1/PD-L1 suggest that tumor cells utilize escape mechanisms to avoid immune recognition and destruction. This data implies that chondrosarcoma will benefit from strategies that enhance the immunogenicity of tumor antigens and/or counteract the escape mechanisms.

Functional and oncological outcome after surgical resection of the scapula and clavicle for primary chondrosarcoma

PURPOSE

The scapula is a relatively common site for chondrosarcoma to develop in contrary to the clavicle, which is rarely affected by these tumors. The aim of this study is to determine the functional and oncological outcome for patients treated operatively for scapular or clavicular chondrosarcoma.

METHODS

In this single-center retrospective study, we included a sample of 20 patients that received the diagnosis of a primary chondrosarcoma of the scapula or clavicle. Of the surviving patients, the functional function was assessed using the DASH and the PROMIS Physical Function-Upper Extremity. Patients were longitudinally tracked for their oncological outcome.

RESULTS

All patients were followed for at least 2 years or until death. The mean age of the cohort was 47 years. Eighteen patients suffered from a chondrosarcoma of the scapula, and in 2 patients, the tumor was located in the clavicle. Metastasis, local recurrence and a higher tumor grade were all associated with a decreased overall survival. For the patients with a chondrosarcoma of the scapula, the average DASH score was 16 ± 16 and the mean PROMIS Physical Function-Upper Extremity score was 48 ± 10. Patients with both an intact rotator cuff and glenoid had a better physical function.

CONCLUSIONS

Upper extremity function after (partial) scapulectomy varied depending on whether the glenoid was spared and whether a functioning shoulder abductor remained. When the resection spared these structures, then excellent functional outcomes were reported. Oncologic outcomes depended upon the grade of the tumor and whether local recurrence and metastases occurred.

The Association of Complementary Health Approaches With Mood and Coping Strategies Among Orthopedic Patients

Background: Variation in pain intensity and magnitude of disability among patients with musculoskeletal illness is largely accounted for by variations in symptoms of depression, catastrophic thinking, and heightened illness concern. It is possible that patients with greater stress, distress, and less effective coping strategies might be more likely to seek the use of Complementary Health Approaches (CHA). This study addressed the primary null hypothesis that there are no demographic, illness-related, or psychological factors associated with CHA use among patients with upper extremity illness. Methods: A cohort of 170 patients completed a web-based Complementary and Alternative Medicine (CAM) questionnaire the Patient Reported Outcomes Measurement Information System (PROMIS) Depression and Pain Interference questionnaires. We evaluated differences between patients who sought CAM treatment regarding the PROMIS Pain Interference and PROMIS Depression scores. Ninety-four patients (56%) use or plan to use CAM treatment. A CAM provider was consulted by 61 patients (37%): most commonly a massage therapist (30/61), chiropractor (26/61), or acupuncturist (14/61). Results: In bivariate analysis patients who sought CAM reported greater average PROMIS Pain Interference than those who did not. In multivariable logistic regression, CAM use was associated with a higher Pain Interference Score and the specific surgeon. Conclusion: In conclusion, CHA use is prevalent amongst orthopaedic patients and associated with less effective coping strategies. Orthopaedic surgeons might consider asking patients about CHA use and determining whether those patients are interested in cognitive behavioral therapy.

Is Social Support Associated With Upper Extremity Disability?

BACKGROUND

Pain intensity and disability correlate with psychosocial factors such as depression and pain interference (the degree to which pain interferes with activities of daily living) as much or more than pathophysiology in upper extremity illness. However, other factors like emotional support (perception of being cared for and valued as a person), instrumental support (perception of availability of tangible assistance when needed), positive psychosocial impact (perception and focus on the positive side of a difficult situation, sometimes characterized as posttraumatic growth, benefit-finding, or meaning making), also might be associated with disability in patients with upper extremity orthopaedic illness. This is the first published study, to our knowledge, addressing the potential association of emotional support, instrumental support, and positive psychosocial illness impact with disability in patients with upper extremity illness.

QUESTIONS/PURPOSES

We asked: (1) Is there a correlation between the QuickDASH and the Patient-reported Outcomes Measurement Information System (PROMIS(®)) emotional support Computer Adaptive Testing (CAT)? (2) Is there a correlation between the QuickDASH and PROMIS(®) instrumental support CAT? (3) Is there a correlation between the QuickDASH and PROMIS(®) positive psychosocial illness impact CAT? (4) Among the PROMIS(®) measures of depression, emotional support, instrumental support, positive illness impact, and pain interference, which accounts for the most variance in QuickDASH scores?

METHODS

One hundred ninety-three patients with upper extremity illness (55% women; average age, 51 ± 18 years) of 213 approached (91% recruitment rate) completed the QuickDASH, and five different PROMIS(®) CATs: pain interference (the degree to which pain interferes with accomplishing one's goals), depression, emotional support, psychosocial illness impact, and instrumental support. We recruited patients from the practice of three surgeons in hand service of the department of orthopaedic surgery at a major urban university hospital.

RESULTS

Pearson Product Moment Correlations showed that emotional support (r = -0.18; p = 0.014) and instrumental support (r = -0.19; p = 0.008) were weakly and inversely associated with the QuickDASH), while positive psychosocial illness impact was moderately and inversely associated with the QuickDASH (r = -0.36; p < 0.001). In multivariable analyses, pain interference, but not the social support measures, was the only psychosocial factor associated with the QuickDASH and alone explained 66% of variance.

CONCLUSIONS

Emotional support, instrumental support and positive psychosocial illness impact are all individually associated with disability to a small degree, but pain interference (the degree to which pain interferes with accomplishing one's goals) has the strongest influence on magnitude of disability.

LEVEL OF EVIDENCE

Level 1, prognostic study.

Progression of Heterotopic Ossification around the Elbow after Trauma

BACKGROUND

This study addresses the null hypothesis that there is no expansion of heterotopic ossification (HO) in the elbow beyond what can be seen early on.

METHODS

The area of HO was measured on lateral radiographs of 38 consecutive patients that had operative treatment of HO between 2000 and 2013. Measurements from radiographs obtained between 3 to 7 weeks were compared to measurements from radiographs made 3 months or more after injury.

RESULTS

There was no significant difference between the average area of HO on the first (median 2.8 square centimeters, Q1: 1.5, Q3: 5.1) and later radiographs (median of 2.8 square centimeters, Q1: 1.4, Q3: 5.0) (P = 0.99).

CONCLUSION

According to our results the area of HO does not expand beyond what can be seen early in the disease process.

Incidence of surgical site infection after spine surgery: what is the impact of the definition of infection?

BACKGROUND

Orthopaedic surgical site infections (SSIs) can delay recovery, add impairments, and decrease quality of life, particularly in patients undergoing spine surgery, in whom SSIs may also be more common. Efforts to prevent and treat SSIs of the spine rely on the identification and registration of these adverse events in large databases. The effective use of these databases to answer clinical questions depends on how the conditions in question, such as infection, are defined in the databases queried, but the degree to which different definitions of infection might cause different risk factors to be identified by those databases has not been evaluated.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether different definitions of SSI identify different risk factors for SSI. Specifically, we compared the International Classification of Diseases, 9th Revision (ICD-9) coding, Centers for Disease Control and Prevention (CDC) criteria for deep infection, and incision and débridement for infection to determine if each is associated with distinct risk factors for SSI.

METHODS

In this single-center retrospective study, a sample of 5761 adult patients who had an orthopaedic spine surgery between January 2003 and August 2013 were identified from our institutional database. The mean age of the patients was 56 years (± 16 SD), and slightly more than half were men. We applied three different definitions of infection: ICD-9 code for SSI, the CDC criteria for deep infection, and incision and débridement for infection. Three hundred sixty-one (6%) of the 5761 surgeries received an ICD-9 code for SSI within 90 days of surgery. After review of the medical records of these 361 patients, 216 (4%) met the CDC criteria for deep SSI, and 189 (3%) were taken to the operating room for irrigation and débridement within 180 days of the day of surgery.

RESULTS

We found the Charlson Comorbidity Index, the duration of the operation, obesity, and posterior surgical approach were independently associated with a higher risk of infection for each of the three definitions of SSI. The influence of malnutrition, smoking, specific procedures, and specific surgeons varied by definition of infection. These elements accounted for approximately 6% of the variability in the risk of developing an infection.

CONCLUSIONS

The frequency of SSI after spine surgery varied according to the definition of an infection, but the most important risk factors did not. We conclude that large database studies may be better suited for identifying risk factors than for determining absolute numbers of infections.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Patients with greater symptom intensity and more disability are more likely to be surprised by a hand surgeon's advice

BACKGROUND

A clash between a patient's assumptions and a doctor's advice can feel adversarial which might influence satisfaction ratings and compliance with treatment recommendations. A better understanding of sources of patients' bewilderment might lead to improved strategies for conveying counterintuitive information that improve patient comfort and wellbeing.

QUESTIONS/PURPOSES

This study addressed the following questions: (1) Are magnitude of disability, pain intensity, symptoms of depression, or health anxiety associated with a higher level of surprise when a patient is presented with diagnostic information and/or therapeutic recommendations? (2) Does the surgeon accurately perceive the patient's bewilderment? (3) Does the surgeon's perception of patient bewilderment correlate with diagnosis or a patient's magnitude of disability, pain intensity, symptoms of depression, or health anxiety?

PATIENTS AND METHODS

In this prospective cohort study, we invited new patients who met prespecified criteria during a 3-month period in one hand-surgery practice to enroll; of 93 patients invited, 84 (90%) agreed to participate. Patients reported demographics and completed the short versions of the DASH questionnaire (QuickDASH), the Patient Health Questionnaire, the Pain Self-Efficacy Questionnaire, and the Short Health Anxiety Inventory; rated their pain intensity; and rated the degree to which the information given by the surgeon was unexpected or surprising on an 11-point ordinal scale. The surgeon also rated his impression of the patient's surprise on an 11-point ordinal scale.

RESULTS

Only greater symptom intensity and magnitude of disability (QuickDASH) correlated with greater unexpected information when rated by the patient (ß = 0.058; p < 0.001). There was a correlation between patient surprise and the surgeon's perception of the patient's surprise (r = 0.58; p < 0.001). Greater surgeon-perceived patient surprise correlated with nonspecific illness (p = 0.007; ß = 3.0).

CONCLUSIONS

Patients with greater symptom intensity and magnitude of disability, and perhaps also patients with nonspecific diagnoses, are more likely to be surprised by a hand surgeon's advice. Future research might address the ability of previsit preparation (using decision aids or other alternative means of education) to ameliorate the discordance between patient assumptions and hand surgeon advice.

Disability and depression after orthopaedic trauma

INTRODUCTION

Musculoskeletal injury is a common cause of impairment (pathophysiology), but the correlation of impairment with pain intensity and magnitude of disability is limited. Psychosocial factors explain a large proportion of the variance in disability for various orthopaedic pathologies. The aim of this study is to prospectively assess the relationship between psychological factors and magnitude of disability in a sample of orthopaedic trauma patients in The Netherlands.

MATERIAL AND METHODS

One hundred and one adult patients between 1 and 2 months after one or more fractures, tendon or ligament injuries were enrolled. Four eligible patients refused to participate. Thirty-five women and 30 men with an average age of 50 years (range, 22-92 years) completed the follow-up evaluation between 5 and 8 months after their injury and their data was analyzed. The patients completed a measure of disability (the Short Musculoskeletal Function Assessment-Netherlands, SMFA-NL), the Dutch Centre for Epidemiologic Study of Depression-scale (CES-D), the Dutch Impact of Event Scale (SVL), and the Dutch Pain Catastrophizing Scale (PCS) at the time of enrollment and again 5-8 months after injury.

RESULTS

There were moderate correlations between symptoms of depression (CES-D, r=0.48, p<0.001) and symptoms of PTSD (SVL, r=0.35, p=0.004) at enrollment and magnitude of disability 5-8 months after trauma. Catastrophic thinking (PCS) at enrollment and magnitude of disability 5-8 months after trauma showed a small correlation (PCS, r=0.26, p=0.034). The Pain Catastrophizing Scale (Beta=0.29; p=0.049), surgery (Beta=0.26; p=0.034), additional surgery (Beta=0.26; p=0.019) and other pain conditions (Beta=0.31; p=0.009) were the significant predictors in the final model (adjusted R-squared=0.35; p<0.001) for greater disability 5-8 months after trauma.

DISCUSSION AND CONCLUSIONS

In The Netherlands, symptoms of depression measured 1-2 months after musculoskeletal trauma correlate with disability 5-8 months after this trauma. The psychological aspects of recovery from musculoskeletal injury merit greater attention.

LEVEL OF EVIDENCE

Level II, Prognostic study.

Do corresponding authors take responsibility for their work? A covert survey

BACKGROUND

Publication of a manuscript does not end an author's responsibilities. Reasons to contact an author after publication include clarification, access to raw data, and collaboration. However, legitimate questions have been raised regarding whether these responsibilities generally are being met by corresponding authors of biomedical publications.

QUESTIONS/PURPOSES

This study aims to establish (1) what proportion of corresponding authors accept the responsibility of correspondence; (2) identify characteristics of responders; and (3) assess email address decay with time. We hypothesize that the response rate is unrelated to journal impact factor.

METHODS

We contacted 450 corresponding authors throughout various fields of biomedical research regarding the availability of additional data from their study, under the pretense of needing these data for a related review article. Authors were randomly selected from 45 journals whose impact factors ranged from 52 to 0; the source articles were published between May 2003 and May 2013. The proportion of corresponding authors who replied, along with author characteristics were recorded, as was the proportion of emails that were returned for inactive addresses; 446 authors were available for final analysis.

RESULTS

Fifty-three percent (190/357) of the authors with working email addresses responded to our request. Clinical researchers were more likely to reply than basic/translational scientists (51% [114/225] versus 34% [76/221]; p<0.001). Impact factor and other author characteristics did not differ. Logistic regression analysis showed that the odds of replying decreased by 15% per year (odds ratio [OR], 0.85; 95% CI, 0.79-0.91; p<0.001), and showed a positive relationship between clinical research and response (OR, 2.0; 95% CI, 1.3-2.9; p=0.001). In 2013 all email addresses (45/45) were reachable, but within 10 years, 49% (21/43) had become invalid.

CONCLUSIONS

Our results suggest that contacting corresponding authors is problematic throughout the field of biomedical research. Defining the responsibilities of corresponding authors by journals more explicitly-particularly after publication of their manuscript-may increase the response rate on data requests. Possible other ways to improve communication after research publication are: (1) listing more than one email address per corresponding author, eg, an institutional and personal address; (2) specifying all authors' email addresses; (3) when an author leaves an institution, send an automated reply offering alternative ways to get in touch; and (4) linking published manuscripts to research platforms.

The PROMIS physical function correlates with the QuickDASH in patients with upper extremity illness

BACKGROUND

To assess disability more efficiently with less burden on the patient, the National Institutes of Health has developed the Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function-an instrument based on item response theory and using computer adaptive testing (CAT). Initially, upper and lower extremity disabilities were not separated and we were curious if the PROMIS Physical Function CAT could measure upper extremity disability and the Quick Disability of Arm, Shoulder and Hand (QuickDASH).

QUESTIONS/PURPOSES

We aimed to find correlation between the PROMIS Physical Function and the QuickDASH questionnaires in patients with upper extremity illness. Secondarily, we addressed whether the PROMIS Physical Function and QuickDASH correlate with the PROMIS Depression CAT and PROMIS Pain Interference CAT instruments. Finally, we assessed factors associated with QuickDASH and PROMIS Physical Function in multivariable analysis.

METHODS

A cohort of 93 outpatients with upper extremity illnesses completed the QuickDASH and three PROMIS CAT questionnaires: Physical Function, Pain Interference, and Depression. Pain intensity was measured with an 11-point ordinal measure (0-10 numeric rating scale). Correlation between PROMIS Physical Function and the QuickDASH was assessed. Factors that correlated with the PROMIS Physical Function and QuickDASH were assessed in multivariable regression analysis after initial bivariate analysis.

RESULTS

There was a moderate correlation between the PROMIS Physical Function and the QuickDASH questionnaire (r=-0.55, p<0.001). Greater disability as measured with the PROMIS and QuickDASH correlated most strongly with PROMIS Depression (r=-0.35, p<0.001 and r=0.34, p<0.001 respectively) and Pain Interference (r=-0.51, p<0.001 and r=0.74, p<0.001 respectively). The factors accounting for the variability in PROMIS scores are comparable to those for the QuickDASH except that the PROMIS Physical Function is influenced by other pain conditions while the QuickDASH is not.

CONCLUSIONS

The PROMIS Physical Function instrument may be used as an upper extremity disability measure, as it correlates with the QuickDASH questionnaire, and both instruments are influenced most strongly by the degree to which pain interferes with achieving goals.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.

Differences in response rates between mail, e-mail, and telephone follow-up in hand surgery research

BACKGROUND

There is a need to determine the difference in response to mail, e-mail, and phone in clinical research surveys.

METHODS

We enrolled 150 new and follow-up patients presenting to our hand and upper extremity department. Patients were assigned to complete a survey by mail, e-mail, or phone 3 months after enrollment, altering the follow-up method every 5 patients, until we had 3 groups of 50 patients. At initial enrollment and at 3 month follow-up (range 2-5 months), patients completed the short version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH), the short version of the Patient Health Questionnaire (PHQ-2), the Pain Self-Efficacy Questionnaire (PSEQ), and rated their pain intensity.

RESULTS

The percent of patients that completed the survey was 34 % for mail, 24 % for e-mail, and 80 % for phone. Factors associated with responding to the survey were older age, nonsmoking, and lower pain intensity. Working full-time was associated with not responding.

CONCLUSIONS

The response rate to survey by phone is significantly higher than by mail or e-mail. Younger age, smoking, higher pain intensity, and working full-time are associated with not responding.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

Heterotopic Ossification around the Knee after Internal Fixation of a Complex Tibial Plateau Fracture Combined with the Use of Demineralized Bone Matrix (DBM): A Case Report

Demineralized bone matrix has been successfully commercialized as an alternative bone graft material that not only can function as filler but also as an osteoinductive graft. Numerous studies have confirmed its beneficial use in clinical practice. Heterotopic ossification after internal fixation combined with the use of demineralized bone matrix has not been widely reported. In this paper we describe a 39 year old male who sustained a complex articular fracture that developed clinically significant heterotopic ossification after internal fixation with added demineralized bone matrix. Although we cannot be sure that there is a cause-and-effect relation between demineralized bone matrix and the excessive heterotopic ossification seen in our patient, it seems that some caution in using demineralised bone matrix in similar cases is warranted. Also, given the known inter- and intraproduct variability, the risks and benefits of these products should be carefully weighed.

Opioid Use, Satisfaction, and Pain Intensity After Orthopedic Surgery

BACKGROUND

Patients in other countries use fewer opioids than patients in the United States with satisfactory pain relief.

OBJECTIVE

This study tested the null hypothesis that opioid intake after orthopedic surgery does not influence satisfaction with pain management.

METHODS

A total of 232 orthopedic surgical inpatients completed measures of pain self-efficacy and symptoms of depression at enrollment and commonly used measures of pain intensity, satisfaction with pain relief, and satisfaction with hospital staff attention to pain approximately 14 days after surgery. Inpatient opioid intake per 24-hour period was quantified.

RESULTS

At a phone evaluation approximately 2 weeks after discharge from the hospital, patients who were always satisfied with their pain relief in hospital and always satisfied with staff attention to pain used significantly less opioids on day 1 compared with patients who were not always satisfied. There were no differences in satisfaction by type of surgery. The final multivariable model for not always satisfied with pain relief included greater opioid use on day 1 (odds ratio = 1.2), and preadmission diagnosis of depression (odds ratio = 2.6). Greater opioid use on day 1 was the only factor associated with less than always satisfied with the staff attention to pain relief (odds ratio = 1.3).

CONCLUSIONS

Patients who take more opioids report less satisfaction with pain relief and greater pain intensity. Evidence-based interventions to increase self-efficacy merit additional study for the management of postoperative pain.

LEVEL OF EVIDENCE

Prognostic, Level 1.

Measurement of upper extremity disability using the Patient-Reported Outcomes Measurement Information System

PURPOSE

Current questionnaires used to measure upper extremity-specific disability can be time-consuming and subject to ceiling effects. The National Institutes of Health developed Patient-Reported Outcomes Measurement Information System (PROMIS) measures based on computer adaptive testing (CAT), a technique that is more efficient and less subject to floor and ceiling effects than traditional questionnaires with a fixed number of questions. This study tested the correlation of the Physical Function-Upper Extremity CAT with the Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire.

METHODS

Patients presenting to our orthopedic outpatient clinic were invited to participate in this observational cross-sectional study between August and October 2013. A study sample of 84 patients completed the QuickDASH and PROMIS Physical Function-Upper Extremity CAT, and 3 other PROMIS measures, as well as the 2-question Pain Self-efficacy Questionnaire and the 2-question Patient Health Questionnaire.

RESULTS

A strong correlation was found between QuickDASH and PROMIS Physical Function-Upper Extremity CAT, with a significantly shorter completion time for the latter.

CONCLUSIONS

We recommend the PROMIS Upper Extremity CAT because it is valid, reliable, and easy to use, and it provides easy reference to population norms (a score of 50 represents the norm in the United States population, and every 10 points represents a standard deviation from the norm).

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.