Reliability, responsiveness and interpretability of the neck disability index-Dutch version in primary care

Evaluating the effectiveness of patient-tailored treatment for patients with non-specific (sub)acute neck pain

BACKGROUND

An important issue in the debate about best practice management of non-specific neck pain (NSNP) is the effectiveness of tailored versus generalized interventions.

METHODS

Participants with (sub)acute NSNP were randomly allocated to a patient-tailored treatment (PTT), non-patient-tailored treatment (NPTT) or control group (no intervention). The outcome measures were pain (NPRS), disability (NDI), global perceived effect and satisfaction (GPES), productivity costs, and medical consumption. Patients were assessed at baseline, post-intervention, and at 3-, 6-, and 12-months post-intervention. Evolution of the complaints, treatment adherence, and medication intake was registered during the intervention period. Linear mixed models were used to examine interaction effects as well as between- and within-group differences.

RESULTS

Sixty-one participants were included. There was no "Group x Time"-interaction effect for all outcome measures. Nevertheless, all groups showed significant and clinically relevant within-group differences at all time points for pain and disability (p < 0.001). At 6 months follow-up, NPTT was superior to PTT for reductions in pain but not for disability. At 1 year, the number of responders in the NPTT group remained higher (75%) compared to the PTT group (40%).

CONCLUSION

This study found a significant and clinically relevant reduction of pain and disability within all groups. Patient-tailored treatment as well as NPTT can be considered an effective method when aiming for a reduction in pain and disability at short-term (12 weeks). However, NPTT seemed to be more effective at 1-year follow-up and therapists should consider spontaneous recovery. The results should be interpreted with caution and further research is warranted.

Psychometric properties of neck disability index - a systematic review and meta-analysis

PURPOSE

To evaluate the data on the psychometric properties of the Neck Disability Index (NDI).

MATERIALS AND METHODS

Medline, Embase, PsychINFO, Web of Science, and Scopus were searched in April 2023. The random effects meta-analysis was conducted when possible.

RESULTS

Of 492 identified records, 79 were included. 70 studies were considered to be of low risk of systematic bias. Alpha was >0.81. Pooled test-retest intraclass correlation coefficient was 0.91 (95% CI 0.90-0.93). The NDI correlations with pain rating scales varied from 0.38 to 0.89. 13 studies found the NDI to be unidimensional and 15 - two- or three-dimensional. The minimal detectable change varied from 3% to 27% and minimal clinically important difference from 5% to 33%. Pooled area under the curve was 0.74 (95% CI 0.68-0.80). Most studies have not detected floor or ceiling effect. Sex-related differential item functioning has been present in one study.

CONCLUSIONS

The NDI demonstrated good internal consistency and test-retest reliability without floor or ceiling effect. In most situations, the NDI could be considered a unidimensional scale. The NDI well correlated with the common scales of pain and disability. The minimal clinically important difference and minimal detectable change were around 15% (7.5/50 points).

Exercise-Induced Hypoalgesia in Patients with Chronic Whiplash-Associated Disorders: Differences between Subgroups Based on the Central Sensitization Inventory

BACKGROUND

Physical exercise is an important element in the rehabilitation of chronic whiplash-associated disorders, with the physiological process underlying pain reduction called exercise-induced hypoalgesia. In chronic whiplash-associated disorders, exercise-induced hypoalgesia appears impaired, and the research suggests a relationship with symptoms of dysfunctional nociceptive processing, such as central sensitization. This study improves our understanding of exercise-induced hypoalgesia in chronic whiplash-associated disorders by examining the differences between the extent of exercise-induced hypoalgesia in subgroups based on scores on the central sensitization inventory (CSI).

METHODS

Data were collected from 135 participants with chronic whiplash-associated disorders who completed a set of questionnaires. Pain pressure thresholds and temporal summations were assessed before and after a submaximal aerobic bicycle exercise test.

RESULTS

We observed no interaction effect between exercise-induced hypoalgesia and the CSI scores for both pain pressure threshold and temporal summation. No overall statistical effect was measured in the analysis of the effect of time. The pain pressure threshold significantly related to the CSI. The temporal summation showed no correlation.

CONCLUSIONS

During this study, we did not find evidence for a difference in the presence of exercise-induced hypoalgesia when the subgroups were created based on the central sensitization cluster calculator. Limited evidence was found for the influence of CSI scores on the delta pain pressure threshold.

Comparison between two patient-reported outcome measures for patients with cervical radiculopathy: A think-aloud study

BACKGROUND

The Cervical Radiculopathy Impact Scale (CRIS) and Patient Specific Functional Scale 2.0 (PSFS 2.0) are patient-reported outcome measures (PROMs) used to assess activity limitations in patients with cervical radiculopathy (CR). This study a) compared the CRIS subscale 3 and the PSFS 2.0 in patients with CR with respect to completeness and patient preference, b) established the correlation between both PROMs in assessing the individual patient's level of functional limitations and c) assessed the frequency of reported functional limitations.

METHODS

Participants with CR participated in semi-structured, individual, face-to-face interviews as part of a "think-aloud" process; verbalising their thoughts while completing both PROMs. Sessions were digitally recorded and transcribed verbatim for analysis.

RESULTS

Twenty-two patients were recruited. The most frequently reported functional limitation on the CRIS was: 'working at a computer' (n = 17) and overhead activities' (n = 10) for the PSFS 2.0. There was significant moderate positive correlation between the scores on the PSFS 2.0 and the CRIS (Spearman's r = 0.55, n = 22 p = .008). Most patients (n = 18; 82%) preferred the ability to present their own individual functional limitations of the PSFS 2.0. Eleven participants (50%) preferred the 11-point scale of the PSFS 2.0 over the 5-point Likert scale scoring option of the CRIS.

CONCLUSION

Both easy to complete PROMs capture functional limitations in patients with CR. Most patients prefer the PSFS 2.0 over the CRIS. The wording and layout of both PROMs need refinement to enhance user-friendliness and avoid misinterpretation.

Responsiveness of the German version of the Neck Disability Index in chronic neck pain patients: a prospective cohort study with a seven-week follow-up

Background

The need for an efficient and feasible strategy to deal with neck pain has a high priority for many countries. Validated assessment tools like the Neck Disability Index (NDI) to evaluate the functional status of a neck pain patient are urgently needed to treat and to follow-up patients purposefully. A German version (NDI-G) was shown to be valid and reliable, but has so far not been tested for responsiveness. The aim of this study was to evaluate the NDI-G`s responsiveness.

Methods

This was a prospective cohort study with a seven-week follow-up. Fifty chronic neck pain patients filled out NDI-G twice. Additionally, the Patients’ Global Impression of Change score (PGIC) was assessed at follow-up. Wilcoxon and Spearman tests were used to assess direction and strength of the association between the change in NDI-G and PGIC. The receiver operating characteristics method and the area under the curve (AUC) were calculated to assess sensitivity and specificity of the NDI-G change over time.

Results

The Wilcoxon test showed statistically significant differences for NDI-G at baseline and follow-up in the total sample, the “clinically improved” and “clinically not improved” subgroups as indicated in the PGIC. Spearman test resulted in a moderate correlation between the NDI-G and the PGIC (rS = -0.53, p = 0.01) at follow-up. AUC showed an acceptable discrimination [AUC = 0.78 (95% confidence interval 0.64 – 0.91)] of the NDI-G, with a cutoff score of 1.5, between clinically improved and clinically not improved patients, based on the PGIC.

Conclusions

The NDI-G is responsive to change in chronic neck pain. Together with the results of a previous study on its validity and reliability, the NDI-G can be recommended for research and clinical settings in patients with neck pain in German speaking countries.

Trial registration

NCT02676141. February 8, 2016.

External validation of prognostic models for recovery in patients with neck pain

Background

Neck pain is one of the leading causes of disability in most countries and it is likely to increase further. Numerous prognostic models for people with neck pain have been developed, few have been validated. In a recent systematic review, external validation of three promising models was advised before they can be used in clinical practice.

Objective

The purpose of this study was to externally validate three promising models that predict neck pain recovery in primary care.

Methods

This validation cohort consisted of 1311 patients with neck pain of any duration who were prospectively recruited and treated by 345 manual therapists in the Netherlands. Outcome measures were disability (Neck Disability Index) and recovery (Global Perceived Effect Scale) post-treatment and at 1-year follow-up. The assessed models were an Australian Whiplash-Associated Disorders (WAD) model (Amodel), a multicenter WAD model (Mmodel), and a Dutch non-specific neck pain model (Dmodel). Models’ discrimination and calibration were evaluated.

Results

The Dmodel and Amodel discriminative performance (AUC < 0.70) and calibration measures (slope largely different from 1) were poor. The Mmodel could not be evaluated since several variables nor their proxies were available.

Conclusions

External validation of promising prognostic models for neck pain recovery was not successful and their clinical use cannot be recommended. We advise clinicians to underpin their current clinical reasoning process with evidence-based individual prognostic factors for recovery. Further research on finding new prognostic factors and developing and validating models with up-to-date methodology is needed for recovery in patients with neck pain in primary care.

Changes in Muscle Morphology in Female Chronic Neck Pain Patients Using Magnetic Resonance Imaging

STUDY DESIGN

Population-based cross-sectional study.

OBJECTIVE

The aim of this study was to gain a better understanding of changes in muscle morphology in patients with chronic idiopathic neck pain (CINP) and chronic whiplash-associated disorder (CWAD).

SUMMARY OF BACKGROUND DATA

Worldwide, neck pain (NP) is a common health problem with high socioeconomic burden. A high percentage of these patients evolves toward chronic symptoms. Efficacy of treatments for these complaints remains variable. In current literature, changes in muscle morphology (muscle fat infiltration and cross-sectional area) have been reported in patients with NP, both CWAD and CINP. However, no strong conclusions could be made.

METHODS

In this study, magnetic resonance imaging was used to obtain data on muscle morphology from 14 cervical flexor and extensor muscles in 117 female subjects with NP (CWAD = 37; CINP = 45) and healthy controls (HC = 35).

RESULTS

The CWAD group had a significantly larger muscle fat infiltration in some extensor (semispinalis and splenius capitis, trapezius, obliquus capitis inferior) and flexor (sternocleidomastoid) muscles compared to the CINP and/or HC group. A significantly larger (muscle) cross-sectional area was found in some extensor (levator scapulae, semispinalis capitis, trapezius) and flexor (longus colli, longus capitis, sternocleidomastoid) muscles in the HC group compared to the CINP and/or CWAD group. No clear associations were found between group differences and factors as pain duration, kinesiophobia, and disability.

CONCLUSION

The results in this study suggest changes in muscle morphology in both NP cohorts. These results show some similarities with earlier findings in this research domain. Further studies based on controlled longitudinal designs are needed to facilitate data compilation, to draw stronger conclusions, and to integrate them into the treatment of patients with chronic NP.Level of Evidence: 4.

Enhanced amygdala-frontal operculum functional connectivity during rest in women with chronic neck pain: Associations with impaired conditioned pain modulation

BACKGROUND

Chronic neck pain is a leading cause of disability worldwide, affecting the lives of millions of people. Research investigating functional brain alterations in relation to somatosensory function is necessary to better understand mechanisms underlying pain development and maintenance in individuals with chronic neck pain, yet remains scarce. This case-control study aimed to examine resting-state functional connectivity alterations and associations with pain outcomes, self-reported central sensitization-related symptoms and quantitative sensory testing (QST) measures in patients with chronic non-traumatic (idiopathic/CINP) neck pain and chronic traumatic (whiplash associated/CWAD) neck pain compared to pain-free controls.

METHODS

Resting-state functional magnetic resonance images were acquired in 107 female participants (38 CINP, 37 CWAD, 32 healthy controls). After data pre-processing, seed-to-seed analyses were conducted focusing on resting-state functional connectivity involving pre-defined regions of interest that have previously been observed to be structurally or functionally altered and/or associated with pain-related measures in this patient population.

RESULTS

Findings demonstrate enhanced left amygdala functional coupling during rest with the left frontal operculum in women with CINP and CWAD compared to controls. This increased resting-state functional connectivity was associated with more self-reported symptoms related to central sensitization and decreased efficacy of conditioned pain modulation. Furthermore, enhanced connectivity between the left amygdala and left frontal orbital cortex, and between the left pallidum and the left frontal operculum was observed only in patients with CWAD compared to healthy controls. In patients, additional associations between local hyperalgesia and enhanced connectivity between the left superior parietal cortex and the left and right precentral gyrus were found.

CONCLUSIONS

In line with our hypotheses, patients with CWAD showed the most pronounced alterations in resting-state functional connectivity, encompassing subcortical limbic (amygdala) and basal ganglia (pallidum), and ventral frontal regions (frontal operculum, orbitofrontal cortex) when compared to CINP and controls. Findings are generally in line with the idea of a continuum, in absence of significant group differences across CINP and CWAD. Enhanced amygdala-frontal operculum functional connectivity was the most robust and only connectivity pair in the cluster that was associated with QST (i.e., dynamic QST; endogenous pain inhibition), and that was observed in both patient groups. In addition, independent of group differences, enhanced resting-state functional connectivity between superior parietal cortex (involved in attention) and primary motor cortex was associated with static QST (i.e., greater local hyperalgesia). Taken together, our findings show a key role for enhanced amygdala-ventral frontal circuitry in chronic neck pain, and its association with diminished endogenous pain inhibition further emphasizes the link between cognitive-affective and sensory modulations of pain in women with chronic non-traumatic and traumatic neck pain.

Convergent Validity of the Central Sensitization Inventory in Chronic Whiplash-Associated Disorders; Associations with Quantitative Sensory Testing, Pain Intensity, Fatigue, and Psychosocial Factors

OBJECTIVE

Central sensitization is present in different pain conditions, including chronic whiplash-associated disorders. In the absence of a gold standard method of assessment to determine the presence of central sensitization, quantitative sensory testing is currently understood as an optimal proxy. Laboratory sensory testing is, however, not feasible in clinical practice, and the Central Sensitization Inventory was developed as an alternative. The aim of the current study was to evaluate the convergent validity of the Central Sensitization Inventory in chronic whiplash-associated patients by determining the association between the Central Sensitization Inventory and quantitative sensory testing, pain intensity, fatigue, and psychosocial factors.

METHODS

A total of 125 chronic whiplash-associated patients completed multiple questionnaires and were subjected to pressure pain thresholds and temporal summation.

RESULTS

. The Central Sensitization Inventory showed a strong association with constructs of general psychopathology, anxiety, distress, depression, and somatization in chronic whiplash-associated disorders. Moderate correlations were found with fatigue and intrusive and avoidant phenomena after a variety of traumatic events. No significant association was found between the Central Sensitization Inventory and pressure pain thresholds and temporal summation, nor between the Central Sensitization Inventory and other pain measurements.

CONCLUSIONS

Overall, we found that the Central Sensitization Inventory is better in identifying the psychosocial factors related to central sensitization in chronic whiplash-associated disorders than the central nervous system adaptations. Thus, the convergent validity of the Central Sensitization Inventory appears to be only partially present in chronic whiplash-associated disorders.

Minimum Clinically Important Differences of the Hospital for Special Surgery Dysphagia and Dysphonia Inventory and Other Dysphagia Measurements in Patients Undergoing ACDF

BACKGROUND

Postoperative dysphagia is a common complication after anterior cervical surgery, and it can be measured using patient-reported outcome measures (PROMs). The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a condition-specific PROM to evaluate dysphagia and dysphonia after anterior cervical discectomy and fusion (ACDF). The minimum clinically important difference (MCID) of the HSS-DDI has not, to our knowledge, been established. Other PROMs have been used to assess dysphagia (SWAL-QOL and MD Anderson Dysphagia Inventory [MDADI]) in ACDF. Currently, few studies have addressed the MCIDs of these PROMs.

QUESTIONS/PURPOSES

To determine (1) the minimum detectable changes (MDC) of the HSS-DDI, SWAL-QOL, and MDADI using a distribution-based approach, and (2) the MCID of the HSS-DDI, SWAL-QOL, and MDADI, using an anchor-based approach.

METHODS

We used a longitudinally maintained database that was originally established for the HSS-DDI development and validation study. In all, 323 patients who underwent elective ACDF were assessed for enrollment eligibility; 83% (268 of 323) met the inclusion criteria and completed the HSS-DDI Week 4 survey. We set six outcomes: distribution-based MDCs for the (1) HSS-DDI, (2) SWAL-QOL, (3) MDADI, in addition to anchor-based MCIDs for the (4) HSS-DDI, (5) SWAL-QOL, and (6) MDADI. The HSS-DDI consists of 31 questions and ranges 0 (worst) to 100 (normal). We used the focused SWAL-QOL, which consists of 14 selected items from the original SWAL-QOL and ranges from 0 (worst) to 100 (normal). The MDADI is a 20-item survey and ranges from 20 (worst) to 100 (normal). A distribution-based approach is used to calculate values defined as the smallest difference above the measurement error. An anchor-based approach is used to determine the MCIDs based on an external scale, called an anchor, which indicates the minimal symptom change that is considered clinically important. All 268 patients were used for the distribution-based (0.5 SD) HSS-DDI MDC analysis. The first 16% (44 of 268) of patients completed retesting of the HSS-DDI via a telephone interview and were used for another distribution-based (standard error of measurement: SEM) MDC analysis. The number of patients for the test-retest group was determined based on the previously reported minimum required sample size of reliability studies. The first 63% (169 of 268, SWAL-QOL and 168 of 268, MDADI) of patients completed two other surveys for the external validation of the HSS-DDI, and were used for the SWAL-QOL and MDADI 0.5 SD analyses. Among the patients, 86% (230 of 268) completed the Week 8 HSS-DDI survey that was used for the anchor-based HSS-DDI MCID analysis, and 56% (SWAL-QOL, 150 of 268 and MDADI, 151 of 268) of patients completed the Week 8 surveys that were used for the SWAL-QOL and MDADI MCID analyses. Subjective improvement grades from the previous assessment were used as the anchor. The MCIDs were calculated as the mean score changes among those who reported little better or greater in the improvement assessment and receiver operating characteristic (ROC) curve analyses. We adopted the higher value of these two as the MCID for each PROM.

RESULTS

The distribution-based MDCs for the HSS-DDI total score, SWAL-QOL, and MDADI were 11 of 100, 9 of 100, and 8 of 80 points, respectively, using the 0.5 SD method. Using the SEM-based method, the MDC for the HSS-DDI total score was 9 of 100 points. Regarding the anchor-based MCIDs, the values calculated with the mean score change method were consistently higher than those of ROC analysis and were adopted as the MCIDs. The MCIDs were 10 for the total HSS-DDI total score, 8 for the SWAL-QOL, and 6 for the MDADI.

CONCLUSIONS

Improvements of less than 10 points for the HSS-DDI score, 9 points for the SWAL-QOL, and 6 points for the MDADI are unlikely to be perceived by patients to be clinically important. Future studies on dysphagia after anterior cervical surgery should report between-group differences in light of this, rather than focusing on p values and statistical significance.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Reliability and discriminative validity of a screening tool for the assessment of neuromuscular control and movement control in patients with neck pain and healthy individuals

Background: To evaluate the reliability and discriminative validity of a proposed adapted tool for the assessment of movement control in patients with and without neck pain.Method: A cross-sectional study at a University hospital center involving 25 pain-free healthy controls and 25 patients suffering from neck pain. Participants were assessed by two raters for inter-rater reliability and 1 week afterwards by a same rater for intra-rater reliability. The assessment involved a test for the axioscapular (adapted scapular holding test; SHT) and craniocervical (adapted craniocervical flexion test; CCFT) region for which intra-class correlation coefficients (ICCs) were computed to define the reliability. Discriminative validity to distinguish patients from controls was assessed by cross-validated computation of sensitivity, specificity, positive and negative likelihood ratios, overall accuracy, and area under the curve.Results: The proposed tool was able to reliably assess sensorimotor impairment in participants at the craniocervical region (ICC_intra = [0.52-0.82]; ICC_inter = [0.60-0.85]), left axioscapular region (ICC_intra = [0.43-0.77]; ICC_inter = 0.71-0.90), and right axioscapular region (ICC_intra = [0.47-0.79]; ICC_inter = [0.42-0.77]). Furthermore, the tool yielded a sensitivity of 0.86, a specificity of 0.57, and accuracy of 0.71 (based on cross-validation).Conclusion: The proposed tool is able to reliably evaluate patients based on their sensorimotor performance in the craniocervical and axioscapular region.Implications for rehabilitationNeck pain is related to sensorimotor impairment including neuromuscular differences and atypical sensormimotor control strategies.Clinicians should not avoid the challenging task of screening for sensorimotor impairment in patients reporting neck pain.The proposed tool supplemented with other tools might guide clinicians in the evaluation of sensorimotor impairment.

Hub disruption in patients with chronic neck pain: a graph analytical approach

Chronic pain is known to alter the brain's network dynamics. These dynamics are often demonstrated by identifying alterations in the brain network topology. A common approach used for this purpose is graph theory. To date, little is known on how these potentially altered networks in chronic pain relate to the symptoms reported by these patients. Here, we applied a graph theoretical approach to identify network changes in patients suffering from chronic neck pain, a group that is often neglected in chronic pain research. Participants with chronic traumatic and nontraumatic neck pain were compared to healthy pain-free controls. They showed higher levels of self-reported symptoms of sensitization, higher levels of disability, and impaired sensorimotor control. Furthermore, the brain suffering from chronic neck pain showed altered network properties in the posterior cingulate cortex, amygdala, and pallidum compared with the healthy pain-free brain. These regions have been identified as brain hubs (ie, regions that are responsible for orchestrating communication between other brain regions) and are therefore known to be more vulnerable in brain disorders including chronic pain. We were furthermore able to uncover associations between these altered brain network properties and the symptoms reported by patients. Our findings indicate that chronic neck pain patients reflect brain network alterations and that targeting the brain in patients might be of utmost importance.

Associations between brain morphology and motor performance in chronic neck pain: A whole-brain surface-based morphometry approach

Changes in brain morphology are hypothesized to be an underlying process that drive the widespread pain and motor impairment in patients with chronic neck pain. However, no earlier research assessed whole-brain cortical morphology in these patients. This case-control study assesses group-differences in whole-brain morphology between female healthy controls (HC; n = 34), and female patients with chronic idiopathic neck pain (CINP; n = 37) and whiplash-associated disorders (CWAD; n = 39). Additionally, the associations between whole-brain morphology and motor performance including balance, strength, and neuromuscular control were assessed. Cortical volume, thickness, and surface area were derived from high resolution T1-weighted images. T2*-weighted images were obtained to exclude traumatic brain injury. Vertex-wise general-linear-model-analysis revealed cortical thickening in the left precuneus and increased volume in the left superior parietal gyrus of patients with CINP compared to HC, and cortical thickening of the left superior parietal gyrus compared to HC and CWAD. Patients with CWAD showed a smaller cortical volume in the right precentral and superior temporal gyrus compared to HC. ANCOVA-analysis revealed worse neuromuscular control in CWAD compared to HC and CINP, and in CINP compared to HC. Patients with CWAD showed decreased levels of strength and sway area compared to CINP and HC. Partial correlation analysis revealed significant associations between the volume of the precentral gyrus, and neuromuscular control and strength together with an association between the volume of the superior temporal gyrus and strength. Our results emphasize the role of altered gray matter alterations in women with chronic neck pain, and its association with pain and motor impairment.

The Odom Criteria: Validated at Last: A Clinimetric Evaluation in Cervical Spine Surgery

BACKGROUND

The Odom criteria, established in 1958, are a widely used, 4-point rating scale for assessing the clinical outcome after cervical spine surgery. Surprisingly, the Odom criteria have never been validated, to our knowledge. The aim of this study was to investigate the reliability and validity of the Odom criteria for the evaluation of surgical procedures of the cervical spine.

METHODS

Patients with degenerative cervical spine disease were included in the study and divided into 2 subgroups on the basis of their most predominant symptom: myelopathy or radiculopathy. Reliability was assessed with interrater and test-retest design using quadratic weighted kappa coefficients. Construct validity was assessed by means of hypotheses testing. To evaluate whether the Odom criteria could act as a global perceived effect (GPE) scale, we assessed concurrent validity by comparing area under the curve (AUC) values of receiver operating characteristic (ROC) curves for the set of questionnaires.

RESULTS

A total of 110 patients were included in the study; 19 were excluded, leaving 91 in our analysis. Reliability assessments showed κ = 0.77 for overall interrater reliability and κ = 0.93 for overall test-retest reliability. Interrater reliability was κ = 0.81 for the radiculopathy subgroup and κ = 0.68 for the myelopathy subgroup. At least 75% of the hypotheses were met. The AUCs showed similar characteristics between the Odom criteria and GPE scale.

CONCLUSIONS

The Odom criteria met the predefined criteria for reliability and validity. Therefore, the Odom criteria may be used to assess surgical outcome after a cervical spine procedure, specifically for patients presenting with radicular symptoms. The results of previous studies that have been deemed less trustworthy because of the use of the Odom criteria should be reconsidered.

Measurement error in the Liebowitz Social Anxiety Scale: results from a general adult population in Japan

Objective: Although the self-report version of Liebowitz Social Anxiety Scale (LSAS) is frequently used to measure social anxiety, data is lacking on the smallest detectable change (SDC), an important index of measurement error. We therefore aimed to determine the SDC of LSAS. Methods: Japanese adults aged 20-69 years were invited from a panel managed by a nationwide internet research agency. We then conducted a test-retest internet survey with a two-week interval to estimate the SDC at the individual (SDC_ind) and group (SDC_group) levels. Results: The analysis included 1300 participants. The SDC_ind and SDC_group for the total fear subscale (scoring range: 0-72) were 23.52 points (32.7%) and 0.65 points (0.9%), respectively. The SDC_ind and SDC_group for the total avoidance subscale (scoring range: 0-72) were 32.43 points (45.0%) and 0.90 points (1.2%), respectively. The SDC_ind and SDC_group for the overall total score (scoring range: 0-144) were 45.90 points (31.9%) and 1.27 points (0.9%), respectively. Conclusions: Measurement error is large and indicate the potential for major problems when attempting to use the LSAS to detect changes at the individual level. These results should be considered when using the LSAS as measures of treatment change.

Motor impairment in patients with chronic neck pain: does the traumatic event play a significant role? A case-control study

BACKGROUND CONTEXT

Motor impairment is a key sign in patients with traumatic (whiplash-associated disorder [WAD]) and non-traumatic (idiopathic neck pain [INP]) neck pain.

PURPOSE

This study aimed to analyze differences in motor impairment between two patient groups and to assess the association between motor performance and self-reported symptoms.

STUDY DESIGN

This is a case-control study.

PATIENT SAMPLE

A total of 38 patients with chronic INP, 35 patients with chronic WAD, and 30 healthy pain-free controls were included in the study.

OUTCOME MEASURES

Outcome measures used in this study were mobility (°), strength (N), repositioning accuracy (°), endurance (seconds), sway velocity (cm/s), sway area (cm²), and neuromuscular control.

METHODS

Group differences of motor impairment, together with questionnaires to evaluate pain intensity, fear avoidance, pain catastrophizing, symptoms of central sensitization, and disability, were analyzed with analysis of covariance, including age as a covariate.

RESULTS

Motor impairment was observed in both patient groups with a higher degree in patients with chronic WAD. These impairments were moderately linked to self-reported disability and were in most cases associated with pain, fear avoidance, and symptoms of central sensitization (|ρ| ranging from 0.28 to 0.59).

CONCLUSIONS

Motor impairment should be addressed when treating both groups of patients, keeping in mind the association with self-reported pain and disability, fear-avoidance, and central sensitization.

Smallest detectable change and test-retest reliability of a self-reported outcome measure: Results of the Center for Epidemiologic Studies Depression Scale, General Self-Efficacy Scale, and 12-item General Health Questionnaire

RATIONALE, AIMS, AND OBJECTIVES

This study aims to examine the smallest detectable change (SDC) and test-retest reliability of the Center for Epidemiologic Studies Depression Scale (CES-D), General Self-Efficacy Scale (GSES), and 12-item General Health Questionnaire (GHQ-12).

METHOD

We tested 154 young adults at baseline and 2 weeks later. We calculated the intra-class correlation coefficients (ICCs) for test-retest reliability with a two-way random effects model for agreement. We then calculated the standard error of measurement (SEM) for agreement using the ICC formula. The SEM for agreement was used to calculate SDC values at the individual level (SDC_ind ) and group level (SDC_group ).

RESULTS

The study participants included 137 young adults. The ICCs for all self-reported outcome measurement scales exceeded 0.70. The SEM of CES-D was 3.64, leading to an SDC_ind of 10.10 points and SDC_group of 0.86 points. The SEM of GSES was 1.56, leading to an SDC_ind of 4.33 points and SDC_group of 0.37 points. The SEM of GHQ-12 with bimodal scoring was 1.47, leading to an SDC_ind of 4.06 points and SDC_group of 0.35 points. The SEM of GHQ-12 with Likert scoring was 2.44, leading to an SDC_ind of 6.76 points and SDC_group of 0.58 points.

CONCLUSION

To confirm that the change was not a result of measurement error, a score of self-reported outcome measurement scales would need to change by an amount greater than these SDC values. This has important implications for clinicians and epidemiologists when assessing outcomes.

Minimum Clinically Important Difference: Current Trends in the Spine Literature

STUDY DESIGN

Review of the 2011 to 2015 minimum clinically important difference (MCID)-related publications in Spine, Spine Journal, Journal of Neurosurgery-Spine, and European Spine Journal.

OBJECTIVE

To summarize the various determinations of MCID and to analyze its usage in the spine literature of the past 5 years in order to develop a basic reference to help practitioners interpret or utilize MCID.

SUMMARY OF BACKGROUND DATA

MCID represents the smallest change in a domain of interest that is considered beneficial to a patient or clinician. The many sources of variation in calculated MCID values and inconsistency in its utilization have resulted in confusion in the interpretation and use of MCID.

METHODS

All articles from 2011 to 2015 were reviewed. Only clinical science articles utilizing patient reported outcome scores (PROs) were included in the analysis. A keyword search was then performed to identify articles that used MCID. MCID utilization in the selected papers was characterized and recorded.

RESULTS

MCID was referenced in 264/1591 (16.6%) clinical science articles that utilized PROs: 22/264 (8.3%) independently calculated MCID values and 156/264 (59.1%) used previously published MCID values as a gauge of their own results. Despite similar calculation methods, there was a two- or three-fold range in the recommended MCID values for the same instrument. Half the studies recommended MCID values within the measurement error. Most studies (97.2%) using MCID to evaluate their own results relied on generic MCID. The few studies using specific MCID (MCID calculated for narrowly defined indications or treatments) did not consistently match the characteristics of their sample to the specificity of the MCID. About 48% of the studies compared group averages instead of individual scores to the MCID threshold.

CONCLUSION

Despite a clear interest in MCID as a measure of patient improvement, its current developments and uses have been inconsistent.

LEVEL OF EVIDENCE

N/A.

The Dutch-Flemish PROMIS Physical Function item bank exhibited strong psychometric properties in patients with chronic pain

OBJECTIVE

The objective of this study was to assess the psychometric properties of the Dutch-Flemish Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function item bank in Dutch patients with chronic pain.

STUDY DESIGN AND SETTING

A bank of 121 items was administered to 1,247 Dutch patients with chronic pain. Unidimensionality was assessed by fitting a one-factor confirmatory factor analysis and evaluating resulting fit statistics. Items were calibrated with the graded response model and its fit was evaluated. Cross-cultural validity was assessed by testing items for differential item functioning (DIF) based on language (Dutch vs. English). Construct validity was evaluated by calculation correlations between scores on the Dutch-Flemish PROMIS Physical Function measure and scores on generic and disease-specific measures.

RESULTS

Results supported the Dutch-Flemish PROMIS Physical Function item bank's unidimensionality (Comparative Fit Index = 0.976, Tucker Lewis Index = 0.976) and model fit. Item thresholds targeted a wide range of physical function construct (threshold-parameters range: -4.2 to 5.6). Cross-cultural validity was good as four items only showed DIF for language and their impact on item scores was minimal. Physical Function scores were strongly associated with scores on all other measures (all correlations ≤ -0.60 as expected).

CONCLUSION

The Dutch-Flemish PROMIS Physical Function item bank exhibited good psychometric properties. Development of a computer adaptive test based on the large bank is warranted.

Cervico-ocular Reflex Is Increased in People With Nonspecific Neck Pain

BACKGROUND

Neck pain is a widespread complaint. People experiencing neck pain often present an altered timing in contraction of cervical muscles. This altered afferent information elicits the cervico-ocular reflex (COR), which stabilizes the eye in response to trunk-to-head movements. The vestibulo-ocular reflex (VOR) elicited by the vestibulum is thought to be unaffected by afferent information from the cervical spine.

OBJECTIVE

The aim of the study was to measure the COR and VOR in people with nonspecific neck pain.

DESIGN

This study utilized a cross-sectional design in accordance with the STROBE statement.

METHODS

An infrared eye-tracking device was used to record the COR and the VOR while the participant was sitting on a rotating chair in darkness. Eye velocity was calculated by taking the derivative of the horizontal eye position. Parametric statistics were performed.

RESULTS

The mean COR gain in the control group (n=30) was 0.26 (SD=0.15) compared with 0.38 (SD=0.16) in the nonspecific neck pain group (n=37). Analyses of covariance were performed to analyze differences in COR and VOR gains, with age and sex as covariates. Analyses of covariance showed a significantly increased COR in participants with neck pain. The VOR between the control group, with a mean VOR of 0.67 (SD=0.17), and the nonspecific neck pain group, with a mean VOR of 0.66 (SD=0.22), was not significantly different.

LIMITATIONS

Measuring eye movements while the participant is sitting on a rotating chair in complete darkness is technically complicated.

CONCLUSIONS

This study suggests that people with nonspecific neck pain have an increased COR. The COR is an objective, nonvoluntary eye reflex and an unaltered VOR. This study shows that an increased COR is not restricted to patients with traumatic neck pain.

Patient-reported outcome measures for non-specific neck pain validated in the Italian-language: a systematic review

BACKGROUND

Patient-reported outcome measures can improve the management of patients with non-specific neck pain. The choice of measure greatly depends on its content and psychometric properties. Most questionnaires were developed for English-speaking people, and need to undergo cross-cultural validation for use in different language contexts. To help Italian clinicians select the most appropriate tool, we systematically reviewed the validated Italian-language outcome measures for non-specific neck pain, and analyzed their psychometric properties and clinical utility.

METHODS

The search was performed in MEDLINE, EMBASE, CINAHL, Scopus, Web of Science, and Cochrane Library. All articles published in English or Italian regarding the development, translation, or validation of patient-reported outcome measures available in the Italian language were included. Two reviewers independently selected the studies, extracted data, and assessed methodological quality using the COSMIN checklist.

RESULTS

Out of 4891articles screened, 66 were eligible. Overall, they were of poor or fair methodological quality. Four instruments measuring function and disability (Neck Disability Index, Neck Pain and Disability Scale, Neck Bournemouth Questionnaire, and Core Outcome Measures Index), and one measuring activity-related fear of movement (NeckPix©) were identified. Each scale showed some psychometric weaknesses or problems with functioning, and none emerged as a gold standard.

CONCLUSIONS

Several patient-reported outcome measures are now available for assessing Italian people with non-specific neck pain. While the Neck Disability Index is the one most widely used, the Neck Bournemouth Questionnaire appears the most promising tool from a psychometric point of view.

Calibration and Validation of the Dutch-Flemish PROMIS Pain Interference Item Bank in Patients with Chronic Pain

The Dutch-Flemish PROMIS Group translated the adult PROMIS Pain Interference item bank into Dutch-Flemish. The aims of the current study were to calibrate the parameters of these items using an item response theory (IRT) model, to evaluate the cross-cultural validity of the Dutch-Flemish translations compared to the original English items, and to evaluate their reliability and construct validity. The 40 items in the bank were completed by 1085 Dutch chronic pain patients. Before calibrating the items, IRT model assumptions were evaluated using confirmatory factor analysis (CFA). Items were calibrated using the graded response model (GRM), an IRT model appropriate for items with more than two response options. To evaluate cross-cultural validity, differential item functioning (DIF) for language (Dutch vs. English) was examined. Reliability was evaluated based on standard errors and Cronbach's alpha. To evaluate construct validity correlations with scores on legacy instruments (e.g., the Disabilities of the Arm, Shoulder and Hand Questionnaire) were calculated. Unidimensionality of the Dutch-Flemish PROMIS Pain Interference item bank was supported by CFA tests of model fit (CFI = 0.986, TLI = 0.986). Furthermore, the data fit the GRM and showed good coverage across the pain interference continuum (threshold-parameters range: -3.04 to 3.44). The Dutch-Flemish PROMIS Pain Interference item bank has good cross-cultural validity (only two out of 40 items showing DIF), good reliability (Cronbach's alpha = 0.98), and good construct validity (Pearson correlations between 0.62 and 0.75). A computer adaptive test (CAT) and Dutch-Flemish PROMIS short forms of the Dutch-Flemish PROMIS Pain Interference item bank can now be developed.