Translation and validation study of Chinese versions of the neck disability index and the neck pain and disability scale

Changes of postural control and muscle activation pattern in response to external perturbations after neck flexor fatigue in young subjects with and without chronic neck pain

PURPOSE

Previous studies have identified sensorimotor disturbances and greater fatigability of neck muscles in patients with neck pain. The purpose of this study was to investigate the effect of neck pain and neck flexor fatigue on standing balance following postural perturbations.

METHODS

Twenty patients with chronic neck pain (CNP) (24.7±3.6 year-old) and 20 age-matched asymptomatic subjects (22.1±2.2 year-old) were recruited. Subjects stood barefoot on a force plate and experienced backward perturbations before and after neck flexor fatigue. Center of pressure, electromyography of cervical and lumbar muscles, and head/trunk accelerations were recorded. Two-way ANOVA (pain×fatigue) was used for statistical analysis.

RESULTS

CNP group showed larger body sway during quiet standing but not during perturbed standing compared with asymptomatic adults. In both groups, neck flexor fatigue resulted in greater body sway during the quiet standing but smaller body sway during perturbed standing, increased neck muscle activations and decreased lumbar muscle activations, as well as increased time to maximal head acceleration.

CONCLUSIONS

Disturbed balance control was observed in CNP patients during the quiet standing. However, a rigid strategy was used to minimize the postural sway and to protect the head against backward perturbations in both CNP and asymptomatic young adults after neck flexor fatigue. The results facilitate the understanding of how the subjects with chronic neck pain and with neck muscle fatigue deal with the challenging condition. Further studies are needed to verify if such phenomenon could be changed after the intervention of specific flexor muscle retraining and balance control exercises.

Ultrasound-Guided Miniscalpel-Needle Release versus Dry Needling for Chronic Neck Pain: A Randomized Controlled Trial

Objective. To compare ultrasound-guided miniscalpel-needle (UG-MSN) release versus ultrasound-guided dry needling (UG-DN) for chronic neck pain. Methods. A total of 169 patients with chronic neck pain were randomized to receive either UG-MSN release or UG-DN. Before treatment and at 3 and 6 months posttreatment, pain was measured using a 10-point visual analogue scale (VAS). Neck function was examined using the neck disability index. Health-related quality of life was examined using the physical component score (PCS) and mental component score (MCS) of the SF-36 health status scale. Results. Patients in the UG-MSN release had greater improvement on the VAS (by 2 points at 3 months and 0.9 points at 6 months) versus in the UG-DN arm; (both P < 0.0001). Patients receiving UG-MSN release also showed significantly lower scores on the adjusted neck disability index, as well as significantly lower PCS. No severe complications were observed. Conclusion. UG-MSN release was superior to UG-DN in reducing pain intensity and neck disability in patients with chronic neck pain and was not associated with severe complications. The procedural aspects in the two arms were identical; however, we did not verify the blinding success. As such, the results need to be interpreted with caution.

Translation, cross-cultural adaptation, and validation of a Chinese version of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire

STUDY DESIGN

Translation and psychometric testing of a questionnaire.

OBJECTIVE

To adapt the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) cross-culturally to Chinese language and to investigate the psychometric properties of the translated Chinese JOACMEQ.

SUMMARY OF BACKGROUND DATA

The recently developed JOACMEQ is a self-reported questionnaire used to assess the severity of the cervical spondylotic myelopathy. Despite its acceptance in the literature, the JOACMEQ has not been translated and validated for Chinese-speaking patients.

METHODS

Translation and cross-cultural adaptation of the original JOACMEQ was performed according to published guidelines. A total of 105 patients with a predominant complain of neck pain that included but not limited to patients with a clinically confirmed cervical spondylotic myelopathy were included. Psychometric testing of the responses included construct validity (factor analysis), internal consistency (Cronbach α), test-retest reproducibility (intraclass correlation coefficient), and concurrent validity (Spearman ρ). The discriminatory power of differentiating those with myelopathy from those without was assessed by the area under the receiver operating characteristic curve and with the optimal cutoff points determined.

RESULTS

Construct validity testing revealed a comparable factorial structure of the Chinese JOACMEQ with the original JOACMEQ. The Cronbach α of the Chinese JOACMEQ was 0.88, indicating good internal consistency. Good to excellent test-retest reliability was demonstrated for all 5 domain scores (intraclass correlation coefficient range = 0.79-0.90). A significant strong association between the Chinese Neck Disability Index and the quality of life domain of the Chinese JOACMEQ (Spearman ρ= -0.76, P < 0.01) was identified. The upper and lower extremity function domain scores were found to be significant, with the area under the receiver operating characteristic curve found to be 0.75 (P = 0.04) and 0.82 (P = 0.02), respectively.

CONCLUSION

The results indicated that the Chinese JOACMEQ successfully retained the psychometric properties of the original JOACMEQ and support the usefulness of the Chinese JOACMEQ as an appropriate supplementary diagnostic and outcome measure for Chinese patients suspected of cervical spondylotic myelopathy.

Clinical trial participants' experiences of completing questionnaires: a qualitative study

OBJECTIVES

To improve clinical study developments for elderly populations, we aim to understand how they transfer their experiences into validated, standardised self-completed study measurement instruments. We analysed how women (mean 78±8 years of age) participating in a randomised controlled trial (RCT) cognised study instruments used to evaluate outcomes of the intervention.

SETTING

The interview study was nested in an RCT on chronic neck pain using common measurement instruments situated in an elderly community in Berlin, Germany, which comprised of units for independent and assisted-living options.

PARTICIPANTS

The sample (n=20 women) was selected from the RCT sample (n=117, 95% women, mean age 76 (SD±8) years). Interview participants were selected using a purposive sampling list based on the RCT outcomes.

OUTCOMES

We asked participants about their experiences completing the RCT questionnaires. Interviews were analysed thematically, then compared with the questionnaires.

RESULTS

Interviewees had difficulties in translating complex experiences into a single value on a scale and understanding the relationship of the questionnaires to study aims. Interviewees considered important for the trial that their actual experiences were understood by trial organisers. This information was not transferrable by means of the questionnaires. To rectify these difficulties, interviewees used strategies such as adding notes, adding response categories or skipping an item.

CONCLUSIONS

Elderly interview participants understood the importance of completing questionnaires for trial success. This led to strategies of completing the questionnaires that resulted in 'missing' or ambiguous data. To improve data collection in elderly populations, educational materials addressing the differential logics should be developed and tested. Pilot testing validated instruments using cognitive interviews may be particularly important in such populations. Finally, when the target of an intervention is a subjective experience, it seems important to create a method by which participants can convey their personal experiences. These could be nested qualitative studies.

TRIAL REGISTRATION NUMBER

ISRCTN77108101807.

Cross-cultural adaptation, reliability, and validity of the Arabic version of neck disability index in patients with neck pain

STUDY DESIGN

Translation and psychometric testing.

OBJECTIVE

To adapt the neck disability index (NDI) cross-culturally to Arabic language and to investigate the reliability and validity of the Arabic version of NDI in an Arabic-speaking sample with neck pain.

SUMMARY OF BACKGROUND DATA

Although largely used, no previous reports exist on the translation process or the testing of the psychometric properties of the Arabic version of the NDI.

METHODS

Cross-cultural adaptation of an outcome questionnaire. The English version of the NDI was translated into Arabic (NDI-Ar) and back-translated according to established guidelines. Sixty-five patients with neck pain completed the NDI -Ar twice during a 1-week period, to assess its test-retest reliability. Further psychometric testing was done by assessing internal consistency, construct validity (factor structure), and responsiveness.

RESULTS

The internal consistency value (Cronbach α) for the NDI-Ar was 0.89. The test-retest reliability (intraclass correlation coefficient) was excellent at 0.96 (95% confidence interval from 0.93 to 0.97). There was a significant correlation (r = 0.92, P < 0.05) between the scores obtained from the first administration of the NDI-Ar and the second administration. Factor analysis demonstrated a 2-factor structure, explaining 67.58% of total variance. The analysis of responsiveness was calculated with an unpaired t test after 1 week of treatment and demonstrating a statically significant difference between stable and improved patients (P < 0.05). The Spearman correlation coefficient (rS = 0.81; P = 0.000) revealed strong relation between the change in score in the NDI-Ar and global rating of change. No ceiling or floor effects were detected in the NDI-Ar.

CONCLUSION

The Arabic version of the NDI has a 2-factor 10-item structure and is a reliable, valid, and responsive tool that can be used to assess neck pain in Arabic-speaking patients with neck pain. Therefore, it can be recommended for clinical and research purposes.

Validity, reliability and responsiveness of the Japanese version of the Neck Disability Index

BACKGROUND

The Neck Disability Index (NDI) is one of the most widely used questionnaires for neck pain. The purpose of this study was to validate the Japanese NDI.

METHODS

We performed two surveys with an 8-week interval in 130 patients with neck pain, radiculopathy and myelopathy. We asked patients to answer two versions of the Japanese NDI: the original NDI, which had been completed by a forward-backward translation procedure, and the modified NDI, which has the phrase "because of neck pain" to the phase "because of neck pain or numbness in the arm." The other parameters examined were the strength of pain and numbness, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, the Hospital Anxiety and Depression Scale, and Short Form 36. Attending surgeons judged the symptom severity. Patients were asked to report the patient global impression of change (PGIC) at the second survey. The internal consistency, criterion-related and discriminative validity, and reliability were evaluated.

RESULTS

The original NDI and the modified NDI were 26.9 ± 17.1 and 29.9 ± 15.5, respectively. The Cronbach α values of the original NDI and the modified NDI were 0.92 and 0.89, respectively. Both versions of the NDI had good to excellent correlative coefficients with the related domains. The modified NDI had a higher validity for numbness and mental health-related QOL. The symptom severity was significantly correlated with the modified NDI. The intraclass correlation coefficients of the two surveys of the modified and original NDI were comparable. The effect sizes of the modified and the original NDI were 0.64 and 0.55, respectively. Spearman's ρ between the change of the NDI and the PGIC was 0.47 in the original NDI and 0.59 in the modified NDI.

CONCLUSIONS

We demonstrated the validity, reliability and responsiveness of the Japanese NDI. The modified NDI was more strongly correlated with numbness and mental health-related QOL.

Normative score and cut-off value of the Neck Disability Index

BACKGROUND

Neck pain is a common health problem that restricts activities of daily living. The Neck Disability Index (NDI) was developed to assess disability in patients with neck pain. The normative score and the cut-off value are mandatory to assess an individual patient or a certain patient group for clinically important neck pain with disability, by distinguishing it from nonsignificant pain. The objective of the present study was to determine the normative score and the cut-off value of the NDI.

METHODS

A total of 1,200 participants who registered with an internet research company were interviewed on the website about their episodes of neck pain during the previous 4 weeks, and completed the online NDI questionnaire. If the participants reported neck pain, they were also asked about the disability in activity of daily living it caused, and the presence of associated symptoms in upper limbs. Disability was defined according to the consensus study on the standardization of back pain definitions. The normative score was determined by calculating the mean in the participants, and the cut-off value was determined by the receiver-operating characteristic curve analysis.

RESULTS

The prevalence of neck pain was 37.8 %. Demographic data of the participants also indicated that they were representative of the normal population in Japan. The mean score was 6.98, and the median was 2. The NDI score was higher in middle age, and at its peak in the 50s age group (50-59 years of age). The female mean was significantly higher. The NDI score was higher in those with upper limb symptoms. We have determined the cut-off value of the NDI to detect neck pain associated with disability to be 15.

CONCLUSIONS

The normative score and the cut-off value of the NDI were determined. Our cut-off value is potentially useful in evaluating the therapeutic effectiveness of various interventions for neck pain.

Crosscultural adaptation, reliability, and validity of the Japanese version of the neck disability index

STUDY DESIGN

Translation and psychometric testing.

OBJECTIVE

To translate and culturally adapt the Neck Disability Index (NDI) and to assess the reliability and validity of the Japanese version of the NDI (NDI-J) in Japanese outpatients with neck pain.

SUMMARY OF BACKGROUND DATA

To date, no previous report exists on the translation process and psychometric testing of the NDI-J.

METHODS

The NDI was translated and culturally adapted into Japanese in accordance with published guidelines. A total of 110 outpatients with neck pain participated in the study. Psychometric testing included reliability by internal consistency (Cronbach α) and test-retest reliability (intraclass correlation coefficient), factor analysis, convergent validity by comparing the NDI-J with the short-form health survey (Pearson correlation) and responsiveness (unpaired t tests, standard error of measurement, and minimal detectable change).

RESULTS

The Cronbach α of the NDI-J was 0.88 and the intraclass correlation coefficient for test-retest reliability was 0.91 (95% confidence interval, 0.82-0.95). Factor analysis demonstrated a 2-factor structure, explaining 61.8% of the total variance. The correlation between the NDI-J and the short-form health survey, version 36, subscales ranged from good to fair (-0.25 to -0.51). The analysis of responsiveness was calculated with an unpaired t test after 3 weeks of treatment demonstrating a statistically significant difference between the stable and improved patients (P ≤ 0.05). The standard error of measurement and minimal detectable change were calculated as 2.9 and 6.8, respectively.

CONCLUSION

The NDI-J is a valid, reliable, and responsive tool that can be used to assess neck pain in Japanese outpatients.

Development of the Italian Version of the Neck Disability Index: cross-cultural adaptation, factor analysis, reliability, validity, and sensitivity to change

STUDY DESIGN

Evaluation of the psychometric properties of a translated and culturally adapted questionnaire.

OBJECTIVE

Translating, culturally adapting, and validating the Italian version of the Neck Disability Index (NDI-I) to allow its use with Italian-speaking patients with neck pain (NP).

SUMMARY OF BACKGROUND DATA

More attention is being given to standardized outcome measures to improve interventions for NP. A translated form of the NDI has never been validated in Italian patients with NP.

METHODS

The NDI-I was developed by forward-backward translation, a final review by an expert committee, and a test of the prefinal version to establish its correspondence with the original English version. The psychometric testing included factor analysis, reliability by internal consistency (Cronbach α) and test-retest reliability (intraclass coefficient correlation), construct validity by comparing NDI-I with the Neck Pain and Disability Scale, a numerical rating scale, the Hospital Anxiety and Depression Scale, and the 36-Item Short Form Health Survey (Spearman correlation), and sensitivity to change by calculating the smallest detectable change.

RESULTS

The questionnaire was administered to 101 subjects with chronic NP and proved to be acceptable. Factor analysis revealed a 2-factor 10-item solution (explained variance: 56%). The questionnaire showed good internal consistency (α = 0.842) and test-retest reliability (intraclass coefficient correlation = 0.846). Construct validity showed a good correlation with Neck Pain and Disability Scale (ρ = 0.687), moderate correlations with the numerical rating scale (ρ = 0.545), and Hospital Anxiety and Depression Scale (ρ = 0.422 for the Anxiety score and ρ = 0.546 for the Depression score), and poor correlations with the 36-Item Short Form Health Survey subscales (ρ = 0.066 to -0.286). The psychometric analyses of the subscales and total scale were similar. The smallest detectable change of the NDI-I was 3.

CONCLUSION

The NDI was successfully translated into Italian and proved to have a good factorial structure and psychometric properties that replicated the results of other versions. Its use is recommended for research purposes.

Superiority of the Bryan(®) disc prosthesis for cervical myelopathy: a randomized study with 3-year followup

BACKGROUND

The current standard of care for cervical myopathy is anterior discectomy and fusion (ACDF). Although well tolerated in the short term, this treatment might ultimately result in progressive degeneration of adjacent motion segments. Artificial disc arthroplasty offers the theoretical advantage of preservation of motion at the operative level with consequent stress reduction at adjacent levels.

QUESTIONS/PURPOSES

We compared function, radiographic measures, and incidence of complications at 3-year followup after cervical disc arthroplasty with the Bryan(®) prosthesis and ACDF in patients with cervical myelopathy.

PATIENTS AND METHODS

Eighty-three patients with cervical myelopathy were randomized to undergo arthroplasty with implantation of a Bryan(®) cervical disc prosthesis (n = 41) or ACDF (n = 42). Patients were assessed preoperatively to 3 years postoperatively using the modified Odom's criteria, Japanese Orthopaedic Association scale, SF-36, and Neck Disability Index. ROM, stability, and subsidence of the prostheses were evaluated radiographically.

RESULTS

Patients who received the Bryan(®) prosthesis scored significantly better in three of the four functional assessment methods used (Japanese Orthopaedic Association scale, SF-36, and Neck Disability Index). ROM was retained by the patients in the Bryan(®) group but not in the patients in the ACDF group. Patients in the Bryan(®) group had fewer complications, primarily because dysphagia occurred in only one patient in the Bryan(®) group but in seven patients in the ACDF group. Other complications included pseudarthrosis in three patients in the ACDF group and one patient had spontaneous fusion, one had deep vein thrombosis, and one had heterotopic ossification in the Bryan(®) group.

CONCLUSIONS

Bryan(®) cervical disc arthroplasty appears reliable and effective in the treatment of cervical myelopathy.

LEVEL OF EVIDENCE

Level II, therapeutic study. See the Guidelines for Authors for a complete description of the levels of evidence.

Cross-cultural adaptation of the Neck Disability Index and Copenhagen Neck Functional Disability Scale for patients with neck pain due to degenerative and discopathic disorders. Psychometric properties of the Polish versions

BACKGROUND

Even though there are several region-specific functional outcome questionnaires measuring neck disorders that have been developed in English-speaking countries, no Polish version has ever been validated. The purpose of our study was to translate, culturally adapt and validate the Neck Disability Index (NDI) and Copenhagen Neck Functional Disability Scale (CDS) for Polish-speaking patients with neck pain.

METHODS

The translation was carried out according to the International Quality of Life Association (IQOLA) Project. Sixty patients were treated due to degenerative and discopathic disorders in the cervical spine filled out the NDI-PL and the CDS-PL. The pain level was evaluated using the Visual Analog Scale. The mean age of the assessed group was 47.1 years (SD 8.9). We used Cronbach's alpha to assess internal consistency. We assessed the test-retest reliability using the Intraclass Correlation Coefficients (ICCs). The Spearman's rank correlation coefficient (rS) was used to determine dependency between quantitative characteristics. The Mann-Whitney test was applied to determine dependency between quantitative and qualitative characteristics.

RESULTS

The Cronbach's alpha values were excellent for the NDI-PL in the test and in the retest (0.84, 0.85, respectively), and for the CDS-PL (0.90 in the test and in the retest). Intraclass Correlation Coefficients were excellent for the CDS-PL and NDI-PL and equalled 0.93 (95% CI from 0.89 to 0.95) and 0.87 (95% CI from 0.80 to 0.92), respectively The concurrent validity was good in the test and in the retest (rs = 0.42 p < 0.001; rs = 0.40 p = 0.002, respectively) for NDI-PL and for CDS-PL (rs = 0.42 p < 0.001; rs = 0.40 p = 0.001, respectively). The adapted questionnaires showed a strong inter-correlation both in the test (0.87 p < 0.001) and in the retest (0.79 p < 0.001).

CONCLUSIONS

The present versions of the NDI-PL and CDS-PL, the first to be published in Polish, have proven to be reliable and valid for patients with degenerative changes in the cervical spine. The NDI-PL and CDS-PL have excellent internal consistency and test-retest reliability, and good concurrent validity. The adapted questionnaires showed a strong inter-correlation both in the test and in the retest. No ceiling or floor effects were detected in the NDI-PL and CDS-PL. The NDI-PL and CDS-PL are comparable with other versions and can be recommended and used in international comparative studies.