Validation of the German version of the Neck Disability Index (NDI).
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ABSTRACT: Background
The Neck Disability Index (NDI) is the most commonly used outcome measure for neck pain. This study aimed to determine the psychometric properties of a German version of the NDI. Cross-cultural translation and psychometric testing of the NDI were performed.Methods
The 10-item NDI was translated into German and administered to 558 patients with chronic unspecific neck pain (Mean age 49.9 ± 11.4 years, 76% female). The factor structure and reliability of the NDI were assessed using factor analysis, Cronbach's alpha, split-half reliability (Spearman-Brown coefficient), and intra-class correlation (ICC2,1). To determine convergent validity, pain intensity (visual analog scale; VAS), pain on movement (VAS), and quality of life (Short Form 36 Health Survey Questionnaire; SF-36) were correlated with the NDI. Correlation with range of motion and sensitivity to change were also assessed in a subsample of 49 patients.Results
The mean NDI score was 32.75 ± 13.09. Factor analysis revealed a single factor that explained 39.8% of the variance. Cronbach's alpha was 0.81; Spearman-Brown coefficient was 0.80; and intra-class correlation was 0.81 (95% confidence interval = 0.78, 0.83). Significant correlations were found for pain intensity (r = 0.22, p < 0.01), pain on movement (r = 0.39, p < 0.01), quality of life (r = -0.30 to -0.45, p < 0.01), and range of motion (r = -0.34, p = 0.02). Patients who reported global improvement of health after an exercise or yoga intervention showed a higher decrease on the NDI than patients who reported no global improvement (p < 0.01).Conclusions
The German version of the NDI has a comparable factor structure as the original version, acceptable psychometric properties, and is sensitive to change after physical activity. Neck disability is associated with other measures of neck pain.
SUBMITTER: Cramer H
PROVIDER: S-EPMC3999938 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundNeck pain is a highly prevalent condition resulting in major disability. Standard scales for measuring disability in patients with neck pain have a pivotal role in research and clinical settings. The Neck Disability Index (NDI) is a valid and reliable tool, designed to measure disability in activities of daily living due to neck pain. The purpose of our study was the translation and validation of the NDI in a Greek primary care population with neck complaints.MethodsThe original version of the questionnaire was used. Based on international standards, the translation strategy comprised forward translations, reconciliation, backward translation and pre-testing steps. The validation procedure concerned the exploration of internal consistency (Cronbach alpha), test-retest reliability (Intraclass Correlation Coefficient, Bland and Altman method), construct validity (exploratory factor analysis) and responsiveness (Spearman correlation coefficient, Standard Error of Measurement and Minimal Detectable Change) of the questionnaire. Data quality was also assessed through completeness of data and floor/ceiling effects.ResultsThe translation procedure resulted in the Greek modified version of the NDI. The latter was culturally adapted through the pre-testing phase. The validation procedure raised a large amount of missing data due to low applicability, which were assessed with two methods. Floor or ceiling effects were not observed. Cronbach alpha was calculated as 0.85, which was interpreted as good internal consistency. Intraclass correlation coefficient was found to be 0.93 (95% CI 0.84-0.97), which was considered as very good test-retest reliability. Factor analysis yielded one factor with Eigenvalue 4.48 explaining 44.77% of variance. The Spearman correlation coefficient (0.3; P = 0.02) revealed some relation between the change score in the NDI and Global Rating of Change (GROC). The SEM and MDC were calculated as 0.64 and 1.78 respectively.ConclusionThe Greek version of the NDI measures disability in patients with neck pain in a reliable, valid and responsive manner. It is considered a useful tool for research and clinical settings in Greek Primary Health Care.
| S-EPMC2492862 | biostudies-literature
Project description:BackgroundDifferent standardized questionnaires are used to assess tinnitus severity, making comparisons across studies difficult. These questionnaires are also used to measure treatment-related changes in tinnitus although they were not designed for this purpose. To solve these problems, a new questionnaire - the Tinnitus Functional Index (TFI) - has been established. The TFI is highly responsive to treatment-related change and promises to be the new gold standard in tinnitus evaluation. The aim of the current study was to validate a German version of the TFI for a German-speaking population in Switzerland.MethodsAt the ENT department of the University Hospital Zurich, 264 subjects completed an online survey including the German version for Switzerland of TFI, Tinnitus Handicap Inventory (THI), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI) and sociodemographic variables. Internal consistency of the TFI was calculated with Cronbach's alpha coefficient. Pearson correlation coefficients were used for the test-retest reliability of the TFI and to investigate convergent and discriminant validity between the THI and the BDI and BAI, respectively. Factor analysis was assessed using a principal component analysis with oblique rotation. The different factors extracted were then compared with the original questionnaire.ResultsThe German version of the TFI for Switzerland showed an excellent internal consistency (Cronbach's alpha of 0.97) and an excellent test-retest reliability of 0.91. The convergent validity with THI was high (r = 0.86). The discriminant validity with BAI and BDI showed moderate results (BAI: r = 0.60 and BDI: r = 0.65). In the factor analysis only five factors with one main factor could be extracted instead of eight factors as described in the original version. Nevertheless, relations to the original eight subscales could be demonstrated.ConclusionThe German version of the TFI for Switzerland is a suitable instrument for measuring the impact of tinnitus. The reliability and validity of this version are comparable with the original version of the TFI. Although this study showed only five factors in the factor analysis, relations to the original eight subscales were identified. Therefore, the German version of the TFI for Switzerland can deliver relevant information regarding the different tinnitus domains.Trial registrationClinical trial registration number on clinicaltrial.gov: NCT01837368 .
| S-EPMC5420117 | biostudies-literature
Project description:Background contextThe Patient-Reported Outcomes Information System (PROMIS) instruments are an important advancement in the use of PROs, but need to be evaluated with longitudinal data to determine whether they are responsive to change in specific clinical populations.PurposeThe purpose of this study was to assess the responsiveness of the PROMIS Physical Function (PF), PROMIS Pain Interference (PI), Neck Disability Index (NDI), and the Oswestry Disability Index (ODI).Study design/settingThis study entailed prospective data collection from consecutive patients aged 18 and older, visiting a university-based orthopaedic spine clinic between October 2013 and January 2017.Patient sampleA total of 763 participants in the sample had a mean age of 58 (SD = 15) years and the sample was 50.2% male and 92.8% Caucasian.Outcome measuresThe PROMIS PF and PROMIS PI Computerized Adaptive Tests along with either the NDI or ODI instruments were administered on tablet computers before clinic visits. Global rating of change questions relating to pain and function levels was also administered.MethodsBaseline scores were compared with follow-up scores at four different time-points from 3-months to 6-months and beyond. Patient demographics, mean scores, paired-sample t tests, Standardized Response Mean (SRM), and Effect Size (ES) were analyzed to determine instrument responsiveness. This project was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award number U01AR067138 and the authors have no conflicts of interest to disclose.ResultsThe PROMIS instruments were strongly correlated with each other as well as with the NDI and ODI. Responsiveness was significant on all four instruments at every time-point assessed (paired sample t tests ranged from p < .001 to p = .049). SRM's were large and over 0.94 for every instrument at every time-point. Cohen's d ES were large and over 0.96 for all at all time-points, except for the NDI which had ES ranging from 0.74 to 0.83. This study showed large effect sizes and responsiveness of the PROMIS PF, PROMIS PI, NDI and ODI in a population of orthopaedic patients with spine pathologies.ConclusionThis study demonstrates strong responsiveness of the PROMIS PF and PROMIS PI in a spine clinic population.
| S-EPMC6309663 | biostudies-literature
Project description:Study designA prospective study.PurposeTo evaluate the reliability and validity of the adapted Korean version of the Neck Pain and Disability Scale (NPDS).Overview of literatureThe validity of Korean version of NPDS has not been completely demonstrated yet.MethodsTranslation/retranslation of the English version of NPDS was conducted, and all steps of the cross-cultural adaptation process were performed. The Korean version of the visual analog scale (VAS) measure of pain, NPDS and the previously validated Short Form-36 (SF-36) were mailed to 91 patients, who had been surgically treated for degenerative cervical disease. Eighty-one patients responded to the first mailing of questionnaires and 69 of the first time responder returned their second survey. Factor analysis and reliability assessment by kappa statistics of agreement for each item, the intraclass correlation coefficient and Cronbach's ? were conducted. Concurrent and construct validity were also evaluated by comparing the responses of NPDS with the results of VAS and responses of SF-36.ResultsFactor analysis extracted 3 factors. All items had a kappa statistics of agreement greater than 0.6. The NPDS showed excellent test/re-test reliability. Internal consistency of Cronbach's ? was found to be very good. The NPDS was correlated with the VAS. The Korean version of NPDS showed good significant correlation with SF-36 total score and with single SF-36 domains scores.ConclusionsThe adapted Korean version of the NPDS was successfully translated and is considered suitable for outcome assessments in the Korean-speaking patients with neck pain.
| S-EPMC3779768 | biostudies-literature
Project description:BackgroundThe purpose of this secondary analysis of clinical databases of people with neck pain was to use a mixed unique conceptual and statistical approach to develop a brief version of the Neck Disability Index (NDI).MethodsAn a priori framework of neck-related function based on the International Classification of Functioning, Disability and Health was used to identify items from the original 10-item NDI that do not conceptually fit. Remaining items were subject to Rasch analysis to identify items that did not statistically fit with axioms of quantitative measurement. Finally, approaches drawn from classical test theory were used to compare stability, responsiveness and concurrent validity of the original NDI, the new brief NDI and the linearly-transformed brief NDI.ResultsConceptual analysis identified 3 items that did not fit with the construct of self-reported ability to perform activity: pain intensity, headache, and sleeping. These items were removed, and responses to the remaining 7 items drawn from an assembled database of 316 physiotherapy patients with neck pain were subject to Rasch analysis. Two items were removed due to either considerable differential item functioning (reading) or statistical redundancy (lifting). The remaining items were considered the NDI-5. Test-retest reliability, responsiveness, sensitivity to change, and concurrent validity were all comparable across the original NDI, NDI-5 and linearly-transformed NDI-5. Sensitivity to change over a 1-month period of physiotherapy was the notable exception, where the linearly-transformed NDI-5 showed superiority over the other two forms.ConclusionsA shortened version of the NDI, the NDI-5, has been constructed that is conceptually and statistically sound. Implications for research and clinical practice are discussed. Comparison with the NDI-8 is provided that suggests overall similar function across the forms, although the latter may be more sensitive to change.
| S-EPMC3718697 | biostudies-literature
Project description:BackgroundClinical outcome measures are important tools to monitor patient improvement during treatment as well as to document changes for research purposes. The short-form Bournemouth questionnaire for neck pain patients (BQN) was developed from the biopsychosocial model and measures pain, disability, cognitive and affective domains. It has been shown to be a valid and reliable outcome measure in English, French and Dutch and more sensitive to change compared to other questionnaires. The purpose of this study was to translate and validate a German version of the Bournemouth questionnaire for neck pain patients.MethodsGerman translation and back translation into English of the BQN was done independently by four persons and overseen by an expert committee. Face validity of the German BQN was tested on 30 neck pain patients in a single chiropractic practice. Test-retest reliability was evaluated on 31 medical students and chiropractors before and after a lecture. The German BQN was then assessed on 102 first time neck pain patients at two chiropractic practices for internal consistency, external construct validity, external longitudinal construct validity and sensitivity to change compared to the German versions of the Neck Disability Index (NDI) and the Neck Pain and Disability Scale (NPAD).ResultsFace validity testing lead to minor changes to the German BQN. The Intraclass Correlation Coefficient for the test-retest reliability was 0.99. The internal consistency was strong for all 7 items of the BQN with Cronbach ?'s of .79 and .80 for the pre and post-treatment total scores. External construct validity and external longitudinal construct validity using Pearson's correlation coefficient showed statistically significant correlations for all 7 scales of the BQN with the other questionnaires. The German BQN showed greater responsiveness compared to the other questionnaires for all scales.ConclusionsThe German BQN is a valid and reliable outcome measure that has been successfully translated and culturally adapted. It is shorter, easier to use, and more responsive to change than the NDI and NPAD.
| S-EPMC3398331 | biostudies-literature
Project description:STUDY DESIGN:Cross-cultural adaptation and psychometric evaluation. OBJECTIVE:The aim of this study was to translate the Neck Disability Index (NDI) into the simplified-Chinese language and to evaluate the reliability, validity, and responsiveness of the new questionnaire. SUMMARY OF BACKGROUND DATA:Neck pain is a major health problem resulting in major disability. NDI is the most frequently used scale for self-rating of disability due to neck pain. At present, there is no simplified-Chinese version of the NDI. The aims of this study were to culturally adapt and translate the NDI into the simplified-Chinese language (NDI-SC) and to evaluate its psychometric properties in patients with neck pain. METHODS:The NDI was translated into simplified-Chinese version based on established guidelines. A total of 70 patients participated in this study. Patients were asked to complete a set of questionnaires comprising of their demographic information, the NDI-SC, and a visual analog scale (VAS) of pain. Fifty-six patients returned after 1 to 2 weeks to complete the same set of questionnaires and the global rating of change (GROC) scale. Then, the NDI-SC was evaluated for content validity, construct validity, internal consistency, test-retest reliability, and responsiveness. RESULTS:The NDI-SC demonstrated excellent internal consistency (Cronbach ??=?0.92) and good test-retest reliability (ICC2,1?=?0.85). Content validity was confirmed as no floor or ceiling effects were detected for the NDI-SC total score. Construct validity was established with factor analysis revealing two-factor subscales explaining 66% of the variance. The NDI-SC showed a strong correlation with VAS (Rp?=?0.61, P?<?0.001) and a moderate correlation with GROC (Rs?=?0.46, P?<?0.001). The correlation between NDI-SC change scores and VAS change scores was also moderate (Rp?=?0.59, P?<?0.001). CONCLUSION:The results showed that the NDI-SC is a reliable, valid, and responsive instrument to measure functional limitations in patients with neck pain. LEVEL OF EVIDENCE:3.
| S-EPMC7208282 | biostudies-literature
Project description:Study designA cross-sectional study with a test-retest design.ObjectiveTo translate and culturally adapt the numerical rating scale (NRS) for neck pain intensity and the Neck Disability Index (NDI), and asses their measurement properties in a Nepalese neck pain population.Summary of background dataNeck pain is one of the most common musculoskeletal disorders in Nepal. Research on neck pain disorders has been hampered by lack of standardized patient-reported outcome measures (PROMs) in Nepali language. Therefore, we aimed at validating a Nepali version of the NDI and NRS neck pain.MethodsAt Dhulikhel hospital in Nepal, 150 patients with neck pain and/or cervical radiculopathy completed the translated self-administered questionnaires. We had made one cultural adaption of the NDI driving item in the final Nepali version. Relative reliability was analyzed with intraclass correlation coefficient (ICC 2.1) and absolute reliability with the smallest detectable change (SDC). Internal consistency was assessed by Cronbach alpha. Construct and discriminative validity was assessed by Spearman correlation for a priori hypotheses, receiver-operating characteristics curves, and analysis of variance. Time spent and assistance needed to complete the questionnaires were used to assess feasibility.ResultsTest-restest reliability was excellent with ICC (95% confidence intervals) of 0.87 (0.66, 0.94) for NDI and 0.97 (0.94, 0.99) for NRS neck pain. The absolute reliability was acceptable (a SDC of 1.6 for NRS and 9.3 for NDI) and a Cronbach alpha (internal consistency) of 0.70 for NDI, as well as acceptable construct validity, discriminative validity, and feasibility.ConclusionThe Nepali versions of the NRS neck pain and NDI can be recommended for assessing pain and disability among patients with neck pain and cervical radiculopathy, but their responsiveness to change remains to be tested.Level of Evidence: 2.
| S-EPMC7864651 | biostudies-literature
Project description:No official German translation exists for the 50-item Expanded Prostate Cancer Index Composite (EPIC), and no minimal important difference (MID) has been established yet. The aim of the study was to translate and validate a German version of the EPIC with cultural adaptation to the different German speaking countries and to establish the MID.We translated and culturally adapted the EPIC into German. For validation, we included a consecutive subsample of 92 patients with localized prostate cancer undergoing radical prostatectomy who participated the Prostate Cancer Outcomes Cohort. Baseline and follow-up assessments took place before and six weeks after prostatectomy in 2010 and 2011. We assessed the EPIC, EORTC QLQ-PR25, Feeling Thermometer, SF-36 and a global rating of health state change variable. We calculated the internal consistency, test-retest reliability, construct validity, responsiveness and MID.For most EPIC domains and subscales, our a priori defined criteria for reliability were fulfilled (construct reliability: Cronbach's alpha 0.7-0.9; test-retest reliability: intraclass-correlation coefficient???0.7). Cross-sectional and longitudinal correlations between EPIC and EORTC QLQ-PR25 domains ranged from 0.14-0.79, and 0.06-0.5 and 0.08-0.72 for Feeling Thermometer and SF-36, respectively. We established MID values of 10, 4, 12, and 6 for the urinary, bowel, sexual and hormonal domain.The German version of the EPIC is reliable, responsive and valid to measure HRQL in prostate cancer patients and is now available in German language. With the suggested MID we provide interpretation to what extent changes in HRQL are clinically relevant for patients. Hence, study results are of interest beyond German speaking countries.
| S-EPMC5819270 | biostudies-other
Project description:PurposePatient-reported outcome measures are essential in the evaluation of facial palsy. Aim of this study was to translate and validate the Facial Disability Index (FDI) for use in the Netherlands.MethodsThe FDI was translated into Dutch according to a forward-backward method. Construct validity was assessed by formulating 22 hypotheses regarding associations of FDI scores with the Facial Clinimetric Evaluation scale, the Synkinesis Assessment Questionnaire, the Short Form-12 and the Sunnybrook Facial Grading System. Validity was considered adequate if at least 75% (i.e. 17 out of 22) of the hypotheses were confirmed. Additionally, confirmatory factor analysis was performed. Cronbach's α was calculated as a measure of internal consistency. Participants were asked to fill out the FDI a second time after 2 weeks to analyse test-retest reliability. Lastly, smallest detectable change was calculated.ResultsIn total, 19 hypotheses (86.4%) were confirmed. Confirmatory factor analysis showed acceptable fit for the two factor structure of the original FDI (root mean square error of approximation = 0.064, standardized root mean square residual = 0.081, comparative fit index = 0.925, Chi-square = 50.22 with 34 degrees of freedom). Internal consistency for the FDI physical function scale was good (α > 0.720). Internal consistency for the FDI social/well-being scale was slightly less (α > 0.574). Test-retest reliability for both scales was good (intraclass correlation coefficients > 0.786). Smallest detectable change at the level of the individual was 17.6 points for the physical function and 17.7 points for the social/well-being function, and at group level 1.9 points for both scales.ConclusionThe Dutch version FDI shows good psychometric properties. The relatively large values for individual smallest detectable change may limit clinical use. The translation and widespread use of the FDI in multiple languages can help to compare treatment results internationally.
| S-EPMC7393719 | biostudies-literature