Reliability and responsiveness of the Norwegian version of the Neck Disability Index

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.

Exploring visual pain trajectories in neck pain patients, using clinical course, SMS-based patterns, and patient characteristics: a cohort study

Background

The dynamic nature of neck pain has so far been identified through longitudinal studies with frequent measures, a method which is time-consuming and impractical. Pictures illustrating different courses of pain may be an alternative solution, usable in both clinical work and research, but it is unknown how well they capture the clinical course. The aim of this study was to explore and describe self-reported visual trajectories in terms of details of patients’ prospectively reported clinical course, their SMS-based pattern classification of neck pain, and patient’s characteristics.

Methods

Prospective cohort study including 888 neck pain patients from chiropractic practice, responding to weekly SMS-questions about pain intensity for 1 year from 2015 to 2017. Patients were classified into one of three clinical course patterns using definitions based on previously published descriptors. At 1-year follow-up, patients selected a visual trajectory that best represented their retrospective 1-year course of pain: single episode, episodic, mild ongoing, fluctuating and severe ongoing.

Results

The visual trajectories generally resembled the 1-year clinical course characteristics on group level, but there were large individual variations. Patients selecting Episodic and Mild ongoing visual trajectories were similar on most parameters. The visual trajectories generally resembled more the clinical course of the last quarter.

Discussion

The visual trajectories reflected the descriptors of the clinical course of pain captured by weekly SMS measures on a group level and formed groups of patients that differed on symptoms and characteristics. However, there were large variations in symptoms and characteristics within, as well as overlap between, each visual trajectory. In particular, patients with mild pain seemed predisposed to recall bias. Although the visual trajectories and SMS-based classifications appear related, visual trajectories likely capture more elements of the pain experience than just the course of pain. Therefore, they cannot be seen as a proxy for SMS-tracking of pain over 1 year.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12998-022-00443-3.

The clinical course of neck pain: Are trajectory patterns stable over a 1-year period?

BACKGROUND

Recent studies with data-driven approaches have established common pain trajectories. It is uncertain whether these trajectory patterns are consistent over time, and if a shorter measurement period will provide accurate trajectories.

METHODS

We included 1,124 patients with non-specific neck pain in chiropractic practice. We classified patients into pre-defined trajectory patterns in each of four quarters of the follow-up year (persistent, episodic, and recovery) based on measures of pain intensity and frequency from weekly SMS. We explored the shifts between patterns and compared patients with stable and shifting patterns on baseline characteristics and clinical findings.

RESULTS

785 (70%) patients were in the same pattern in 1st and 4th quarters. Patients with episodic pattern in the 1st quarter shifted to other patterns more frequently than patients in the other patterns. A stable persistent pattern was associated with reduced function and higher scores on psychosocial factors. There was a decreased frequency of patients classified as persistent pattern (75% to 63%) and an increase of patients in recovery pattern (4% to 15%) throughout the four quarters. The frequency of patients classified as episodic remained relatively stable (21% to 24%).

CONCLUSIONS

We found an overall stability of the persistent pattern, and that episodic patterns have more potential for shifts. Shifts mostly occurred between patterns closest in pain variation. The deviation in pattern distribution compared with previous studies suggests that the duration of measurement periods has an impact on the results of the classification.

SIGNIFICANCE

Having persistent pain and having very minor pain is relatively stable over one year, while episodic pain has more potential for shifts. The duration of measurement periods appears to have an impact on the results of the classification. The given criteria resulted in a reduced frequency of episodic pattern due to shorter measurement periods. Our findings contribute to improved understanding and predicting NP using a combination of patient characteristics and trajectory patterns.

The Short-Form Neck Disability index has adequate measurement properties in chronic neck pain patients

Objectives

To assess test–retest reliability, internal consistency, construct validity, and the presence of ceiling and floor effects in the Brazilian version of the Short-Form Neck Disability Index (SF-NDI) in patients with chronic neck pain.

Methods

One hundred and fifty-six patients answered the Numerical Pain Rating Scale (NPRS), Short-Form Neck Disability Index (SF-NDI), Tampa Scale of Kinesiophobia (TKS), Pain Catastrophizing Scale (PCS), and the 36-Item Short-Form Health Survey questionnaire (SF-36). Another sample (n = 51) filled the SF-NDI at two different times, and test–retest reliability was measured using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimum detectable change (MDC). The internal consistency of the SF-NDI was analyzed by Cronbach's alpha. To determine construct validity, Spearman's correlation coefficient was used to determine the magnitude of the correlation between the score of the SF-NDI and other measurement instruments: NPRS, TKS, PCS, SF-36, and original NDI.

Results

SF-NDI presented substantial reliability (ICC = 0.844) and adequate internal consistency (Cronbach's alpha = 0.778). We observed significant values and with a correlation magnitude greater than 0.80 for the SF-NDI with the original NDI, between 0.30 and 0.50 for the correlations with TKS, and the functional capacity and pain domains of the SF-36, and less than 0.30 with the other study instruments. No participant reached the maximum score. Ceiling and floor effects were not observed.

Conclusions

SF-NDI with 5 items has adequate measurement properties in Brazilian chronic neck pain patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00586-021-07019-4.

Neck pain patterns and subgrouping based on weekly SMS-derived trajectories

BACKGROUND

Neck and low back pain represent dynamic conditions that change over time, often with an initial improvement after the onset of a new episode, followed by flare-ups or variations in intensity. Pain trajectories were previously defined based on longitudinal studies of temporal patterns and pain intensity of individuals with low back pain. In this study, we aimed to 1) investigate if the defined patterns and subgroups for low back pain were applicable to neck pain patients in chiropractic practice, 2) explore the robustness of the defined patterns, and 3) investigate if patients within the various patterns differ concerning characteristics and clinical findings.

METHODS

Prospective cohort study including 1208 neck pain patients from chiropractic practice. Patients responded to weekly SMS-questions about pain intensity and frequency over 43 weeks. We categorized individual responses into four main patterns based on number of days with pain and variations in pain intensity, and subdivided each into four subgroups based on pain intensity, resulting in 16 trajectory subgroups. We compared baseline characteristics and clinical findings between patterns and between Persistent fluctuating and Episodic subgroups.

RESULTS

All but two patients could be classified into one of the 16 subgroups, with 94% in the Persistent fluctuating or Episodic patterns. In the largest subgroup, "Mild Persistent fluctuating" (25%), mean (SD) pain intensity was 3.4 (0.6) and mean days with pain 130. Patients grouped as "Moderate Episodic" (24%) reported a mean pain intensity of 2.7 (0.6) and 39 days with pain. Eight of the 16 subgroups each contained less than 1% of the cohort. Patients in the Persistent fluctuating pattern scored higher than the other patterns in terms of reduced function and psychosocial factors.

CONCLUSIONS

The same subgroups seem to fit neck and low back pain patients, with pain that typically persists and varies in intensity or is episodic. Patients in a Persistent fluctuating pattern are more bothered by their pain than those in other patterns. The low back pain definitions can be used on patients with neck pain, but with the majority of patients classified into 8 subgroups, there seems to be a redundancy in the original model.

Cross-cultural adaptation and psychometric evaluation of the Malay version of the Neck Disability Index

Purpose: Translating the Neck Disability Index (NDI) into the Malay language (NDI-M); evaluation of psychometric properties in patients with neck pain.Methods: The NDI-M was translated according to established guidelines. In the first visit, 120 participants completed the NDI-M, visual analogue scale (VAS) for pain and demographic details. 98 participants returned to complete similar questionnaires and the Global Rating of Change (GRoC) scale. The NDI-M was evaluated for internal consistency, test-retest reliability, content validity, construct validity and responsiveness.Results: The NDI-M demonstrated excellent internal consistency (Cronbach's α = 0.84) and good test-retest reliability (ICC_2,1 = 0.79). Content validity was confirmed with no floor or ceiling effects. Construct validity was established revealing three-factor subscales explaining 68% of the total variance. The NDI-M showed a moderate correlation with VAS (R_p = 0.49, p < 0.001). Regarding responsiveness, a moderate correlation between NDI-M change scores and VAS change scores was found (R_p = 0.40, p < 0.001). However, there was no significant correlation between NDI-M with GRoC (R_s = 0.11, p = 0.27).Conclusions: The NDI-M is a reliable and valid tool to measure functional outcomes in patients with neck pain. It is responsive in detecting changes in pain intensity during a patient's rehabilitation journey.Implications for rehabilitationThe NDI was translated into the Malay language and culturally adapted for Malay-speaking patients with neck pain.The NDI-M demonstrated an excellent level of internal consistency and good test-retest reliability. It demonstrated content and construct validity, with three-factor subscales, and moderate responsiveness for pain intensity.The NDI-M is a reliable, valid and responsive instrument to measure functional limitations in patients with neck pain for rehabilitation.

The Responsiveness of the Persian Version of Neck Disability Index and Functional Rating Index Following Physiotherapy Intervention in People with Chronic Neck Pain

Background:

Clinicians and researchers commonly use responsive outcome measures to interpret changes in a patient’s condition as a result of an intervention. This study was conducted to assess the ability of the Persian version of Neck Disability Index and Functional Rating Index to detect responsiveness in the patients with neck pain.

Methods:

A diagnostic accuracy study was done in Ahvaz, Iran, 2016. A convenience sample of 57 Persian-speaking patients with non-specific chronic neck pain completed the Neck Disability Index and the Functional Rating Index at the beginning and after physiotherapy intervention. The responsiveness was investigated by the receiver operating characteristics method and the correlation analysis. Statistical analysis was done using SPSS (version 21), with a P<0.05 as the level of significance.

Results:

The Functional Rating Index showed that the area under the curve was greater than 0.70 (range=0.651-0.942). The optimal cutoff points for the Functional Rating Index and the Neck Disability Index were 9.5 and 7.5, respectively. Gamma correlation between change scores of the Functional Rating Index and the Neck Disability Index and the Global Rating of Change Scores was 0.53 and 0.33, respectively.

Conclusion:

The results indicated that the Persian version of the Functional Rating Index could detect clinical changes following physiotherapy intervention in a group of patients with chronic non-specific neck pain. Therefore, we recommend that this instrument be used as a responsive measure of neck pain disability in patients with 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.

Test-retest reliability of self-reported diabetes diagnosis in the Norwegian Women and Cancer Study: A population-based longitudinal study (n =33,919)

Objective:

Self-reported information from questionnaires is frequently used in epidemiological studies, but few of these studies provide information on the reproducibility of individual items contained in the questionnaire. We studied the test–retest reliability of self-reported diabetes among 33,919 participants in Norwegian Women and Cancer Study.

Methods:

The test–retest reliability of self-reported type 1 and type 2 diabetes diagnoses was evaluated between three self-administered questionnaires (completed in 1991, 1998, and 2005 by Norwegian Women and Cancer participants) by kappa agreement. The time interval between the test–retest studies was ~7 and ~14 years. Sensitivity of the kappa agreement for type 1 and type 2 diabetes diagnoses was assessed. Subgroup analysis was performed to assess whether test–retest reliability varies with age, body mass index, physical activity, education, and smoking status.

Results:

The kappa agreement for both types of self-reported diabetes diagnoses combined was good (⩾0.65) for all three test–retest studies (1991–1998, 1991–2005, and 1998–2005). The kappa agreement for type 1 diabetes was good (⩾0.73) in the 1991–2005 and the 1998–2005 test–retest studies, and very good (0.83) in the 1991–1998 test–retest study. The kappa agreement for type 2 diabetes was moderate (0.57) in the 1991–2005 test–retest study and good (⩾0.66) in the 1991–1998 and 1998–2005 test–retest studies. The overall kappa agreement in the 1991–1998 test–retest study was stronger than in the 1991–2005 test–retest study and the 1998–2005 test–retest study. There was no clear pattern of inconsistency in the kappa agreements within different strata of age, BMI, physical activity, and smoking. The kappa agreement was strongest among the respondents with 17 or more years of education, while generally it was weaker among the least educated group.

Conclusion:

The test–retest reliability of the diabetes was acceptable and there was no clear pattern of inconsistency in the kappa agreement stratified by age, body mass index, physical activity, and smoking. The study suggests that self-reported diabetes diagnosis from middle-aged women enrolled in the Norwegian Women and Cancer Study is reliable.