The Neck Disability Index: state-of-the-art, 1991-2008

BACKGROUND: Published in 1991, the Neck Disability Index (NDI) was the first instrument designed to assess self-rated disability in patients with neck pain. This article reviews the history of the NDI and the current state of the research into its psychometric properties--reliability, validity, and responsiveness--as well as its translations. Focused reviews are presented into its use in studies of the prognosis of whiplash-injured patients as well as its use in clinical trials of conservative therapies for neck pain. SPECIAL FEATURES: The NDI is a relatively short, paper-pencil instrument that is easy to apply in both clinical and research settings. It has strong psychometric characteristics and has proven to be highly responsive in clinical trials. As of late 2007, it has been used in approximately 300 publications; it has been translated into 22 languages, and it is endorsed for use by a number of clinical guidelines. SUMMARY: The NDI is the most widely used and most strongly validated instrument for assessing self-rated disability in patients with neck pain. It has been used effectively in both clinical and research settings in the treatment of this very common problem.     

Relationship Between Intensity of Neck Pain and Disability and Shoulder Pain and Disability in Individuals With Subacromial Impingement Symptoms: A Cross-Sectional Study

ObjectiveThis study aimed to verify a possible relationship between shoulder disability and shoulder pain intensity and the variables related to cervical-spine dysfunction, and determine which of these can differentiate moderate to severe shoulder pain (>4 on a numerical rating scale [NRS]) from mild shoulder pain (≤4 on the NRS) in individuals with subacromial impingement symptoms.MethodsOne hundred and forty volunteers with shoulder pain were evaluated. Demographic information and variables related to the shoulder and neck were collected. Self-reported pain and disability of the shoulder and cervical spine were measured using the Shoulder Pain and Disability Index (SPADI) and Neck Disability Index (NDI) questionnaires, respectively. An NRS was used to measure pain in the shoulder and cervical spine. A purposeful modeling strategy was used to determine the best model to predict shoulder disability and shoulder pain (dependent variables). Multiple logistic regression analysis followed by receiver operating curve analysis was used to determine which variables better differentiated moderate to severe shoulder pain from mild shoulder pain.ResultsVariables such as Neck Disability Index (NDI) score (β = 1.09, P = .00) and age (β = −0.19, P = .03) were associated with the total SPADI score. Neck pain was significantly associated with shoulder pain (β = 0.40, P = .00). The combination of variables predicting moderate to severe shoulder pain was total SPADI score (odds ratio [OR] = 1.15, P = .003), neck pain (OR = 3.20, P = .04), and age (OR = 1.01, P = .05).ConclusionOur results demonstrate the important connection between shoulder- and neck-related symptoms in individuals with subacromial impingement symptoms.     

Validity of the Neck Disability Index and Neck Pain and Disability Scale for measuring disability associated with chronic, non-traumatic neck pain

The purpose of this study was to evaluate the construct and content validity of the Neck Disability Index (NDI) and the Neck Pain and Disability Scale (NPAD) in patients with chronic, non-traumatic neck pain. Twenty patients (mean age=64.5 years) completed a patient-specific questionnaire, the Problem Elicitation Technique (PET), followed by the NDI and NPAD. Content validity was assessed by comparing the items of the NDI and NPAD with problems identified from the PET. Construct validity of the fixed-item questionnaires was examined by establishing the correlation with each other, and with the PET score. Eleven common problems were identified by patients through the PET, of which six were included in the NDI and seven included in the NPAD. The NDI and NPAD scores were strongly correlated (r=0.86, p<0.01), while the correlation between the PET and the fixed-item questionnaires was moderate (NDI: r=0.62, p<0.01; NPAD: r=0.71, p<0.01). Both the NDI and the NPAD include most of the functional problems common to this patient group, and display good content validity. The PET is better able to evaluate the problems specific to the individual patient and is therefore measuring a somewhat different construct to the fixed-item questionnaires.     

Psychometric properties of the Neck Disability Index and Numeric Pain Rating Scale in patients with mechanical neck pain

Cleland JA, Childs JD, Whitman JM. Psychometric properties of the Neck Disability Index and numeric pain rating scale in patients with mechanical neck pain.

Objective

To examine the psychometric properties including test-retest reliability, construct validity, and minimum levels of detectable and clinically important change for the Neck Disability Index (NDI) and the numeric rating scale (NRS) for pain in a cohort of patients with neck pain.

Design

Single-group repeated-measures design.

Setting

Outpatient physical therapy (PT) clinics.

Participants

Patients (N=137) presenting to PT with a primary report of neck pain.

Interventions

Not applicable.

Main Outcome Measures

All patients completed the NDI and the NRS at the baseline examination and at a follow-up. At the time of the follow-up, all patients also completed the global rating of change, which was used to dichotomize patients as improved or stable. Baseline and follow-up scores were used to determine the test-retest reliability, construct validity, and minimal levels of detectable and clinically important change for both the NDI and NRS.

Results

Test-retest reliability was calculated using an intraclass correlation coefficient (ICC) (NDI ICC=.50; 95% confidence interval [CI], .25-.67; NRS ICC=.76; 95% CI, .51-.87). The area under the curve was .83 (95% CI, .75-.90) for the NDI score and .85 (95% CI, .78-.93) for the NRS score for determining between stable and improved patients. Thresholds for the minimum clinically important difference (MCID) for the NDI were 19-percentage points and 1.3 for the NRS.

Conclusions

Both the NDI and NRS exhibit fair to moderate test-retest reliability in patients with mechanical neck pain. Both instruments also showed adequate responsiveness in this patient population. However, the MCID required to be certain that the change in scores has surpassed a level that could be contributed to measurement error for the NDI was twice that which has previously been reported. Therefore the ongoing analyses of the properties of the NDI in a patient population with neck pain are warranted.     

The Bournemouth Questionnaire for Neck Pain: Cross-cultural Adaptation,Reliability, and Validity of the Turkish Version

ObjectiveThe aim of this study was first to translate and culturally adapt the BQN, and then to investigate the validity and reliability of the Turkish version of the BQN in Turkish individuals with chronic neck pain.MethodsThe English version of the BQN was translated into Turkish with permission from its authors. That translation was assessed using 85 participants with a mean age of 46.75 years who had chronic neck pain. At the same time, the participants were assessed sociodemographically and with the Neck Disability Index (NDI) and the Neck Pain and Disability Scale (NPAD). A test–retest procedure was performed with 62 participants who underwent a second assessment with the BQN within 24 hours of the first assessment, to test its reliability.ResultsInternal consistency was strong and all Cronbach alpha values were between 0.97 and 0.99. The BQN showed high test–retest reliability (intraclass correlation coefficient ˃ 0.92) for all domains. The total mean (± standard deviation) scores for the 3 questionnaires were as follows: BQN, 30.9 (± 11.18); NPAD, 48.16 (± 12.93); NDI, 17.85 (± 6.29). The results of the Turkish version of the BQN illustrated adequate external construct validity and sensitivity. A Turkish translation of the test has not previously been available for chronic pain.ConclusionThe BQN was successfully translated and culturally adapted into Turkish. The reliability and validity were tested against the NPAD and the NDI. The Turkish version of the BQN is multidimensional, short, practical, and suitable for use with individuals with neck pain.     

Prospective Cohort Study of Patients With Neck Pain in a Manual Therapy Setting: Design and Baseline Measures

ObjectivesThe purpose of this study was to describe the design and baseline measurements of a prospective multicenter cohort study in patients with neck pain treated by Dutch manual therapists. Objectives of the study were to determine which patients seek help from a manual therapist, to describe usual care manual therapy in patients with neck pain, to examine the occurrence of nonserious adverse events after treatment, to describe predictors of adverse events, and to determine whether the occurrence of nonserious adverse events affect outcome after manual therapy care.MethodsDuring a 3-month inclusion period, consecutive patients aged between 18 and 80 years presenting with neck pain in manual therapy practices in The Netherlands were included in the study. Baseline questionnaires included the Numeric Rating Scale, Neck Disability Index (NDI), Neck Bournemouth Questionnaire, Fear Avoidance Beliefs Questionnaire (FABQ), and Patient Expectancy List. Within the treatment episode, manual therapist clinical reasoning and applied interventions were registered and patients reported on adverse events. At the end of the treatment episode and at 12-month follow-up, pain intensity (Numeric Rating Scale), functional outcomes (NDI, Neck Bournemouth Questionnaire), personal factors (FABQ), and global perceived effect were measured.ResultsDuring the 3-month inclusion period, 263 participating manual therapists collected data on 1193 patients with neck pain. Most patients (69.4%) were female. The mean age was 44.7 (±13.7) years. The NDI showed overall mild disability (mean score 26%). Mean scores in pain intensity were moderate (4.8), and there was low risk of prolonged disability owing to personal factors (FABQ).ConclusionThis study provides information on baseline characteristics of patients visiting manual therapists for neck pain. In The Netherlands, patients seeking care of manual therapists are comparable to patients in other countries regarding demographics and neck pain characteristics.     

Self-rated disability,fear-avoidance beliefs,nonorganic pain behaviors are important mediators of ranges of active motion in chronic whiplash patients

Abstract

Purpose: The influence of self-rated disability and fear-avoidance beliefs on whiplash sufferers in their performance of active ranges of motion has not been studied well. We undertook a cross-sectional study to determine this. Methods: Chronic whiplash subjects completed a standard clinical examination. They completed the Neck Disability Index (NDI), the Tampa Scale for Kinesiophobia (TSK) and pain visual analog scale (VAS). Active ranges of motion (goniometer) and cervical nonorganic simulation signs (C-NOSS) were obtained by the examiner. Univariate and multivariable analyses were conducted on these scores. Results: Sixty-four subjects (37 female) with a mean age of 41.4 (SD 16.1) years completed all scores. NDI, pain VAS and C-NOSS correlated significantly with ROM. In a multivariable model, only the NDI score contributed significantly to the variance of the ROM scores (14%). Conclusion: As chronic whiplash sufferers perform ROM in a clinical examination, these ranges are importantly influenced by their self-perceived disability. Cervical nonorganic simulation signs can be helpful in distinguishing high from very high levels of disability and motion restriction. The lack of correlation with the TSK may present a challenge to the Fear Avoidance Model in whiplash.

• Implications for Rehabilitation

• Self-ratings of disability in chronic whiplash sufferers are influenced by their fear-avoidance beliefs.

• While self-ratings of disability are known to predict chronicity of whiplash, there is less known about how these ratings affect impairment assessment during recovery.

• This study shows that self-ratings of disability influence the presentation of impairment by chronic whiplash sufferers with respect to their ranges of neck motion.

• Signs of nonorganic behavior also influence ranges of motion and self-ratings of disability.

• These findings should be incorporated into the interpretation of impairment findings in chronic whiplash sufferers in order to improve management.

     

The Neck Disability Index: a study of reliability and validity.

Injuries to the cervical spine, especially those involving the soft tissues, represent a significant source of chronic disability. Methods of assessment for such disability, especially those targeted at activities of daily living which are most affected by neck pain, are few in number. A modification of the Oswestry Low Back Pain Index was conducted producing a 10-item scaled questionnaire entitled the Neck Disability Index (NDI). Face validity was ensured through peer-review and patient feedback sessions. Test-retest reliability was conducted on an initial sample of 17 consecutive "whiplash"-injured patients in an outpatient clinic, resulting in good statistical significance (Pearson's r = 0.89, p less than or equal to .05). The alpha coefficients were calculated from a pool of questionnaires completed by 52 such subjects resulting in a total index alpha of 0.80, with all items having individual alpha scores above 0.75. Concurrent validity was assessed in two ways. First, on a smaller subset of 10 patients who completed a course of conservative care, the percentage of change on NDI scores before and after treatment was compared to visual analogue scale scores of percent of perceived improvement in activity levels. These scores correlated at 0.60. Secondly, in a larger subset of 30 subjects, NDI scores were compared to scores on the McGill Pain Questionnaire, with similar moderately high correlations (0.69-0.70). While the sample size of some of the analyses is somewhat small, this study demonstrated that the NDI achieved a high degree of reliability and internal consistency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mechanical Pain Sensitivity and the Severity of Chronic Neck Pain and Disability Are Not Modulated Across the Menstrual Cycle

Despite the high prevalence of neck pain among women, menstrual effects on regional pain outcomes have not been investigated in this clinical population. This study evaluated menstrual effects on mechanical pain sensitivity (pressure pain threshold [PPT]), neck pain intensity (numeric pain rating scale [NPRS]), and neck-related disability (Neck Disability Index [NDI]) in 22 normally menstruating (NM) and 17 hormonal contraceptive users with chronic neck pain. Sex hormones, PPT, and NDI were measured during the early follicular (F1), late follicular (F2), and luteal (L) menstrual phases. Daily NPRS scores were recorded in an online symptom diary and averaged within each phase. Estradiol and progesterone increased only for NM women in F2 and L, respectively. Phase effects on PPT (η² = .003), NDI (η² = .003), and NPRS (η² = .016) for NM women were small and did not differ from those for the hormonal contraceptive users (P ≥ .386). Averaged across the menstrual cycle, PPT scores explained 29% of the variance in NPRS scores for NM women but were not associated with NDI scores in either group. Results indicate that the magnitude of menstrual effects on mechanical pain sensitivity and the severity of neck pain and disability do not exceed thresholds of clinically detectable change in women with chronic neck pain.     

Correlation Between Chronic Neck Pain and Heart Rate Variability Indices at Rest: A Cross-sectional Study

ObjectiveThe purpose of this study was to correlate the heart rate variability (HRV) indices with variables of pain that were experienced by individuals with chronic neck pain.MethodsThis was a blinded cross-sectional study. Individuals with chronic neck pain (n = 15) and healthy participants (n = 15), both sedentary and between 18 and 45 years of age, were included. The neck pain was assessed with the Numerical Rating Scale at rest and during cervical movements, Neck Disability Index, Catastrophic Thoughts about Pain Scale, and Tampa Scale of Kinesiophobia. The HRV indices (linear and nonlinear) were used for assessment of autonomic function at rest (in supine, sitting, and standing positions).ResultsWe observed significant correlations between the NRS, Neck Disability Index, and Catastrophic Thoughts about Pain Scale with the linear and nonlinear HRV indices (P < .05, r ≥ 0.362), so that the worst HRV indices are associated with conditions of more intense and disabling neck pain.ConclusionThe HRV indices were significantly associated with pain intensity, disabilty, and catastrophizing in individuals with chronic neck pain.     

Photogrammetric Variables Used by Physical Therapists to Detect Neck Pain and to Refer for Physiotherapeutic Intervention: A Cross-Sectional Study

ObjectiveThe purpose of this study were as follows (1): to investigate photogrammetry variables that physiotherapists may detect by visually inspecting the static body posture that distinguishes young adults with or without neck pain, which may lead to referral to a physiotherapy intervention, and (2) to assess the reliability of postural assessment and clinical decision-making.MethodsWe conducted a cross-sectional, observational, balanced, controlled, single-blinded study. Fourteen physiotherapists aged 33 (6) years were recruited as raters for postural assessment of adults aged 28 (7) years with (n = 30) or without neck pain (n = 30). Photogrammetry was performed to quantify the static body posture alignments and angles. Visual inspection was performed to indicate the presence of postural misalignment and neck pain and to refer to physiotherapy intervention.ResultsSymptomatic participants showed low- to moderate-intensity neck pain, a high frequency of chronic neck pain, and low disability scores. Photogrammetry analysis revealed no statistically significant difference between groups. Classification of the participants according to the raters’ visual inspection yielded sets of photogrammetry variables with significant differences, with a large variability among those sets. Intrarater and interrater reliability of photogrammetry varied from moderate to excellent (intraclass correlation coefficient_2,1 = [0.502; 0.995]; intraclass correlation coefficient_2,2 = [0.564; 0.996). Interrater reliability for visual inspection was no better than chance (κ_Light = -0.013 to 0.011; ι = -0.002).ConclusionNeither photogrammetry nor visual inspection distinguished the presence of neck pain in young adults. Using visual inspection, physiotherapists had unreliable clinical decision-making owing to high variability of photogrammetry variables used to distinguish postural misalignments, the presence of neck pain, and whether to refer young adults for physiotherapy intervention.     

Physical and psychological factors predict outcome following whiplash injury

Predictors of outcome following whiplash injury are limited to socio-demographic and symptomatic factors, which are not readily amenable to secondary and tertiary intervention. This prospective study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds, brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK, IES) were measured in 76 acute whiplash participants. The outcome measure was Neck Disability Index scores at 6 months. Stepwise regression analysis was used to predict the final NDI score. Logistic regression analyses predicted membership to one of the three groups based on final NDI scores (<8 recovered, 10-28 mild pain and disability, >30 moderate/severe pain and disability). Higher initial NDI score (1.007-1.12), older age (1.03-1.23), cold hyperalgesia (1.05-1.58), and acute post-traumatic stress (1.03-1.2) predicted membership to the moderate/severe group. Additional variables associated with higher NDI scores at 6 months on stepwise regression analysis were: ROM loss and diminished sympathetic reactivity. Higher initial NDI score (1.03-1.28), greater psychological distress (GHQ-28) (1.04-1.28) and decreased ROM (1.03-1.25) predicted subjects with persistent milder symptoms from those who fully recovered. These results demonstrate that both physical and psychological factors play a role in recovery or non-recovery from whiplash injury. This may assist in the development of more relevant treatment methods for acute whiplash.     

Adding Temporomandibular joint treatments to routine physiotherapy for patients with non-specific chronic neck pain: A randomized clinical study

IntroductionNeck Pain can be related to the disorders of other adjacent areas such as the Temporomandibular Joint (TMJ). This study aimed to investigate whether there is value in adding TMJ treatments to routine physiotherapy in patients with non-specific chronic neck pain compared with a control group.MethodsA randomized, single-blind, clinical study desined including two groups of patients. Group A (20 people) received routine physiotherapy for neck pain and group B (20 people) received TMJ manual therapy plus exercise therapy in addition to routine physiotherapy for neck pain. The Treatment program included six sessions for two days a week over a period of 21 days. Assessments were performed during the first session, in the last session and one month after treatment as a follow-up. Outcome measures included neck range of motion (ROM), neck disability index (NDI) and visual analogue scale (VAS). Before starting the study, the reliability of methods for measuring neck ROM was evaluated.ResultsParticipants were 21 women and 19 men. Initially, a pilot study was carried out on the 40 volunteers to assess the reliability of the measurement methods, and the results were acceptable. With both the control group and the intervention group, the indexes showed significant improvement (p < 0.001), although the intervention group showed more improvement (p < 0.001).ConclusionThis result means adding treatments of TMJ to routine neck physiotherapy can magnify the effect of the intervention, a significant change still in evidence at follow up. Moreover, given the clinically important differences, our results for VAS and NDI were acceptable.     

Spanish Version of the Whiplash Disability Questionnaire in Adults With Acute Whiplash-Associated Disorders

ObjectiveThe purpose of this study was to develop and validate a Spanish version of the Whiplash Disability Questionnaire (WDQ) for the Spanish population with acute whiplash-associated disorder (WAD).MethodsThis was a cross-sectional questionnaire validation study. Adults with acute WAD (grade I to III) were enrolled within 3 weeks of their injury. A blinded forward and back translation of the WDQ was made from English to Spanish, and the resulting back-translation version was compared with the original. Patients with WAD completed the Spanish version of the 13-item WDQ. The developed questionnaire was assessed using psychometric statistical analysis including correlation with the numerical rating score for pain, Northwick Park Neck Pain Questionnaire, Neck Disability Index, and 36-item Short Form Health Survey.ResultsFifty-six patients completed the questionnaire, the mean age was 33.9 years (standard deviation [SD] = 10.5), and 76.8% were women. Participants were enrolled 13.9 days (SD 4.9) after the injury, with 14.3% presenting with WAD grade I and 85.7% with WAD grade II. The mean WDQ score was 62 (SD = 31). Two factors were detected, and the factor structure remained stable after translation. Positive correlations were identified between the total WDQ score and the numerical rating score, Neck Pain Questionnaire, and Neck Disability Index results, with a strong negative correlation with the 36-item Short Form Health Survey.ConclusionThe Spanish version of WDQ is psychometrically reliable and a valid instrument to measure the disability status in patients with acute WAD within the clinic.     

Management of acute neck pain: A case series describing immediate and short term clinical outcomes following use of the Multifidus Isometric Technique

BackgroundAcute facet capsular entrapment results in sudden onset of pain and reduced ability to perform active cervical motions. The Multifidus Isometric Technique (MIT) is a type of manual therapy intervention theorized to target the entrapped facet capsule and pull the entrapped synovial folds from the facet joint resulting in decreased pain and increased function.PurposeTo describe immediate MIT clinical outcomes for patients with acute neck pain.MethodsConsecutive patients (n = 30; 70% female) with sudden onset of neck pain received MIT within 48 hours of symptom onset. Clinical outcome measures included: 1) 11-point Numeric Pain Rating Scale (NPRS); 2) cervical AROM, and 3) the Neck Disability Index (NDI). Paired-sample t-testing was used to assess for within and between-session changes in outcome measure scores.ResultsWithin-session NPRS improvements were observed during all cervical AROM movements (p < .01), with initial treatment associated with greater improvements on average (M = 2.4 ± 1.6 points) compared to the second treatment (M = 0.6 ± 0.9 points). Similarly, most within-session AROM measures improved during both sessions (p < .01) with greater average improvements observed following the initial treatment session and for cervical rotation to the symptomatic side (M = 26.5 ± 9.6 vs. 8.0 ± 9.7°). Between-session NDI scores improved (M = 15.3 ± 9.8, p < .01) with approximately 60% of patients achieving a minimally clinically important difference of 14 percentage points.DiscussionThe MIT is a potentially beneficial intervention for patients with acute neck pain. Future studies consisting of longer follow-up time points and comparison treatment groups are needed to test MIT effectiveness.     

Validation of the Neck Disability Index in Serbian Patients With Cervical Radiculopathy

Objective

The purpose of this study was to translate the Neck Disability Index into the Serbian language (NDI-S) and to investigate the validity of this version for use in Serbian population.

The effect of pre-injury physical fitness on the initial severity and recovery from whiplash injury, at six-month follow-up

OBJECTIVE: To evaluate the effect of pre-injury physical fitness on the initial severity and recovery of motor vehicle-induced neck injury (whiplash injury). DESIGN: A quantitative experimental design using both retrospective and prospective data. SETTING: Metropolitan Police physiotherapy and rehabilitation department in the UK. SUBJECTS: One-hundred and two patients with neck pain following whiplash injury. INTERVENTIONS: Patients were divided into three groups based on pre-injury physical fitness (low, medium and high). Recovery was compared between the three groups initially then again at three and six months. MAIN MEASURES: Three measurement scales were used: the Neck Disability Index, the Problem Percentage, and the Physical Activity Scale. RESULTS: Pre-injury physical fitness had a marked effect on recovery at three and six months, with the medium and high fitness groups having significantly better recovery than the low fitness group. At three months the Neck Disability Index score for the low fitness group was 12 compared with 7 and 7.5 for the medium and high fitness groups respectively (P = 0.009). At six months the Neck Disability Index score was 9 for the low fitness group compared with 0 and 3 for the medium and high fitness groups (P = 0.002). In addition, the return to work rate was almost twice as high for individuals with medium/high fitness. CONCLUSION: Early recovery from whiplash injury was significantly more likely for individuals with medium to high levels of pre-injury physical fitness than for individuals with low levels of pre-injury physical fitness.     

Comparison Between Neck Pain Disability and Cervical Range of Motion in Patients With Episodic and Chronic Migraine: A Cross-Sectional Study

ObjectiveThe purpose of this study was to evaluate neck pain–related disability and cervical range of motion (CROM) in patients with episodic migraine (EM) and chronic migraine (CM) and to examine the correlation of both outcomes.MethodsThis cross-sectional study consisted of 91 patients with EM and 34 with CM. Cervical range of motion was measured with the CROM device, and pain during the cervical movement was recorded. Self-reported disability related to neck pain was assessed with the Neck Disability Index.ResultsPatients with CM showed higher Neck Disability Index scores and more moderate and severe disability (P = .01). Severe disability as a result of neck pain was associated with 7.6-fold risk of developing CM (P = .003). No significant differences in CROM were identified between groups. Moderate negative correlations between CROM and disability were found for 4 motions within the CM group (− 0.60 < r < − 0.39) and with 3 in the EM group (− 0.48 < − 0.45). Disability was positively and moderately correlated to pain evoked during CROM in both groups (0.34 < r < 0.51).ConclusionThis study found that neck pain was highly prevalent in patients with migraine. Neck pain–related disability increased with increased frequency of the migraine attacks and was associated with the risk of migraine chronicity. The correlation between CROM and neck pain disability was more evident in patients with CM and in patients with pain during cervical movement.     

Assessment and validation of prognostic models for poor functional recovery 12 months after whiplash injury: a multicentre inception cohort study

Uncertainty surrounds prognostic factors after whiplash injury. Previously we identified a prognostic model for 6-month pain-related disability in a cohort of 80 participants with acute whiplash. Predictors included initial disability, older age, decreased cold pain thresholds, decreased neck rotation movement, posttraumatic stress symptoms and decreased sympathetic vasoconstriction. The objective of this study was to externally validate this model. In a multicentre inception cohort study, 286 participants with acute whiplash (I, II or III) were assessed at <3 weeks and 12 months after injury. The Neck Disability Index (NDI) was the outcome. Observed and predicted NDI scores were generated using the published equation of the original model. Model discrimination between participants with no or mild disability from those with moderate to severe disability was examined by receiver operating characteristic curves. Initial NDI and cold pain threshold predicted current observed 12-month NDI scores (r(2) = 0.50, 95% confidence interval 0.42 to 0.58). There was a significant site effect, and the estimated marginal mean ± SE of 12-month NDI for Iceland (27.6 ± 1.79%) was higher than the other 3 sites (Melbourne 11.2 ± 5.03%, Canada 16.4 ± 2.36%, Brisbane 16.8 ± 1.17%). After adjusting for site, age and Impact of Events Scale scores regained significance (r(2) = 0.56, 95% confidence interval 0.48 to 0.64). The tested model was not precise in predicting NDI as a continuous variable. However, it found good accuracy to discriminate participants with moderate to severe disability at 12 months (area under the receiver operating characteristic curve 0.89 [95% confidence interval 0.84-0.94], P<.001) which is clinically useful.     

Validity of the neck disability index,Northwick Park neck pain questionnaire,and problem elicitation technique for measuring disability associated with whiplash-associated disorders

The Neck Disability Index (NDI) and Northwick Park Neck Pain Questionnaire (NPQ) were developed to measure self-perceived disability from neck pain, including that which may arise from whiplash injury. However, there is little data specifically concerning their validity for whiplash-associated disorders (WAD). The aim of this study was to assess the validity of the NDI and NPQ as measures of outcome in WAD by comparing them to a patient preference questionnaire, the problem elicitation technique (PET), which identifies problems that are of most importance to the individual patient. A cross-sectional study of 71 patients with varying severity and duration of WAD were recruited from a private physiotherapy practice. All patients completed a standardized self-administered questionnaire that included demographic and clinical details as well as self-perceived pain and severity of symptoms, NDI and NPQ. A trained interviewer administered the PET. Construct validity of the disability measures was examined by determining their correlation with each other and with pain and severity of symptoms by calculating Pearson's correlation coefficients. Content validity of the NDI and NPQ was assessed by comparing the items of both questionnaires to the problems identified by the PET. Participants' mean age was 40.1 years (SD=14.3) and 59 were women (83.1%). Most patients were in WAD category I (n=23, 32.1%), or II (n=42, 59.2%). Mean NDI, NPQ, and PET scores were 40.7 (SD=17.0), 38.7 (SD=15.8), and 160.2 (SD=92.0, range 6.0-509.5), respectively. Correlations between the NDI and PET, NPQ and PET, and NDI and NPQ were r=0.57, 0.56 and 0.88, respectively. The PET identified an average of 7.7 problems per patient (SD=4.2, range 1-17 problems). Problems most commonly identified were work for wages (52.1%), fatigued during the day (50.7%), participation in sports (47.9%), depression (43.7%), drive a car (43.7%), socialize with friends (33.8%), sleep through the night (31.0%), frustration (31.0%), and anger (28.2%). Only three of these problems are included in the NDI (work, driving, and sleeping) and only four are included in the NPQ (work, driving, sleeping, and social activities). While both the NDI and NPQ include some problems that are common in patients with WAD, frequently identified problems, such as emotional and social items are absent. In contrast to the PET, neither instrument captures the full spectrum of disabilities judged to be important by the patient.