Roy E. Stewart

Reliability and validity of the visual analogue scale for disability in patients with chronic musculoskeletal pain

To determine the reliability and concurrent validity of a visual analogue scale (VAS) for disability as a single-item instrument measuring disability in chronic pain patients was the objective of the study. For the reliability study a test–retest design and for the validity study a cross-sectional design was used. A general rehabilitation centre and a university rehabilitation centre was the setting for the study. The study population consisted of patients over 18 years of age, suffering from chronic musculoskeletal pain; 52 patients in the reliability study, 344 patients in the validity study. Main outcome measures were as follows. Reliability study: Spearmans correlation coefficients (ρ values) of the test and retest data of the VAS for disability; validity study: ρ values of the VAS disability scores with the scores on four domains of the Short-Form Health Survey (SF-36) and VAS pain scores, and with Roland–Morris Disability Questionnaire scores in chronic low back pain patients. Results were as follows: in the reliability study ρ values varied from 0.60 to 0.77; and in the validity study ρ values of VAS disability scores with SF-36 domain scores varied from 0.16 to 0.51, with Roland–Morris Disability Questionnaire scores from 0.38 to 0.43 and with VAS pain scores from 0.76 to 0.84.The conclusion of the study was that the reliability of the VAS for disability is moderate to good. Because of a weak correlation with other disability instruments and a strong correlation with the VAS for pain, however, its validity is questionable.

Optimizing Cutoff Scores for the Barthel Index and the Modified Rankin Scale for Defining Outcome in Acute Stroke Trials

Background and Purpose— There is little agreement on how to assess outcome in acute stroke trials. Cutoff scores for the Barthel Index (BI) and modified Rankin Scale (mRS) are frequently arbitrarily chosen to dichotomize favorable and unfavorable outcome. We investigated sensitivity and specificity of BI cutoff scores in relation to the mRS to obtain the optimal corresponding BI and mRS scores. Methods— BI and mRS scores were collected from 1034 ischemic stroke patients. Sensitivity and specificity were calculated for BI cutoff scores from 45 to 100 in mRS score 1, 2, and 3 and were plotted in receiver operator characteristic (ROC) curves. Results— The cutoff scores for the BI with the highest sum of sensitivity and specificity were 95 (sensitivity 85.6%; specificity 91.7%), 90 (sensitivity 90.7%; specificity 88.1%), and 75 (sensitivity 95.7%; specificity, 88.5%) for, respectively, mRS 1, 2, and 3. The area under the ROC curve was 0.933 in mRS 1, 0.960 in mRS 2, and 0.979 in mRS 3. Conclusions— The optimal cutoff scores for the BI were 95 for mRS 1, 90 for mRS 2, and 75 for mRS 3. For future acute stroke trials that assess stroke outcome with the BI and mRS, we recommend the use of these BI cutoff score(s) with the corresponding mRS cutoff score(s), to ensure the use of consistent and uniform end points.

Effect of intrathecal baclofen delivered by an implanted programmable pump on health related quality of life in patients with severe spasticity

OBJECTIVES To compare clinical effectiveness and health related quality of life in patients with severe spasticity who received intrathecal baclofen or a placebo. METHODS In a double blind, randomised, multicentre trial 22 patients were followed up during 13 weeks and subsequently included in a 52 week observational longitudinal study. Patients were those with chronic, disabling spasticity who did not respond to maximum doses of oral baclofen, dantrolene, and tizanidine. After implantation of a programmable pump patients were randomly assigned to placebo or baclofen infusion for 13 weeks. After 13 weeks all patients received baclofen. Clinical efficacy was assessed by the Ashworth scale, spasm score, and self reported pain, and health related quality of life by the sickness impact profile (SIP) and the Hopkins symptom checklist (HSCL). RESULTS At three months the scores of the placebo and baclofen group differed slightly for the spasm score (effect size=0.20) and substantially for the Ashworth scale (effect size=1.40) and pain score (effect size=0.94); health related quality of life showed no significant differences. Three months after implantation the baclofen group showed a significant, substantial improvement on the SIP “physical health”, “mental health”, “mobility”, and “sleep and rest” subscales and on the HSCL mental health scale; patients receiving placebo showed no change. After one year of baclofen treatment significant (P<0.05) improvement was found on the SIP dimensions “mobility” and “body care and movement” with moderate effect sizes. Improvement on the SIP subscale “physical health” (P<0.05; effect size 0.86), the SIP overall score (without “ambulation”), and the “physical health” and overall scale of the HSCL was also significant, with effect sizes >0.80. Changes in health related behaviour were noted for “sleep and rest” and “recreation and pastimes” (P<0.01, P<0.05; effect size 0.95 and 0.63, respectively). Psychosocial behaviour showed no improvement. CONCLUSIONS Intrathecal baclofen delivered by an implanted, programmable pump resulted in improved self reported quality of life as assessed by the SIP, and HSCL physical health dimensions also suggest improvement.

Two subdomains of negative symptoms in psychotic disorders: Established and confirmed in two large cohorts

Negative symptoms of schizophrenia are normally grouped into a single category. However, the diversity of such symptoms suggests that they are actually made up of more than one dimension. The DSM-V proposes two negative symptom domains, namely expressive deficits and avolition/asociality. We investigated whether the negative symptoms do indeed have two dimensions. An exploratory factor analysis was carried out based on interviews with the PANSS (664 patients). We restricted our analysis to items that had been described as negative symptoms in previous factor analyses. The symptom structure was then tested for stability by performing a confirmatory factor analysis on PANSS interviews from a separate cohort (2172 patients). Exploratory factor analysis yielded a two-factor structure of negative symptoms. The first factor consisted of PANSS items Flat affect, Poor rapport, Lack of spontaneity, Mannerisms and posturing, Motor retardation, and Avolition. The second factor consisted of Emotional withdrawal, Passive/apathetic social withdrawal, and Active social avoidance. The first factor could be related to expressive deficits, reflecting a loss of initiative, and the second factor to social amotivation, related to community interaction. This factor structure supports the DSM-V classification and may be relevant for pathophysiology and treatment of schizophrenia and other psychotic disorders.

Smallest Detectable Difference in Outcome Variables Related to Painful Restriction of the Temporomandibular Joint

The smallest detectable difference is the smallest statistically significant change in measurement results. In the field of temporomandibular disorders, the smallest detectable difference is not a commonly used concept. Most outcome studies are based on comparisons of group means, although this does not provide information about individual changes or about the clinical relevance thereof. The smallest detectable difference for maximal mouth opening was calculated from previously published reliability coefficients and the standard deviations of different samples of healthy subjects and patients with complaints of the temporomandibular joint. The smallest detectable difference of pain intensity measured with different visual analogue scales was calculated from the reliability coefficients and standard deviations of a heterogeneous group of pain patients. The smallest detectable difference of function impairment was calculated for a group of patients with complaints of the temporomandibular joint. For maximal mouth opening in healthy subjects, the smallest detectable difference was 5 mm. Repeated measurements improved it to 3 mm. The smallest detectable difference on a visual analogue scale was 28 mm for actual pain intensity and 22 mm for minimal pain as well as for maximal pain intensity. For total function impairment of patients with complaints of the temporomandibular joint, the smallest detectable difference was 8 units on a 0 to 68 scale.

Cut-off points for mild, moderate, and severe pain on the visual analogue scale for pain in patients with chronic musculoskeletal pain.

Summary Visual analogue scale scores ⩽3.5 indicated mild pain; the cut‐off points between moderate and severe pain were 5.8, 6.5, and 7.5, depending on the statistical methods used. ABSTRACT The aim of this study was to find the cut‐off points on the visual analogue scale (VAS) to distinguish among mild, moderate, and severe pain, in relation to the following: pain‐related interference with functioning; verbal description of the VAS scores; and latent class analysis for patients with chronic musculoskeletal pain. A total of 456 patients were included. Pain was assessed using the VAS and verbal rating scale; functioning was assessed using the domains of the Short Form (36) Health Survey (SF‐36). Eight cut‐off point schemes were tested using multivariate analysis of variance (MANOVA), ordinal logistic regression, and latent class analysis. The study results showed that VAS scores ⩽3.4 corresponded to mild interference with functioning, whereas 3.5 to 6.4 implied moderate interference, and ≥6.5 implied severe interference. VAS scores ⩽3.4 were best described for patients with chronic musculoskeletal pain as mild pain, 3.5 to 7.4 as moderate pain, and ≥7.5 as severe pain. Latent class analysis found that a 3‐class solution fitted best, resulting in the classes 0.1 to 3.8, 3.9 to 5.7, and 5.8 to 10 cm. Findings from our study agree with those of some other studies, although many other studies found different optimal cut‐off point schemes. As there appear to be no universally accepted cut‐off points, and in view of the low‐to‐moderate associations between VAS scores and functioning and between VAS and verbal rating scale scores, the correct classification of VAS scores as mild, moderate. or severe in clinical practice seems doubtful.

Comparing self-report, clinical examination and functional testing in the assessment of work-related limitations in patients with chronic low back pain

Purpose. To compare the work-related limitations assessed using self-report, clinical examination and functional testing in patients with chronic low back pain (CLBP). Methods. Work-related limitations of 92 patients were assessed using self-report, clinical examination and functional testing. To obtain the assessed limitations the patient (self-report), the physician (clinical examination) and a trained evaluator (functional testing) completed a scorings form about the work-related limitations of the patient. The Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) was used to obtain the functional testing results. A κ value of more than 0.60, absolute agreement of more than 80% and ICC of more than 0.75 were considered as acceptable. Results. Little agreement and correlation among self-report, clinical examination and functional testing were found for the assessment of work-related limitations. Self-reported limitations were considerably higher than from those derived from clinical examination or functional testing. Additionally, the limitations derived from the clinical examination were higher than those derived from the IWS FCE. Conclusion. Comparing self-report, clinical examination and functional testing for assessing work-related limitations in CLBP patients showed large considerable differences in limitations. Professional health care workers should be aware of these differences when using them in daily practice.

Influence of Socio-Economic Status, Parents and Peers on Smoking Behaviour of Adolescents

With the aim of analysing the importance of psycho-social factors in predicting adolescents’ smoking behaviour, a model of the interrelations between socio-economic status, parents’, peers’ and adolescents’ own smoking behaviours was tested. The sample consisted of 2,616 adolescents. LISREL analyses were used to support the model; males and females were evaluated separately. Peers’ smoking is the strongest predictor of adolescent smoking. Parents’ smoking behaviour influences adolescents’ smoking directly, but also indirectly through the parents’ influence on peers’ smoking behaviour. Socio-economic status influences adolescent smoking indirectly through its influence on parents’ and peers’ smoking behaviour. Our model is significant in both males and females and explains 42–51% of the variance in adolescent smoking behaviour. Accentuation of peers’ influence on adolescents’ smoking behaviour without considering the interrelations between the influence of socio-economic status, parents and peers may lead us to incorrect conclusions in research as well as in prevention.

A LITERATURE REVIEW ON SICK LEAVE DETERMINANTS (1984-2004)

OBJECTIVES A literature review for the years 1984-2004 was performed to identify the determinants of the sick leave frequency and duration over that period and to establish the continuity in the character of those determinants. MATERIALS AND METHODS The review referred to national and international studies on the determinants of the frequency and duration of sick leave. RESULTS The review presented a highly consistent picture of the factors determining sick leave frequency and duration. CONCLUSION Over the study period, the frequency and duration of sick leave were determined by a broad range of factors, a substantial number of which had a similar influence on both the study parameters.

Perfusion Computed Tomography in the Acute Phase of Mild Head Injury : Regional Dysfunction and Prognostic Value

Traumatic brain injury is a major cause of disability and death. Most patients sustain a mild head injury with a subgroup that experiences disabling symptoms interfering with return to work. Brain imaging in the acute phase is not predictive of outcome, as 20% of noncontrast computed tomographic (CT) scans on admission is normal in patients with a suboptimal outcome. The aim of this study was to perform perfusion CT imaging in the acute phase of mild head injury in patients without intracranial abnormalities on the noncontrast CT, to assess whether these patients had cerebral perfusion abnormalities. Furthermore, the relation between perfusion CT parameters and severity of head injury and outcome was evaluated.