Paula Kersten

Body perception disturbance: A contribution to pain in complex regional pain syndrome (CRPS)

Abstract In spite of pain in the CRPS limb, clinical observations show patients pay little attention to, and fail to care for, their affected limb as if it were not part of their body. Literature describes this phenomenon in terms of neurological neglect‐like symptoms. This qualitative study sought to explore the nature of the phenomenon with a view to providing insights into central mechanisms and the relationship with pain. Twenty‐seven participants who met the IASP CRPS classification were interviewed using qualitative methods to explore feelings and perceptions about their affected body parts. These semi‐structured interviews were analysed utilising principles of grounded theory. Participants revealed bizarre perceptions about a part of their body and expressed a desperate desire to amputate this part despite the prospect of further pain and functional loss. A mismatch was experienced between the sensation of the limb and how it looked. Anatomical parts of the CRPS limb were erased in mental representations of the affected area. Pain generated a raised consciousness of the limb yet there was a lack of awareness as to its position. These feelings were about the CRPS limb only as the remaining unaffected body was felt to be normal. Findings suggest that there is a complex interaction between pain, disturbances in body perception and central remapping. Clinically, findings support the use of treatments that target cortical areas, which may reduce body perception disturbance and pain. We propose that body perception disturbance is a more appropriate term than ‘neglect‐like’ symptoms to describe this phenomenon.

Wherever is my arm? Impaired upper limb position accuracy in Complex Regional Pain Syndrome

&NA; Knowledge of the position of ones limbs is an essential component of daily function and relies on complex interactions of sensorimotor body schema‐related information. Those with Complex Regional Pain Syndrome (CRPS) express difficulty in knowing where their affected limb is positioned. The aim of this study was to determine the degree to which experimental data supported the reported difficulty in limb position sense. A controlled experimental design was used to measure upper limb position accuracy amongst those with CRPS of one arm. Position accuracy was individually measured in both arms and compared to a known target position. Video captured each of 36 trials (half with arm in full view and half with vision obscured). The error in degrees between actual and known targets was determined using video analysis software. The Brief Pain Inventory measured pain. A subjective mental image representation of both upper limbs was documented. The CRPS group had moderate pain intensity and were significantly less accurate in positioning both the affected and unaffected limbs compared to controls (p < 0.001). Position accuracy of the CRPS affected limb significantly improved with vision (8.3° in view, 10.7° not in view). Subjective mental representations of the affected limb were visualised as distorted. Evidence of bilateral arm positioning impairments in unilateral arm CRPS suggests that central mechanisms are involved. Cortical reorganisation in regions associated with the body schema (i.e. primary somatosensory and parietal cortices) is proposed as an explanation. The exact relationship between pain and limb position deficits requires further exploration.

Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis

Background Recurrent instability following a first-time anterior traumatic shoulder dislocation may exceed 26%. We systematically reviewed risk factors which predispose this population to events of recurrence. Methods A systematic review of studies published before 1 July 2014. Risk factors which predispose recurrence following a first-time traumatic anterior shoulder dislocation were documented and rates of recurrence were compared. Pooled ORs were analysed using random-effects meta-analysis. Results Ten studies comprising 1324 participants met the criteria for inclusion. Recurrent instability following a first-time traumatic anterior shoulder dislocation was 39%. Increased risk of recurrent instability was reported in people aged 40 years and under (OR=13.46), in men (OR=3.18) and in people with hyperlaxity (OR=2.68). Decreased risk of recurrent instability was reported in people with a greater tuberosity fracture (OR=0.13). The rate of recurrent instability decreased as time from the initial dislocation increased. Other factors such as a bony Bankart lesion, nerve palsy and occupation influenced rates of recurrent instability. Conclusions Sex, age at initial dislocation, time from initial dislocation, hyperlaxity and greater tuberosity fractures were key risk factors in at least two good quality cohort studies resulting in strong evidence as concluded in the GRADE criteria. Although bony Bankart lesions, Hill Sachs lesions, occupation, physiotherapy treatment and nerve palsy were risk factors for recurrent instability, the evidence was weak using the GRADE criteria—these findings relied on poorer quality studies or were inconsistent among studies.

Measuring autonomy in disabled people: validation of a new scale in a UK population

Objective: To evaluate the validity and reliability of an English version of the Impact on Participation and Autonomy Questionnaire (IPA). The original Dutch IPA has been shown to load onto five factors. Design: A validation study. Setting: Outpatients clinics and people’s homes. Subjects: Two hundred and thirteen people with multiple sclerosis, rheumatoid arthritis, spinal cord injury, and general practice attendees, stratified by level of disability (median age 54, 42% male, 58% female). Inclusion criteria: English as first language, aged 18-75, Mental Status Questionnaire score >6. Interventions: Self- and interviewer-administered outcome measures. Main measures: IPA, including one new item (66 participants completed the IPA on a second occasion). Other measures: Short Form-36 Health Survey (SF-36), London Handicap Scale, three domains of the Functional Limitations Profile (FLP): household management, social integration, emotion. Results: Confirmatory factor analysis confirmed the construct validity of the IPA (Normal Fit Index=0.98, Comparative Fit Index=0.99), indicating a good fit to the model. Convergent and discriminant validity were confirmed by the predicted associations, or lack of, with the exception of a poor association between the ‘social life/relationships’ IPA subscale and FLP-emotion. Internal reliability of the IPA was confirmed (Cronbach alphas >0.8; item-total correlations for all subscales >0.5). Test-retest reliability was confirmed for all items (weighted kappas >0.6) and subscales (intraclass correlation coefficients >0.90). Conclusions: The English IPA is a valid, reliable and acceptable measure of participation and autonomy in people with a range of conditions and can make a unique and fundamental contribution to outcome assessment. Further research is required to examine the responsiveness of the IPA to change over time, its clinical utility and suitability for use with people from ethnic minorities and with older people.

A pragmatic parallel arm multi-centre randomised controlled trial to assess the effectiveness and cost-effectiveness of a group-based fatigue management programme (FACETS) for people with multiple sclerosis

Background Fatigue is a common and troubling symptom for people with multiple sclerosis (MS). Aim To evaluate the effectiveness and cost-effectiveness of a six-session group-based programme for managing MS-fatigue (Fatigue: Applying Cognitive behavioural and Energy effectiveness Techniques to lifeStyle (FACETS)). Methods Three-centre parallel arm randomised controlled trial with economic evaluation. Patients with MS and significant fatigue were randomised to FACETS plus current local practice (FACETS) or current local practice alone (CLP), using concealed computer-generated randomisation. Participant blinding was not possible. Primary outcomes were fatigue severity (Fatigue Assessment Instrument), self-efficacy (Multiple Sclerosis-Fatigue Self-Efficacy) and disease-specific quality of life (Multiple Sclerosis Impact Scale (MSIS-29)) at 1 and 4 months postintervention (follow-up 1 and 2). Quality adjusted life years (QALYs) were calculated (EuroQoL 5-Dimensions questionnaire and the Short-form 6-Dimensions questionnaire). Results Between May 2008 and November 2009, 164 patients were randomised; primary outcome data were available for 146 (89%). Statistically significant differences favour the intervention group on fatigue self-efficacy at follow-up 1 (mean difference (MD) 9, 95% CI (4 to 14), standardised effect size (SES) 0.54, p=0.001) and follow-up 2 (MD 6, 95% CI (0 to 12), SES 0.36, p=0.05) and fatigue severity at follow-up 2 (MD −0.36, 95% CI (−0.63 to −0.08), SES −0.35, p=0.01) but no differences for MSIS-29 or QALYs. No adverse events reported. Estimated cost per person for FACETS is £453; findings suggest an incremental cost-effectiveness ratio of £2157 per additional person with a clinically significant improvement in fatigue. Conclusions FACETS is effective in reducing fatigue severity and increasing fatigue self-efficacy. However, it is difficult to assess the additional cost in terms of cost-effectiveness (ie, cost per QALY) as improvements in fatigue are not reflected in the QALY outcomes, with no significant differences between FACETS and CLP. The strengths of this trial are its pragmatic nature and high external validity. Trial registration: Current Controlled Trials ISRCTN76517470.

Is the pain visual analogue scale linear and responsive to change? An exploration using Rasch analysis.

Objectives Pain visual analogue scales (VAS) are commonly used in clinical trials and are often treated as an interval level scale without evidence that this is appropriate. This paper examines the internal construct validity and responsiveness of the pain VAS using Rasch analysis. Methods Patients (n = 221, mean age 67, 58% female) with chronic stable joint pain (hip 40% or knee 60%) of mechanical origin waiting for joint replacement were included. Pain was scored on seven daily VASs. Rasch analysis was used to examine fit to the Rasch model. Responsiveness (Standardized Response Means, SRM) was examined on the raw ordinal data and the interval data generated from the Rasch analysis. Results Baseline pain VAS scores fitted the Rasch model, although 15 aberrant cases impacted on unidimensionality. There was some local dependency between items but this did not significantly affect the person estimates of pain. Daily pain (item difficulty) was stable, suggesting that single measures can be used. Overall, the SRMs derived from ordinal data overestimated the true responsiveness by 59%. Changes over time at the lower and higher end of the scale were represented by large jumps in interval equivalent data points; in the middle of the scale the reverse was seen. Conclusions The pain VAS is a valid tool for measuring pain at one point in time. However, the pain VAS does not behave linearly and SRMs vary along the trait of pain. Consequently, Minimum Clinically Important Differences using raw data, or change scores in general, are invalid as these will either under- or overestimate true change; raw pain VAS data should not be used as a primary outcome measure or to inform parametric-based Randomised Controlled Trial power calculations in research studies; and Rasch analysis should be used to convert ordinal data to interval data prior to data interpretation.

Using feedback from patient-reported outcome measures in mental health services: a scoping study and typology.

OBJECTIVE Routine evaluation of mental health services has become widespread, and the use of patient-reported outcome measures (PROMs) as clinical aids or discussion tools has been receiving increasing attention. The purpose of this scoping study was to provide a typology of the diverse ways in which studies reporting on PROM use in mental health services have utilized PROMs. METHODS Iterative scoping searches of the literature identified articles reporting on the use of PROM feedback in mental health settings, which were then categorized to develop a typology along a dimension of intensity of use of PROM feedback, ranging from no feedback to patient and clinician to clinician-patient discussion that followed a formalized structure. RESULTS Of the 172 studies that were identified, 27 were grouped into five categories, ranging from studies in which there was no PROM feedback to clinician or patient to studies in which a formalized structure was available by which PROM feedback could be discussed between clinician and patient. Of the 11 studies in the category with formalized feedback, nine reported some significant effects of feedback compared with a control condition, and two reported partial significant effects. CONCLUSIONS The proposed procedural typology helps explain the diversity of results from studies reporting on the effects of PROM feedback, by highlighting that PROM feedback appears to be more effective when integrated in a formalized and structured manner. Future work is required to isolate these effects from common procedural correlates, such as monitoring of the therapeutic alliance.

The Visual Analogue WOMAC 3.0 scale - internal validity and responsiveness of the VAS version

BackgroundMany people suffer with Osteoarthritis (OA) and subsequent morbidity. Therefore, measuring outcome associated with OA is important. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been a widely used patient reported outcome in OA. However, there is relatively little evidence to support the use of the Visual Analogue Scale (VAS) version of the scale. We aimed to explore the internal validity and responsiveness of this VAS version of the WOMAC.MethodsPatients with chronic hip or knee pain of mechanical origin, waiting for a hip or knee joint replacement completed the WOMAC as part of a study to investigate the effects of acupuncture and placebo controls. Validity was tested using factor analysis and Rasch analysis, and responsiveness using standardised response means.ResultsTwo hundred and twenty one patients (mean age 66.8, SD 8.29, 58% female) were recruited. Factor and Rasch analysis confirmed unidimensional Pain and Physical Functioning scales, capable of transformation to interval scaling and invariant over time. Some Differential Item Functioning (DIF) was observed, but this cancelled out at the test level. The Stiffness scale fitted the Rasch model but adjustments for DIF could not be made due to the shortness of the scale. Using the interval transformed data, Standardised Response Means were smaller than when using the raw, ordinal data.ConclusionsThe WOMAC Pain and Physical Functioning subscales satisfied unidimensionality and ordinal scaling tests, and the ability to transform to an interval scale. Some Differential Item Functioning was observed, but this cancelled out at the test level and, by doing so, at the same time removed the disturbance of unidimensionality. The scaling characteristics of sets of items which use VAS require further analysis, as it would appear that they can lead to spurious levels of responsiveness and scale compression because they exaggerate the distortion of the ordinal scale.Trial numberUKCRN study ID: 4881ISRCTN78434638

Validity of the impact on participation and autonomy questionnaire: A comparison between two countries

Purpose. To evaluate the cross-cultural validity of the five subscales of the Impact on Participation and Autonomy (IPA) measure and the full 31-item scale. Method. Data from two validation studies (Dutch and English) were pooled (n = 106). Participants (aged 18 – 75), known to rehabilitation services or GP practices, had conditions ranging from minor ailments to significant disability. Validity of the five subscales and the total scale was examined using Rasch analysis (Partial Credit Model). P values smaller than 0.01 were employed to allow for multiple testing. Results. A number of items in all the subscales except ‘Outdoor Autonomy’ needed rescoring. One ‘Indoor Autonomy’ item showed uniform DIF by country and was split by country. One ‘Work and Education’ item displayed uniform and non-uniform DIF by gender. All the subscales fitted the Rasch model and were invariant across country. A 30-item IPA also fitted the Rasch model. Conclusion. The IPA subscales and a 30-item scale are invariant across the two cultures and gender. The IPA can be used validly to assess participation and autonomy in these populations. Further analyses are required to examine whether the IPA is invariant across differing levels of disability and other disease groups not included in this study.

Validation of the WHOQOL-BREF quality of life questionnaire for general use in New Zealand: confirmatory factor analysis and Rasch analysis

PurposeThe present study validated the abbreviated version of the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire for general use in New Zealand.MethodsA random postal sample from the national electoral roll was used, and 808 questionnaires were returned. Psychometric properties of the instrument were assessed, including tests of the four-domain factor structure using confirmatory factor analysis and Rasch analysis.ResultsGoodness-of-fit from the confirmatory factor analysis were good, and the overall conclusion of the Rasch analysis supported the confirmatory factor analysis (CFA) findings after dealing with problems of threshold ordering, local dependency, and differential item functioning (DIF).ConclusionsThe WHOQOL-BREF is valid for general use in New Zealand. In the future work, the WHOQOL-BREF domain scores should either be analyzed using non-parametric statistics or data should be fitted to the Rasch model to derive interval person estimates.