Search

Objectives: The aim of the present study was to describe handwriting difficulties of primary school children with juvenile idiopathic arthritis (JIA), and to investigate possible correlations with hand function and writing performance., Methods: In a cross-sectional approach, 15 children with JIA and reported handwriting difficulties were included together with 15 healthy matched controls. Impairments (signs of arthritis or tenosynovitis, reduced grip force and limited range of motion of the wrist (wrist-ROM)), activity limitations (reduced quality and speed of handwriting, pain during handwriting), and participation restrictions (perceived handwriting difficulties at school) were assessed and analysed., Results: Although selected by the presence of handwriting difficulties, the majority of the JIA children (73%) had no active arthritis of the writing hand, and only minor hand impairments were found. Overall, the JIA children performed well during the short handwriting test, but the number of letters they wrote per minute decreased significantly during the 5-minute test, compared to the healthy controls. JIA patients had significantly higher pain scores on a 100 mm Visual Analogue Scale, compared to the healthy controls. The actual presence of arthritis, and limitation in grip force and wrist-ROM did not correlate with reported participation restrictions with regard to handwriting at school. The JIA children reported pain during handwriting, and inability to sustain handwriting for a longer period of time., Conclusions: The results of this pilot study show that JIA children with handwriting difficulties, experience their restrictions mainly through pain and the inability to sustain handwriting for a longer period of time. No correlations could be found with impairments.

Objective: To investigate the interrater reliability and construct validity of the Stroke Upper Limb Capacity Scale (SULCS)., Design: Cohort study., Setting: Inpatient department of a rehabilitation center., Participants: Patients after stroke (N=21; mean age ± SD, 61.7 ± 7.9y; 57% men), undergoing inpatient rehabilitation., Interventions: Not applicable., Main Outcome Measures: The SULCS was administered by occupational therapists (OTs) within 6 weeks after stroke (t1), 3 months after t1 by the same OT (t2), and within 1 week after t2 by another OT (t3). Interrater reliability, the repeatability between different raters, was assessed by calculating the intraclass correlation coefficient (ICC) based on the scores at t2 and t3. Construct validity, indicating agreement with hypotheses concerning the construct that is being measured, was assessed with Spearman rank correlation coefficient (ρ). The SULCS scores were cross-sectionally correlated with those of the Action Research Arm Test (ARAT) and the Rivermead Motor Assessment (RMA) at t1, and longitudinally with the respective change scores between t1 and t2., Results: The SULCS (range, 0-10) had a high ICC (.94; 95% confidence interval, .86-.97) and strong cross-sectional correlation with both the ARAT and the RMA (ρ=.91 and ρ=.85, respectively), while the respective change scores showed a strong correlation with the ARAT (ρ=.71) and a moderate correlation with the RMA (ρ=.48)., Conclusions: The SULCS has good interrater reliability and construct validity., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the construct validity and test-retest reliability of the Questionnaire Rising and Sitting Down (QR&S), a patient-reported measure of activity limitations in rising and sitting down, in lower-limb amputees., Design: Cross-sectional study., Setting: Outpatient department of a rehabilitation center., Participants: Lower-limb amputees (N=171; mean age ± SD, 65±12y; 71% men; 83% vascular cause) participated in the study, 33 of whom also participated in the reliability study., Interventions: Not applicable., Main Outcome Measures: Construct validity was investigated by testing 8 hypotheses: limitations in rising and sitting down according to the QR&S would be: (1) greater in lower-limb amputees who are older, (2) independent of level of amputation, (3) greater in lower-limb amputees with a bilateral amputation, and (4) greater in lower-limb amputees who had rehabilitation treatment in a nursing home. Furthermore, limitations in rising and sitting down will be positively related to activity limitations according to (5) the Locomotor Capabilities Index (LCI), (6) the questions about rising and sitting down in the LCI, (7) the Climbing Stairs Questionnaire, and (8) the Walking Questionnaire. Construct validity was quantified with an independent t test and Pearson correlation coefficient. Test-retest reliability was assessed with a 3-week interval and quantified with the intraclass correlation coefficient (ICC), standard error of measurement, and smallest detectable difference (SDD)., Results: Construct validity (7 of 8 null hypotheses not rejected) and test-retest reliability were good (ICC=.84; 95% confidence interval, .65-.93; standard error of the measurement=6.7%; SDD=18.6%)., Conclusions: The QR&S has good construct validity and good test-retest reliability in lower-limb amputees., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To develop a Rasch-based version of a mobility questionnaire (MobQues28) for children with cerebral palsy (CP)., Design: Cross-sectional study., Setting: Private physical therapy practices and outpatient departments of hospitals and rehabilitation centers., Participants: Parents of 323 ambulatory children with CP (Gross Motor Function Classification System [GMFCS] level I-IV; aged, 2-13y)., Interventions: Not applicable., Main Outcome Measure: The mobility questionnaire measures mobility limitations in children with CP by rating the difficulty of executing 47 mobility activities, as reported by the parents. Items for the Rasch-based version were selected based on fit to the Rasch measurement (partial credit) model and invariance of item characteristics across GMFCS level, age group, or sex., Results: Analysis revealed a fitting model when nonambulant and/or 2- and 3-year aged children were excluded (leaving a final sample of n=246) and answering categories were collapsed from 9 to 5. Thirteen items were removed from the questionnaire due to misfit to the model, 5 because of disordered thresholds, and 1 because of invariance across age group. Twenty-eight items out of the original 47 items showed good fit to the model., Conclusions: The 28-item version of the mobility questionnaire (MobQues28) provides sound measurement properties for measuring mobility limitations in ambulant children with CP, aged 4 to 13 years, and shows promise as an instrument for research purposes., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To give an overview of the literature on knee proprioception in knee osteoarthritis (OA) patients., Method: A literature search was performed and reviewed using the narrative approach., Results: (1) Three presumed functions of knee proprioception have been described in the literature: protection against excessive movements, stabilization during static postures, and coordination of movements. (2) Proprioceptive accuracy can be measured in different ways; correlations between these methods are low. (3) Proprioceptive accuracy in knee OA patients seems to be impaired when compared to age-matched healthy controls. Unilateral knee OA patients may have impaired proprioceptive accuracy in both knees. (4) Causes of impaired proprioceptive accuracy in knee OA remain unknown. (5) There is currently no evidence for a role of impaired proprioceptive accuracy in the onset or progression of radiographic osteoarthritis (ROA). (6) Impaired proprioceptive accuracy could be a risk factor for progression (but not for onset) of both knee pain and activity limitations in knee OA patients. (7) Exercise therapy seems to be effective in improving proprioceptive accuracy in knee OA patients., Conclusions: Recent literature has shown that proprioceptive accuracy may play an important role in knee OA. However, this role needs to be further clarified. A new measurement protocol for knee proprioception needs to be developed. Systematic reviews focusing on the relationship between impaired proprioceptive accuracy, knee pain and activity limitations and on the effect of interventions (in particular exercise therapy) on proprioceptive accuracy in knee OA are required. Future studies focusing on causes of impaired proprioceptive accuracy in knee OA patients are also needed, taking into account that also the non-symptomatic knee may have proprioceptive impairments. Such future studies may also provide knowledge of mechanism underlying the impact of impaired proprioceptive accuracy on knee pain and activity limitations., (Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: Reduced range of motion (ROM) is supposed to be a characteristic feature of osteoarthritis (OA). Because little is known about determinants of ROM, the objective of the present study was to explore the association between demographic, articular, and clinical factors and ROM in patients with early symptomatic knee and/or hip OA., Design: Baseline data of 598 participants of the Cohort Hip and Cohort Knee (CHECK) study were used in this cross-sectional study., Methods: Separate analyses were performed for participants with knee and participants with hip symptoms. Active knee flexion, and hip internal rotation, external rotation, flexion, adduction, and abduction were assessed using a goniometer. Participants underwent a standardised physical and radiographic examination, and completed a questionnaire. Exploratory regression analyses were performed to explore the association between ROM and demographic [i.e., age, gender, body mass index (BMI)], articular [i.e., osteophytosis, joint space narrowing (JSN)], and clinical (i.e., pain, stiffness) factors., Results: In patients with early symptomatic knee OA, osteophytosis, bony enlargement, crepitus, pain, and higher BMI were associated with lower knee flexion. JSN was associated with lower ROM in all planes of motion. In addition, osteophytosis, flattening of the femoral head, femoral buttressing, pain, morning stiffness, male gender, and higher BMI were found to be associated with lower hip ROM in two planes of motion., Conclusion: Features of articular degeneration are associated with lower knee ROM and lower hip ROM in patients with early OA. Pain, stiffness, higher BMI, and male gender are associated with lower ROM as well., (Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Background: Conservative management of foot problems in patients with rheumatoid arthritis (RA) may consist of the prescription of customised foot orthoses. Indications for foot orthoses are not clear and the effectiveness of the intervention is highly variable among patients. Knowledge on which patients benefit the most from foot orthoses can help to select patients eligible for this type of intervention. The objective of the present study was to determine clinical and demographic factors that predict the outcome of customised foot orthoses on pain and disability in patients with RA., Methods: A total of 135 RA patients who were supplied with customised foot orthoses were included in this prospective cohort study. Pain and disability were measured before and after the intervention period using a Numeric Rating Scale (NRS) for foot pain, the Foot Function Index (FFI), the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) and a 10-meter walking test. The intervention period consisted of one or more appointments with the podiatrist during which the foot orthoses were customised.Swollen foot joint count, foot deformity scores, forefoot peak pressure, disease duration, age, gender, body mass index and baseline values of the outcome measures were selected as potential factors predicting outcome. Multivariate linear regression analyses were performed to determine factors associated with change in pain and disability (at P < 0.05)., Results: Disease duration was negatively associated with the change scores in NRS foot pain (P = 0.018), WOMAC pain (P = 0.001), FFI disability (P = 0.003) and WOMAC physical function (P = 0.002). Age was negatively associated with the change score in 10 meter walking time (P = 0.008). For all outcome measures baseline values were positively associated with the change scores (P < 0.001)., Conclusions: Shorter disease duration predicted greater improvements in self-reported foot pain and disability, and younger age predicted greater improvements in walking time after intervention with foot orthoses. Also, higher baseline values of pain and disability predicted greater improvements. Referral for conservative management with foot orthoses in the early stage of RA seems important when aiming to achieve reduction in pain and improvement in daily activities.

Objectives: To develop an easy-to-use scale that measures upper limb capacity, according to the International Classification of Functioning, Disability and Health definition, in patients after stroke, and to investigate certain psychometric properties of this scale., Design: Cohort study., Setting: Inpatient department of a rehabilitation center., Participants: Patients (N=546; mean age ± SD, 60.1±11.2y; 56% men) undergoing rehabilitation after stroke., Interventions: Not applicable., Main Outcome Measures: Mokken scale analysis was used to investigate the following psychometric properties: (1) fit of the monotone homogeneity model, indicating that the items form a scale; (2) unidimensionality, indicating that the items measure only 1 concept (or construct); (3) fit of the double monotonicity model, indicating invariant (hierarchical) item ordering; (4) differential item functioning (DIF), indicating the validity of comparison between subgroups; and (5) internal consistency, indicating the degree of interrelatedness of the items. The mean time needed to complete the scale was calculated to indicate (6) feasibility., Results: The Stroke Upper Limb Capacity Scale (SULCS) was developed on the basis of interviews with experts. Ten of 15 items had (1) good fit of the monotone homogeneity model (coefficient H=.88), were (2) unidimensional, and had (3) good fit of the double monotonicity model (coefficient H(T)=.71), (4) absence of DIF (Crit-values <40), and (5) good internal consistency (coefficient ρ=.96). When applying start-and-stop rules, the (6) feasibility of the SULCS was good (6min)., Conclusions: The SULCS is an easy-to-use, unidimensional, hierarchical, and internally consistent scale that assesses upper limb capacity in patients after stroke., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objectives: To identify early predictors of stenosing tenosynovitis in the hand and hand-related activity limitations in patients with rheumatoid arthritis (RA)., Design: A longitudinal study of an inception cohort., Setting: A large outpatient clinic., Participants: Consecutive patients who attended the Early Arthritis Clinic for at least 2 years and fulfilled the American College of Rheumatology criteria for RA at baseline and/or at the 1-year follow-up were invited to participate until 200 patients were included., Interventions: Not applicable., Main Outcome Measures: Stenosing tenosynovitis, assessed by means of a standardized physical examination. Hand-related activity limitations, assessed with the Disabilities of Arm, Shoulder and Hand questionnaire (DASH). A DASH score above the upper limit of the 95% range of the normative score was defined as abnormal. Prognostic factors: demographic and disease activity-related variables, radiographic damage, the Health Assessment Questionnaire (HAQ) total score and category scores at the 2-year follow-up., Results: The mean age ± SD of the patients was 59.7±10.7 years (75% female). The mean time ± SD between the 2-year follow-up and the assessment of the dependent variables was 3.9±2.7 years. Stenosing tenosynovitis was present in 33%. The median (interquartile range) DASH score was 26.7 (10.8-42.5); 30% were abnormal. Stenosing tenosynovitis was predicted by the HAQ subscale regarding the use of hands (HAQ-hand) at the 2-year follow-up (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.2-4.2). Hand-related activity limitations were predicted by the Disease Activity Score in 28 joints (OR, 1.8; 95% CI, 1.3-2.4) and HAQ-hand (OR, 2.4; 95% CI, 1.3-5.8) at the 2-year follow-up., Conclusions: Stenosing tenosynovitis in patients with RA was predicted by HAQ-hand at the 2-year follow-up, and hand-related activity limitations were predicted by disease activity and HAQ-hand at the 2-year follow-up., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To determine the prevalence of hand and wrist symptoms and impairments, and the resulting activity limitations in relation to disease duration in patients with rheumatoid arthritis., Design and Patients: A cross-sectional study included 200 consecutive patients with rheumatoid arthritis in 4 categories of disease duration: 2-4, 4-6, 6-8 and ≥ 8 years. Patients were asked about the presence of various hand and wrist symptoms, and underwent a standardized physical examination. To evaluate activity limitations, patients completed the Disabilities of the Arm Shoulder and Hand questionnaire and scored their limitations on a Numerical Rating Scale (0 = no to 10 = maximum limitation)., Results: Of all patients, 94% suffered from at least one symptom, and 67% had at least one impairment, mostly from the earliest stages onwards. The median standardized Disabilities of the Arm Shoulder and Hand score (interquartile range) was 26.7 (10.8-42.5). The mean Numerical Rating Scale score for activity limitations was 2.99 (standard deviation 2.50) in the dominant hand and 2.59 (standard deviation 2.49) in the non-dominant hand., Conclusion: A high prevalence of hand and wrist symptoms and impairments is often already present after 2 years of disease duration. We recommend that physicians specifically screen for these symptoms and impairments, starting 2 years after the diagnosis of rheumatoid arthritis.

Objectives: To assess possible relationships between disease activity, foot-related impairments, activity limitations and participation restrictions in children with juvenile idiopathic arthritis (JIA)., Methods: Thirty-four children were studied. Disease activity was assessed with the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71). Foot-related impairments, activity limitations and participation restrictions were measured with the Juvenile Arthritis Foot Disability Index (JAFI), the Childhood Health Assessment Questionnaire (CHAQ), self-reported or parent-reported and doctor-reported VAS scales. Relationships were quantified with Spearman's correlation coefficient., Results: The mean age was 12.4±3.7 years, the median disease duration 1.5 years (interquartile range (IQR) 1.0-4.0), 88% were girls, and 76% had polyarticular disease course. The median JADAS-71 score (range 0-101) was 6 (IQR 1-13). On the JAFI sub-scores (range 0-4) 88% of the children reported some foot-related impairments (median 1.1, IQR 0.4-2.0); 82% reported some foot-related activity limitations (median 0.9, IQR 0.3-2.0), and 65% reported some foot-related participation restrictions (median 0.6, IQR 0-2.1). The median CHAQ score was 0.9 (IQR 0.1-1.8). The JADAS-71 correlated with all impairment, activity limitation and participation restriction variables (r=0.48-0.81, p<0.01). Most of the impairment variables correlated with activity limitation (r=0.39, p<0.05 to r=0.92, p<0.01) and participation restriction variables (r=0.44, p<0.05 to r=0.81, p<0.01). All activity limitation variables correlated with participation restriction variables (r=0.62-0.84, p<0.01)., Conclusions: We observed strong relationships between disease activity, foot-related impairments, activity limitations and participation restrictions in children with JIA, and therefore suggest that standard screening for foot problems should be included in follow-up care for JIA patients.

Objective: To predict the 2-year course of activity limitations in patients with early knee and/or hip osteoarthritis (OA)., Methods: The Cohort Hip & Cohort Knee (CHECK) study is a prospective followup study. The CHECK cohort, comprising participants (n = 1,002) with early OA-related knee and/or hip symptoms, was followed for 2 years. Participants completed questionnaires and underwent physical, laboratory, and radiographic examination. Regression models were used to examine whether baseline variables predicted the course of activity limitations as measured with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Analyses were performed separately for participants with knee symptoms and participants with hip symptoms., Results: After 2 years of followup, activity limitations slightly decreased. Large between-subject variation was observed in WOMAC change scores. In participants with knee symptoms, young age, non-Western ethnicity, bilateral hip pain, morning stiffness in the knee, high comorbidity count, high body mass index, high bodily pain, poor general health perception, and pain coping strategy were associated with a poor 2-year outcome on activity limitations. In participants with hip symptoms, few activity limitations at baseline, bilateral hip pain, morning stiffness in the knee, high comorbidity count, low active hip flexion, poor general health perception, and pain coping strategy were associated with a poor 2-year outcome on activity limitations., Conclusion: After 2 years of followup, large between-subject variation was observed in the course of activity limitations. The course of activity limitations is to some extent already predictable at an early stage of knee and hip OA.

Objective: To investigate the construct validity and test-retest reliability of the Climbing Stairs Questionnaire, a patient-reported measure of activity limitations in climbing stairs, in lower-limb amputees., Design: A cross-sectional study., Setting: Outpatient department of a rehabilitation center., Participants: Lower-limb amputees (N=172; mean +/- SD age, 65+/-12y; 71% men; 82% vascular cause) participated in the study; 33 participated in the reliability study., Interventions: Not applicable., Main Outcome Measure(s): Construct validity was investigated by testing 10 hypotheses: limitations in climbing stairs according to the Climbing Stairs Questionnaire will be greater in lower-limb amputees who: (1) are older, (2) have a vascular cause of amputation, (3) have a bilateral amputation, (4) have a higher level of amputation, (5) have more comorbid conditions, (6) had their rehabilitation treatment in a nursing home, and (7) climb fewer flights of stairs. Furthermore, limitations in climbing stairs will be related positively to activity limitations according to: (8) the Locomotor Capabilities Index, (9) the Questionnaire Rising and Sitting down, and (10) the Walking Questionnaire. Construct validity was quantified by using the Mann-Whitney U test, Kruskal-Wallis test, and Spearman correlation coefficient. Test-retest reliability was assessed with a 3-week interval and quantified using the intraclass correlation coefficient (ICC)., Results: Construct validity (8 of 10 null hypotheses not rejected) and test-retest reliability were good (ICC=.79; 95% confidence interval, .57-.90)., Conclusion: The Climbing Stairs Questionnaire has good construct validity and test-retest reliability in lower-limb amputees.

Objectives: To develop a questionnaire that specifically and comprehensively measures mobility limitations in children with cerebral palsy (CP) and to investigate certain psychometric properties (scalability, unidimensionality, internal consistency) of this questionnaire., Design: Cross-sectional study., Setting: Private physical therapy practices and outpatient departments of hospitals and rehabilitation centers., Participants: Children with CP undergoing physical therapy or rehabilitation. The Mobility Questionnaire, 47-item (MobQues47), was completed by the mothers of these children (N=323; mean age +/- SD, 7.1+/-2.9y; 57% boys; Gross Motor Function Classification levels: I [48%], II [26%], III [19%], IV [7%])., Interventions: Not applicable., Main Outcome Measures: Mokken scale analysis was used to investigate (1) scalability, indicating that the items form a scale; (2) unidimensionality, indicating that the items measure only 1 concept; and (3) internal consistency, indicating the degree of interrelatedness of the items., Results: The MobQues47, made up of 47 items, was developed on the basis of 3 pilot studies and careful operationalization of the concept (or construct) of mobility limitations. The scalability (coefficient H=.70), unidimensionality, and internal consistency (coefficient rho=.99) of the MobQues47 were found to be very good., Conclusions: The MobQues47 is a unidimensional scale with excellent internal consistency that can be used to measure caregiver-reported mobility limitations in children with CP.

Objective: There is no consensus on the best method to determine the minimal important change (MIC) of patient-reported outcomes. Recent publications recommend the use of multiple methods. Our aim was to assess whether different methods lead to consistent values for the MIC., Study Design and Setting: We used two commonly used anchor-based methods and three commonly used distribution-based methods to determine the MIC of the subscales: pain and physical functioning of the Western Ontario and McMaster University Osteoarthritis Index questionnaire in five different studies involving patients with hip or knee complaints. We repeated the anchor-based methods using relative change scores, to adjust for baseline scores., Results: We found large variation in MIC values by the same method across studies and across different methods within studies. We consider it unlikely that this variation can be explained by differences between disease groups, disease severity, or lengths of follow-up. The variation persisted when using relative change scores. It was not possible to conclude whether this variation is because of true differences in MIC values between populations or to conceptual and methodological problems of the MIC methods., Conclusion: To better disentangle these two possible explanations, the MIC methodology should be improved and standardized. In the meantime, caution is needed when interpreting and using published MIC values.

Objective: Determining "minimally important change" (MIC) facilitates the interpretation of change scores on multi-item instruments. This article focuses on how MIC values should be interpreted when applied to individual patients., Study Design and Setting: The MIC value of a hypothetical questionnaire "Q" was determined in a sample of 400 patients who improved and 100 patients who did not improve, using the receiver operating characteristic (ROC) method, and three methods to quantify the uncertainty., Results: The MIC value on questionnaire Q was 10.5. Firstly, the 95% confidence interval (CI) of the MIC value (for questionnaire Q: 5.6-14.2) quantifies the uncertainty of the estimation of the MIC value. Secondly, "how sure we are that this MIC value holds for every patient" is quantified by the values for sensitivity (74%) and specificity (91%). Thirdly, the smallest detectable change (SDC) on questionnaire Q is calculated (16.0) to consider whether the MIC value (10.5) falls outside or within the measurement error., Conclusion: For application in clinical research and practice, MIC values are always considered at the individual level, but determined in groups of patients. The interpretation comes with different forms of uncertainty. To appreciate the uncertainty, knowledge of the underlying distributions of change scores is indispensable.

Objective: To provide a practical example showing how to relate measurement error to minimal important change (MIC) to estimate sample sizes required for detecting important changes in research, and to determine the usefulness of patient-reported outcomes (PROs) in daily clinical practice., Study Design and Setting: The standard error of measurement (SEM) can be calculated as a parameter of measurement error. MIC can be determined by taking the mean change in score on the questionnaire in the subgroup of patients that reported to be "a little better" or "better" on a global rating scale minus the mean change in score in the subgroup of patients that reported to be "not changed." Based on SEM and MIC, formulas are presented that can be used to estimate sample sizes and to determine whether the questionnaire can be used to monitor changes in individual patients in daily clinical practice., Results: A fully worked-out example is presented, using Western Ontario and McMaster University Osteoarthritis Index data from a cohort of patients undergoing hip or knee replacement., Conclusion: We strongly recommend investigators to present the SEM and MIC of PROs and use these to estimate sample sizes for research and to determine the usefulness of these outcomes in daily clinical practice.

Objective: To describe the osteoarthritis study population of CHECK (Cohort Hip and Cohort Knee) in comparison with relevant selections of the study population of the Osteoarthritis Initiative (OAI) based on clinical status and radiographic parameters., Methods: In The Netherlands a prospective 10-year follow-up study was initiated by the Dutch Arthritis Association on participants with early osteoarthritis-related complaints of hip and/or knee: CHECK. In parallel in the USA an observational 4-year follow-up study, the OAI, was started by the National Institutes of Health, on patients with or at risk of symptomatic knee osteoarthritis. For comparison with CHECK, the entire cohort and a subgroup of individuals excluding those with exclusively hip pain were compared with relevant subpopulations of the OAI., Results: At baseline, CHECK included 1002 participants with in general similar characteristics as described for the OAI. However, significantly fewer individuals in CHECK had radiographic knee osteoarthritis at baseline when compared with the OAI (p<0.001). In contrast, at baseline, the CHECK cohort reported higher scores on pain, stiffness and functional disability (Western Ontario and McMaster osteoarthritis index) when compared with the OAI (all p<0.001). These differences were supported by physical health status in contrast to mental health (Short Form 36/12) was at baseline significantly worse for the CHECK participants (p<0.001)., Conclusion: Although both cohorts focus on the early phase of osteoarthritis, they differ significantly with respect to structural (radiographic) and clinical (health status) characteristics, CHECK expectedly representing participants in an even earlier phase of disease.

Objective: To investigate the cross-cultural validity of international Dutch-English comparisons when using the Dutch Rivermead Mobility Index (RMI), and the intra-test reliability and construct validity of the Dutch RMI., Methods: Cross-cultural validity was studied in a combined data-set of Dutch and English patients undergoing rehabilitation after stroke, who were assessed with the Dutch version of the RMI and the original English RMI, respectively. Mokken scale analysis was used to investigate unidimensionality, monotone homogeneity model fit, and differential item functioning between the Dutch and the English RMI. Intra-test reliability and construct validity were studied in the Dutch patients by calculating the reliability coefficient and correlating the Dutch RMI and the Dutch Barthel Index., Results: The RMI was completed for Dutch (n = 200) and English (n = 420) patients after stroke. The unidimensionality and monotone homogeneity model fit of the RMI were excellent: combined Dutch-English data-set (coefficient H = 0.91); Dutch data-set (coefficient H = 0.93); English data-set (coefficient H = 0.89). No differential item functioning was found between the Dutch and the English RMI. The intra-test reliability of the Dutch RMI was excellent (coefficient rho = 0.97). In a sub-sample of patients (n = 91), the Dutch RMI correlated strongly with the Dutch Barthel Index (Spearman's correlation coefficient rho = 0.84)., Conclusion: The Dutch RMI allows valid international Dutch-English comparisons, and has excellent intra-test reliability and construct validity.

Background: This study investigates the usefulness of the nonparametric monotone homogeneity model for evaluating and constructing Health-Related Quality-of-Life Scales consisting of polytomous items, and compares it to the often-used parametric graded response model., Methods: The nonparametric monotone homogeneity model is a general model of which all known parametric models for polytomous items are special cases. Merits, drawbacks, and possibilities of nonparametric and parametric models and available software are discussed. Particular attention is given to the monotone homogeneity model (also known as the Mokken model), and the often-used parametric graded response model., Results: Data from the WHOQOL-Bref were analyzed using both the monotone homogeneity model and the graded response model. The monotone homogeneity model analysis yielded unidimensional scales for each content domain. Scalability coefficients further showed that some items have limited scalability with respect to the other items in the same scale. The parametric IRT analyses lead to the rejection of some of the items., Conclusions: The nonparametric monotone homogeneity model is highly suited for data analysis in a health-related quality-of-life context, and the parametric graded response model may add interesting features to measurement provided the model fits the data well.

Objective: To assess the predictive value of selected sociodemographic characteristics, rheumatoid arthritis (RA)-specific clinical factors, and comorbidity with respect to patient-reported health outcomes, i.e., pain, disability, and health-related quality of life, among patients with RA., Methods: Data were collected between 1997 and 2002 among 882 patients with RA of varying disease duration using questionnaires and clinical examinations. Health outcomes were evaluated over 5 years as a function of disease duration by means of random intercept linear regression. Then we selected the 10% of patients with the poorest and best health outcomes during the 5 years of followup compared to others with equal disease duration. Separate multivariate logistic regression analyses were conducted to identify factors associated with poor and good outcomes., Results: Sociodemographic characteristics seemed to be less important in the prediction of health outcomes. After RA-specific clinical factors, comorbidity appeared to be a major predictive factor for health outcomes. In particular, psychological comorbidity, i.e., depressive symptomatology, was a consistent predictive factor with respect to all health outcomes., Conclusion: Assessment of comorbidity needs to be incorporated into the management of RA in order to prevent poor outcomes and to adapt therapies to the specific situation of individual patients. Periodic routine screening for and monitoring of somatic and psychological comorbidity should be included in clinical practice.

Objective: To describe health outcomes reported by patients with rheumatoid arthritis (RA), i.e., pain, disability and health-related quality of life, as a function of disease duration in a longitudinal approach, and to compare the course of patient-reported health outcomes by a longitudinal versus a cross-sectional approach., Methods: Data were collected with 4 series of questionnaires between 1997 and 2002 among patients with RA (maximum number = 882) of varying disease duration. The course of patient-reported health outcomes as a function of disease duration was evaluated using both longitudinal data and cross-sectional data of the first series., Results: The course of RA shows a different pattern for various health outcomes. We observed similar trends in health outcomes in this large patient sample using the longitudinal and the cross-sectional approach., Conclusion: Although longterm consequences of RA are preferably assessed in longer duration followup studies, cross-sectional studies, including patients with a broad range of disease durations, seem to provide fairly reliable estimates of the course of health outcomes.

Objective: To develop a hierarchical scale that measures activity limitations in walking in patients with lower-extremity disorders who live at home., Design: Cross-sectional study., Setting: Orthopedic workshops and outpatient clinics of secondary and tertiary care centers., Participants: Patients (N=981; mean age +/- standard deviation, 58.6+/-15.4 y; 46% men) living at home, with different lower-extremity disorders: stroke, poliomyelitis, osteoarthritis, amputation, complex regional pain syndrome type I, and diabetic and degenerative foot disorders., Interventions: Not applicable., Main Outcome Measures: (1) Fit of the monotone homogeneity model, indicating whether items can be used for measuring patients; (2) fit of the double monotonicity model, indicating invariant (hierarchical) item ordering; (3) intratest reliability, indicating repeatability of the sum score; (4) robustness, addressing the clinimetric properties within subgroups of patients; and (5) differential item functioning, addressing the validity of comparisons between subgroups of patients., Results: Thirty-five of 41 dichotomous items had (1) good fit of the monotone homogeneity model (coefficient H=.50), (2) good fit of the double monotonicity model (coefficient H(T)=.33), (3) good intratest reliability (coefficient rho=.95), (4) satisfactory robustness (within subgroups of patients defined by age, sex, and diagnosis), and (5) some differential item functioning (6 items in amputees compared with nonamputees)., Conclusions: A hierarchical scale, with excellent scaling characteristics, was developed to measure activity limitations in walking in patients with lower-extremity disorders who live at home. The measurements should be interpreted cautiously when making comparisons between amputees and nonamputees.

Objective: To improve a self-administered questionnaire that includes 42 dichotomous items and measures activity limitations in rising and sitting down (R&S) in patients with lower-extremity disorders who live at home., Design: Cross-sectional study., Setting: Outpatient clinics of secondary and tertiary care centers., Participants: Patients (N=759; 47% men; mean age +/- standard deviation, 60.7+/-15.2y) living at home, with lower-extremity disorders resulting from stroke, poliomyelitis, osteoarthritis, amputation, and complex regional pain syndrome type I., Interventions: Not applicable., Main Outcome Measures: (1) Unidimensionality, indicating that items assess only a single construct; (2) fit with the one-parameter logistic model (OPLM), yielding information about patient and item location parameters; (3) intratest reliability, indicating consistency of patients' item scores; and (4) content validity, indicating completeness with which the items cover the important aspects of the construct that they are attempting to represent., Results: Thirty-nine of 42 items: (1) loaded on 1 component (variance explained, 59%; item component loadings, >or=.51), (2) showed good fit with the OPLM (P=.15), (3) had a good intratest reliability (Cronbach alpha=.96), and (4) had a good content validity (all important aspects represented)., Conclusions: A unidimensional scale that fits with the OPLM has been developed for measuring activity limitations in R&S in patients with lower-extremity disorders who live at home.

Background: The Action Research Arm (ARA) test is a performance test of upper extremity motor function which consists of 19 items divided into four hierarchical subtests. This multidimensionality has not yet been tested empirically., Objective: To investigate the dimensionality of the ARA test., Design: Cross-sectional study involving a sample of 63 chronic stroke patients., Methods: A Mokken scale analysis was performed., Results: The Mokken scale analysis revealed one strong unidimensional scale containing all 19 items, of which the scalability coefficient H was 0.79, while H per item ranged from 0.69 to 0.86. The reliability coefficient rho equalled 0.98, indicating a very high internal consistency. A subset of 15 out of 19 items showed an invariant hierarchical item-ordering., Conclusion: The ARA test is a unidimensional scale. The use of subtests, as proposed in the original description of the instrument, is not supported by the present findings. The 15-item scale presented here can be used for adaptive testing, i.e. using only a selected subset of items based on prior knowledge about the patient's abilities, thus minimizing testing time.

Objective: Develop and test a self-administered questionnaire that measures perceived and actual functional limitations in rising and sitting down., Setting: Private practices for physical therapy and outpatient clinics of hospitals and rehabilitation centers., Patients: 345 outpatients (43% male, aged 14 to 92 years) with different grades of functional limitations and different types of lower extremity orthopedic or rheumatologic disorders., Methods: The Questionnaire Rising and Sitting Down (QR&S) was developed on the basis of a literature review and careful operationalization of functional limitations. Five dimensions concerning different objects (high chair, low chair, toilet, bed, and car) and one global dimension were postulated to be contained in the instrument. Mokken scale analysis was used to test the postulated dimensions (scalability coefficient H). Furthermore, robustness with respect to patient characteristics was determined, as well as intratest reliability (reliability coefficient Rho), test-retest reliability (intraclass correlation coefficient [ICC]), content validity (coverage of operationalized aspects), and construct validity (testing of seven hypotheses)., Results: Mokken scale analysis confirmed the existence of 5 object dimensions (H = .53-.59). However, two global dimensions were found (H = .50-.54). The resulting hierarchical scales, consisting of subsets of the 32 final QR&S items, are robust and measure functional limitations in a reliable (Rho .77-.91; ICC .72-.90) and valid (3 out of 4 aspects covered, 2 hypotheses rejected for 3 out of 7 scales) manner., Conclusion: The QR&S is a reliable and valid self-administered questionnaire. It consists of hierarchical scales and measures perceived and actual functional limitations in rising and sitting down.