Functional Index-2 Research Articles

Feasibility of Muscle Endurance Testing in Critically Ill Trauma Patients: A Pilot Study.

Intensive care unit-acquired weakness (ICUAW) occurs secondary to patients treated for life-threatening conditions in the ICU being diagnosed based on the Medical Research Council sum score (MRC-SS). However, patients often complain of fatigability and poor endurance, which are not evaluated by muscle strength. In this study, we explored the feasibility of assessing muscle quality and endurance in trauma ICU patients. The modified Functional Index-2 (FI2) testing was applied to evaluate muscle endurance. The maximal voluntary contraction (MVC) was measured when evaluating the MRC-SS using surface electromyography (sEMG), and the fatigue index (FI) was also recorded at the time of endurance testing. The ultrasonic muscle echogenicity by gray-scale analysis of rectus femoris (RF) and tibialis anterior (TA) muscles was evaluated at the initial (<72 h) and end of ICU care. A total of 14 patients were enrolled in this study. Fatigue was induced in eight patients (fatigue group), and six (non-fatigue group) completed endurance testing. All patients except one had an MRC-SS exceeding 48 points. There was no difference in US echogenicity, MRC-SS, and FI between groups. In sEMG, the root mean square (RMS) values of MVC in RF and TA muscles showed a significant difference (p < 0.05). To evaluate and predict the functional activity of ICU patients, measuring muscle strength alone is insufficient, and it is necessary to evaluate muscle endurance. In this respect, the modified FI2 test and sEMG monitoring are considered to be promising procedures for evaluating the muscle condition of critically ill patients even in complex situations in the ICU.

POS0839 RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL TO EVALUATE EFFICACY AND SAFETY OF SC ABATACEPT IN ADULTS WITH ACTIVE IDIOPATHIC INFLAMMATORY MYOPATHY

BackgroundLimited therapies are available for patients with idiopathic inflammatory myopathy (IIM), a heterogenous group of chronic, systemic, autoimmune inflammatory diseases characterized by progressive muscle weakness and/or distinct skin rashes.1 Abatacept, a selective co-stimulation modulator, may be a useful treatment option.2ObjectivesTo evaluate efficacy, safety, and tolerability of abatacept + standard of care (SOC) in patients with IIM compared with SOC alone (placebo).MethodsA 24-week, randomized, double-blind, placebo-controlled phase 3 trial of SC abatacept (125 mg weekly) + SOC (corticosteroids and immunosuppressants alone or combined; NCT02971683) in patients with active, treatment-refractory IIM (Manual Muscle Testing-8 [MMT-8] ≤ 135) was performed. Primary endpoint was proportion of patients meeting International Myositis Assessment and Clinical Studies definition of improvement (IMACS DOI) at week 24. Change from baseline in myositis Functional Index-2 (FI-2), HAQ-DI, Myositis Disease Activity Assessment Tool (MDAAT), and Myositis Response Criteria (MRC) were secondary endpoints with safety. Post hoc analyses by disease subtype were performed.ResultsOverall, 148 patients were randomized (75 abatacept; 73 placebo); IIM subtypes were dermatomyositis (DM; 53.3% vs 57.5%), polymyositis (PM; 25.3% vs 34.2%), and autoimmune necrotizing myopathy (ANM; 21.3% vs 8.2%). Mean baseline MMT-8 and HAQ-DI scores were 112.7 and 1.5, respectively. Approximately 90% of patients completed week 24. Week 24 IMACS DOI rates were abatacept 56.0% vs placebo 42.5% (adjusted odds ratio, 1.8 [95% CI, 0.9–3.5]; P = 0.083). Pre-specified IMACS DOI analysis showed no differences for patients with DM but notable benefit for those with non-DM subtypes, PM and ANM (Table 1). Secondary endpoints showed similar differences (Table 1). MRC at day 169 by category is shown in Figure 1. Proportion of AEs (69.3% and 75.3%) and serious AEs (5.3% and 5.5%) were similar in the abatacept and placebo arms.Table 1.Primary and secondary (mean change from baseline at week 24) endpointsOutcomeIIMAbataceptPlaceboNominal P value (abatacept vs placebo) or adjusted mean difference from placebo (95% CI)IMACS DOI,a n/N (%)All42/75 (56.0)31/73 (42.5)P = 0.083DM22/40 (55.0)21/42 (50.0)P = 0.679Non-DM20/35 (57.1)10/31 (32.3)P = 0.040FI-2All4.1 (1.3)1.2 (1.4)2.9 (0 to 5.8)DM2.3 (1.6)0.3 (1.4)1.9 (−2.3 to 6.2)Non-DM3.2 (1.4)−0.6 (1.5)3.7 (−0.3 to 7.8)HAQ-DIAll−0.31 (0.07)0.20 (0.07)−0.12 (−0.28 to 0.04)DM−0.31 (0.08)−0.19 (0.07)−0.11 (−0.32 to 0.10)Non-DM−0.25 (0.09)−0.07 (0.09)−0.18 (−0.44 to 0.07)MDAAT, Extramuscular Global Activity, (95% CI)bAll−1.56 (−1.96 to −1.16)−1.40 (−1.81 to −0.99)−0.16 (−0.63 to 0.30)DM−1.90 (−2.43 to −1.37)−1.85 (−2.35 to 1.36)−0.05 (−0.77 to 0.68)Non-DM−1.09 (−1.46 to −0.72)−0.85 (−1.27 to −0.43)−0.24 (−0.80 to 0.32)MMT-8All12.9 (1.9)11.0 (2.0)1.8 (−2.7 to 6.4)DM14.4 (2.2)14.0 (2.2)0.4 (−5.7 to 6.4)Non-DM12.1 (2.5)7.8 (2.7)4.3 (−3.0 to 11.7)Physician Global AssessmentbAll−2.89 (0.30)−2.69 (0.30)−0.20 (−0.92 to 0.52)DM−2.78 (0.29)−2.43 (0.28)−0.35 (−1.15 to 0.46)Non-DM−2.35 (0.43)−2.21 (0.48)−0.14 (−1.43 to 1.15)Patient Global AssessmentbAll−1.4 (0.31)−0.98 (0.32)−0.38 (−1.11 to 0.35)DM−1.4 (0.33)−1.4 (0.31)−0.00 (−0.91 to 0.90)Non-DM−1.2 (0.41)−0.3 (0.44)−0.93 (−2.14 to 0.29)Data are adjusted mean change from baseline score (SE) unless stated.aDefined as improvement of ≥ 20% in 3 IMACS core measures, worsening by ≥ 25% in ≤ 2 IMACS core measure scores, and a reduction of &lt; 25% in MMT-8; b100 mm visual analog scale.ConclusionIn this double-blind trial of SC abatacept vs placebo, abatacept failed to meet primary or secondary endpoints. Post hoc analyses suggest a treatment benefit in patients with PM and ANM (not DM) when treated with abatacept. Abatacept use was well tolerated.

Performance of timed function tests as outcome measures in idiopathic inflammatory myopathy-results from a single-centre cohort.

To evaluate performance of timed function tests (TFTs) in assessing muscle strength and endurance as determined by Manual Muscle Testing 8 (MMT-8) and Functional Index 2 (FI-2), respectively, in idiopathic inflammatory myopathies (IIM). This cohort study included 42 IIM patients satisfying 2017 EULAR/ACR criteria. Patients were classified as active (n = 18) or inactive disease (n = 24) based on clinical status at baseline. MMT-8, FI-2, 30 s rise from chair test, 30 s 1 kg arm rise test and 2-min walking distance (2MWD) were administered at baseline, 3 months and 6 months. Pearson rank correlation analysis and receiver operating curves were performed to assess the performance of timed function tests. All patients were followed up at 3 months and 39 completed 6 months' follow-up. All the three TFTs had excellent convergent (r > 0.7, P < 0.05) and divergent validity (P < 0.05). Only 2MWD had moderate to strong correlation with ΔMMT-8 at 3 and 6 months among those with active disease (P = 0.001). All the TFTs correlated with ΔFI-2 in active disease but only Δ2MWD correlated with ΔFI-2 in inactive disease at 6 months (r = 0.506, P = 0.036). At a cut-off of 5% improvement in MMT-8, 2MWD had an area under the curve (AUC) of 0.868 with 95% sensitivity with 2% improvement at 3 months. To detect a 10% ΔMMT-8, Δ2MWD at a cut of 8% and 7% had an AUC of 0.909 and 0.893 with a sensitivity of 92% at 3 and 6 months, respectively (P < 0.05). 2MWD is a reliable indicator of muscle strength, endurance and treatment response. The 2MWD can be self-administered by patients, making it a potential patient-reported outcome measure.

Effects of Conventional Rehabilitative and Aerobic Training in Patients with Idiopathic Inflammatory Myopathy.

To investigate the efficacy of conventional rehabilitation alone and conventional rehabilitation combined with aerobic training on muscle strength and function, health condition, and quality of life for patients with stable idiopathic inflammatory myopathy (IIM). This is a historical retrospective cohort study, in which the medical records of patients with IIM, who received the combination of conventional rehabilitative therapy and aerobic training (combined training group [CTG]), from February 2015 to December 2017 were reviewed. Patients with IIM who received conventional therapy alone were matched based on their age, gender, and disease activity as the control group (CG). Scores obtained on manual muscle testing of eight designated muscles (MMT8) was the primary outcome measure, and scores on the myositis Functional Index-2 (FI-2), Health Assessment Questionnaire (HAQ), and 36-item Short Form Medical Outcomes Study Questionnaire (SF-36) at 12 weeks during training were the secondary outcomes. Fifty-six patients (28 in the CTG and 28 in the CG) were included in this analysis. Patients in both groups had improved MMT8, FI-2, HAQ, and SF-36 scores after 12 weeks of physical therapy. The CTG had a significantly higher score on the MMT8 and HAQ than the CG in the 12th week. The FI-2 scores were significantly higher in the CTG for the four items (P < 0.05) of hip flexion, step test, heel lift, and toe lift. SF-36 scores of the CTG were also higher than those of the CG for the five items (P < 0.05) of physical functioning, general health, vitality, social functioning, and mental health. Physical exercise training including conventional rehabilitation and aerobic training improved muscle function, health condition, and quality of life. Conventional rehabilitative training combined with aerobic training achieved better improvement compared with conventional rehabilitation training alone.

Diagnostic measures for patients with systemic sclerosis-associated myopathy.

To evaluate the clinico-serological profile and to assess diagnostic parameters of myopathy in patients with systemic sclerosis (SSc)-associated myopathy. We explored the profiles of SSc-myopathy patients and matched non-myopathy SSc patients as well as different diagnostic measures for muscle affection. Additionally, the muscle performance of SSc-myopathy patients, assessed by the Manual Muscle Test for 8 muscle groups (MMT-8) and the Functional Index-2 (FI-2), was compared with that of patients with primary myositis. In SSc-myopathy patients, the following features occurred significantly more often even after Bonferroni correction for multiple comparisons: immunosuppressive treatment (56.0% vs. 24.1%; p=0.0003), elevated levels of creatine kinase (CK) (48.3% vs. 5.3%, p<0.0001), anti-PM-Scl antibodies (30.4% vs. 4%, p=0.00048), and absence of RNA Polymerase III antibodies (7.3% vs. 28.3%, p<0.0001). The MMT-8 showed a mild muscle weakness in SSc-myopathy as well as in primary myositis patients with similar age and sex. Muscle endurance tested by the FI-2 was generally compromised in both cohorts, yet the distribution pattern of affected muscle groups differed between the two cohorts. We confirmed previously described clinic-serological characteristics of SSc-myopathy patients. Our study suggests that autoantibody profile and CK levels may be helpful in establishing the diagnosis of SSc-myopathy. Whole-body MRI might be more accurate to capture the disease extent than MRI of selected muscle groups. Functional muscle tests validated for primary myositis did not perform well for the assessment of muscle function in patients with SSc-myopathy. Both, potential confounders such as skin, joint, and cardiovascular involvement as well as lack of sensitivity might have negatively affected the test performance in this population.

The effect of a 24-week training focused on activities of daily living, muscle strengthening, and stability in idiopathic inflammatory myopathies: a monocentric controlled study with follow-up

BackgroundThe structural and functional changes of the skeletal muscles in idiopathic inflammatory myopathies (IIM) caused by inflammation and immune changes can be severely disabling. The objective of this study was to assess the effect of a 24-week program combining a supervised training of activities of daily living (ADL), resistance, and stability with home exercise for improving muscle function, compared to a daily home-based exercise representing the regular outpatient care.MethodsFifty-seven patients with IIM were consecutively and non-selectively enrolled in an intervention (IG, n = 30) or control (CG, n = 27) group. Both groups were provided a standard-of-care pharmacological treatment and follow-up. Only the IG underwent the supervised intervention twice a week for 1 h per session. At baseline, 12, 24, and 48 weeks, all patients were assessed by an assessor blinded to the intervention for primary outcomes: muscle strength (Manual Muscle Testing of eight muscle groups [MMT-8]) and endurance (Functional Index-2 [FI-2]), and secondary outcomes: stability and body composition. Secondary outcomes also included questionnaires evaluating disability (Health Assessment Questionnaire [HAQ]), quality of life (Short Form 36 [SF-36]), depression (Beck’s Depression Inventory-II [BDI-II]), and fatigue (Fatigue Impact Scale [FIS]), and analysis of the systemic and local inflammatory response and perceived exertion to assess the safety of the intervention.ResultsTwenty-seven patients in the IG and 23 in the CG completed the entire program and follow-up. At week 24, compared to deterioration in the CG, we found a significant improvement in the IG in muscle strength (mean % improvement compared to baseline by 26%), endurance (135%), disability (39%), depression (26%), stability (11%), and basal metabolism (2%) and a stabilization of fitness for physical exercise. The improvement was clinically meaningful (a 24-week change by >20%) in most outcomes in a substantial proportion of patients. Although the improvement was still present at 48 weeks, the effect was not sustained during follow-up. No significant increase in the systemic or local expression of inflammatory markers was found throughout the intervention.ConclusionsThis 24-week supervised intervention focused on ADL training proved to be safe and effective. It not only prevented the progressive deterioration, but also resulted in a significant improvement in muscle strength, endurance, stability, and disability, which was clinically meaningful in a substantial proportion of patients.Trial registrationISRCTN35925199 (retrospectively registered on 22 May 2020).

Validation of Motor Outcome Measures in Myotonic Dystrophy Type 2.

Introduction: Myotonic dystrophy type 2 (DM2) lacks disease-specific, validated, motor outcome measures (OMs), and patients' reported outcomes (PROs). This represents a limit for the monitoring of disease progression and treatment response. Our aim was to identify the most appropriate OMs to be translated in clinical practice and clinical trials on DM2. This study has been registered on clinicaltrials.gov NCT03603171 (https://clinicaltrials.gov/ct2/show/NCT03603171).Methods: Sixty-six patients with genetically confirmed DM2 underwent a baseline and a follow-up visit after 1 year. The tested OMs included: hand opening time, pressure pain threshold (PPT), manual muscle testing (MMT), hand held dynamometry (HHD), scale for the assessment and rating of ataxia (SARA), quantitative motor function test (QMFT), gait stairs Gowers chair (GSGC), 30-s sit to stand test, functional index 2 (FI-2) and 6MWT. The PROs included DM1-Active-C, Rasch-built Pompe-specific activity scale (R-Pact), fatigue and daytime sleepiness (FDSS), brief pain inventory short form (BPI-sf), myotonia behavior scale (MBS), and the McGill pain questionnaire.Results: All patients completed the MBS and the results correlated well with the hand-opening time. The PPT showed a low reliability, no correlation with pain questionnaires, and did not differentiate patients with or without myalgia. Both muscle strength assessments, MMT and HHD, showed good construct validity. The QMFT showed an acceptable ceiling effect (14.5%), good convergent and differential validity and performed overall better than GSGC. The SARA score showed high flooring effect and is not useful in DM2. 6MWT proved a valid outcome measure in DM2. The 30-s sit to stand is a feasible test with good convergent validity, showing a flooring effect of 20% as it cannot be used in more severely affected patients. The FI-2 is time-consuming and has a high ceiling effect. At the 1-year visit the only assessments able to detect a worsening of DM2 were HHD, QMFT, and 6MWT, which are the most sensitive to change, and therefore clinically meaningful OMs in DM2.Conclusion: The clinical meaningful motor outcome measures that best depict the multifaceted phenotype of DM2 and its slow progression are MBS, MMT, or HHD (depending on the clinical setting), QMFT, and the 6MWT.

Functional Index-3: A Valid and Reliable Functional Outcome Assessment Measure in Patients With Dermatomyositis and Polymyositis.

Patients with dermatomyositis (DM) and polymyositis (PM) have reduced muscle endurance.The aim of this study was to streamline the Functional Index-2 (FI-2) by developing the Functional Index-3 (FI-3) and to evaluate its measurement properties, content and construct validity, and intra- and interrater reliability. A dataset of the previously performed and validated FI-2 (n = 63) was analyzed for internal redundancy, floor, and ceiling effects. The content of the FI-2 was revised into the FI-3. Construct validity and intrarater reliability of FI-3 were tested on 43 DM and PM patients at 2 rheumatology centers. Interrater reliability was tested in 25 patients. The construct validity was compared with the Myositis Activities Profile (MAP), Health Assessment Questionnaire (HAQ), and Borg CR-10 using Spearman correlation coefficient. Spearman correlation coefficients of 63 patients performing FI-3 revealed moderate to high correlations between shoulder flexion and hip flexion tasks and similar correlations with MAP and HAQ scores; there were lower correlations for neck flexion task. All FI-3 tasks had very low to moderate correlations with the Borg scale. Intraclass correlation coefficients (ICC) of FI-3 tasks for intrarater reliability (n = 25) were moderate to good (0.88-0.98). ICC of FI-3 tasks for interrater reliability (n = 17) were fair to good (range 0.83-0.96). The FI-3 is an efficient and valid method for clinically assessing muscle endurance in DM and PM patients. FI-3 construct validity is supported by the significant correlations between functional tasks and the MAP, HAQ, and Borg CR-10 scores.

Muscle endurance deficits in myositis patients despite normal manual muscle testing scores.

It is unclear whether quantitating muscle endurance adds nonredundant information useful for the care of patients with muscular disease. Records were retrospectively reviewed for all Johns Hopkins Myositis Center patients with a muscle endurance assessment (n = 128, 226 patient-visits). Muscle endurance and strength were quantitated with the Myositis Functional Index-2 (FI2) and manual muscle testing (MMT), respectively. Composite FI2 muscle endurance scores were comparable in inclusion body myositis (n = 58), dermatomyositis (n = 31), and polymyositis (n = 39). Overall, muscle endurance correlated with and evolved similarly to strength, inversely to serum creatine kinase. However, in patients with normal or near-normal strength (mean MMT > 9.75/10), muscle endurance was typically abnormal and highly variable (mean FI2, 5.6/10; interquartile range, 3.3-7.8/10). Muscle endurance testing may identify muscle impairment inadequately described by MMT, particularly in patients with high MMT scores. Muscle Nerve 59:70-75, 2019.

Effect of CTLA4-Ig (abatacept) treatment on T cells and B cells in peripheral blood of patients with polymyositis and dermatomyositis.

We aimed to evaluate in vivo effects of abatacept on phenotypes of T and B cells in the circulation of myositis patients in a sub-study of the ARTEMIS trial. Twelve patients with paired frozen PBMCs before and after 6-month abatacept treatment were included in this sub-study where mass cytometry (CyTOF) was chosen as a technology to be tested for its utility in a real-life clinical immune monitoring setting. Using CyTOF, the peripheral T cell phenotypes demonstrated considerable variation over time and between individuals precluding the identification of treatment-specific changes. We therefore conclude that studies of patient cohorts displaying wide clinical heterogeneity using mass cytometry must be relatively large in order to be suited for discovery research and immune monitoring. Still, we did find some correlations with functional muscle outcome, namely positive correlations between the ratio of CD4+ T cells and CD8+ T cells (CD4/CD8) in peripheral blood samples both at baseline and after treatment with muscle endurance improvement as assessed by the functional index-2 (FI-2) test. Our data suggest that the CD4/CD8 ratio in circulation at time of active disease may be a predictor of treatment efficacy in myositis patients.

Muscle endurance, strength, and active range of motion in patients with different subphenotypes in systemic sclerosis: a cross-sectional cohort study

Objective: Proximal muscle weakness is common in patients with systemic sclerosis (SSc). Dynamic muscle endurance, muscle strength in the lower extremities, and active range of motion (AROM) in the upper extremities are less studied. We investigated functional muscle endurance, strength, and AROM, and explored differences depending on skin and/or lung involvement in SSc patients.Method: The study divided 205 patients with limited/diffuse cutaneous systemic sclerosis (lcSSc/dcSSc) into no–mild and moderate–end-stage lung involvement, the latter based on the Medsger disease severity score. Dynamic muscle endurance in shoulder and hip flexion was assessed by the Functional Index-2, lower extremity muscle strength by the Timed-Stands Test (TST), and shoulder–arm AROM by the Functional Shoulder Assessment (FSA).Results: Shoulder and hip flexion muscle endurance were reduced in relation to reference values median (IQR) [53% (27–100%) and 40% (23–90%), respectively, p < 0.001]. Patients with moderate–end-stage lung involvement had less endurance in shoulder [39% (21–71%) and hip flexion 35% (20–70%)] than patients with no-mild lung involvement [57% (33–99%) and 48% (28–100%), p < 0.05]. All patients, regardless of subtype/grouping, needed longer to complete the TST [21 s (17–27 s)] compared to reference values [17 s (15–18 s), p < 0.001], and patients with moderate-end-stage lung involvement had worse TST score than patients with no-mild lung involvement, [25 s (18–30 s) vs 19 s (16–25 s), p < 0.001]. The FSA sum scores were lower compared with reference values (p < 0.01). DcSSc patients had a lower FSA-sum score [53 (48–57)] than lcSSc patients [57 (52–60), p < 0.01].Conclusion: SSc patients have markedly reduced muscle endurance in the upper and lower extremities, reduced muscle strength in the lower extremities, and impaired AROM in the shoulders and arms. Patients with moderate–end-stage lung involvement had more impaired muscle endurance and strength but no differences were found between lcSSc and dcSSc patients. Not only muscle strength, but also dynamic muscle endurance should be measured in SSc patients.

Physical impairment in patients with idiopathic inflammatory myopathies is associated with the American College of Rheumatology functional status measure.

The goals of this study were to assess the predictive value of chart-abstracted American College of Rheumatology functional status (ACR-FS) with patient-reported ACR-FS and to relate it with measures of muscle function in a single-institution cohort of patients with idiopathic inflammatory myopathies (IIMs). Demographic and clinical data of 102 patients with IIMs regularly followed in the Rheumatology and Neurology Clinics at the University of Kentucky Medical Center between 2006 and 2012 were obtained through retrospective chart review. Clinical and functional status evaluation, muscle performance testing, and body composition measures were performed on a subset of 21 patients. ACR-FS was obtained by both chart abstraction and direct patient report. Spearman's correlations were used to examine the relationship of ACR-FS derived from chart abstraction with direct patient report, as well as the relationship of measures of physical function and body composition with ACR-FS. ACR-FS derived from chart abstraction was significantly correlated with ACR-FS derived from direct patient report (ρ = 0.78, p < 0.001). ACR-FS derived from chart abstraction was also significantly correlated with patient-reported physical function (ρ = -0.71, p < 0.001) and physical activity (ρ = -0.58, p < 0.05), manual muscle testing (ρ = -0.66, p < 0.01), and skeletal muscle endurance as measured by the functional index-2 test (shoulder flexion ρ = -0.62, p < 0.01; hip flexion ρ = -0.65, p < 0.0; heel lift ρ = -0.67, p < 0.01; and toe lift ρ = -0.68, p < 0.01). The ACR-FS is a simple measure of disability that can be used in chart abstraction studies involving IIM patients. We have demonstrated that ACR-FS correlates well with muscle performance tests of strength and endurance.

The Myositis Activities Profile — Initial Validation for Assessment of Polymyositis/Dermatomyositis in the USA

To evaluate some measurement properties of the Myositis Activities Profile (MAP) in adult patients with polymyositis (PM) and dermatomyositis (DM) in the United States. To assess content validity, patients with PM/DM rated difficulty and importance of items of the MAP using a visual analog scale (VAS), range 0-10. For construct validity, consecutive patients with PM/DM performed the 6-item core set for disease activity including the manual muscle test (MMT) and the Health Assessment Questionnaire (HAQ), the Functional Index-2 (FI-2; muscle endurance), and the MAP plus disease effect on well-being on a VAS. Item fit within subscales was analyzed by Cronbach's alpha. Patients with stable disease activity filled out the MAP again 1 week later. The median combined difficulty and importance, 0-10, of the 31 items was 5.00 (range 2.10-5.95). One item was added, giving a 32-item MAP. Correlations between the median of subscales/single items of the MAP and the HAQ and disease effect on well-being were r(s) = 0.69 and r(s) = 0.68, respectively, with lower correlations to the MMT (r(s) = -0.35), and the FI-2 (r(s) = -0.29 to -0.47) and disease activity measures (r(s) = 0.36-0.41). Cronbach's alpha coefficients for the 4 subscales varied between 0.85 and 0.95. Weighted kappa coefficients (K(w)) ranged between 0.77 and 0.93 for the 4 subscales and between 0.74 and 0.83 for the 4 single items without systematic variations (p > 0.05). This initial validation of the MAP indicates promising measurement properties for assessing limitations in activities of daily living and participation in patients with PM/DM in the United States.

Measures of adult and juvenile dermatomyositis, polymyositis, and inclusion body myositis: Physician and Patient/Parent Global Activity, Manual Muscle Testing (MMT), Health Assessment Questionnaire (HAQ)/Childhood Health Assessment Questionnaire (C‐HAQ), Childhood Myositis Assessment Scale (CMAS), Myositis Disease Activity Assessment Tool (MDAAT), Disease Activity Score (DAS), Short Form 36 (SF‐36), Child Health Questionnaire (CHQ), Physician Global Damage, Myositis Damage Index (MDI), Quantitative Muscle

The idiopathic inflammatory myopathies, including adult and juvenile dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM), are rare systemic autoimmune diseases that are characterized by chronic proximal muscle inflammation and weakness. In previous decades, there were few commonly used outcome measures in myositis, and those outcome measures were not validated. Thus, in the past the assessment of outcomes in therapeutic trials was focused on non-standardized measurement of muscle strength and function only. Over the last decade, however, two international collaborative groups, the International Myositis Assessment and Clinical Studies Group (IMACS) and the Paediatric Rheumatology International Trials Organisation (PRINTO), have defined consensus core set measures to assess myositis disease activity and damage in adults and children and have begun to validate and standardize these measures (1;2). IMACS and PRINTO have also developed preliminary definitions of improvement, which can be used as outcomes for therapeutic trials. These response criteria combine the core set activity measures to determine clinically meaningful improvement (3;4). Our section on myositis assessment focuses first on these core set measures of disease activity, quality of life (which is part of the PRINTO core set of activity, but a separate assessment domain for IMACS), and disease damage. To date, most of the validation data available for these core set measures are in patients with juvenile DM, with more limited validation in adult patients with DM or PM. Despite these efforts, there are still important gaps in validation of these core set measures, and no validation studies have yet been performed in patients with IBM, although they are now being used frequently in myositis therapeutic trials. We end the chapter with tools that have been used primarily in research studies and a few therapeutic trials, which have some supporting validation in certain subgroups of patients with myositis. These tools are primarily organ-specific measures, including strength and functional assessments and cutaneous assessment tools. Quantitative muscle testing and the IBM Functional Rating Scale are the most commonly used instruments to assess patients with IBM, and although they have little supporting validation in myositis, quantitative muscle testing has been well validated in other myopathies and has been used frequently as an endpoint in therapeutic trials for IBM. Although the methods for the assessment of myositis patients have been limited in their scope, great strides have been made in the last decade in the development of new partially validated tools (see Table 1) and international multidisciplinary consensus in using these measures that should enhance our understanding of the diverse effects of myositis on many organ systems and the development of new therapies. Table 1 Summary of Measures of Disease Activity in Myositis Physician and Patient/Parent Global Activity General Description Purpose An overall rating of the disease activity related to myositis, defined as potentially reversible pathology or physiology resulting from the underlying disease process (1).