Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.


Patients with Polymyositis, Dermatomyositis and Inclusion Body Myositis Have Activity Limitations Despite Low Disease Activity: A Registry Study.

Munters1,  Li Alemo, Regardt2,  Malin, Jansson3,  Therese, Johansson3,  Susanna, Ottosson4,  Christina, Dastmalchi5,  Maryam, Lundberg3,  Ingrid E.

Rheumatology Unit, Karolinska University Hospital in Solna, Karolinska Institutet, Stockholm, Sweden
Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
Karolinska Institutet, Stockholm, Sweden
Rheumatology Unit, Karolinska University Hospital, Stockholm, Sweden
Rheumatology Unit, Karolinska University Hospital in Solna, Karolinska Institutet, Stockholm, Sweden

Background/Purpose:

Polymyositis (PM), dermatomyositis (DM) and inclusion body myositis (IBM) are rare diseases characterized by slowly progressive muscle weakness. Although patients with PM and DM respond to treatment with clinical improvement several develop a sustained disability that increase during the disease course, limiting activities in daily life. The knowledge of activity limitations in PM, DM and IBM is limited. All patients with PM, DM and IBM at Karolinska University Hospital are registered annually in the Swedish Myositis Network Registry (SWEMYONET). The aims of this registry study were to investigate activity limitation in a cohort of patients with PM, DM and IBM and to evaluate correlations between two activity limitation measures and disease activity.

Methods:

All patients registered in SWEMYONET from Karolinska University Hospital during 2009 were included. Activity limitation was measured by Health Assessment Questionnaire (HAQ) (score range, 0–3.00) and Myositis Activities Profile (MAP) (score range, 1–7). The cohort consisted of 84 patients of whom 33 had PM (73% women), 40 had DM (55% women) and 11 had IBM (55% women). Median disease duration for PM was 9 years (range, 1–28), for DM 10 years (1–41) and IBM 6 years (2–11). Median of Physician's global assessment of disease activity (0–100mm) was 5 mm (range, 0–50). Mann Whitney U-test was applied to test the sub-groups differences, level of significance was set to <0.05. Spearman rang correlation (rs) was used to test correlations between measures.

Results:

Median HAQ values indicated mild activity limitation for both PM, Md=1.00 (range, 0–2.50) and DM 0.25 (0–1.88) and moderate for IBM 1.5 (0.5–2.75). Activity limitation measured by MAP in PM indicate moderate limitation Md=3.75 (range, 1–7), in DM mild limitation 2 (1–7) and for IBM moderate limitation 4 (1–7).The most limited activity domains measured by MAP in PM were work/school work and leisure, in DM moving around, work/school work and leisure and in IBM moving around, work/ school work and leisure. Patients with DM had significantly less activity limitation compared to PM and IBM whereas IBM had significantly higher activity limitation than PM and DM. High correlations (rs= 0.70 – 0.79) were revealed between HAQ and four domains of MAP (Movement, Self Care, Moving around, Domestic). There were low correlations between HAQ/MAP and Physician's global assessment of disease activity (rs=0.39 / 0.21–0.41).

Conclusion:

Although low disease activity was revealed in the cohort, patients still perceived mild to moderate activity limitation. Patients with DM had less activity limitation than patients with PM and IBM while patients with IBM had greater activity limitation than PM and DM. The most limited activity domain in the cohort was leisure. The correlations between HAQ and MAP are equivalent to findings in a previous study (1).

Reference

(1)Alexanderson, H, Lundberg, IE & Stenström, CH. Development of the myositis activities profile – validity and reliability of a self-administered questionnaire to assess activity limitations in patients with polymyositis/dermatomyositis. Journal of Rheumatology. 2002; 29 (11): 2386–2392.

To cite this abstract, please use the following information:
Munters, Li Alemo, Regardt, Malin, Jansson, Therese, Johansson, Susanna, Ottosson, Christina, Dastmalchi, Maryam, et al; Patients with Polymyositis, Dermatomyositis and Inclusion Body Myositis Have Activity Limitations Despite Low Disease Activity: A Registry Study. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1549
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