Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Association of Physical Function and Disability with Physical Activity in Women with Rheumatoid Arthritis

Piva1,  Sara R., Almeida1,  Gustavo J. M., Murphy1,  Yanique, Wasko2,  M. C.

University of Pittsburgh, Pittsburgh, PA,
Univ of Pittsburgh Med Ctr, Pittsburgh, PA

Purpose:

Measures of physical function (PF) and disability traditionally have been used as the primary outcomes of rehabilitation in patients with rheumatoid arthritis (RA). While informative about the patient's ability to perform everyday tasks, they do not provide information about the amount of everyday tasks one performs, defined as physical activity (PA). Studies demonstrated that PA is associated only to a small degree with PF and disability and perhaps represent independent constructs. The purpose of this study was to determine the cross-sectional associations between measures of PA and measures of PF and disability prior and after controlling for social and biomedical characteristics in women with RA.

Method:

Forty seven women with RA, mean age 58 ± 6 years. PA was measured by a portable activity monitor worn for 7 days, and was characterized in 2 ways: daily average # of steps, and daily energy expenditure during moderate levels of PA (EEPA). Disability was measured by the Health Assessment Questionnaire (HAQ). PF was measured by self-selected gait speed and the timed 5-chair rise test. Non-normally distributed variables were square root-transformed. Analyses: Step 1- Pearson coefficients were calculated between PA, PF and disability. Step 2- Pearson or Spearman coefficients were calculated between social and biomedical characteristics and PA, PF and disability. Step 3- partial correlations between measures of PA and measures of PF and disability were calculated controlling for associated social and biomedical characteristics.

Results:

Results are reported in the Table. Associations between measures of PA and measures of PF and disability, although significant, were small (r = -.23 to.48). After controlling for social and biomedical characteristics, the associations were not significant (r=.07 to.28).

Step 1. Associations between PA and measures of PF and disability
  PFDisability 
  Gait SpeedChair RiseHAQ
PAEEPA.37*-.23-.38**
 # of steps.39**-.41**-.48**
Step 2. Associations of social and biomedical characteristics with PA, PF, and disability
 PAPFDisability  
 EEPA# of stepsGait SpeedChair RiseHAQ
Age-.24-.21-.25.30*.27
Race†.03.06.12-.22-.20
BMI-.03-.18-.36*.10.10
Marital Status†-.19-.04-.06.04.10
Education.27.31*.35*-.35*-.28
Comorbidities†-.13-.26-.17.24.34*
RA Duration-.09.39*.06.39**.37*
RA Activity (DAS28)-.21-.18-.28.21.30*
Step 3. Associations between PA and measures of PF and disability controlling for age, BMI, education, comorbidities, disease duration and activity
  PF Disability
  Gait SpeedChair RiseHAQ
PAPAEE.25-.07-.28
 # of steps.24-.27-.27
† Spearman Rho;* p <.05;** p <.01

Conclusion:

Small associations between measures of PA and measures of PF and disability are explained by patient's social and biomedical characteristics. The results indicate that measures of PF and disability may represent constructs different than PA and suggest that measures of PA should be included in rehabilitation research in RA.

To cite this abstract, please use the following information:
Piva, Sara R., Almeida, Gustavo J. M., Murphy, Yanique, Wasko, M. C.; Association of Physical Function and Disability with Physical Activity in Women with Rheumatoid Arthritis [abstract]. Arthritis Rheum 2009;60 Suppl 10 :1976
DOI: 10.1002/art.27049

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