The Relationship Between Social Deprivation, Disease Outcome Measures, and Response to Treatment in Patients with Stable, Long-Standing Rheumatoid Arthritis

MARK J. HARRISON, KAREN J. TRICKER, LINDA DAVIES, ANDREW HASSELL, PETER DAWES, DAVID L. SCOTT, SUSAN KNIGHT, MARTIN DAVIS, DIARMUID MULHERIN, and DEBORAH P.M. SYMMONS

ABSTRACT.

Objective. Patients with rheumatoid arthritis (RA) with lower socioeconomic status (SES) are known to have more severe disease, more comorbidity, and higher mortality. It is not known whether SES influences response to treatment in RA. We examined the relationship between area of residence (as a surrogate for SES) and baseline outcome measures and response to treatment, using data from the British Rheumatoid Outcome Study Group randomized controlled trial of aggressive versus symptomatic treatment of long-standing, stable RA.

Methods. A total of 466 patients from 5 centers were recruited to the trial. Baseline data included age, sex, smoking status, and comorbidity. Patients were assigned a Townsend score (a measure of social deprivation) according to their area of residence. Outcome measures including the Disease Activity Score (DAS28), Health Assessment Questionnaire, Medical Outcomes Study Short Form-36, and EuroQol (EQ5D) were recorded at the beginning and end of the 3 year trial. The baseline, 3 year values, and change data were examined by Townsend quintile adjusting for each treatment arm.

Results. Significant relationships between increasing social deprivation by area of residence and higher disease activity, higher pain, poorer physical function, poorer emotional aspects of mental health, and lower quality of life were found at baseline (adjusted for age, sex, disease duration, current smoking, treatment center, and treatment group). During the 3 year trial period, patients from the most deprived areas showed greater improvement, with statistically significant greater improvement on DAS28 (p = 0.041) and 28 tender joint count (p = 0.015).

Conclusion. Area of residence is related to the severity of RA at recruitment and is a predictor of response in a clinical trial situation. The results suggest that measures of SES should be recorded for patients enrolled in clinical trials, longitudinal observational studies, and in the clinical setting. (J Rheumatol 2005;32:2330-6)

Key Indexing Terms:

RHEUMATOID ARTHRITIS
SOCIOECONOMIC FACTORS
HEALTH STATUS
QUALITY OF LIFE

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From the ARC Epidemiology Unit; North West Genetics Park; and Health Economics Research (HER@M), The University of Manchester, Manchester; Department of Rheumatology, University Hospital of North Staffordshire NHS Trust, Stoke on Trent; Academic Rheumatology Unit, King's College Hospital NHS Trust, London; Department of Rheumatology, East Cheshire NHS Trust, Macclesfield; Department of Rheumatology, Royal Cornwall Hospitals NHS Trust, Truro; Department of Rheumatology, Mid Staffordshire General Hospitals NHS Trust, Staffordshire, UK.

Supported by the NHS Executive, UK (NHS HTA project number 94/45/02).

M.J. Harrison, MSc, Research Assistant; D.P.M. Symmons, MD, Professor of Rheumatology and Musculoskeletal Epidemiology, ARC Epidemiology Unit; K.J. Tricker, PhD, Research Fellow, North West Genetics Park; L. Davies, MSc, Reader and Director of Health Economics Research, HER@M, The University of Manchester; A. Hassell, MD, Consultant Rheumatologist; P.T. Dawes, MD, Consultant Rheumatologist, University Hospital of North Staffordshire NHS Trust; D.L. Scott, MD, Consultant Rheumatologist, King's College Hospital NHS Trust; S.M. Knight, MD, Consultant Rheumatologist, East Cheshire NHS Trust; M.J. Davis, MD, Consultant Rheumatologist, Royal Cornwall Hospitals NHS Trust; D. Mulherin, MD, Consultant Rheumatologist, Mid Staffordshire General Hospitals NHS Trust.

Address reprint requests to Dr. D.P.M. Symmons, ARC Epidemiology Unit, Stopford Building, The University of Manchester, Oxford Road, Manchester M13 9PT UK. E-mail: deborah.symmons@manchester.ac.uk

Accepted for publication July 13, 2005.

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