Paradoxical Differences in RA Outcomes by Wealth

Patients in poorer countries report better outcomes

• by Pam Harrison
  

  Contributing Writer

Action Points

• Physician-reported outcomes for patients with rheumatoid arthritis (RA) are worse in low-income compared with high-income countries.
• Note that paradoxically, patient-reported outcomes are better in low-income than in high-income countries, suggesting cultural factors are likely involved in shaping physician and patient perceptions about RA.

Physician-reported outcomes for patients with rheumatoid arthritis (RA) are worse in low-income compared to high-income countries but paradoxically, patient-reported outcomes are better in low-income than in high-income countries, suggesting cultural factors are likely involved in shaping physician and patient perceptions about RA, a cross-sectional study indicated.
In a cohort of 3,920 patients with RA from 17 countries, the mean swollen joint count (SJC) was highest at 6.7 in Morocco and the lowest at 0.9 in the Netherlands, reported Polina Putrik, MSc, of Maastricht University Medical Center, Maastricht, the Netherlands and colleagues in the Annals of the Rheumatic Diseases.
The mean modified Health Assessment Questionnaire (mHAQ) in turn ranged from 0.7 in Taiwan to 1.5 in the Netherlands.
Venezuela scored the lowest on measures of fatigue, at 1.7, compared with the Netherlands, which had the highest score on fatigue at 5.0.
Large variations in both physician and patient-reported outcomes were observed across different countries as well.
Adjusted for potential confounders and using the Netherlands as a comparator country, SJC varied from +0.9 (95% CI 0.1-1.7) in Germany to +5.8 (95% CI 5.0-6.6) in Morocco.
Similarly adjusted differences in the mHAQ were observed across different countries as well, from 0.2 (95% CI 0.1-0.3) in Korea to 0.9 (95% CI 0.8-1.0) in Morocco, both compared with Taiwan.
Compared with Venezuela, adjusted fatigue scores ranged from 1.8 (95% CI 1.3-2.3) in Spain to 3.8 (95% CI 3.2-4.4) in the Netherlands.
When investigators replaced country by Gross Domestic Product (GDP), patients from low-GDP countries had, on average, 1.9 and 2.8 more swollen and tender joints, respectively, in fully adjusted models.
Erythrocyte sedimentation rates (ESRs) were also 11 mm/hour higher and the disease activity score in 28 joints (DAS28) 1.0 points higher in low-GDP countries, while mHAQ scores were 0.15 points higher than in countries with high-GDP.
On the other hand, patients from low-GDP societies had a 0.43 lower score on patient assessments and a 0.15 lower score on physician global assessment.
The same patients also had a 0.97 lower score on fatigue compared with high-GDP countries.
"The present study showed that patients from countries with lower socioeconomic welfare score worse on most of physician-reported measures for disease activity...and on perceived difficulties in physical functioning," the authors noted.
"Paradoxically, patients in poorer societies evaluated their patient global assessment and fatigue as being similar or better than wealthy countries although the absolute differences were smaller."
Data from the cross-sectional multinational observational study, Comorbidities in RA (COMORA), were used for the analysis.
Physician-reported outcomes included tender and swollen joint counts, ESR, and the DAS28 while patient-reported outcomes included the mHAQ, patient global assessment, and fatigue.
The DAS 28 including patient global was considered as a mixed measure.
For the mixed outcome, low-GDP countries scored 0.94 points higher than high-GDP countries.
As the investigators noted, explaining the paradoxical findings where physician-reported outcomes were worse in low income but patient-reported outcomes were similar or better is not straightforward.
The higher disease activity in poorer countries may be partly attributed to greater uptake of biological disease-modifying anti-rheumatic drugs (DMARDs) in the high-income countries compared to their poor income counterparts.
But it may also be due in part to a delay in diagnosis and poorer access to rheumatologic care in poor countries.
"Lower income societies may also set less pressure with regard to execution of multiple social roles," the authors speculate.
"And withdrawal from societal roles due to sickness and reliance on extended family for care may be more acceptable [in low income countries] than in wealthier but more individualistic societies."
Limitations to the study include the fact that a sample such as the COMORA sample may not be representative of patients with RA in participating countries.
"Centres with research interest in RA are more likely to participate, [and this could lead to] an over-representation of the optimally treated group in each country."
Cross-sectional designs also hinder conclusions about the direction of associations, they added.
"Interestingly, the differences between high-GDP and low-GDP countries in patient global assessment are higher than differences in physician global assessment," the investigators observed.
"Since the models with perceived and evaluated outcomes were adjusted [for measures of disease activity], it appears that physicians mostly base their judgment on these objective parameters while patients' assessment is likely more subjective," they add.
"Future research should [therefore] focus more on how nondisease-driven cultural and other contextual factors impact objectively measures and experienced health."

The authors reported no financial conflicts.

• Reviewed by Robert Jasmer, MD Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner

last updated 09.08.2015

• Primary Source

  Annals of the Rheumatic Diseases

  Source Reference: Putrik P, et al "In wealthier countries, patients perceive worse impact of the disease although they have lower objectively assessed disease activity: results from the cross-sectional COMORA study" Ann Rheum Dis 2015; doi:10.1136/annrheumdis-2015-207738.