OBJECTIVES: The aim is to assess the prevalence of comorbidities and to further analyse to which degree fatigue can be explained by comorbidity burden, disease activity, disability and gross domestic product ( @entity3006 ) in @entity1 with @entity309 ( @entity309 ). METHODS: Nine thousands eight hundred seventy-four @entity1 from 34 countries, 16 with high @entity3006 (>24.000 US dollars [USD] per capita) and 18 low- @entity3006 countries (<24.000 USD) participated in the Quantitative Standard monitoring of @entity1 with @entity309 ( @entity309 ) study. The prevalence of 31 comorbid conditions, fatigue (0-10 cm visual analogue scale [VAS] [10=worst]), disease activity in 28 joints (DAS28), and @entity717 (Health Assessment Questionnaire score [HAQ]) were assessed. Univariate and multivariate linear regression analyses were performed to assess the association between fatigue and comorbidities, disease activity, disability and @entity3006 . RESULTS: Overall, @entity1 reported a median of 2 comorbid conditions of which @entity101 (31.5%), @entity170 (17.6%), @entity571 (15.5%) and hyperlipidaemia (14.2%) were the most prevalent. The majority of comorbidities were more common in high- @entity3006 countries. The median fatigue score was 4.4 (4.8 in low- @entity3006 countries and 3.8 in high- @entity3006 countries, p<0.001). In low- @entity3006 countries 25.4% of the @entity1 had a high level of fatigue (>6.6) compared with 23.0% in high- @entity3006 countries (p<0.001). In univariate analysis, fatigue increased with increasing number of comorbidities, disease activity and disability in both high- and low- @entity3006 countries. In multivariate analysis of all countries, these 3 variables explained 29.4% of the variability, whereas @entity3006 was not significant. CONCLUSIONS: Fatigue is a widespread problem associated with high comorbidity burden, disease activity and disability regardless of @entity3006 .

The association of fatigue, comorbidity burden, disease activity, disability and gross domestic product in @entity1 with @entity309 . Results from 34 countries participating in the Quest- XXXX program.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity101 :: ('MESH:D006973', 'Disease') :: ['hypertension'] @entity571 :: ('MESH:D010003', 'Disease') :: ['osteoarthritis'] @entity170 :: ('MESH:D010024', 'Disease') :: ['osteoporosis'] @entity3006 :: ('MESH:D006153', 'Chemical') :: ['GDP'] @entity717 :: ('MESH:D009069', 'Disease') :: ['physical disability'] @entity309 :: ('MESH:D001172', 'Disease') :: ['rheumatoid arthritis', 'QUEST-RA', 'RA']
@entity309 :: (MESH:D001172,Disease) :: ['RA']
