title: Pain rather than self-reported sedentary time explains variation in perceived health and activity limitation in persons with rheumatoid arthritis: a cross sectional study in Sweden.
abstract: To investigate (1) the amount of self-reported time spent sedentary among a large cohort of persons with rheumatoid arthritis (RA), and (2) the contribution of sedentary time to explain perceived health and activity limitation in RA beyond that of previously known correlates. This cross-sectional study used data from a postal questionnaire and the Swedish Rheumatology Quality registers (SRQ). The International Physical Activity Questionnaire was used to assess sedentary time (sitting) and moderate, vigorous and walking activity (MVPA). Sociodemographics, pain, fatigue, fear-avoidance beliefs, anxiety/depression, disease duration, MVPA and sedentary time were included in multiple regression models with perceived health (Visual Analogue Scale 0-100) and activity limitation (Stanford Health Assessment Questionnaire) as dependent variables.
  
  
  RESULTS
  In all 3152 (59%) of 5391 persons identified as eligible from the SRQ, responded to the questionnaire. 2819 individuals with complete data on all study variables were analysed. Mean time (SD) spent sedentary was 257 (213) minutes per day. Sedentary time did not contribute significantly to explain perceived health and only minimally to explain activity limitation. Instead, variation was mainly explained by pain; for perceived health (Beta = 0.780, p < 0.001) and for activity limitation (Beta = 0.445, p < 0.001).The results indicate a non-significant role of sedentary time and a need for increased focus on pain in the management of RA. Future studies should use prospective designs and objective assessment methods to further investigate the associations between sedentary time and health outcomes in persons with RA.
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 23100, Alfred Nobels Allé 23, 141 83, Huddinge, Sweden. ingrid.demmelmaier@ki.se.
authors.forename: Ingrid
authors.identifier: http://orcid.org/0000-0002-2068-4708
authors.initials: I
authors.lastname: Demmelmaier
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Åsenlöf
authors.affiliation: School of Education, Psychology and Sports Science, Linnaeus University, Kalmar, Sweden.
authors.forename: Patrick
authors.initials: P
authors.lastname: Bergman
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 23100, Alfred Nobels Allé 23, 141 83, Huddinge, Sweden.
authors.forename: Birgitta
authors.initials: B
authors.lastname: Nordgren
authors.affiliation: Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, 23100, Alfred Nobels Allé 23, 141 83, Huddinge, Sweden.|Department of Rheumatology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Christina H
authors.initials: CH
authors.lastname: Opava
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D010147:Pain Measurement; D012042:Registries; D012307:Risk Factors; D057185:Sedentary Behavior; D057566:Self Report; D011795:Surveys and Questionnaires; D013548:Sweden; D013997:Time Factors
keywords: Disability; Health; Multiple regression; Rheumatoid arthritis; Sedentary time; Sitting