title: The concurrence of musculoskeletal pain and associated work-related factors: a cross sectional study.
abstract: Several recent studies have described the presence of musculoskeletal complaints, presenting evidence that multisite musculoskeletal pain (MP) is more often present than single-site musculoskeletal pain. However, less is known about determinants of this multimorbidity, particularly, concerning the role of occupational factors and, mainly, what determines single or multisite pain. This study described the associations between pain in different body sites and investigated related factors to MP in workers from Brazil.
  
  
  
  A total of 1070 workers (228 women and 842 men), from urban cleaning services and from shoe manufacturers, participated in this cross sectional study (response 97 %). Interviewer-administered questionnaire included sociodemographic factors, physical and psychosocial work demands, leisure-time activities and musculoskeletal pain which was presence of pain in previous seven days, considering eight body sites and MP, the sum score of all painful sites, varying 0-8. A factor analysis was performed that captured the nine variables of physical exposure into two latent factors. Associations of pain between different body sites were assessed. Cox regression analyses, presenting the prevalence ratio (PR), showed the related factors to MP.
  
  
  
  In the previous seven days, 30 % of workers had MP. For all body sites, comorbidity ranged from 72 % to 91 %. Having pain in one body site is associated with pain in other site and the associations between proximal sites were stronger than between more distal sites. High exposure to manual material handling and awkward postures (PR = 1.5, 95 % CI 1.1-2.0), job strain (PR = 1.2, 95 % CI 1.0-1.6), and low social support (PR = 1.3, 95 % CI 1.0-1.7) and being woman (PR = 1.7, 95 % CI 1.3-2.3) were associated with MP. Risk factors for single-site pain and for subsequent musculoskeletal comorbidity were very similar, suggesting an additive effect of risk factors.
  
  
  
  Most workers reported MP that was associated with several work-related factors. The findings support the idea that multisite pain is a continuum of single-site pain, maintained by exposure to several risk factors, rather than the result of a specific risk factor that initiates the multisite pain but not single-site pain. Workplace interventions are needed to decrease the number of pain sites, in order to improve the worker's health.
authors.affiliation: Departamento de Medicina Preventiva e Social, Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Largo do Terreiro de Jesus, s/n. Centro Histórico, 40.026-010, Salvador, Bahia, Brazil.|Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands.
authors.forename: Rita
authors.initials: R
authors.lastname: de Cássia Pereira Fernandes
authors.affiliation: Departamento de Medicina Preventiva e Social, Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Largo do Terreiro de Jesus, s/n. Centro Histórico, 40.026-010, Salvador, Bahia, Brazil.
authors.forename: Silvana Maria Santos
authors.initials: SMS
authors.lastname: Pataro
authors.affiliation: Departamento de Medicina Preventiva e Social, Faculdade de Medicina da Bahia, Universidade Federal da Bahia, Largo do Terreiro de Jesus, s/n. Centro Histórico, 40.026-010, Salvador, Bahia, Brazil.
authors.forename: Roberta Brasileiro
authors.initials: RB
authors.lastname: de Carvalho
authors.affiliation: Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands. a.burdorf@erasmusmc.nl.
authors.forename: Alex
authors.identifier: 0000-0003-3129-2862
authors.initials: A
authors.lastname: Burdorf
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D059352:Musculoskeletal Pain / Q000453:epidemiology*; D009784:Occupational Diseases / Q000453:epidemiology*; D009786:Occupational Health Services; D010147:Pain Measurement; D015995:Prevalence; D012307:Risk Factors; D011795:Surveys and Questionnaires; D017132:Workplace
keywords: Co-morbidity; Low back; Lower limbs; Multi-site pain; Musculoskeletal; Neck; Pain; Upper limbs; Widespread pain; Workload