title: Individual participant data meta-analysis of mechanical workplace risk factors and low back pain.
abstract: OBJECTIVE
  We used individual participant data from multiple studies to conduct a comprehensive meta-analysis of mechanical exposures in the workplace and low back pain.
  
  
  METHODS
  We conducted a systematic literature search and contacted an author of each study to request their individual participant data. Because outcome definitions and exposure measures were not uniform across studies, we conducted 2 substudies: (1) to identify sets of outcome definitions that could be combined in a meta-analysis and (2) to develop methods to translate mechanical exposure onto a common metric. We used generalized estimating equation regression to analyze the data.
  
  
  RESULTS
  The odds ratios (ORs) for posture exposures ranged from 1.1 to 2.0. Force exposure ORs ranged from 1.4 to 2.1. The magnitudes of the ORs differed according to the definition of low back pain, and heterogeneity was associated with both study-level and individual-level characteristics.
  
  
  CONCLUSIONS
  We found small to moderate ORs for the association of mechanical exposures and low back pain, although the relationships were complex. The presence of individual-level OR modifiers in such an area can be best understood by conducting a meta-analysis of individual participant data.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. griffith@mcmaster.ca
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Griffith
authors.forename: Harry S
authors.initials: HS
authors.lastname: Shannon
authors.forename: Richard P
authors.initials: RP
authors.lastname: Wells
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Walter
authors.forename: Donald C
authors.initials: DC
authors.lastname: Cole
authors.forename: Pierre
authors.initials: P
authors.lastname: Côté
authors.forename: John
authors.initials: J
authors.lastname: Frank
authors.forename: Sheilah
authors.initials: S
authors.lastname: Hogg-Johnson
authors.forename: Lacey E
authors.initials: LE
authors.lastname: Langlois
mesh_terms: D000367:Age Factors; D006801:Humans; D017770:Lifting / Q000009:adverse effects; D017116:Low Back Pain / Q000453:epidemiology / Q000209:etiology*; D055595:Mechanical Phenomena; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D016272:Occupational Health; D009790:Occupations; D016017:Odds Ratio; D011187:Posture / Q000502:physiology; D012307:Risk Factors; D012737:Sex Factors; D017132:Workplace / Q000706:statistics & numerical data*