title: Systematic reviews of workplace injury interventions: what are we missing?
abstract: BACKGROUND
  There are pitfalls associated with applying a biomedical model with its emphasis on experimental designs to the evaluation of workplace injury interventions.
  
  
  OBJECTIVE
  Evaluation over enough time is essential in occupational safety when interventions are expected to have a latent effect as well as to assess sustained effects. Controlled trials are not well-suited to this task and are not even possible in circumstances where a policy change, such as legislative action, affects a population of workers simultaneously. Social context influences occupational injury interventions, their evaluation and the wider generalization of findings but is lost in the pooling of data for meta-analyses. Some of these issues can be addressed through recognition of the contribution of diverse observational methodologies in intervention evaluation, improvement and maintenance of robust surveillance systems, and inclusion of qualitative methodologies not typically embraced by epidemiologists or medical researchers.
  
  
  METHODS
  Through consideration of an evaluation of a legislative effort to prevent falls from height in construction, we demonstrate lack of flexibility in current methods used for evaluating time series analyses in systematic reviews of occupational injury intervention effectiveness.
  
  
  CONCLUSIONS
  These include the manner in which downward change in slope is assessed and the call to demonstrate a significant initial downward change in level. We illustrate essential contextual detail regarding this intervention that is lost in the pooling of data from multiple studies into a combined measure of effect. This reduction of occupational injury intervention evaluation to one of pure statistical significance is ill-conceived, irresponsible, and should be stopped.
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Community and Family Medicine, Duke University Medical Center, Durham, NC 27710, USA. hester.lipscomb@duke.edu
authors.forename: Hester J
authors.initials: HJ
authors.lastname: Lipscomb
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Pompeii
authors.forename: D J
authors.initials: DJ
authors.lastname: Myers
authors.forename: Ashley L
authors.initials: AL
authors.lastname: Schoenfisch
authors.forename: J M
authors.initials: JM
authors.lastname: Dement
mesh_terms: D000041:Absenteeism; D000058:Accidental Falls / Q000191:economics / Q000517:prevention & control / Q000706:statistics & numerical data*; D000062:Accidents, Occupational / Q000191:economics / Q000517:prevention & control / Q000706:statistics & numerical data*; D015984:Causality; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D019317:Evidence-Based Medicine / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D015201:Meta-Analysis as Topic; D008962:Models, Theoretical; D016272:Occupational Health / Q000331:legislation & jurisprudence; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012196:Review Literature as Topic; D017751:Safety Management / Q000331:legislation & jurisprudence / Q000379:methods*; D012924:Social Conditions; D014481:United States / Q000453:epidemiology; D014942:Workers' Compensation / Q000706:statistics & numerical data; D017132:Workplace / Q000331:legislation & jurisprudence / Q000592:standards