title: Reflections on the process of using systematic review techniques to evaluate the literature regarding the neurotoxicity of low level exposure to organophosphate pesticides.
abstract: We undertook a systematic review (incorporating meta-analysis) of the literature concerning the neurotoxicity of cumulative low level occupational exposure to organophosphate pesticides, which was published online by the journal Critical Reviews in Toxicology in 2012. As far as we are aware, we were the first research team to attempt quantitative evaluation of study findings on this topic, using meta-analysis. We wish to encourage others to apply systematic review techniques in chemical risk assessment to reduce bias, increase transparency and better inform public policy. We thought it would be useful to share our experience of undertaking a systematic review in the hope of dispelling misconceptions about the complexity, time and resource issues involved along with the view that meta-analysis is meaningless when studies are not homogeneous. In this commentary paper we reflect on aspects of the process which were relatively straightforward; aspects which were more challenging; the advantages of using systematic review techniques; and the advantages and limitations of using statistical techniques such as meta-analysis in this context.
authors.affiliation: Research Department of Clinical, Educational and Health Psychology, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: s.mackenzie-ross@ucl.ac.uk.
authors.forename: Sarah
authors.initials: S
authors.lastname: Mackenzie Ross
authors.affiliation: Research Department of Clinical, Educational and Health Psychology, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: McManus
authors.affiliation: Department of Psychology, Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
authors.forename: Virginia
authors.initials: V
authors.lastname: Harrison
authors.affiliation: Research Department of Clinical, Educational and Health Psychology, University College London, Gower Street, London WC1E 6BT, UK.
authors.forename: Oliver
authors.initials: O
authors.lastname: Mason
mesh_terms: D006801:Humans; D015982:Bias; D004781:Environmental Exposure / Q000009:adverse effects; D015201:Meta-Analysis as Topic; D020258:Neurotoxicity Syndromes / Q000209:etiology; D010755:Organophosphates / Q000633:toxicity; D010575:Pesticides / Q000633:toxicity; D000078202:Systematic Reviews as Topic
chemical_list: D010755:Organophosphates; D010575:Pesticides
keywords: Low-level exposure; Meta-analysis; Neurobehavioural function; Organophosphates; Systematic review