Evaluation of interventions to reduce occupational injuries in the construction industry are relatively scarce. Various interventions to prevent occupational injuries have been proposed and studied. In a Cochrane review we systematically summarise the most current scientific evidence on the effectiveness of interventions to prevent injuries associated with construction work. Most of these studies are analysed with an interrupted time series design, which are characterised by a higher risk of bias.
We use the GRADE (Grades of Recommendations, Assessment, Development and Evaluation) approach that systematically represents the factors important in interpretating evidence and results in a current update of our review. While the evidence can be different for each outcome, GRADE considers the evidence for each outcome and takes into account the magnitude of effect and ensures the process is systematic and transparent.
Rating of the evidence was done as follows: with RCTs we started at high quality and with observational studies we started at low quality. Then we downgraded if one of the following criteria were met: study limitations, inconsistency, indirectness, imprecision and publication bias. We upgraded observational studies if there have been dose-response, large effect size or an opposite effect of confounding. We constructed tables for every comparison for our interventions and our two primary outcomes fatal and non-fatal injuries because these were our inclusion criteria for the studies.
Applying GRADE and the difference with strength of association will be discussed based on the above mentioned update of our review. Also the differences in clarity of the conclusions with and without GRADE will be discussed.