This is not original research it is just presentation of the actual data used by Rodgers in his research abstracted directly from his paper from an earlier paper by Petty which Rodgers is re analysing in his paper and from a US National Safety Council report which Rodgers cites However from these data one can assess what importance should be attached to the Rodgers study After reading the Rodgers paper and assembling the data he used it became clear that quoting one sentence from Rodgers conclusion overstated what could validly be drawn from the Rodgers analysis of the data shown above The following text would be an acceptable compromise Rodgers analysed annual 1973 to 1987 national time series estimates of cycling injuries annual counts of cycling and pedestrian road accident fatalities estimates of bicycle use and bicycle standards compliance and estimates of helmet use based on sales of one particular brand of now obsolete hard shell helmet After fitting a linear regression model to these data he concluded that There is no evidence that hard shell helmets have reduced the head injury and fatality rates The most surprising finding is that the bicycle related fatality rate is positively and significantly correlated with increased helmet use