Evaluation Of An Observational Study

1036 WordsJan 7, 20155 Pages
Evaluation of an observational study ——Are SUVs dangerous vehicles? Reference: Michael D. Keall, Stuart Newstead SUVs (Sport utility vehichles) are, nowadays, generally acknowledged as a road safety concern, considering that their injury-causing potential to pedestrians (Simms and O’Neill, 2005) and to other light passenger vehicles when in collision (Gabler and Hollowell, 1998) and their propensity to rollover (Keall, 1998). However, comparatively, SUVs have a low risk to cause driver fatal injury except for rollover crashes. To find out whether SUVs are dangerous or not, Michael D. Keall and Stuart Newstead decided to conduct this study in order to evaluate the effect on road safety of SUVs compared to other passenger vehicle types. This…show more content…
Besides, in an observational study, the investigator is not able to control the system, meanwhile, reflecting it’s possible to detect clear effects on road safety of vehicles. Based on decision above, a cohort population study has been designed. Different transport requirements is on the basis of driver groups, vehicle types were also correspondingly various, which is a confounding factor to vehicle-based crash rate estimates. Thus distance driven, driver and vehicle characteristics, such as vehicle type, age, make and model and also drivers’ age, gender and place of residence, are most importantly attempted to be exposure to risk. To examine response variable crash involvement risk and casualty rates, this study use data from motor vehicle register (MVR) containing all 2,996,000 New Zealand licensed vehicles together with data on 17,245 crash-involved vehicles provided by New Zealand Ministry of Transport. The authors tried to analyse the damages quantitatively regarding SUVs and other vehicle types while controlling for their distance driven and owner characteristics (Keall and Newstead, 2007). Distance driven was estimated by two sequential odometer readings of any twice inspected vehicle pulling out from database, and then converted these estimation into annual distance driven were allowed with assumption that the vehicle is driven at the same frequency every day in all year. 5% motor vehicle were omitted due to unsuitable age (too new or
Open Document