Study finds police crash data flawed

The Otago University study says the police inaccurately assess the severity of injuries because they lack medical expertise and use inadequately designed incident report forms. Photo / Christchurch Star

Police data on the severity of injuries suffered in vehicle crashes is seriously flawed and differs significantly from injuries recorded in hospital discharge information, a study has found.

Fifteen per cent of injuries recorded as minor at crash sites were actually life-threatening, while 48 per cent of injuries recorded as serious by police did not meet hospital standards of serious injury.

The University of Otago study assessed the validity of 14,869 injury severity reports by police against hospital discharge data between 2000 and 2004, and assigned a severity score to each case using an international threat-to-life classification system, ICISS.

Researcher Gabrielle McDonald said the results showed police were underestimating and overestimating the severity of injuries, because they were not medical professionals and because the forms they used had broad diagnoses such as "fracture", which applied to a broken arm and a broken back.

Some injuries, such as internal ones, were also not immediately apparent.

Dr McDonald said police data was entered into a crash analysis system and used in road safety statistics. These statistics could be made more accurate if the police crash report system was replaced with an objective one based on hospital discharge codes and ICISS.

"Improved information would ensure that the effectiveness of New Zealand's road safety programmes could be more accurately evaluated and funding targeted towards problem areas that may currently be being overlooked," she said.

Dr McDonald presented the study's findings to the Australasian Epidemiological Association's 18th annual scientific meeting in Dunedin yesterday.

- NZPA