Improving the accuracy of traffic crash injury statistics would ensure that the effectiveness of road safety programmes was better evaluated, University of Otago researcher Dr Gabrielle McDonald said yesterday.
New Zealand's current way of counting injury severity in people admitted to hospital from traffic crashes had serious flaws and could be replaced by a more accurate system, according to Otago University research presented yesterday.
Dr McDonald, the study co-investigator, presented the findings during the Australasian Epidemiological Association's annual scientific meeting at the university.
"Improved information would ensure that the effectiveness of New Zealand's road safety programmes was more accurately evaluated and funding targeted towards problem areas that may be being overlooked.
"If you're spending money on prevention programmes, you want to spent it as effectively as you can," she said in an interview.
Good data showed where "problem areas" were and where most effective interventions could be made.
The study found that pedestrians were 1.6 times more likely to have a severe injury overlooked than crash victims in passenger vehicles, under the current statistics system.
Because the present system tended to underestimate the severity of injuries to pedestrians, they could be missing out on potential safety programmes designed to protect them, she said.
Data recorded by police at road crash sites is entered into a crash analysis system and used in road safety statistics.
Fifteen percent of injuries recorded by police as minor at crash sites were actually life-threatening, while 48% of injuries recorded as serious did not meet an international standard for assessing life-threatening injury, the study showed.
The 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 ICISS, an international threat-to-life classification system.
Police were both underestimating and overestimating the severity of injuries because they were not medical professionals, and the forms they used had broad diagnoses such as "fracture", which applied to a broken arm and a broken back.
Injury severity 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, she said.
Dr McDonald is a research fellow in the Otago department of women's and children's health, and undertook the research as part of her Master of Public Health studies