An independent statistics watchdog agency that reports directly to the UK parliament issued a report yesterday criticizing a key element of the government's road casualty figures. The UK Statistics Authority praised the general credibility of numbers generated by the Department for Transport (DfT), but the agency threatened to withhold the designation of "national statistics" from DfT reports if the department failed by November to reform the system of serious injury data collection known as STATS19.

"The major unmet user need is for statistical information about road casualties that reflect the well-documented fact that the STATS19 system under-records the numbers of those injured in road accidents and the severity of injuries," the Statistics Authority report explained.

The British Medical Journal (BMJ) documented the problem in a 2006 report (view study). While government statements lauded the benefits of speed cameras based on a claimed road injury rate that had fallen from 85.9 per 100,000 in 1996 (before cameras) to 59.4 in 2004 (after cameras), hospital admission records showed that the road injury rate actually increased slightly from 90.0 in 1996 to 91.1 in 2004. The BMJ attributed the discrepancy to the police undercounting the number of injury accidents that take place. The House of Commons Transport Committee earlier this month insisted that something be done to force DfT to produce more reliable reports.

"We were disappointed that although the government's response acknowledged that there might be a problem, they did not propose any steps that we thought would deal with it," Transport Committee Chairman Louise Ellman said. "I am thinking particularly of the discrepancies between some of the reporting of serious accidents and data received by hospitals. We want the government to do more on that issue, as we are not satisfied that the information that we are getting is accurate."

The Statistics Authority laid mandatory changes that it believes will address the core problem. DfT must publish estimates of uncounted injury accidents so that readers of official publications will be informed of the scale of the undercounting problem. The department must also develop a plan to remedy the undercounting and more accurately label data and their sources. Because STATS19 data collection is currently overseen by a board comprised exclusively of government and police officials, the authority recommended that "broader membership of the Standing Committee on Road Accident Statistics might make user input more effective."

A copy of the Statistics Authority report is available in an 80k PDF file at the source link below.