Research: Motorcycle rider conspicuity and crash related injury: case-control study

Stumbled across this whilst doing some research on another subject.
Study was conducted in 1993-1996, but only published last year.

Might be interesting considering the differences of opinion I've
seen in here (ausmoto) in the past re brightly coloured bling-bling,
lights-on and general visibility wrt accident risk for bikes...

What follows is just an abstract. I can probably come up with
the full paper if anyone is interested.

GB




Citation is:
Wells, S., Mullin, B., Norton, R., Langley, J., Connor, J., Lay-Yee, R.
and Jackson, R. 2004, "Motorcycle Rider Conspicuity and Crash Related
Injury: Case-Control Study", BMJ, vol. 328, no. 7444, pp. 857-.




Abstract:
Objective To investigate whether the risk of motorcycle crash related
injuries is associated with the conspicuity of the driver or vehicle.

Design Population based case-control study.

Setting Auckland region of New Zealand from February 1993 to February
1996.

Participants 463 motorcycle drivers (cases) involved in crashes leading
to hospital treatment or death; 1233 motorcycle drivers (controls)
recruited from randomly selected roadside survey sites.

Main outcome measures Estimates of relative risk of motorcycle crash
related injury and population attributable risk associated with
conspicuity measures, including the use of reflective or fluorescent
clothing, headlight operation, and colour of helmet, clothing, and
motorcycle.

Results Crash related injuries occurred mainly in urban zones with 50
km/h speed limit (66%), during the day (63%), and in fine weather (72%).
After adjustment for potential confounders, drivers wearing any
reflective or fluorescent clothing had a 37% lower risk (multivariate
odds ratio 0.63, 95% confidence interval 0.42 to 0.94) than other
drivers. Compared with wearing a black helmet, use of a white helmet was
associated with a 24% lower risk (multivariate odds ratio 0.76, 0.57 to
0.99). Self reported light coloured helmet versus dark coloured helmet
was associated with a 19% lower risk. Three quarters of motorcycle riders
had their headlight turned on during the day, and this was associated
with a 27% lower risk (multivariate odds ratio 0.73, 0.53 to 1.00). No
association occurred between risk and the frontal colour of drivers'
clothing or motorcycle. If these odds ratios are unconfounded, the
population attributable risks are 33% for wearing no reflective or
fluorescent clothing, 18% for a non-white helmet, 11% for a dark coloured
helmet, and 7% for no daytime headlight operation.

Conclusions: Low conspicuity may increase the risk of motorcycle crash
related injury. Increasing the use of reflective or fluorescent clothing,
white or light coloured helmets, and daytime headlights are simple, cheap
interventions that could considerably reduce motorcycle crash related
injury and death.