Comparison of cycling hospitalization rates in ... - carsp.ca · Causal pathway? •drivers more alert to cyclists •more drivers are cyclists •safer infrastructure attracts more

Kay Teschke, Mieke Koehoorn, Hui Shen, Jessica DennisSchool of Population & Public Health

& Department of Medical Genetics

University of British Columbia

Comparison of cycling

hospitalization rates

in Canadian provinces

with different

helmet laws &

bike commuting

Photo: Ken Ohrn

Photo Flickr: Café Mama

North America3-6 deaths/100 million km

• helmets & laws common

• bike traffic separation rare

• mode share low

Holland, Denmark1-2 deaths/100 million km

• bike traffic separation common

• mode share high

• helmets rare

Photos: Flickr, WD Vanlue; The Alternative Department for Transport

Source: Buehler & Pucher, TR News 2012: Teschke et al. CJPH 2013

Comparisons within Canada

transport systems & laws consistent

Photo: Ken Ohrn

HospitalizationsCanadian Institute for Health Information

Cycling trips Canadian Community Health Survey

Hospitalization

Rates=

2006 to 2011

3690 hospitalizations/year

593 million trips/year

633 hospitalizations/100 million trips

0

200

400

600

800

1000

1200

1400

0 0.5 1 1.5 2

All injury hospitalizations per 100 million trips

Mode Share: % of commute trips by bike

Each province … 4 hospitalization ratesadult male, adult female, youth male, youth female

Hospitalization rates vary.

A lot.

Why?

0

200

400

600

800

1000

1200

1400

0 0.5 1 1.5 2

All injury hospitalizations per 100 million trips

Mode Share: % of commute trips by bike

Does sex make a difference?

Female vs. MaleOR = 0.45 95% CI: 0.37, 0.53

Photo: Ken Ohrn

Photo: Ken OhrnPhoto: Ken Ohrn

Females much

lower injury rate

than males

Less risk-taking• ride more slowly

• less likely to ride on major

streets without bike

infrastructure

Photo: Ken Ohrn

No helmet law

Child only law

All ages law

2006 – 2011

study period:

no change in

helmet laws

Do helmet laws make a difference?

No helmet law

Child only law

All ages law

2006 – 2011

study period:

no change in

helmet laws

Do helmet laws make a difference?

%

helmet

use

0

10

20

30

40

50

60

70

80

90

100

No

law

Helmet

law

66.9%

39.3%

0

100

200

300

400

500

0 0.5 1 1.5 2

Mode Share: % of commute trips by bike

Brain, head,

scalp, skull, face

injury

hospitalizations

per 100 million

trips

Do helmet laws make a difference?

Helmet law vs. no law OR = 1.16 95% CI: 0.82, 1.65

Photo: Ken Ohrn

Helmet laws not

associated with

hospitalization rates

Potential explanations• other factors more important

• helmet wearers ride faster

• drivers pass closer to helmet

wearers

• helmets give permission for

more dangerous types of

riding (e.g., mountain biking)

Photo: Ken Ohrn

≥ 2

1.5 - 2

1 - 1.5

0.5 – 1

< 0.5

% of commute

trips by bike

(mode share)

Does "mode share" make a difference?

0

1000

2000

3000

4000

5000

0 0.5 1 1.5 2

Traffic injuryhospitalizations per 100 million trips to work or school

bike mode share (%)

Does "mode share" make a difference?

Rate per 1% increase in mode share

OR = 0.69 95% CI: 0.49, 0.97

Safety in numbers

Consistent pattern

Causal pathway? • drivers more alert to

cyclists

•more drivers are cyclists

• safer infrastructure

attracts more cycling

Photo: Dandyhorse

Policy implications

To reduce cycling injury

rates, focus on factors

related to increased

cycling & female

cycling choices.

Cycling routes

physically separated

from traffic or along

quiet streets fit both

these criteria & are

associated with lower

injury risk.

Photo: Google Streetview

Photo: Ken Ohrn

BMJ Open 2015

Cycling in Cities, UBC

@kteschke

Research on Canadian

hospitalization patterns

& infrastructure safety

support Dutch, Danish

policy choices

Adjusted odds ratios, helmet law vs. no law

Do helmet laws make a difference?

Cycling

Other, no helmet

Head, helmet

Head, no helmet

Most Studies: given injury, odds of head

injury vs. other injury, with & without

helmet use / law

No injury

Rare Evidence: given cycling, incidence of head injury, with & without helmet use / law

No helmet

Helmet

Other injury is surrogate for cycling exposure

Injury

Other, helmet

25%

40%

5%

24%

32%

Photo: Ken Ohrn

87% of

hospitalizations

involve body sites

other than head

…………………..

1 hospitalization

per 160,000 trips

1 head injury

hospitalization per

650,000 trips

What about injuries that aren’t mitigated by helmets?

Deaths / 100 million km travelled

5.5

1.11.5

United States Denmark The NetherlandsSource: Buehler & Pucher, TR News 2012