=+4.6 The ministry of Health and Long-Term Care in Ontario, Canada, publishes information on its web site

(www.health.gov.on.ca) on the time that patients must wait for various medical procedures. For two cardiac procedures completed in fall of 2005 the following information was provided:

Number 90%

of Com- Median Mean Completed Wait Wait pleted Proce- Time Time Within dures (days) (days) (days)

Angioplasty 847 14 18 39 Bypass surgery 539 13 19 42

a. The median wait time for angioplasty is greater than the median wait time for bypass surgery but the mean wait time is shorter for angioplasty than for bypass surgery.