We're pretty used to hearing about regional variation in medical costs and practices, but we still get pretty surprised (even if we shouldn't by now) by how much variation there is in adjacent zip codes. Even in cities that we tend to think of as sensible places, like Seattle. If you can always get a good cup of coffee, how come you can't always get good diabetes care?

A recent study, described in the Seattle Times, shows significant variability in the five-county Puget Sound region. With way too many patients not getting appropriate basic treatment.

Nearly half of clinics surveyed were below average at ensuring patients with diabetes got regular eye exams to detect vision problems caused by the disease. The percentage of heart-surgery patients who received standard treatment to prevent blood clots ranged from 59 percent to 96 percent at area hospitals. And at some clinics, fewer than one-in-four sexually active young women were screened for chlamydia, a bacterial infection that can cause infertility and other complications.

The study was done by the Puget Sound Health Alliance, which includes 160 organizations including insurers, providers, and big companies like Starbucks. The report looked at 46 medical groups and all 170 clinics in the region with six or more doctors. Data is available online at www.WACommunityCheckup.org.

The region did score well in some areas—not giving unnecessary antibiotics for the common cold, for instance. Asthma treatment was another bright spot. But there was a lot of inconsistency across the board, including some cancer screenings. By doing the study and making a lot of the data public, the goal is to get people paying attention to, talking about, and strengthening the weak spots in the health care chain.