Longevity with a caveat

Brief by Central Staff

Mountain Life – November 2006 – Colorado Central Magazine

Coloradans were understandably interested in September when the Harvard University Initiative for Global Health released a study of longevity in the United States, and the seven top counties were all in our mountains.

All with a life expectancy of 81.3 years, the counties were Clear Creek, Eagle, Gilpin, Grand, Jackson, Park and Summit. Not far behind them, ranking 24 to 29 at 80.8 years, were the mountain counties of Archuleta, Gunnison, Hinsdale, Mineral, Ouray, and San Miguel.

But before we break out the champagne, a couple of caveats are in order. It struck us as odd that so many neighboring counties would have identical life expectancies. When we looked at the report accompanying the statistics, we learned why.

To get sufficient numbers for reasonably valid statistical analysis, the researchers wanted populations of at least 10,000 men and 10,000 women in 1980. To get to that number, the populations of adjacent lower-population counties were aggregated for the study. So that explains why Clear Creek, Eagle, Gilpin, Grand, Jackson, Park and Summit all came out at 81.3 years, since that number was derived from their aggregate populations. Ditto for Archuleta, Gunnison, Hinsdale, Mineral, Ouray, and San Miguel at 80.8, or Chaffee and Lake both at 80.1.

So the results aren’t as detailed as they appear at first glance. The Gunnison County life-expectancy, for instance, isn’t for only Gunnnison County, but for an aggregation of seven counties, Gunnison among them.

The second caution is that the numbers were based on place of residence at time of death. So if a man lived 65 years in Leadville, then got tired of thin air and long winters and moved to Cañon City, where he died three years later, his death would affect the life-expectancy statistics from Frémont County, rather than Lake County where he spent most of his life.

And that’s not an uncommon scenario, since people with heart and respiratory problems frequently move to lower altitudes, or larger cities with more services. Thus the life-expectancy numbers for mountain counties may not reflect true longevity in these hills. Also, there may be a certain amount of self-selection, in that unhealthy people are unlikely to migrate uphill for “the active mountain lifestyle.”

For what it’s worth, then, life expectancy in other counties hereabouts are Alamosa, 78.5; Conejos, Rio Grande, and Saguache, 76.5; Costilla, 76.3; Custer, 76.8; and Frémont, 76.4.

(Martha notes that she has lived in three of the longest-lived 10: Grand and Summit in Colorado, and No. 8 Montgomery in Maryland.)

Aside from Colorado, the healthiest states were Hawaii, California, Connecticut, Massachusetts, Minnesota, North Dakota, New Hampshire, Vermont, and Washington. The least healthy were the District of Columbia, Mississippi, Louisiana, Alabama, and South Carolina. The counties with the lowest life expectancy, 66.6 years, were in rural South Dakota.

The study concludes “that disparities seem to be caused by a number of chronic diseases, such as heart disease and cancer, and to injuries with well-established risk factors, like alcohol-related traffic accidents. Income, infant mortality, violence, HIV/AIDS, and lack of health insurance only explained a small percentage of the differences.”

The study also found that “The life expectancy gap between the highest and lowest counties has been rising since 1984.”