Lives Schmives

We and other networks like to toss around "covered lives" as a statistic with which to impress funders. I think this probably claims too much and too little at the same time.

It's too much because we don't literally have e.g., 13-million complete birth-to-death life stories in our data. But it's too little in that looking at a snapshot of who's enrolled over any particular period of time understates the *depth* of coverage over time. A lot of our members stay members over long periods of time. Not all, to be sure, but plenty do. They retire; change employers; move from place to place, but they very often stay with our orgs.

So what would be a better statistic for us to brag on? Summing up person-years goes some distance to address the issue, though that too undersells the longevity. Here are some candidate statistics we might use to give a better sense of what we've got:

• total person/years
• the median length of terminated enrollments (or maybe show percentiles on that distribution)
• the proportion of terminations that are due to death.
• Average proportion of live covered (so--(#covered days /(DOB - min(DOD, &sysdate)))

What other statistics can you think of?  Leave a comment & make your case!