Guest blogger Linda K. Riddell maintains that when it comes to health care data, you may not have learned everything you need to know in kindergarten. What health care data challenges do you face? Share your thoughts in the comments.
Along with tying your shoes and naming your colors, you learned to count in preschool. So, how hard can it be to count things in health data? It’s not hard, but your preschool strategies won’t give you the right answer.
Take, for example, a very common counting problem – the number of primary care provider visits. There are many reasons this count might be important. Perhaps you raised the office visit co-pay and want to make sure that people aren’t postponing care. Or maybe the company cut overtime hours; with people earning less, they might put off visits even if the co-pay hasn’t changed.
If you simply count the number of office visits, you will get an answer that is misleading at best and dead wrong at worst. The reason is that the one-two-three approach leaves out several important factors.
Consider, for example, that your covered group changes every month: People retire, change jobs, have babies, get married, and get sick. The group you have this year is not the same as the group you had last year, or even last month. There are more dramatic changes that can happen to a group – layoffs, mergers, restructurings can all add or subtract large numbers of employees.
To get a true picture of PCP office visits, you should look at two numbers: The number of office visits, and the number of people who potentially could have an office visit. This will give you a “rate” of office visits, which is a more stable measure than the simple number of office visits.
PCP office visits can be calculated as visits per 100 people covered. Emergency room visits are typically expressed as visits per 1,000 member months. Other types of care have different definitions. Be consistent in calculating the numerator (visits) and denominator (members, member months). Never compare one calendar quarter to the next calendar quarter. Seasonal changes have an impact on people and their health care habits. If you can only get data in three-month chunks, compare this winter to the previous winter; summer to the previous summer, etc.
After all of that, you get a number that can be compared and trended. Keep in mind that things beyond your control may be pushing the numbers up or down. For example, in the fall of 2009, lots of people saw their PCP to get an H1N1 (swine flu) vaccination. If you compared that to the fall of 2010, you would think that your people had forgotten they had health insurance.
You can put the numbers into context, once you have good measures at your fingertips.
Riddell is a principal at Health Economy, LLC. She can be reached at
