Medical Claims: Don’t Always Believe the Numbers

Today’s Managing Health Care Cost Indicator is 17,000

Click on image to enlarge.  Source
Two articles that have caught my attention over the last few days demonstrate that claims data doesn’t always tell the truth.

A report in the April 4 JAMA shows that while claims data suggests that there has been a dramatic decline in hospital admissions for pneumonia – much of that decline is accounted for by a coding change  More hospitals are billing sepsis with pneumonia. There’s still a decline –it’s just not nearly as impressive.    The implication – the accuracy of claims data over sequential time periods can be undermined by changing coding incentives. I’m sure you can imagine which of these diagnoses has a higher associated payment!

Sarah Kliff of the Washington Post’s WonkBlog picked up a letter to the editor from BMJ  which pointed out a series of absurd conclusions one could draw from billing statistics. The NHS data set suggests that there were 1700 MEN in the UK who received services associated with…. Pregnancy.

Claims data is critical for health services research and policy.  The advantages of claims data over chart review include:
- Well structured with agreed-upon definitions
- Includes all billed services, regardless of where these services are delivered.
- Inexpensive to obtain and to analyze

Here’s why claims data doesn’t always give us the right answer, though

- Plain carelessness.
o A number of years ago I saw a contention that claims for vaginal births for women who had a Caesarian section represented fraud.  Not really – just careless billing practices.

- Gaming.
o Remember – providers bill to get paid. They tend to adapt their billing practices to maximize the amount they will get paid.  If sepsis with pneumonia pays more than pneumonia with sepsis – well, you know what happens.  
o It’s likely that full coverage for preventive care will convert many previous problem-oriented visits to preventive visits. The content of care will not necessarily change – but the way it’s covered will.

- Local area variation
o In Eastern Massachusetts, pediatricians historically didn’t bill for vaccinations, since the serum was supplied by the state.  The state usually had one of the highest rates of childhood vaccination in the country according to the CDC, but you couldn’t have guessed this from reviewing claims data!

Claims data will continue to play a critical role in helping us evaluate the impact health care policy.  When the data doesn't make sense, though, we'll have to question it.