Diabetes Control and Lower Weight Is Associated With Statistically Significant Savings

A complication of diabetes

The study is reported here in the American Journal of Managed Care.

Researchers at the western Massachusetts Reliant Medical Group were interested in knowing whether there was any association between control of blood sugar among persons with diabetes and their health insurance claims expense. Using combined data from their electronic health record (EHR) plus insurance claims, they identified all (continuously enrolled) adults with at least one physician encounter between January 2007 through December 2011 for a diagnosis of diabetes, who also were being treated with metformin and a sulfonylurea drug.  This yielded a population of 2044 patients.

This study had some useful benchmark data for other providers with caring for a similar diabetic population. 27% had an A1C goal of less than 7%, 64% had an A1C goal of less than 8%, 33% had a blood pressure less than 140/90 mm Hg, 68 % had a LDL of less than 100 mg/d, and 34% had a body mass index (BMI) less than 30.

After controlling for age, gender, enrollment date, race, payer type and comorbidities, the researchers found that having a target A1c less than 7% (indicating good diabetes control) was associated with $992 per member per year (PMPY) in savings. There were $1445 PMPY in savings for an A1c less than 8%, and $1218 for a BMI less than 30 - all versus persons who did not achieve those goals.  Just controlling blood pressure, or cholesterol levels did not result in statistically significant savings  

Combining a low A1c, blood pressure control less than 140/90, low LDL cholesterol and BMI in various combinations seemed to result in savings in excess of $2000 per member PMPY.  Most of the savings related to diabetes control appeared in the outpatient category, while most of the savings related to BMI appeared in the inpatient category.

The DMCB's take:

1. Not all persons with diabetes may have a "diabetes" diagnosis in the EHR or a bill submitted to an insurance company that uses that particular code. The DMCB likes this study because it's more likely that a person with diabetes will eventually show up in a 5 year period. Plus, the use of metformin and a sulfonylurea medication makes it easier to accurately capture persons with diabetes.

2. This is another in a series of observational studies that infers that persons with target control of blood glucose or who are not overweight experience lower claims expense compared to persons with poor control or who are overweight.

3. What this study does not prove is that blood glucose control or weight control causes low insurance claims expense.  Association does not equal causality any more than "white hair" causes heart attacks.  In order to prove causality, persons with diabetes and similar baseline claims would need to be randomly allocated to good vs. bad control of their blood glucoses (or good vs. bad weight) with prospective and simultaneous comparison of the future expenses over time.  That's called a randomized controlled trial.

4. Remember the ACCORD study?  Persons were randomly allocated to tight vs. very tight control of their blood glucoses and the death rate unexpectedly causally went up for persons with very tight control. The DMCB brings that up because, in the AJMC study described above, less tight control of diabetes (A1c less than 8% vs. the target of 7%) was associated with even greater reductions in claims expense.  Is this further evidence that tight control of diabetes leads to problems?

5.  Unexpectedly, blood pressure or LDL control was not independently associated with lower claims expense.  That's important because Accountable Care Organizations that assume blood pressure and cholesterol lowering pill compliance will result in shared savings may need to reconsider.

Ultimately, while this study doesn't prove that successful population health management for diabetes would save money, it's one more piece of evidence pointing in that direction.  Let the studies continue.