Use of Open Claims Vs Closed Claims on Health Outcomes Research

OBJECTIVES:

Closed claims databases such as MarketScan®, IQVIA®, Optum®, Milliman’s CHSD Data, Medicare, Medicaid, Veteran’s Affairs, and Department of Defense datasets are frequently used in outcomes research studies. Lately, the availability of open claims has increased the possibility of obtaining information faster on a larger scale. However, there is a chance of missing claims with open files if patients switch doctors who don’t use the same clearing houses.

METHODS:

Between 2017-2021, we identified 35 different diseases and compared the trend over the years between two closed claims databases and one open claims database. We analyzed the trends by gender, age group, and region. In addition, we calculated utilization such as hospitalization, length of stay, office visits, and emergency room visits, as well as total inpatient, outpatient, and pharmacy costs associated with each disease category. We applied Mann-Whitney U tests to compare the means and Mood’s median test to compare the medians for each outcome.

RESULTS:

The closed claims analyzed had around 16M patients per year, whereas open claims had about 300M patients. The sample size from each closed claims database ranged from 9,500-675,000 depending on the disease, and the sample sizes from open claims ranged from 171,000 to 12 million for the same disease group. The mean and median of each outcome for each disease reported that there were no significant differences (p<0.001). Standard errors for the estimates from open claims were minor due to large sample sizes, which provided more robust estimates.

CONCLUSIONS:

Open claims have a larger sample size and more up-to-date information (usually a one-week lag). The possible missing claims in the open file did not create a statistically significant difference in major utilization and cost estimates in outcomes research. Open claims can include specific fields that closed-payer claims don’t, such as referring physicians.