Is the expansion of secondary diagnosis codes in January 2011 and incentive payments for health information technology associated with changes in measured severity of illness?
Bottom line: Expansion of secondary diagnosis coding positions is associated with a statistically significant increase in measured severity of illness among hospitalizations for all diagnoses, diagnoses commonly targeted by incentive programs, and untargeted diagnoses.
Explore This IssueFebruary 2020
BACKGROUND: In January 2011, the Centers for Medicare and Medicaid Services (CMS) expanded the number of secondary diagnosis coding slots, capturing up to an additional 15 diagnoses in inpatient claims. Similarly, the expansion of electronic health record (EHR) capabilities may have allowed hospitals to capture more detail about patient risk.
STUDY DESIGN: Cohort study of 47,951,443 Medicare fee-for-service beneficiary discharges between Jan. 1, 2008, and Aug. 31, 2015, at 2,850 hospitals.
SETTING: University of Michigan Medical School, Ann Arbor, Mich., USA.
SYNOPSIS: Approximately 14% of all discharges were for targeted diagnoses. Between 2008 and 2015, the mean number of condition categories increased from 1.70 to 2.67, the Medicare severity diagnosis related group (MS-DRG) weight increased from 1.50 to 1.64, and the Hierarchical Condition Category (HCC) score increased from 1.23 to 1.69. Over the same period, the mean number of condition categories increased from 2.24 to 3.44 for targeted diagnoses and from 1.61 to 2.54 for untargeted diagnoses. Larger hospitals experienced a greater absolute and relative change in the number of condition categories. Incentives for meeting health information technology criteria were associated with a modest change in the number of condition categories for all diagnoses. A sensitivity analysis found that, as the degree of EHR use increased, the differential change in measured severity of illness increased. The differential change in the C statistic from adding condition category indicators before and after the expansion of secondary diagnoses was 0.90% among all diagnoses, 0.95% among targeted diagnoses, and 0.81% among untargeted diagnoses. Limitations included a deviation from the traditional condition category derivation and lack of measured participation in the Medicaid meaningful use program.
CITATION: Sukul D, Hoffman GJ, Nuliyalu U, et al. Association between Medicare policy reforms and changes in hospitalized Medicare beneficiaries’ severity of illness. JAMA Netw Open. 2019;2:e193290.