Using United States medicare program claims to identify reliable measures of low value services influenced by primary care physician decisions

BACKGROUND: Among an existing set of 31 LVS are invasive procedures not typically performed by primary care physicians (PCPs), and other LVS that may be commonly provided by specialists. To facilitate research on the role of primary care physicians in low-value care, we sought to identify the reliability of two subsets of LVS measures that are more directly subject to PCPs' decisions. We refer to these as primary care adjacent ("PCA") LVS measures. METHODS: Retrospective observational cohort study to identify which of a 31-item LVS measure set were most commonly performed, ordered, or referred by PCPs and examine the reliability of subsets of PCA-LVS measures. Setting was primary care practices in the Comprehensive Primary Care Plus (CPC+) model evaluation. 5,741,061 Medicare fee-for-service (FFS) beneficiaries attributed to 11,910 practices and 40,981 physicians in 2018 were observed. Based on percentages of LVS commonly performed, ordered, or referred by PCPs, we defined a 4-item and an 11-item PCA-LVS measure. We compared the reliability of the 4-item, 11-item, and 31-item LVS measure sets using Spearman ρ (rho) rank-order correlation and the Intra-Class correlation coefficient (ICC). Limitations included that PCP performing, ordering, and referring data are not available in all claims. Claims-based analyses of diagnosis codes may misclassify some appropriate services as PCA-LVS. RESULTS: The 4-item PCA-LVS measure has a significantly higher mean reliability estimate than the original 31-item measure in identifying PCPs who provide low versus high rates of LVS. The 11-item PCA-LVS measure also had significantly higher reliability than the 31-item measure but lower reliability than the 4-item measure. CONCLUSIONS: We identified two LVS subsets reflecting LVS events most influenced by PCPs. Further work will be required to ascertain how best to use this or related PCA-LVS measures to enhance the quality of primary care.