Underreporting of nursing home utilization on the CMS-2728 in older incident dialysis patients and implications for assessing mortality risk

BACKGROUND: The usage of nursing home (NH) services is a marker of frailty among older adults. Although the Centers for Medicare & Medicaid Services (CMS) revised the Medical Evidence Report Form CMS-2728 in 2005 to include data collection on NH institutionalization, the validity of this item has not been reported. METHODS: There were 27,913 patients ≥ 75 years of age with incident end-stage renal disease (ESRD) in 2006, which constituted our analysis cohort. We determined the accuracy of the CMS-2728 using a matched cohort that included the CMS Minimum Data Set (MDS) 2.0, often employed as a “gold standard” metric for identifying patients receiving NH care. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the CMS-2728 NH item. Next, we compared characteristics and mortality risk by CMS-2728 and MDS NH status agreement. RESULTS: The sensitivity, specificity, PPV and NPV of the CMS-2728 for NH status were 33%, 97%, 80% and 79%, respectively. Compared to those without the MDS or CMS-2728 NH indicator (No MDS/No 2728), multivariable adjusted hazard ratios (95% confidence interval) for mortality associated with NH status were 1.55 (1.46 – 1.64) for MDS/2728, 1.48 (1.42 – 1.54) for MDS/No 2728, and 1.38 (1.25 – 1.52) for No MDS/2728. NH utilization was more strongly associated with mortality than other CMS-2728 items in the model. CONCLUSIONS: The CMS-2728 underestimated NH utilization among older adults with incident ESRD. The potential for misclassification may have important ramifications for assessing prognosis, developing advanced care plans and providing coordinated care. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12882-015-0021-9) contains supplementary material, which is available to authorized users.