Functional status decline as a measure of adverse events in home health care: an observational study

Background: Research that examines the quality of home health care is complex because no gold standard exists for measuring adverse outcomes, and because the patient and clinician populations are highly heterogeneous. The objectives in this study are to develop models to predict functional decline for three indices of functional status as measures of adverse events in home health care and determine which index is most appropriate for risk-adjusting for future quality research. Methods: Data come from the Outcomes and Assessment Information Set (OASIS) from a large urban home health care agency and other agency data. Prognostic data yields 49,437 episodes, while follow-up data yields 47,684 episodes. We tested three indices defined as substantial decline in three or more (gt3̱ADLs), two or more (gt2̱ADLs), and one or more (gt1̱ADLs) ADLs. Multivariate logistic regression determines the performance of the models for each index as measured by the c-statistic and Hosmer-Lemeshow chi square (÷2). Results: Frequencies for gt3̱ADLs, gt2̱ADLs, and gt1̱ADLs are 212 (0.43%), 783 (1.58%), and 4,271 (8.64%) respectively. Follow-up results are comparable with frequencies of 218 (0.46%), 763 (1.60%), and 3,949 (8.28%) for each index. Gt3̱ADLs does not produce valid models. The model for gt2̱ADLs consistently yields a higher c-statistic compared to gt1̱ADLs (0.754 vs. 0.679, respectively). Both indices' models yield non-significant Hosmer-Lemeshow chi square indicating reasonable model fit. Findings for gt2̱ADLs and gt1̱ADLs are consistent over time as indicated by follow-up data results. Conclusion: Gt2̱ADLs yields the best models as indicated by a high c-statistic and a nonsignificant Hosmer-Lemeshow ÷2, both of which exhibit exceptional consistency. We conclude that gt2̱ADLs may be preferable in defining ADL adverse events in the context of home health care. [ABSTRACT FROM AUTHOR]; Copyright of BMC Health Services Research is the property of BioMed Central and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)