Improving the home health acute-care hospitalization quality measure.

The Centers for Medicare & Medicaid Services (CMS) considers acute-care hospitalization (ACH) during home health to be one of the key quality measures for care given to homebound Medicare beneficiaries. Defined as the percentage of patients who had to be admitted to the hospital while receiving services of a home health agency (HHA) (Centers for Medicare & Medicaid Services 2002), the measure is one of 11 currently listed on CMS' Home Health Compare website (Centers for Medicare & Medicaid Services 2007). CMS recently completed a year-long national campaign to reduce ACH rates (Quality Insights of Pennsylvania 2008). Preventing unnecessary readmissions to the hospital from HHAs and other community providers is a key objective of the current work of CMS-funded Quality Improvement Organizations (Centers for Medicare & Medicaid Services 2008). The stated rationale for the ACH measure includes the following: “… some inpatient hospital care may be avoided if the home health clinical staff is doing a good job at checking the health condition of patients at each visit to detect problems early, including monitoring nutritional status, taking medicines correctly, and home safety” (Centers for Medicare & Medicaid Services 2002). This rationale is based on the work of Shaughnessy et al. (2002), who observed modest reductions in risk-adjusted ACH rates in HHAs given performance feedback and training in continuous quality improvement methods. It is unclear whether the ACH rate as calculated can reliably represent avoidable inpatient care. The measure is subject to reporting errors and one major bias. Reporting errors include intentional or unintentional failure to code hospital admission on the CMS Outcomes and Assessment Information Set (OASIS) form used for reporting, and failure to count a hospital admission occurring immediately after discharge from home health care. The bias is due to variation in length of service (LOS—the number of days between the beginning and the end of an episode of home health care), because the probability of hospital admission increases with increasing time following hospital discharge whether or not there is intercurrent home health care. As a consequence, differences in LOS over time or among agencies may confound comparisons of ACH rates. At present, there is substantial interest in improving how patients are supported through transitions of care, for example, from hospital to long-term care (Parry et al. 2003; Coleman et al. 2004; Naylor et al. 2004;). Experts believe that patient health and well-being suffer when useful information related to the patient is lost between care settings, or patients are excessively transferred. CMS has made care transitions an important component of the work assigned to Medicare Quality Improvement Organizations between 2008 and 2011 (Centers for Medicare & Medicaid Services 2008). The ACH rate is a potential measure of HHAs' contribution to effective care during transitions, as reduced readmissions might result from better patient management in the home care setting, improved communication between agency and other providers, or more effective patient/caregiver self-management training. Higher quality home care might require longer LOS. Alternatively agencies might reduce risk of early hospitalization through more intensive services early in care (“front loading” services), allowing shorter LOS for the same outcome. In either instance, an LOS-biased quality measure might yield incorrect conclusions about the benefits of high-quality home care. Comparisons among agencies based on such a measure are problematic, as shown in Figure 1, which illustrates a dramatic impact of average length of service (ALOS) on ACH rates measured in two agencies caring for identical patients. Figure 1 Time Course of Home Care and Hospital Readmissions for Five Hypothetical Patients in Two Home Health Agencies with Differing Average Length of Service (ALOS) In this paper, we present evidence supporting an alternative to the current ACH measure. We demonstrate that agency ALOS is by far the most important of the provider characteristics predicting agency ACH rates; We replicate the effect of ALOS on ACH rates in a patient-level simulation of a system of HHAs similar to Medicare agencies; and We use the simulation to show that measuring ACH against a fixed time interval following hospital discharge is not ALOS biased. Such an alternative measure might better reflect agencies' impacts on readmission rates when ALOS varies over time, as some changes in the reported ACH measure might only reflect changes in ALOS. It would also support fair comparison of rehospitalization rates among HHAs with differing ALOS. An agency-specific hospital readmission rate would be consistent with measures CMS currently uses in assessing management of care transitions in other settings.