Acute care is defined by a discrete event with a beginning and end, whereas chronic care is defined by long-term, ongoing treatment. However, post-acute care refers to the period of care that follows an acute event. For example, acute stroke care involves diagnosis of the type of stroke and extent of neurologic damage, life support and acute interventions such as thrombolytic agents to minimize the extent of brain damage, and intensive monitoring of neurologic signs. Once a stroke victim is stabilized, post-acute care involves continuation of stroke treatments (e.g., anticoagulation); rehabilitation of physical, cognitive, speech and language impairments; prevention of future stroke; and diagnosis and treatment of associated conditions such as depression.22 Patients needing post-acute care may also require ongoing, chronic care, either due to pre-existing conditions or as a result of the severity of the acute event precipitating the need for post-acute care. For example, chronic care of a stroke victim then involves continued management of the underlying diseases related to stroke, such as hypertension, and long-term management of residual impairment and disability.22
Because acute, post-acute, and chronic care represent different phases of illness requiring different types of care, a unique set of quality measures is required for each. Emphasis has been placed on measures of acute care quality, including appropriate process criteria for making the diagnosis and treating the acute phase of illness, as well as outcomes such as mortality.23 Quality measures relating to chronic care include process attributes, such as treating hypertension and arrhythmias to prevent further stroke, and outcomes such as recurrent stroke, rehospitalization for stroke or decline in function and quality of life.24;25 Because post-acute care has historically been part of extended acute hospital stays, quality measures for post-acute care are less well specified. However, post-acute care quality measures must not only encompass elements of acute treatment, but also aspects of care that are unique to the post-acute period (e.g., maximizing recovery of function).
The structures (i.e., settings) where post-acute care is provided are sometimes the same venues that also provide chronic care, such as SNFs and HHAs, but may also be unique (e.g., rehabilitation hospitals). The processes of post-acute care include continued monitoring of acute illness begun in the hospital and a strong emphasis on rehabilitation services such as physical therapy, occupational therapy, and speech therapy aimed at restoring function and quality of life. Outcome measures thus include both avoidance of acute events leading to rehospitalization and/or death, as well as recovery in physical, cognitive, psychological, and social function with the hope of ultimately restoring a persons lifestyle prior to the acute event. This multiplicity of care objectives represents one of the major challenges in quality measurement of post-acute care.
The fact that similar types of care and services may be delivered in different settings depending on the characteristics of the individual and the availability of services in the community, renders comparisons of quality across post-acute settings difficult, in part because each setting may rely on different processes to meet the same objectives. For example, institutional providers (SNFs and rehabilitation hospitals) spend more time treating the individual patient, while home health providers may rely more on training caregivers to provide some services and teaching patients exercises to perform independently. However, while the two institutional providers are paid very different rates, differences in processes of care in these settings are less clear. Both SNFs and rehabilitation hospitals provide the range of therapies. It is poorly understood how the mix and intensity of these services vary across provider types and the impact of these differences on length of post-acute care stays, quality of care, and outcomes.
There are several clinical reasons to be concerned about measuring the quality of post-acute care. First, a critical time window exists during which older persons recover function and the capacity to return to their previous lifestyle in the community following acute illness.15;19 Generally, if this transition does not take place within the first 60-90 days, it will not take place.15 Second, the highest rehospitalization rate occurs in the period shortly after discharge from the hospital.26;27 Third, acute hospital lengths of stay have been continually declining for Medicare beneficiaries, dropping an average of two days over the last decade, and thereby increasing the acuity level of patients at the time they begin post-acute care.5
In addition, substantial variation in the utilization of post-acute care across geographic regions creates additional challenges in understanding the relative outcomes associated with different post-acute care options.28;29;30 Our lack of understanding about the relative effectiveness of post-acute care use creates questions regarding the appropriateness of current payment and coverage policies.29;30 Complicating our ability to evaluate the quality of post-acute care, and determine relationships between post-acute care settings and outcomes, is the fact that a large proportion (17% as of 1996) of Medicare beneficiaries receive post-acute care in more than one setting. Receiving care in multiple settings may jeopardize the quality of care because of the need for clinical information to flow from one provider to another. To the extent needed information is not transmitted to a subsequent provider, services may be replicated or omitted.