Population Health at the Intersection of Mortality and Morbidity

In a recent Health Affairs Blog1, authors Chokshi and Stine posit that part of the reason that public health is ‘out of sight, out of mind’ is the disconnect between mortality and morbidity tracking. Major causes of mortality are tracked by public health. Major causes include diseases such as hypertension and diabetes that are often silent killers and may have few symptoms until advanced disease stages. Conversely, the most common causes of reduced quality of life are low back and neck pain, depression, and other musculoskeletal complaints (see Figure 1). Patients seek care quickly for quality of life issues but not for so-called silent killers. The authors’ prescription for bringing both groups together in the name of population health is to develop strategies that address diseases with high quality of life (morbidity) burdens, not just those with high mortality (life expectancy) burdens. As VHHA’s research team studied this proposition, we wondered if readmissions occur when patients suffer from diseases with high mortality as well as diseases with high morbidity. The readmission diseases and procedures (acute myocardial infarction [AMI], heart failure, pneumonia, stroke, chronic obstructive pulmonary disease [COPD], and hip and knee replacements) have specific symptoms and pathology that predict readmission. However, readmitted patients are more likely to return to the hospital with symptoms related to a disease or condition other than the index diagnosis. Is it possible that the intersection of a disease with high mortality and diseases with high morbidity contribute to readmission rates? As Figure 1 (see below) shows, ischemic heart disease shortens life span, but diabetes and chronic obstructive pulmonary disease (COPD) cause significant mortality and morbidity. To explore the likelihood of readmitted patients with a high mortality diagnosis also having a high morbidity disease, we reviewed the most recent four quarters of readmissions for AMI.

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As Table 1 illustrates, the high morbidity conditions found in ischemic heart disease cases are diabetes and COPD. More than half of the readmitted AMI patients have diabetes and nearly 40 percent have COPD. Other diseases associated with morbidity are not listed in the database. However, if diabetes and COPD are viewed as causes of mortality, their presence is joined by dementia, cancer, and cerebrovascular disease. Nearly 1-in-5 AMI readmissions has dementia, and 1-in-10 has cerebrovascular disease (stroke) or cancer. In the predictive model for AMI readmission, diabetes, cancer, and dementia are not predictive of a readmission. COPD and stroke are only mildly predictive (14 percent and 17 percent, respectively). However, they frequently are secondary diagnoses. It would seem that our predictive model is specific to AMI as a disease, yet many patients are presenting with other diagnoses that are associated with high mortality and reduced life span.

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From this exploratory analysis, it seems to makes sense that patients who return to the hospital are more likely to do so with a diagnosis other than a second AMI because they have coexisting high mortality diseases. Diseases with both mortality and morbidity effects make managing such patients in the community difficult because they require consistent and continued care. Lack of medical resources within patients’ communities makes it likely many will return to the hospital through the emergency room. The high coexistence of diabetes and COPD would indicate that discharge instructions should focus on managing these conditions, too. This includes reviewing medication and treatment regimens for those diagnoses. The presence of high mortality diseases coexisting with ischemic heart disease also indicates the need for palliative care resources. (4/22)

1 Chokshi, Dave and Stine, Nicholas: Milestones on the Path to Population Health, Health Affairs Blog, April 11, 2016