Targeting comorbidities may reduce avoidable readmissions

Hospitals striving to reduce avoidable 30-day readmissions should look beyond the cause of patients’ index admission to their comorbidities, according to a study published Dec. 16 in BMJ. Heart failure was one of three comorbidities that carried a higher risk for potentially avoidable readmissions.

Medicare penalizes hospitals that report higher-than-expected 30-day readmission rates for heart failure, acute MI and infection. Previous research has shown that sizable numbers of 30-day readmissions were not related to the index admission. In this study, Jacques Donze, MD, of Brigham and Women’s Hospital in Boston, and colleagues looked beyond the primary index diagnosis to include comorbidities and patterns of 30-day readmissions.

Their retrospective cohort study included consecutive discharges of 10,731 adult patients who remained at Brigham and Women’s Hospital for more than 24 hours between 2009 and 2010. The outcome was 30-day readmission in three hospitals in the network. They used a validated algorithm to identify potentially avoidable readmissions.

About one in five patients were readmitted within 30 days, which is on par with other studies. Eight percent of all admissions and 35.8 percent of readmissions were deemed potentially avoidable readmissions. The most common primary diagnoses for 30-day readmissions were neoplasm (16.8 percent), infection (10.9 percent), heart failure (4.9 percent) and gastrointestinal disorders (3.6 percent).

Infection (11.6 percent), neoplasm (8.4 percent) and heart failure (7.1 percent) ranked as the most common primary readmission diagnoses. Heart failure led the list for primary diagnoses of 30-day readmission in patients with five common comorbidities (diabetes mellitus, chronic heart failure, ischemic heart disease, atrial fibrillation and chronic kidney disease) and also tied for first in patients with chronic obstructive pulmonary disease.

Patients discharged with a primary diagnosis of heart failure had a 23 percent increased adjusted risk of a potentially avoidable readmission.

“[W]e found that the five most frequent primary diagnoses of readmission were often related, either directly or indirectly, to patients’ specific comorbidities,” Donze and colleagues wrote. “Also, although infection was the most frequent cause of potentially avoidable readmission overall, acute heart failure was the most frequent cause of potentially avoidable readmission among patients with five of the seven comorbidities we studied, especially the cardiovascular ones.”

Some physicians have reasoned that a “post-hospital syndrome” caused by stressors experienced during a patient’s hospital stay may fuel readmissions. “Our study results bring another dimension to this theory: that comorbidities of patients also play a significant role in the post-discharge period,” they suggested. “They might be well exacerbated by the acute illness and the stress of the index admission, and may consequently lead to new acute illnesses that increase the risk of readmission.”

Donze and colleagues recommended addressing underlying comorbidities during transitions of care and close follow-up and monitoring of comorbidities after discharge. “More attention could be paid in particular to patients with neoplasm, heart failure, and chronic renal failure who are at higher risk of potentially avoidable readmission than are patients without these conditions. Heart failure in particular should be a focus (for example, with close monitoring of weights and renal function) in patients who have the condition, regardless of the other heart conditions with which it frequently coexists.”

Results from the study, which included only one medical center, may not be applicable to other types of hospitals. Nor could the study account for the severity of comorbidities.