Inpatient HF Discharge Volume Predicts Readmissions

Study Questions:

The study evaluated the contributions of structural factors, both on the unit level and patient levels, and patient-level process factors to the outcome of all-cause 30-day readmission for patients hospitalized with heart failure (HF).

Methods:

Retrospective electronic health record review from 2 urban hospitals within the same healthcare system identified 425 patients who were admitted with primary diagnosis of HF. Variables included discharging medical team, patient-to-nurse ratio, and inpatient unit HF discharge volume. Patient-to-nurse ratio was dichotomized as patient-to-nurse ratio of 3:1 or less and 4:1 or greater. Patient characteristics that were collected included causes of HF, length of stay, serum laboratory values, left ventricular ejection fraction, implantable cardioverter-defibrillator status, previous hospitalizations, and discharge medications.

Results:

The results suggest that compared with a patient-to-nurse ratio of 3 or less, a patient-to nurse ratio of 4 or greater was associated with 76% increased odds of all-cause 30-day hospital readmission. In a multivariable analysis controlling for patient factors, only inpatient unit HF discharge volume was a significant unit-level predictor of 30-day hospital readmission (p = .05). After controlling for patient-level variables at discharge (heartrate, beta-blockers, loop diuretics, creatinine and sodium levels, emergency department presentation, patient-to-nurse ratio, and median household income), on average, those units with higher HF discharge volume had higher odds of all-cause 30-day hospital readmission (odds ratio 1.006; 95% confidence interval, 1.000-1.012; p = .05). On average, 1 additional patient discharge increased readmission by 0.6%. This contrasted with bivariate results showing that a higher patient-to-nurse ratio was related to higher readmission rates. The significant patient-level structural and process predictors of readmission in the bivariate models included abnormal creatinine level (p = .001), hyponatremia (p < .001), discharge without beta-blockers (p < .001), length of stay (p = .05), emergency department presentation during normal business hours (p = .05), and median household income quintile 1 (p = .05). These factors were associated with increased risk of readmission. Based on markers of disease severity such as cardiorenal syndrome (hyponatremia, blood pressure, and abnormal creatinine), cardiology medical teams had over 3 times the odds of discharging patients with hyponatremia (p < .001), with discharge systolic blood pressure about 21 points lower (p < .001) than in non-cardiology medical teams. The results showed that cardiology medical teams had nearly 4 times the odds of discharging patients on aldosterone antagonists compared with non-cardiologist medical teams (p = .001), 59% lower odds of discharging patients home on calcium channel blockers (p = .01), 3.3 times the odds of discharging patients home on loop diuretics (p = .002), 3 times higher odds of discharging patients on allopurinol (p < .001), and 36% lower odds of discharging patients on statins.

Conclusions:

When controlling for patient and provider process variables, patient-to-nurse ratios have a significant impact on all cause HF 30-day readmissions. This could be possible due to the complexity of discharge teaching that requires more time than available on units with patient-to-nurse ratios greater than 4:1.

Perspective:

Patient education is a primary nursing function and is a critical component of the discharge process. The information that needs to be covered at the time of a HF discharge is complex and can be overwhelming for patients and caregivers. Hospital units that provide care to patients with HF need to consider patient-to-nurse ratios to allow the necessary time to review discharge medications and instructions with patients and caregivers.

Clinical Topics: Heart Failure and Cardiomyopathies, Acute Heart Failure

Keywords: Blood Pressure, Emergency Service, Hospital, Heart Failure, Heart Rate, Hospitalization, Inpatients, Length of Stay, Patient Discharge, Patient Readmission, Primary Nursing


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