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Discharges of Cardiac Surgery Patients Buck 'Weekend Effect'

Analysis  |  By Christopher Cheney  
   October 18, 2018

Hospital admission for a serious condition over a weekend or holiday has been linked to compromised patient outcomes, but researchers have found discharges may not be susceptible to the 'weekend effect.'

Discharge over weekends or holidays does not appear to impact readmission rates for major cardiac surgery patients, new research shows.

The finding runs counter to earlier research that has shown a negative impact on outcomes for major illness patients admitted to hospitals over weekends or holiday.

"Given the vast literature demonstrating the impact of the 'weekend effect' on admission outcomes, we expected a similar phenomenon surrounding the complex discharge process after cardiac surgery," Yas Sanaiha, MD, lead author of the new research in The Annals of Thoracic Surgery, told HealthLeaders this week.

"Our team was somewhat surprised to find that day of discharge did not impact adjusted odds of readmission," said Sanaiha, a resident physician in the Division of General Surgery at the David Geffen School of Medicine at UCLA.

The research features more than 4,800 cardiac surgery patients discharged from a UCLA Health hospital, with 20% discharged on a weekend or holiday. For all patients, the readmission rate within 30 days was 11.3%. The readmission rates for weekends (11.4%) and holidays (10.9%) were closely comparable.

"In this retrospective single institution study of patients undergoing elective major cardiac operations, weekend or holiday discharge was not associated with worse readmission performance after adjusting for patient comorbidities and intraoperative variables," Sanaiha and her fellow researchers wrote.

The research team found three predictors of readmission for the patients in the study. "Use of preoperative b-antagonist medications, tobacco use, and surgical site infections were independent predictors of rehospitalization within 30 days," they wrote.

Gauging 'weekend effect'

Readmission reduction is a complex challenge with multiple variables, Sanaiha told HealthLeaders.

"Hospital readmission reduction programs have focused on various measures such as patients with more severe baseline comorbidities, postoperative complications, poor social support, discharge to facilities other than home, among a variety of factors that impact continuity of outpatient care such as transportation for postoperative visits. To further complicate matters, each patient population and operation likely confer variable significance to risk factors, undermining a standardized method of identifying high risk-patients," she said.

The range of readmission variables motivated Sanaiha's research group to evaluate one potentially modifiable aspect of the discharge process—day of discharge. Specifically, the researchers sought to determine whether the "weekend effect" of worse outcomes after admissions for heart attack, stroke, sepsis, and other serious conditions over weekends and holidays also applied to discharges.

"This effect has been attributed to decreased staffing and increased transitions of care. The aim of the current study was to evaluate whether this 'weekend effect' also applied to the discharge process, which is an equally resource intensive phase of hospitalization that requires medical providers to be familiar with a patient and family's needs," Sanaiha said.

"Our study demonstrated that patients with active smoking and depressed ejection fraction (preoperative heart failure) were at higher odds of readmission. Further, we found that weekend or holiday discharge—after controlling for patient medical complexity, complications, and discharge disposition—did not impact odds of readmission."

Preventing readmission

While Sanaiha's team did not identify individual components of post-acute care that reduce readmissions for cardiac surgery patients, the researchers did glean insights.

"Bundled discharge interventions may diminish the impact of limited weekend staff and restricted outpatient resources on risk of rehospitalization after cardiac surgery," Sanaiha said.

Several elements of the UCLA Health bundle of discharge interventions for cardiac surgery patients likely help reduce readmissions, she said.

"Our discharge protocol includes early postoperative planning of clinic visits, and a thorough educational resource named our 'Healing Heart Handbook' tailored to institutional practices with approachable information about the numerous modifications to patient routine after cardiac surgery. Arguably the most important component of the discharge protocol is accessibility at any time of day to the cardiac surgery team who are familiar with discharged patients," Sanaiha said.

Christopher Cheney is the CMO editor at HealthLeaders.


For serious cardiac surgery, readmission rates are similar for patients discharged on weekdays, weekends, and holidays, new research shows.

The finding is unexpected because compromised patient outcomes have been well-documented among patients admitted to hospitals over weekends and holidays.

Execution of post-acute bundled interventions for cardiac surgery patients may explain why discharge over weekends and holidays is not susceptible to the 'weekend effect.'

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