SAN DIEGO – More nurses, robust ancillary services, and an electronic medical record (EMR) helped reduce hospital length of stay when an urgent general surgery procedure was performed on the weekend. When these surgeon-independent resources were present, hospitals were able to overcome the weekend effect.

When a patient needs urgent surgery over the weekend, the result can be increased length of stay, higher charges, increased major and minor complications, and even increased mortality. Overall, patients admitted on the weekend have worse outcomes than do those admitted on a weekday. Factors contributing to the weekend effect for hospitals in one state were explored in a presentation at the American Surgical Association annual meeting.

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“Not all hospitals are created equal in their ability to avoid the weekend effect,” noted presenter Matthew Zapf, a second-year medical student at Stritch School of Medicine, Loyola University Chicago. The work of Mr. Zapf and his colleagues at the university showed that hospitals with full electronic medical records, increased nurse-to-bed ratios, pain and wound management services, and home health programs were more likely to overcome the weekend effect, as defined by length of stay for specific urgent and emergent surgical procedures.

The study used Florida’s Healthcare Cost and Utilization Project State Inpatient Dataset (HCUP-SID), an all-payer dataset, and linked that information to Florida’s American Hospital Association annual survey database, which assesses hospital characteristics. Outcomes were assessed for cholecystectomy, hernia repair for obstructed or gangrenous hernias, and appendectomy for 126,666 people aged 18-90 years. To ensure that the study captured just urgent or emergency procedures, only procedures performed within 2 days of hospital admission were included.

By assessing whether length of stay was longer for weekend vs. weekday admissions for these procedures, the researchers identified which hospitals demonstrated the weekend effect. Of the 197 acute care hospitals identified, 117 performed more than 10 emergent cases per year and were included in the analysis. The presence or absence of a weekend effect was recorded for each hospital for each year of the study. Hospital characteristics were assessed for association with the weekend effect for a given facility in a given year.

None of the 117 hospitals were free of the weekend effect – an outcome that had not been anticipated by the study authors. “I was shocked by the fact that nobody was immune to the weekend effect,” Dr. Anai Kothari said in an interview. Dr. Kothari, also of Loyola University Chicago and first author of the study, said that 41 of the hospitals had a persistent weekend effect through all years of the study. Seventeen hospitals overcame the weekend effect during the time period studied, while 21 others developed the weekend effect during this time. Most hospitals (n = 87) oscillated between states, exhibiting a weekend effect only in some years.

Institutions with an EMR in place during the study period had an odds ratio (OR) of nearly 5 of being able to overcome the weekend effect (P = .010). The EMR, said Dr. Kothari, is especially helpful in effecting safe care transitions. “We are going to see a strong effect, especially in situations where there’s a care transition” as institutions learn how to make full use of the EMR, he said.

Inpatient resources linked with overcoming the weekend effect included a higher ratio of registered nurses to beds (P = .0036), a physical rehabilitation program (P = .017), and a pain management program (P = .001). After-care resources in the form of home health (P = .001) and wound management (P = .043) also contributed significantly to being able to overcome the weekend effect.

Discussant Dr. Lena Napolitano of the University of Michigan commented on the “incredibly robust statistical analysis” performed by the study investigators.

How, she asked, did investigators select median length of stay as the marker for outcomes, when an extended stay over the weekend may just represent poor discharge planning, and not really represent increased adverse outcomes? Senior author Dr. Paul Kuo of Loyola University Chicago replied: “We put a lot of thought into this. We found that length of stay was predictive of each outcome during modeling.”

Study limitations included the fact that data were administrative and were drawn from a single state. It was not possible, for example, to differentiate weekend vs. weekday distribution of resources at a given institution. The next steps will include searching for richer data sources to explore the full set of hospital resources that contribute to patient outcomes for urgent surgeries, said Dr. Kothari.

The authors reported no disclosures.

The complete manuscript of this study and its presentation at the American Surgical Association’s 135th Annual Meeting, April 2015, in San Diego, California, are anticipated to be published in the Annals of Surgery pending editorial review.

Weekend surgery safer with more nurses, EMR use