Time-of-Day Effects on Surgical Outcomes in the Private Sector: A Retrospective Cohort Study

Department of Surgery, Philadelphia VA Medical Center, Philadelphia, PA, USA.
Journal of the American College of Surgeons (Impact Factor: 5.12). 10/2009; 209(4):434-445.e2. DOI: 10.1016/j.jamcollsurg.2009.05.022
Source: PubMed


Surgical care is delivered around the clock. Elective cases within the Veterans Affairs health system starting after 4 pm appear to have an elevated risk of morbidity, but not mortality, compared with earlier cases. The relationship between operation start time and patient outcomes is not described in private-sector patients or for emergency cases.
We performed a retrospective cohort study of 56,920 general and vascular surgical procedures performed from October 2001 through September 2004, and entered into the National Surgical Quality Improvement Program database. Operation start time was the independent variable of interest. Random effects, hierarchical logistic regression models adjusted for patient, operative, and facility characteristics. Two independent models determined associations between start time and morbidity or mortality. Subset analysis was performed for emergency and nonemergency cases.
After adjustment for patient and procedure characteristics, mortality had a moderately strong association with start time, but only for nonemergency cases starting 9:30 pm to 7:30 am (odds ratio = 1.752; p = 0.028; reference 7:30 am to 9:30 am). As for morbidity, after adjustment, operations starting 9:30 am to 1:30 pm and 5:30 pm to 9:30 pm were associated with a weakly elevated risk of morbidity, but those starting 9:30 pm to 7:30 am demonstrated a strong effect on morbidity (odds ratio = 1.32; p < 0.0001). Subgroup analysis showed this effect was largely a result of elevated risk of morbidity in emergency cases from this overnight time period (odds ratio = 1.48; p = 0.001).
Surgical start times are associated with risk-adjusted patient outcomes. In terms of facility operations management and resource allocation, consideration should be given to the capacity to accommodate cases with differences in risk during different time periods.

32 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: An online posture modification method termed Jacobi compensation is proposed which is suitable to modify precalculated step trajectories for a humanoid robot in certain task coordinate directions. This method can account for modeling errors in trajectory precalculation by shifting e.g. the center of mass (CoM) or certain parts of the humanoid mechanism to increase walking stability and performance. A theoretical analysis of stability properties is given.
    Intelligent Robots and Systems, 2004. (IROS 2004). Proceedings. 2004 IEEE/RSJ International Conference on;
  • [Show abstract] [Hide abstract]
    ABSTRACT: A network/database server is presented in this paper. The PC serves as the data acquisition controller of a polled multidrop network that retrieves information from input terminals. The PC server simultaneously receives data from any combination of terminals on the network. It then updates a local SQL database, prompts the operator at the terminal for the next bit of information, while allowing access to the database from users connected to the server via a local area network. This system was developed to replace an out dated inventory tracking and control process which is currently in use by a local manufacturing company. The system presented will provide greater efficiency and productivity to the company by allowing its employees access to an inventory database that is updated in real-time. The use of a multitasking operating system and modern networking methods are the tools that will provide the company with the ability to keep its employees on top of inventory issues. This paper illustrates the practicality and benefits of taking advantage of the multitasking, networking, and processing capabilities of modern computers and operating systems
    Intelligent Control, 1997. Proceedings of the 1997 IEEE International Symposium on; 08/1997
  • [Show abstract] [Hide abstract]
    ABSTRACT: The traditional on-call system for the management of acute general surgical admissions is inefficient and outdated. A new model, Acute Surgical Unit (ASU), was developed at Nepean Hospital in 2006. The ASU is a consultant-driven, independent unit that manages all acute general surgical admissions. The team has the same make up 7 days a week and functions the same every day, including weekends and public holidays. The consultant does a 24-h period of on-call, from 7 pm to 7 pm. They are on remote call from 7 pm to 7 am and are in the hospital from 7 am to 7 pm with their sole responsibility being to the ASU. The ASU has a day team with two registrars, two residents and a nurse practitioner. All patients are admitted and stay in the ASU until discharge or transfer to other units. Handover of the patients at the end of each day is facilitated by a comprehensive ASU database. The implementation of the ASU at Nepean Hospital has improved the timing of assessment by the surgical unit. There has been significant improvement in the timing of operative management, with an increased number and proportion of cases being done during daylight hours, with an associated reduction in the proportion of cases performed afterhours. There is greater trainee supervision with regard to patient assessment, management and operative procedures. There has been an improvement in the consultants' work conditions. The ASU provides an excellent training opportunity for surgical trainees, residents and interns in the assessment and management of acute surgical conditions.
    ANZ Journal of Surgery 06/2010; 80(6):419-24. DOI:10.1111/j.1445-2197.2010.05331.x · 1.12 Impact Factor
Show more