Fisher: A simple model for predicting postoperative delirium in older patients undergoing elective orthopedic surgery
To determine the incidence, and severity of postoperative delirium (POD) in older patients undergoing elective orthopedic procedures and to identify potential preoperative risk factors.
Research authors: Fisher BW, Flowerdew G.
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Model author
Model ID
1550
Version
1.40
Revision date
2018-10-19
MeSH terms
  • Geriatrics
  • Delirium
  • Risk
  • Postoperative Care
  • Model type
    Custom model (Conditional)
    Status
    public
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    Condition Formula

    Additional information

    OBJECTIVE: To determine the incidence, and severity of postoperative delirium (POD) in older patients undergoing elective orthopedic procedures and to identify potential preoperative risk factors.

    DESIGN: A prospectively studied cohort of elective orthopedic surgery patients.

    SETTING: A University teaching hospital.

    PATIENTS: Eighty patients who attended a preadmission clinic and, subsequently, underwent elective orthopedic surgery. All patients were aged 60 years or older, and all spoke English.

    MEASUREMENTS: Patients underwent preoperative medical, cognitive, and activities of daily living assessment with standardized instruments and were followed postoperatively with daily visits, telephone interviews with attending nurses using a modified confusion assessment model (CAM), and repeated cognitive testing. Suspected delirium was verified by direct physician assessment.

    RESULTS: The elective group had 14 (17.5%) cases of POD, of which six (7.5%) were severe. These incidences are low compared with those of nonelective surgery groups reported elsewhere in the literature. Stepwise multiple logistic regression identified two POD risk factors: clock-drawing scores < or = 6 (OR = 9.0, CI, 2.8 to 45.6) and male gender (OR = 5.6, CI 1.9 to 33.8).

    CONCLUSION: A simple model using clock-drawing scores and male gender for preoperative identification of elective patients at greatest risk for POD appears sensitive, predictive, and practical for the preadmission clinic setting, but it should be validated in a prospective trial.

    Study Population

    Total population size: 80
    Males: {{ model.numberOfMales }}
    Females: {{ model.numberOfFemales }}

    Additional characteristics

    No additional characteristics defined

    Predicted probability of postoperative delirium:
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    %

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    Result
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    Predicted probability of postoperative delirium: %

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    Outcome stratification

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    Conditional information

    Result interpretation

    In the original study by Fisher and Flowerdew (1995), 14 out of 80 (17.5%) patients developed a postoperative delirium following an elective orthopedic procedure.1

    Gender of the patient and total clock score were used to differentiate between low and high risk groups for postoperative delirium, with probabilities ranging from 5.4 to 83.3%.

    Source:

    1. Fisher BW, Flowerdew G. A simple model for predicting postoperative delirium in older patients undergoing elective orthopedic surgery. J Am Geriatr Soc. 1995;43(2):175-8.

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    Calculations alone should never dictate patient care, and are no substitute for professional judgement. See our full disclaimer.

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