Validity of Frailty Screening Tools as a Measure for Postoperative Outcomes

Frailty is a common geriatric syndrome defined as a clinical state of decreased physiologic reserve resulting in increased vulnerability to stressors. It is associated with several unfavorable postoperative complications independent of age such as readmission, length of hospital stay and mortality. To address these concerns, medical societies have acknowledged a need for routine screening to identify elderly patients who are at high risk for major complications before undergoing surgery.

In the absence of a golden standard for frailty assessment, there are multiple assessment tools available. However, the challenge with many frailty tools is that they can be time-consuming, and require expertise and clinical training.This poses a challenge for screening a large elderly population before surgery. Some frailty assessment tools, such as PRISMA7 (The Program of Research to Integrate Services for the Maintenance of Autonomy), timed up and go (TUG) and the clock drawing test (CDT), have been demonstrated to be quick, simple and easy to use with minimal training.

The PRISMA-7 is a frailty screening questionnaire that consists of seven dichotomous items considering age, gender, health problems that affect activities of daily living (ADLs), assistance from others with ADLs, having to count on someone if needed, and the use of mobility aids.

The TUG test is used for assessing fall risk and frailty in older patients. It is measured by the time it takes an individual to stand up from a seated position, walk three meters and return back to a seated position. There is no standard cut-off for TUG, however, a cut-off of > 10 seconds has been used to identify frailty.

Cognitive impairment in older surgical patients may predispose patients to executive dysfunction that many elderly patients experience postoperatively and has shown to be a risk factor for surgical complications. Some studies suggest a strong relationship between cognitive impairment and physical frailty resulting in cognitive frailty when evaluating older adults.The CDT has shown to be a valuable screening tool for cognitive concerns. When administering the CDT, a patient receives instructions to draw a clock. Performing the test requires auditory comprehension, planning, sustained attention, visual-spatial skills and executive skills.

The prevalence of surgical frailty in Iceland has not been researched thoroughly enough to provide an accurate estimate. This is important to reveal the number of senior surgical patients at high risk of adverse postoperative outcomes who could benefit from a preoperative intervention. However, there is a lack of consensus on an optimal frailty assessment to screen patients for identifying frail patients prior to surgery, and more research is needed to evaluate which group of patients would benefit the most from prehabilitation.

The scientific value of this study is to elucidate the extent of frailty risk and its associated postoperative outcomes in older surgical patients undergoing elective surgery. We opt to find a convenient screening routine prior to surgery to identify patients at risk of frailty. Therefore, the study aims to validate three frailty screening methods and to assess a positive screening result as an independent risk factor for adverse postoperative outcomes in a cohort of elderly surgical patients undergoing elective surgery. We hypothesize that elderly patients at risk of frailty have a higher rate of surgical complications than patients not at risk of frailty.

Patients aged ≥ 70 years who undergo elective surgery will be prospectively examined at the Department of Anesthesiology and Critical Care of Landspítali. The screening assessments to be evaluated are the Program of Research to Integrate Services for the Maintenance of Autonomy (PRISMA-7), a combination of Timed Up \& Go (TUG), Clock Drawing Test (CDT) and the FRAIL questionnaire, and a combination of PRISMA-7, TUG and CDT. Additional clinical data and outcomes will be obtained from the electronic medical records of Landspítali. The postoperative outcomes measured will be 180-day mortality, surgical complications, 90-day readmission, delirium, non-home discharge and length of hospital stay.

Patients who screen positive on the CDT (≤ 2/3 points) and TUG (≥ 11 seconds) will be considered frail. Those who do not screen positive on both of these tests will be part of the control group (non-frail).