Frailty for Perioperative Clinicians: A Narrative Review

Daniel I. McIsaac, MD, MPH, FRCPC; David B. MacDonald, MD, FRCPC; Sylvie D. Aucoin, MD, MSc, FRCPC


Anesth Analg. 2020;130(6):1450-1460. 

In This Article

The Impact of Frailty on Perioperative Outcomes

Surgery induces substantial physiologic stress even for healthy individuals.[32] Therefore, it is not surprising that the presence of frailty before surgery is strongly associated with increased risk of adverse outcomes and higher resource utilization. Across an ever-expanding epidemiologic literature that now includes large studies using administrative data, prospective registries, primary prospective observational studies, and systematic reviews, frailty is consistently associated with at least a 2-fold increase in the risk of major morbidity, mortality, and readmissions.[33–35] Furthermore, given the increasing focus on patient-reported outcomes and the importance of functional measures for older surgical patients, it is of primary importance to recognize that frailty doubles the odds of new patient-reported disability,[26] impaired quality of life,[33,34] and increases the odds of nonhome discharge 5-fold among older people previously living in the community.[26,36] In addition, length of stay, costs, and other measures of resource use are consistently higher for older people with frailty, with a 15%–60% increase across a variety of studies.[26,36,37]

While relative increases in risk, as well as risk estimates adjusted for important confounders (such as surgery type, urgency, indication, etc) are important to clinicians and help to communicate expected outcomes to patients and their families, absolute risk estimates are typically better understood and more meaningful when providing prognostic information before surgery.[38,39] Fortunately, the absolute risk of death in the month after surgery is relatively low, even for individuals with frailty (typically <5% after major, elective noncardiac surgery).[8] However, 1-year mortality rates are often substantial and may exceed 40% after major elective surgery for cancer (which likely reflects the interplay between surgery, frailty, and the underlying oncologic process).[15,30,40] There is also a consistent dose-response relationship, where higher frailty scores (regardless of instrument) are associated with greater risk of death.[29,33]

Complications are common in people with frailty, with rates exceeding 50%.[41] Accordingly, a recent systematic review has identified frailty as the strongest risk factor for the development of postoperative morbidity in older patients.[41] Delirium is also common in older surgical patients, with rates estimated between 10% and 50% depending on the type and urgency of surgery.[42] Frailty is a strong risk factor for developing delirium after major surgery (odds ratio = 4.1),[43,44] and its strength of association with delirium incidence was exceeded only by a history of delirium in a recent systematic review.[44]

While older people place a high value on survival, expected function, and quality of life outcomes may be of even greater importance in the setting of acute illness.[45] Unfortunately, these patient-centered and patient-reported outcomes are rarely evaluated in perioperative frailty studies, and an even lower proportion provide clinically meaningful information.[34] Where these data do exist, evidence suggests that frailty is a strong predictor of adverse functional outcomes. In a multicenter cohort study of over 700 participants, our group found that 1 in 5 older people with frailty were experiencing a new or meaningfully worsened disability 3 months after major elective noncardiac surgery. We have also found that 15%–50% of older people with frailty who lived independently in the community before surgery were unable to achieve home discharge after elective procedures.[26,36] Overall, our prospective data suggest that 29% of people with frailty either die, are institutionalized, or go home with a new disability in the 90 days after major, elective noncardiac surgery.[26] These data are consistent with the cardiac literature, where older people with frailty face an approximately 20% absolute increase in the likelihood of dying or having reduced quality of life (compared to people without frailty) a year after surgery.[46]

Finally, while most studies describing the association of frailty with adverse outcomes focus on major inpatient surgery, it is also important to recognize that frailty predicts adverse outcomes in surgeries typically considered low risk. These include urgent and emergent appendectomy and cholecystectomy procedures, where the relative impact of frailty on mortality is stronger than for laparotomy or bowel resection.[28] Furthermore, after ambulatory hernia, breast, thyroid, or parathyroid surgery, frailty is associated with a greater than 3-fold increase in the odds of complications.[47]