Modified Frailty Index (mFI) in major gynaecological surgery: does it predict outcome?

Frailty, commonly associated with older adults, is identified by decreased reserves in multiple organ systems. Frailty has been associated with increased risk of cardiovascular disease, hypertension, cancer and death, even after adjusting for chronic conditions and disability. In the infirm, there is homeostenosis; a decreased ability to maintain homeostasis in times of acute stress. Surgery is a form of ‘acute stress’, and frailty has been associated with higher complication rates and prolonged recovery. The accumulating deficits model was applied to the National Surgical Quality Improvement Program (NSQIP) Participant Use File (2005–09) for inpatient surgical patients, and it was demonstrated that frailty affects postoperative morbidity and mortality across all surgical specialties. Frailty may also affect a patient’s ability to recover from a complication, once it has occurred (Velanovich et al. J Surg Res 2013;183:104–10). Moreover, when 25 698 women with endometrial cancer (1998–2007) were evaluated from the Nationwide Inpatient Sample in the USA, the morbidity that was associated with surgery was significantly higher in women who were >80 years old, even after adjusting for medical comorbidities (Wright et al. Am J Obstet Gynecol 2011;205:66. e1–8). More recently, in 6551 women with gynaecological cancer (2008–11), from NSQIP, the modified frailty index (mFI) was predictive of the need for critical care support and 30-day mortality after surgery. Two preoperative factors, namely albumin and mFI, allowed for greater precision in identifying women who were at higher risk for requiring transfer to an intensive care unit (>10% risk) (Uppal et al. Gynecol Oncol 2015;137:98–101). In this study by Wright et al., the authors have presented a retrospective cohort to determine the association between mFI and morbidity and mortality in women who underwent hysterectomies in US hospitals that were participating in the NSQIP (2008–12). A combined model with age, ASA class (American Society of Anesthesiologists physical status classification system; a six-category physical status classification system for assessing the fitness of cases before surgery), functional status and mFI was evaluated and was found to have a better predictive value; however, age and ASA were shown to be of higher predictive ability than mFI. In the population studied, 20% of participants were older than 60 years, and 14% had gynaecological cancers (only 1% had metastatic cancer). In addition, 99% had independent functional status; surgical complexity was not used as a prognostic factor and elective and emergency procedures were not evaluated separately. It is therefore not clear whether mFI could be useful in prospective studies for higher-severity disease or increased complexity of the surgical procedure, especially in gynaecological cancer surgery. Modified frailty index may add to the overall risk assessment for major gynaecological surgery; however, it is still unclear whether the addition of mFI would allow modification of a ‘pre-frail’ status before surgery or whether mFI would be useful as a tool for informed decision-making for an individual patient.