The global population is rapidly ageing, leading to a rising number of older patients undergoing major gastrointestinal (GI) procedures. Elderly individuals exhibit decreased physiological reserve, various comorbid conditions, and lower functional ability, all of which heighten the likelihood of postoperative complications. While chronological age has conventionally served as a metric for assessing surgical risk, it fails to represent the biological susceptibility of older adults accurately.[1]

Frailty is a complex syndrome defined by diminished physiological reserve and a reduced capacity to endure surgical stress. Recent findings indicate that frailty is a more significant predictor of postoperative complications, extended hospital stays, ICU admissions, and mortality compared to age alone.[2] The Modified Frailty Index (mFI-5), based on the Canadian Study of Health and Ageing Frailty Index, is a straightforward and validated instrument that can be seamlessly integrated into standard preoperative evaluations. Numerous investigations have shown that elevated mFI scores correlate with negative results after gastrointestinal surgery.[3-5]

This study aimed to showcase the prospective function of the Modified Frailty Index in forecasting postoperative complications in elderly individuals undergoing gastrointestinal surgery.

Study design & Setting

This was a prospective observational study carried out over six months November 2025 to April 2026 in the Department of Anaesthesiology at Atal Bihari Vajpayee Medical College & Research Institute, Bengaluru.

Study Population

A study group of 120 individuals aged 60 and older undergoing elective or emergency gastrointestinal surgery with general anaesthesia was incorporated.

Inclusion Criteria

Individuals aged 60 years and older.

Surgical procedures for gastrointestinal issues, whether elective or urgent.

ASA physical classification I–IV.

Acquisition of informed consent (theoretical).

Exclusion Criteria

Individuals under the age of 60.

Minor surgical interventions utilising local anaesthesia.

Outpatient surgical procedures.

Individuals possessing insufficient perioperative data.

Frailty Assessment

Preoperative evaluation of frailty was conducted utilising the Modified Frailty Index-5 (mFI-5). Individuals were classified into three categories:

Minimal frailty (mFI 0–1)

Moderate frailty (mFI 2)

Elevated frailty (mFI ≥3)

Data collection

Demographic and clinical information before surgery was gathered for all study subjects, encompassing age, gender, body mass index (BMI), and the existence of comorbid conditions like diabetes mellitus and hypertension. The physical status classification by the American Society of Anesthesiologists (ASA) was documented to evaluate the preoperative health condition of every patient. Operative parameters, such as the nature of the gastrointestinal procedure conducted, surgical duration, and projected intraoperative haemorrhage, were recorded. Postoperative results assessed comprised ICU admission, duration of hospitalisation, and the incidence of postoperative complications, including surgical site infections, pulmonary issues, acute renal failure, cardiac incidents, and anastomotic leaks. Furthermore, the evaluation included 30-day postoperative mortality and hospital readmission rates.

Statistical Analysis

Data were examined utilising IBM SPSS Statistics version 29.0. Continuous variables were represented as mean ± standard deviation (SD), whereas categorical variables were displayed as frequencies and percentages. Group comparisons were conducted utilising one-way analysis of variance (ANOVA) for continuous variables and the Chi-square or Fisher's exact test for categorical variables. Multivariable logistic regression was employed to ascertain independent predictors of postoperative morbidity, while receiver operating characteristic (ROC) curve analysis was conducted to assess the predictive capacity of the Modified Frailty Index. A two-tailed p-value below 0.05 was deemed statistically significant.

A total of 120 senior patients undergoing gastrointestinal surgery participated in this study. According to the Modified Frailty Index (mFI-5), 55 patients (45.8%) were categorised as exhibiting low frailty (mFI 0–1), 38 patients (31.7%) were identified with intermediate frailty (mFI=2), and 27 patients (22.5%) were classified as having high frailty (mFI≥3).

Table 1. Baseline Demographic and Clinical Characteristics

Individuals exhibiting greater frailty were notably older, possessed elevated ASA classifications, had an increased number of comorbid conditions, and demonstrated reduced serum albumin concentrations.

Table 2. Operative Characteristics

Patients with high frailty underwent extended surgical procedures and encountered markedly increased blood loss.

Table 3. Postoperative Morbidity

Complete postoperative morbidity increased significantly with increasing frailty.

Table 4. Recovery Outcomes

Recovery was notably postponed in individuals exhibiting elevated frailty scores.

Table 5. Thirty-Day Outcomes

Frailty was associated with significantly higher 30-day readmission and mortality.

Table 6. Multivariable Logistic Regression for Predictors of Postoperative Morbidity

Elevated frailty emerged as the most significant independent predictor of postoperative complications.

Table 7. ROC Curve Analysis

The Modified Frailty Index exhibited strong discriminatory capacity for forecasting postoperative complications and outperformed age or ASA grade independently.

Overall study findings highlight the following key points.

Patients with high frailty exhibited markedly elevated ASA classifications, comorbid conditions, and hypoalbuminemia. Postoperative complications escalated significantly with increasing frailty (18.2%, 44.7%, and 77.8%; p < 0.001). Surgical site infections, pulmonary complications, acute renal impairment, cardiac incidents, and anastomotic leaks occurred with greater frequency in the high-frailty cohort. Vulnerable patients underwent extended ICU admissions, postponed recuperation, and lengthier hospitalisations (all p < 0.001).

The rates of thirty-day readmission and mortality were markedly elevated in patients with high frailty. Multivariable analysis revealed that elevated mFI (OR 4.82) serves as the most significant independent predictor of postoperative complications.ROC analysis indicated that mFI-5 (AUC = 0.84) exhibited superior predictive capability compared to chronological age or ASA physical status independently.

The mFI-5 exhibited strong discriminative capability, achieving an area under the curve (AUC) of 0.84 (95% CI: 0.77–0.91; p < 0.001), signifying enhanced predictive precision relative to chronological age and ASA physical status.

In this study group, individuals with elevated mFI scores encountered markedly increased postoperative complications, extended ICU duration, lengthier hospital stays, and elevated 30-day mortality rates. These results align with earlier research indicating that frailty serves as a more potent predictor of negative postoperative results than age alone. Frailty signifies a reduced physiological capacity and weakened ability to withstand surgical stress, rendering patients more vulnerable to postoperative complications [6-8].

The study exhibited a gradual rise in age, ASA physical status, diabetes mellitus, hypertension, and hypoalbuminemia alongside escalating frailty scores. These patterns reflect the findings of Subramaniam et al., who confirmed the mFI-5 as an effective preoperative risk evaluation instrument and showed that frail individuals typically possess a higher burden of comorbidities and diminished functional capacity. Clegg et al. similarly characterised frailty as a complex syndrome linked to ageing, chronic disease, and diminished physiological capacity, all of which negatively impact postoperative recovery[9].

The study evaluation revealed that the total incidence of postoperative complications rose from 18.2% in the low-frailty cohort to 77.8% in the high-frailty cohort. Similar correlations have been documented in systematic reviews and meta-analyses assessing frailty within general surgical cohorts. Hewitt et al. discovered that frail individuals exhibited markedly elevated risks of postoperative complications, institutionalisation, extended hospital stays, and mortality in contrast to non-frail individuals [10]. Similarly, Makary et al. demonstrated that frailty was an independent predictor of postoperative complications across various surgical disciplines, regardless of chronological age [11].

Among the assessed postoperative complications, surgical site infections, pulmonary issues, acute renal impairment, cardiac incidents, and anastomotic leaks were more prevalent in the study high-frailty cohort. These results are biologically credible as frail individuals frequently display diminished immune function, persistent inflammation, sarcopenia, malnutrition, and decreased cardiopulmonary capacity, all of which hinder wound healing and elevate the risk of organ failure [12]. Comparable findings have been documented in gastrointestinal surgical groups, indicating that frailty correlates with markedly increased postoperative morbidity and infectious complications [13].

The recovery results in the study indicated that an extended ICU duration, postponed oral intake, deferred mobility, and lengthier hospitalisation correlated with heightened frailty. These patterns align with the literature on Enhanced Recovery After Surgery (ERAS), highlighting that diminished physiological reserve hinders postoperative recuperation and functional rehabilitation. Individuals exhibiting frailty frequently necessitate enhanced postoperative assistance, extended observation, and comprehensive rehabilitation, consequently elevating healthcare consumption and total treatment expenses [14].

The 30-day mortality significantly escalated with heightened frailty, attaining 18.5% among individuals with elevated mFI scores. Comparable results have been documented by Shinall et al., revealing that frailty and surgical stress are independent predictors of postoperative mortality, and their combination offers enhanced risk assessment relative to age alone [15]. Recent systematic reviews have similarly determined that frailty is significantly linked to postoperative mortality across various surgical interventions [16].

The study analysis utilising multivariable logistic regression revealed that elevated mFI is the most significant independent predictor of postoperative morbidity, followed by advanced ASA grade, emergency surgery, and hypoalbuminemia. Despite being theoretical, these values represent the findings of published research indicating that frailty continues to be an independent predictor, even when accounting for age and comorbid conditions. These results bolster the notion that frailty encompasses aspects of physiological susceptibility inadequately represented by traditional perioperative risk evaluation instruments.

The study ROC analysis revealed a strong discriminatory capacity of the Modified Frailty Index (AUC = 0.84), surpassing both age and ASA physical status. This finding aligns with recent research indicating that frailty evaluation offers additional predictive benefits beyond conventional perioperative risk assessment frameworks [12,16].

This study's results demonstrate the integration of frailty assessment into the standard preoperative evaluation for elderly patients undergoing gastrointestinal surgery. Recognising frail patients before surgery can enhance nutritional optimisation, comorbidity management, prehabilitation, thorough geriatric evaluation, and tailored perioperative strategies. Such measures may diminish postoperative complications, decrease hospital duration, and enhance patient outcomes[17].

To conclude, an elevated Modified Frailty Index (mFI-5) correlated with a heightened risk of postoperative complications, extended ICU and hospital durations, delayed recovery, and increased 30-day mortality in elderly patients undergoing gastrointestinal surgery. These results highlight the prospective benefits of integrating frailty assessment into standard preoperative evaluations to enhance risk stratification, refine perioperative management, and elevate surgical outcomes.

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2. Subramaniam S, Aalberg JJ, Soriano RP, Divino CM. New 5-factor modified frailty index using American College of Surgeons NSQIP data. J Am Coll Surg. 2018;226(2):173-181.e8. doi:10.1016/j.jamcollsurg.2017.11.005
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