Older adults admitted under Internal Medicine represent a clinically vulnerable population with high risks of in-hospital complications, functional decline, readmission, and short-term mortality after discharge. Chronological age alone, however, does not adequately capture this heterogeneity in prognosis, and there is increasing emphasis on identifying bedside markers that reflect biological reserve and vulnerability more accurately [1,2]. Frailty has emerged as one such construct, describing a state of decreased physiological reserve and increased susceptibility to stressors, and has consistently been associated with adverse clinical outcomes across medical and geriatric settings [1,3].

The frailty index, based on the cumulative deficit model described by Rockwood and Mitnitski, conceptualizes frailty as the proportion of age-related health deficits present in an individual and provides a graded measure of vulnerability rather than a purely syndromic classification [4]. This approach has shown strong biological and prognostic validity, with higher frailty index scores associated with mortality, institutionalization, and other adverse outcomes in older adults [4]. In hospitalized elders, frailty assessment is particularly relevant because acute illness may unmask limited reserve, thereby increasing the risk of poor recovery even when the index admission diagnosis appears manageable [2,5].Among practical bedside tools, handgrip strength has received considerable attention as a simple and objective measure of muscle strength and global physical reserve. Reduced handgrip strength has been linked to sarcopenia, disability, prolonged hospitalization, and mortality in older populations [6]. The FNIH Sarcopenia Project demonstrated that weakness assessed by grip strength is strongly associated with mobility impairment [7], while Bohannon’s meta-analysis showed that lower handgrip strength predicts all-cause mortality across diverse populations [8]. These observations support the concept that handgrip strength may serve as a clinically useful surrogate of frailty-related vulnerability.

Frailty and handgrip strength are related but not identical constructs. Frailty reflects multidimensional deficit accumulation, whereas handgrip strength captures a more focused aspect of physical reserve. Evaluating both at admission may therefore provide complementary prognostic information in elderly medical inpatients. Although frailty and weakness have individually been associated with adverse outcomes, prospective data examining their combined prognostic value for short-term outcomes in elderly patients admitted under Internal Medicine remain limited in routine hospital practice, particularly in Indian settings. The present study was therefore undertaken to assess the prognostic value of frailty index and handgrip strength in predicting 90-day outcomes in elderly patients admitted under Internal Medicine.

AIM

To evaluate the prognostic value of frailty index and handgrip strength in predicting 90-day outcomes in elderly patients admitted under Internal Medicine.

OBJECTIVES

1. To assess frailty index and handgrip strength at the time of admission in elderly patients admitted under Internal Medicine.
2. To determine the association of frailty index and handgrip strength with adverse 90-day outcomes, including mortality, readmission, and functional decline.
3. To examine whether frailty index and handgrip strength independently predict adverse 90-day outcomes after adjusting for relevant clinical and comorbidity-related factors.

Study design and setting

This prospective cohort study was conducted in the Department of Internal Medicine at Malati Multispeciality Hospital and Medical College, Akola, Maharashtra, over a period of 1 year in 2021. The study was undertaken to evaluate the prognostic value of frailty index and handgrip strength in predicting 90-day outcomes in elderly patients admitted under Internal Medicine.

Study population

The study included elderly patients admitted under the Department of Internal Medicine during the study period. A total of 60 eligible participants were enrolled consecutively after obtaining written informed consent.

Inclusion criteria

1. Patients aged 60 years and above.
2. Patients admitted under the Department of Internal Medicine during the study period.
3. Patients willing to participate and provide written informed consent.
4. Patients in whom frailty index assessment and handgrip strength measurement could be performed within 48 hours of admission.

Exclusion criteria

1. Patients who were critically ill and unable to undergo frailty or handgrip assessment at admission.
2. Patients with severe cognitive impairment, delirium, or altered sensorium without a reliable caregiver/informant.
3. Patients with conditions interfering with handgrip strength assessment, such as upper limb deformity, recent fracture, severe arthritis, hemiplegia, or amputation.
4. Patients admitted for terminal illness or palliative care alone.
5. Patients unwilling to participate or not giving consent.
6. Patients unavailable for completion of 90-day follow-up.

Baseline clinical assessment

All participants underwent detailed clinical evaluation at admission. Baseline demographic details, presenting illness, and comorbidities were recorded in a predesigned proforma. Particular attention was paid to hypertension, diabetes mellitus, chronic obstructive pulmonary disease, chronic kidney disease, ischemic heart disease, prior stroke, nutritional risk, and medication burden. Clinical parameters including systolic and diastolic blood pressure were documented. Relevant laboratory variables including haemoglobin, serum albumin, serum creatinine, and C-reactive protein were recorded. Functional status at admission was assessed using the Barthel Index. Length of hospital stay, ICU transfer, and in-hospital complications were also documented.

Frailty assessment

Frailty was assessed within 48 hours of admission using a frailty index based on the cumulative deficit model. The frailty index was calculated as the ratio of the number of deficits present to the total number of deficits assessed. The predefined deficits included comorbid illnesses, functional limitations, nutritional risk, selected clinical variables, and other relevant health parameters available at admission. Frailty index was analyzed both as a continuous variable and as a categorical variable. For categorical analysis, participants were classified as non-frail, pre-frail, or frail according to the calculated frailty index, and a frailty index of 0.25 or more was considered frail.

Handgrip strength assessment

Handgrip strength was measured within 48 hours of admission using a standard hand dynamometer. Measurements were obtained in a standardized position, preferably with the patient seated comfortably and the elbow flexed at 90 degrees. Three readings were taken, and the best value was used for analysis. Handgrip strength was analyzed both as a continuous variable and as a categorical variable. Participants were categorized as having low or normal handgrip strength according to age- and sex-appropriate cutoffs.

Follow-up and outcome assessment

All enrolled participants were followed for 90 days from the date of admission. Follow-up information was obtained from hospital records, outpatient visits, or telephone contact. The following outcomes were assessed at 90 days:

1. Mortality
2. Hospital readmission
3. Functional decline compared with baseline status

A composite adverse 90-day outcome was defined as the occurrence of one or more of the above events.

Data collection

Data were recorded in a predesigned and pretested proforma and included:

1. Demographic details
2. Clinical diagnosis and comorbidities
3. Vital parameters and selected laboratory variables
4. Functional status at baseline
5. Frailty index score and frailty category
6. Handgrip strength value and handgrip category
7. Length of stay, ICU transfer, and in-hospital complications
8. Ninety-day mortality, readmission, and functional decline

Outcome measures

Primary outcome

• Composite adverse outcome at 90 days in elderly patients admitted under Internal Medicine.

Secondary outcomes

1. Ninety-day mortality
2. Ninety-day readmission
3. Ninety-day functional decline
4. Association of frailty category with composite adverse outcome
5. Association of handgrip category with composite adverse outcome
6. Independent association of frailty index and handgrip strength with composite adverse outcome

Statistical analysis

Data were entered into Microsoft Excel and analyzed using appropriate statistical software. Continuous variables were expressed as mean ± standard deviation for normally distributed data and as median with interquartile range (IQR) for skewed data. Categorical variables were expressed as frequency and percentage.

Comparisons of composite 90-day adverse outcome across frailty categories and handgrip strength categories were performed using the Chi-square test or Fisher’s exact test, as appropriate. The relationship between frailty index and handgrip strength was assessed using correlation analysis.

To evaluate independent predictors of composite adverse outcome at 90 days, multivariable logistic regression analysis was performed. The dependent variable was the presence or absence of composite adverse outcome at 90 days. The explanatory variables entered into the model were age, sex, chronic kidney disease, prior stroke, frailty index, and handgrip strength. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. A p-value <0.05 was considered statistically significant.

Ethical considerations

The study was conducted after obtaining approval from the Institutional Ethics Committee. Written informed consent was obtained from all participants or their legally acceptable representatives before inclusion in the study.

Baseline characteristics

Sixty older medical inpatients were included. The mean age was 69.9 ± 7.5 years and 55.0% were male. Hypertension (65.0%) and diabetes mellitus (43.3%) were common comorbidities. The median length of stay was 8.8 days (IQR 6.0–11.6). Baseline clinical, laboratory, and functional characteristics are summarized in Table 1.

Table 1. Baseline clinical, laboratory, and functional profile of the cohort

Frailty and handgrip strength at admission

The mean frailty index was 0.288 ± 0.100. Most participants were categorized as frail (70.0%), with 28.3% pre-frail and 1.7% non-frail. Low handgrip strength was observed in 46.7% of participants. Distribution of frailty, handgrip status, and 90-day outcomes is presented in Table 2.

Table 2. Frailty status, handgrip strength, and 90-day outcomes

Ninety-day outcomes

Within 90 days, mortality occurred in 12 participants (20.0%), readmission in 28 (46.7%), and functional decline in 18 (30.0%). The composite adverse outcome was observed in 44 (73.3%).

Association of frailty and handgrip strength with 90-day adverse outcomes

Adverse outcomes were more frequent among frail participants compared with non-frail/pre-frail participants, although this difference did not reach statistical significance in this cohort (Table 3). Similarly, adverse outcomes were comparable between low and normal handgrip groups (Table 4). Figure 1 illustrates the graded pattern of adverse outcome rates across frailty categories. Figure 2 shows the inverse relationship between frailty index and handgrip strength. 

Table 3. Composite 90-day adverse outcome according to frailty category

Table 4. Composite 90-day adverse outcome according to handgrip category

Multivariable analysis

In multivariable logistic regression including age, sex, CKD, prior stroke, frailty index, and handgrip strength, neither frailty index nor handgrip strength demonstrated an independent association with the composite adverse outcome; effect estimates are shown in Table 5. These findings should be interpreted in the context of the modest sample size and distribution of frailty categories.

Table 5. Multivariable logistic regression for composite 90-day adverse outcome (adjusted odds ratios)

This study found a high burden of frailty and adverse 90-day outcomes among elderly medical inpatients. Frailty was present in 70.0% of participants, low handgrip strength in 46.7%, and the composite adverse outcome in 73.3%. Although neither frailty index nor handgrip strength remained independently associated with the composite outcome in multivariable analysis, the overall pattern still suggests a clinically vulnerable cohort with substantial short-term risk.

The prevalence of frailty in our cohort was higher than that reported in several hospitalized older-adult studies. Hao et al. reported frailty in 49.1% of acute-care inpatients and found that frailty independently predicted 3-year mortality (adjusted HR 2.09, 95% CI 1.20–3.63) and readmission (adjusted HR 1.40, 95% CI 1.04–1.88) [9]. Chehrehgosha et al., in 304 hospitalized older adults, found 11.5% frailty and 33.6% pre-frailty, with worse post-discharge outcomes among frail patients [10].

The higher frailty burden in our study likely reflects a sicker internal medicine inpatient population, but it also reduced discrimination because only one participant was non-frail.

A similar explanation may apply to handgrip strength. Low handgrip was observed in 46.7% of our patients, close to the 49.6% reported by Zhang et al. in a national multicenter cohort of 8,910 older inpatients, where low handgrip independently predicted 90-day mortality (OR 1.64, 95% CI 1.14–2.37) [11].

Pontes et al. also showed that at 90 days, disability occurred in 15.1% of older emergency patients with low handgrip versus 4.1% in those with normal handgrip (OR 4.44, 95% CI 1.50–13.14) [12]. Chites et al. further reported that reduced handgrip strength increased the risk of in-hospital death by 9.11-fold and was associated with prolonged hospital stay [13]. In contrast, our null finding may reflect the modest sample size and the use of a broad composite endpoint rather than a more specific outcome such as mortality or disability.

These findings are consistent with broader evidence that frailty-related markers are clinically relevant, but their predictive performance depends on cohort size and case mix. In a meta-analysis of unplanned hospital admissions, Boucher et al. found that frailty was consistently associated with mortality, length of stay, and discharge outcomes across hospital-wide and general medicine cohorts [14].

Similarly, Carlson et al. reported an overall adverse outcome rate of 78.1% versus 50.0% and a 6-month readmission rate of 59.4% versus 39.7% in hospitalized elderly patients with poorer functional reserve [15]. Against this background, our results do not argue against the clinical importance of frailty and weakness; rather, they suggest that in a small, highly vulnerable internal medicine cohort, these markers may be more useful for bedside risk recognition than as statistically robust independent predictors.

Overall, the study supports routine assessment of frailty and handgrip strength in elderly medical inpatients, while also indicating that larger prospective cohorts are needed to define their independent prognostic value for specific 90-day outcomes.

Limitation

This was a single-center study with a small sample size, which may have limited the power to detect independent associations.

Frailty and low handgrip strength were common among elderly patients admitted under Internal Medicine and were accompanied by a high burden of adverse 90-day outcomes. Although neither measure independently predicted the composite outcome in this cohort, both remain clinically useful markers of vulnerability and may help identify high-risk older inpatients at admission.

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