Cachexia is a serious yet under-recognized condition that is widespread globally.^1,2) It is a complex metabolic syndrome characterized by muscle loss, with or without fat loss, typically associated with chronic diseases. This leads to fatigue, functional impairment, increased treatment toxicity, reduced quality of life (QOL), and lower survival rates.^3,4) Cachexia affects approximately 1% of the general population; however, its prevalence increases significantly among patients with chronic diseases (3%–66%) and those with cancer (6%–93%), contributing to an estimated two million deaths annually, based on data from Europe, the USA, and Japan.^5-7) However, cachexia often remains underrecognized by healthcare professionals.^8-10) Early detection is therefore essential, as it may help maintain physical function, independence, and QOL in older adults, while also reducing the caregiving burden on families.^4,11)

Dysphagia is also a serious health issue in older adults, affecting both the risk of aspiration pneumonia and overall QOL.^12,13) It is a disorder resulting from disuse of the muscles involved in swallowing or from central nervous system impairment.¹²⁾ The prevalence of dysphagia varies by setting, with rates ranging from 11%–34% among community-dwelling older adults and from 29%–47% among inpatients.¹³⁾ Dysphagia is associated with several adverse outcomes, including aspiration pneumonia, dehydration, reduced functional performance, and diminished QOL.^12,13) Therefore, developing effective management strategies for dysphagia in rehabilitation settings is essential for improving patient safety and functional outcomes.

Previous studies have reported inconsistent findings regarding the association between cachexia and functional recovery. A multicenter cohort study in Japan reported that neither malnutrition nor cachexia, as defined by the Asian Working Group for Cachexia (AWGC) criteria, was significantly associated with improvements in the Barthel Index at discharge among inpatients with sarcopenic dysphagia.¹⁴⁾ In addition, a cohort study at a university hospital in Germany reported no significant differences in baseline Barthel Index scores between older inpatients with and without cachexia, as defined by the criteria of Evans, Fearon, and Bozzetti; however, follow-up functional status was not reported.¹⁵⁾ Moreover, another cohort study from an inpatient rehabilitation facility in the United States found that gains in motor and cognitive Functional Independent Measure (FIM) scores were comparable between patients with and without cachexia (defined by Fearon’s criteria) among individuals with cancer.¹⁶⁾ However, these studies had notable limitations. They focused on patients with cancer across various rehabilitation settings or examined those with sarcopenic dysphagia spanning both acute and rehabilitation phases, while also using different diagnostic criteria for cachexia. More recently, a recent study reported an association between AWGC-defined cachexia and reduced functional recovery at discharge among post-stroke patients capable of oral intake during the convalescent rehabilitation phase.¹⁷⁾ Nevertheless, the impact of cachexia on functional recovery in patients with dysphagia remains unclear, highlighting a critical evidence gap. Furthermore, cachexia may directly impact key determinants of discharge outcomes. Patients with dysphagia often exhibit increased vulnerability and features of cachexia, making them a crucial population for studying cachexia-related outcomes in rehabilitation settings. Clarifying the relationship between cachexia, functional recovery, and discharge destination may provide a better understanding of the factors influencing rehabilitation outcomes in Asian populations and identify potential targets for multidisciplinary intervention.

Therefore, the present study aimed to evaluate the association between cachexia, as defined by the AWGC, and both functional status and discharge destination among inpatients with dysphagia in rehabilitation hospitals. We hypothesized that cachexia would be significantly associated with functional status at discharge and discharge destinations.  

Of the total 212 patients aged ≥20 years with dysphagia who were hospitalized at eight rehabilitation hospitals in the database, 14 were excluded due to missing data on cachexia diagnosis. Finally, the analysis included 198 inpatients (44% male; median age, 83.0 years [IQR, 77.0–88.0]) (Fig. 1). Thirty-three (16.7%) patients had cachexia as defined by the AWGC criteria. While patients with cachexia had a higher prevalence of all diagnostic components, the prevalence of these components in those without cachexia was also notably high (e.g., 86% had low grip strength and 63% had low BMI/weight loss) (Supplementary Table S1). Table 1 and Supplementary Tables S2–S3 show the patient characteristics. Patients with cachexia were more likely to be women, older, have low BMI, cerebrovascular diseases, and weight loss, but were less likely to have other fractures and high BMI compared with those without cachexia. The median follow‐up period was 80.0 days (IQR, 59.0–92.0). Two patients in the cachexia group died; the causes of death were colon cancer and stroke.

Table 2, Supplementary Fig. S1 and Tables S1–S2 summarize the outcome measurements of patients with or without cachexia. In the descriptive summaries, both FIM and FILS scores at follow-up were higher than those at baseline. In the repeated-measures two-way ANOVA, the time factor showed a significant change in both FIM and FILS scores (p<0.05), whereas cachexia and the interaction term (time×cachexia) were not significant. Regarding discharge destinations, patients with cachexia showed a significant difference compared to those without cachexia (Fisher exact test, p<0.05). For example, discharge to home was 72.7% vs. 76.4%, transfer to other hospitals/facilities was 18.2% vs. 9.1%, continued hospitalization was 3.0% vs. 14.5%, and death was 6.1% vs. 0%. Regarding LOS, patients with cachexia were likely to have a shorter LOS for transfer to other hospitals/facilities compared with those without cachexia (48 days [IQR, 25.5–63] vs. 65 days [IQR, 47.5–91.5], p=0.22).

Table 3 and Supplementary Table S4 present the associations of cachexia with total FIM and FILS scores at discharge. After adjusting for covariates, cachexia was not significantly associated with total FIM (β = 0.03, 95% CI -0.10 to 0.15, p=0.66) or FILS (β=0.23, 95% CI -0.53 to 1.00, p=0.55) at discharge. The sensitivity analyses demonstrated similar results. The difference in the change in total FIM score between the cachexia and non-cachexia groups was not statistically significant (Cohen’s d=0.11, 95% CI -0.26 to 0.48).

Table 4 and Supplementary Table S5 show the associations between cachexia and discharge destinations. After adjusting for covariates, cachexia was not significantly associated with discharge to home (β=0.25, 95% CI -0.75 to 1.34, p=0.64) or transfer to other hospitals/facilities (β=0.71, 95% CI -0.47 to 1.80, p=0.22). There may be differences in coefficients in the subgroup analyses, particularly for conditions leading to dysphagia, fractures, other diseases, and dementia. For patients with dementia, cachexia was associated with discharge to home (Model 3: β=-0.75, 95% CI -0.62 to 1.83, p=0.38) compared to those without dementia (Model 3: β=0.54, 95% CI -3.54 to 1.94, p=0.57), although this difference was not statistically significant. Supplementary Tables S6 and S7 present the overall fit of the regression models.

This multicenter prospective cohort study primarily aimed to examine how cachexia, defined by AWGC criteria, is associated with functional status and discharge destinations among inpatients with dysphagia across eight convalescent rehabilitation hospitals. Our key findings were that cachexia was not significantly associated with FIM, FILS, or discharge destination in convalescent rehabilitation hospitals, in both multivariate and subsequent subgroup analyses.

First, contrary to our hypothesis, cachexia as defined by the AWGC criteria was not significantly associated with functional status at discharge among patients with dysphagia in convalescent rehabilitation hospitals. This result is similar to those previously reported.^14,16) Although patients with cachexia presented with a higher prevalence of diagnostic factors, such as weight loss and low grip strength, those without cachexia could also present a high degree of vulnerability (Supplementary Table S1). For instance, many patients without cachexia have low grip strength and BMI. Thus, both groups may represent vulnerable populations. In the context of intensive multidisciplinary rehabilitation for vulnerable patient populations, cachexia may not have been sufficient to produce a statistically significant difference in the measured functional outcomes. However, our findings differ from those of some studies involving patients with sarcopenia. Nishioka et al.³²⁾ reported that sarcopenia was associated with poor recovery of swallowing function and lower FIM gains in post-stroke patients in a similar convalescent rehabilitation setting. This discrepancy may be attributable to differences in the definitions used (cachexia vs. sarcopenia) or the specific patient populations studied. Furthermore, Miura et al.³³⁾ suggested that differences in physical function may not manifest until 6 months post-discharge. Therefore, future research with long-term follow-up after discharge is required.

Second, cachexia was not significantly associated with discharge destination; however, patients with cachexia were likely to have a shorter LOS and more frequent transfers to other hospitals/facilities. This could reflect clinical efforts to initiate discharge planning at an early stage for patients with dysphagia and cachexia at convalescent rehabilitation hospitals. The goal of convalescent rehabilitation hospitals is to discharge patients to their homes once their activities of daily living have plateaued.^24,34) Our results showed lower FIM scores at baseline and older age in patients with cachexia, which could lead to earlier consideration of transfer options. We did not collect information on the types of transfer destinations, such as long-term care hospitals or nursing facilities. Future studies examining the specific transfer destinations from convalescent rehabilitation hospitals may provide further insights into the reasons for transfer among patients with cachexia. Regarding mortality, previous studies have reported that cachexia is a poor prognostic factor for survival.^25,35-37) In this present study, the target population comprised patients admitted to convalescent rehabilitation hospitals. As a result, the follow-up period was limited to 90 days, and most patients were likely in stable condition. These factors may explain why the proportion of deaths among patients with cachexia was lower compared to the previous studies mentioned above.^25,35-37)

An interesting finding was the potential effect modification by dementia status, although the wide CIs indicated substantial uncertainty owing to the limited sample size in this subgroup. Patients with both cachexia and dementia represent a particularly vulnerable population for whom the benefits of convalescent rehabilitation may be limited, potentially requiring more aggressive care approaches or settings beyond standard rehabilitation interventions.³⁸⁾ However, as our study lacked information on pre-admission living conditions, some patients with dementia and cachexia may have been residing in care facilities prior to their acute hospitalization. This may have influenced the discharge planning decisions. Additionally, the shorter length of stay observed among patients with cachexia who were transferred to other hospitals/facilities (48 vs. 65 days) suggests earlier identification of alternative care needs in this population.

This study has some limitations. First, the generalizability of the findings may be limited, as this study was conducted in Japanese convalescent rehabilitation hospitals. However, the prevalence of dysphagia is high, at 29%–60% or more in hospitalized patients and 38%–92% in those hospitalized for community-acquired pneumonia.¹³⁾ Second, this study did not collect information on the frequency, intensity, time, and type of rehabilitation program, which could have affected the improvement in functional status. Unmeasured variations in specific interventions between facilities or patients may have influenced our findings, potentially masking the subtle effects of cachexia. Furthermore, a stratified analysis using the FITT (frequency-intensity-time-type) program components, if available, could have provided additional clinically valuable insights. Therefore, future studies should focus on specific patient groups or employ designs with highly standardized protocols to minimize such variability. Third, due to the sparse data from the small sample size, we were unable to conduct comprehensive subgroup analyses to identify more specific subgroups that could show different associations. Fourth, the observed improvement in FILS scores could be partly attributed to a ceiling effect (Supplementary Fig. S2).

In conclusion, the results of this study demonstrated that cachexia, as defined by the AWGC criteria, was not significantly associated with functional status at discharge or discharge destination among inpatients with dysphagia in convalescent rehabilitation hospitals.