Disease trajectories and medical expenditures of older adults with disabilities: insights from China’s long-term care insurance program | BMC Geriatrics

Our study examined disease progression over time and evaluated medical expenditures using longitudinal data from an older population with disabilities. The key findings were as follows: (1) Complications related to malnutrition and infections were the predominant direct causes of death, including anemia, hypoproteinemia, electrolyte disorders, pneumonia, respiratory failure, and urinary infections. (2) Medical expenditures decreased with advancing age. Among the most prevalent diseases, intracerebral hemorrhage, sepsis, and respiratory failure incurred the highest medical costs.

Direct causes of death

Previous studies from developed countries have shown that disability at the end of life follows distinct yet predictable trajectories, including cancer, organ failure, sudden death, advanced dementia, and frailty [18, 19]. Recent research has incorporated chronic kidney disease and cirrhosis into the spectrum of late-life disability trajectories [20]. In China, common non-communicable diseases (NCDs), such as hypertension, diabetes, dementia, COPD, cerebral infarction, and coronary artery disease, can all contribute to disability. However, our study demonstrated that these NCDs do not directly cause death. Instead, malnutrition and infection-related complications were identified as critical pathways leading to mortality in our LTCI cohort.

Malnutrition and disability dynamics

Malnutrition and disability are closely interconnected, with substantial overlap and mutual influence [21]. Physical mobility limitations may prevent older adults from obtaining or preparing food independently. Poor oral health or swallowing disorders further alter eating patterns, exacerbating the risk of malnutrition. This risk is particularly high in those with chronic wasting disease, such as cancer, organ failure, or those undergoing hemodialysis. Sarcopenia, which is closely related to malnutrition, is prevalent among older adults, with a prevalence rate of 41% in LTC facilities [22]. In China, 32.4% of LTC participants were at risk of malnutrition, and 49.7% were diagnosed with sarcopenia [23]. Severe sarcopenia and malnutrition, characterized by low muscle mass and poor physical performance, can exacerbate disability severity in older adults.

Malnutrition and infections

The relationship between malnutrition and infection in LTC settings has been well established [24]. In our analysis, pneumonia and respiratory failure emerged as prominent infection-related causes of death. Older individuals are particularly at high risk of mortality from infections, largely due to their pro-inflammatory status and dysfunctional immune response, collectively referred to as immunosenescence [25].

In LTC settings, malnutrition and hypoproteinemia further weaken the immune system, impairing antibody responses to infections [26]. Sarcopenia is also strongly associated with infection in both acute and LTC settings [27, 28]. Empirical data suggest that older patients with sarcopenia have higher infection rates and poorer prognoses during the COVID-19 pandemic [29]. Additionally, COVID-19 exacerbates sarcopenia due to increased muscle wasting from systemic inflammation, reduced physical activity, and insufficient nutrient intake. Therapeutic interventions, such as increased protein intake, specific probiotics, and targeted physical therapy, have demonstrated significant efficacy in improving the functional status of older patients recently infected with COVID-19 [30].

Systematic reviews also have demonstrated that targeted nutritional interventions can significantly reduce infection risks in LTC settings [31]. Effective interventions included whey protein (any infection), Black Chokeberry (urinary tract infection), and vitamin D (acute respiratory tract infection, skin and soft tissue infection). Both zinc and dedicated mealplans significantly improved lymphocyte parameters [26]. These nutritional interventions may warrant further rigorous clinical trials.

Medical expenditures

Among decedents, medical expenditures increased rapidly as death approached, consistent with findings from previous studies [32, 33]. Although adults aged 85 years and older have more comorbidities, their frailty often necessitates less invasive interventions, aligning with the growing emphasis on palliative care. This shift in care strategy is reflected in the lower inpatient expenditures among the very elderly.

Our analysis identified sepsis as one of the most costly conditions, second only to intracerebral hemorrhage. In LTC settings, advanced age, multimorbidity, long-term bed rest, and disability increase the susceptibility of older adults to pneumonia or other infection-related diseases. Older adults in LTC settings worldwide have been disproportionately affected by COVID-19, with high infection and mortality rates [34, 35]. In addition, malnutrition and frailty can weaken the immune response to influenza and pneumococcal vaccines, reducing their effectiveness [26]. Although vaccines may not completely prevent pneumonia, they can significantly reduce its severity and hospitalizations [36]. Similarly, COVID-19 vaccinations have been found to decrease infections in nursing homes or alleviate symptoms [37, 38]. Another study showed that vaccinating LTC residents against respiratory syncytial virus disease would be cost-effective, averting significant direct healthcare costs [39]. Vaccinating LTC residents against respiratory diseases, such as influenza, pneumococcal disease, pertussis, and COVID-19, is a simple, cost-effective, and efficient strategy to reduce the infection burden in this vulnerable population [40]. It is imperative for governments to ensure access to these critical preventive measures and conduct health economic assessments to evaluate their impact.

Implications for long-term care system

In high-income countries, the LTC system has been developed over decades, with the public sector covering at least 70% of formal care costs and maintaining 2 to 4.5 nursing home residents per 100 older adults [41]. However, the COVID-19 crisis in nursing homes has led to changes in the provision of LTC in these countries. Smaller-scale, high-quality group models, such as the Green House Project, provide care in small, self-contained, family-style houses with a limited number of residents. Such models could offer a community-based alternative to traditional nursing homes, potentially reducing the risk of infection [42].

In China, our previous research have demonstrated that the implementation of LTCI can significantly reduce overall mortality, alleviate functional deterioration, and decrease hospitalizations related to infections [43, 44]. These findings have driven continual improvements to the LTCI program, including expanding coverage to moderately disabled individuals, enhancing institutional care, and increasing the availability of basic care at home [45]. However, the risk of malnutrition in the LTC population in China may be more common and easily overlooked. Our research highlights the strong association between inadequate nutrition, infections, increased mortality, and higher healthcare costs. Enhancing nutritional assessments, early identification of sarcopenia, and providing targeted nutritional interventions could reduce infection risks and contribute to the sustainability of the LTC system.

Strengths and limitations

This study is the first to apply disease trajectory analysis to an older disabled population using administrative data from the LTCI program in China. This innovative approach allows for a detailed examination of disease progression patterns, providing valuable insights into the health care needs and resource utilization of this vulnerable population. Despite its contributions, this study has several limitations. First, as only diseases with a prevalence of more than 5% were included in the analysis, this approach limits the identification of disease pairs involving rare medical conditions. Second, the medical expenditure extracted from medical insurance system did not include the cost for outpatient care or LTC services, and lacked sub-analyses of different levels of functional impairment. Finally, the study relied on data from a single pilot city in China, which may limit the generalizability of the findings.

Conclusions

This study comprehensively analyzed disease trajectories and medical expenditures among older disabled adults, revealing that malnutrition and infections collectively account for nearly half of the leading causes of death, with infections incurring the highest medical costs. Future research in the field of LTC should focus on nutritional assessment and interventions, vaccination, and innovative LTC models to prevent infections. The implications of these findings and subsequent recommendations are not only relevant to China but also provide valuable insights for other countries worldwide striving to improve care for their disabled older populations.