Abstract
Background
Down syndrome is the most common genetic disorder, and the life expectancy of patients with Down syndrome has increased over the decades. However, the diseases and social problems experienced by patients with Down syndrome remain unknown in Japan. Therefore, we aimed to investigate the disease status of such patients admitted to acute care hospitals in Japan.
Methods
This observational study was conducted using the Diagnosis Procedure Combination data from 2016 to 2021 to evaluate routes of admission, principal diagnoses, comorbidity of dementia, orthopedic surgeries for limb fractures, and discharge destinations of patients with Down syndrome (International Classification of Diseases, Tenth Revision code: Q90).
Results
Overall, 26,195 individuals with Down syndrome were included, of whom 5195 were ≥20 years of age. As the age increased, the number of admissions from home decreased and that from nursing homes increased. Pneumonia was the most common principal diagnosis, with the incidence of aspiration pneumonia increasing in patients >40 years of age. We observed an increase in the incidence of dementia and surgery for limb fractures after 40 years of age. The number of discharges to home decreased with increasing age, whereas that to nursing homes increased with increasing age.
Conclusions
These results suggest that patients with Down syndrome are often hospitalized because of pneumonia and that the incidence of aspiration pneumonia, dementia, and limb fractures increases after 40 years of age. Therefore, a system to prevent pneumonia, especially aspiration pneumonia, and limb fractures in patients with Down syndrome is needed.
Keywords: aging society, Diagnosis Procedure Combination, Down syndrome, observational study, pneumonia
1. INTRODUCTION
Down syndrome (DS) is the most common genetic disorder caused by an abnormality in chromosome 21, with a frequency of approximately 22 per 10,000 live births in Japan. 1 DS includes standard trisomy 21 DS, translocation DS, and mosaic DS, which are observed in approximately 95%, 3%, and 2% of patients with DS, respectively. 2 DS is associated with an increased risk of congenital heart disease, respiratory infection, hearing impairment and intellectual disability, leukemia, sleep disorders, autoimmune diseases, musculoskeletal disorders, neurodevelopmental disorders, and dementia. 3 In general, patients with DS age faster and have an increased risk of dementia, bone fractures, epilepsy, and visual impairment. 4 , 5
Although the average life expectancy of patients with DS was 30 years in 1973, it reached 60 years in 2002. 3 In Japan, the life expectancy of patients with DS has been increasing over the decades, and a previous study has reported that one of every three individuals with DS in Japan is >60 years of age. 6 It has also been suggested that the development of medical and welfare services may further extend the life expectancy of this patient population. 6
In Japan, the understanding of DS in childhood and available medical treatments for this condition have significantly improved; however, there are few reports on the diseases and social problems that frequently occur in adults with DS. 6 , 7 , 8 As the average life expectancy of patients with DS has been increasing, it is important to understand the medical and social problems experienced by patients with DS.
Therefore, in this study, we aimed to clarify the disease status of patients with DS admitted to acute care hospitals in Japan.
2. METHODS
2.1. Study design and data source
This retrospective observational study was conducted using the Diagnosis Procedure Combination (DPC) data from April 1, 2016, to March 31, 2021. The details regarding the DPC data have been described in a previous study. 9 The DPC data include the following information on hospitalized patients: (1) basic patient information, such as gender, age, and admission/discharge route; (2) information on the disease; and (3) information on the medical procedures performed during hospitalization. The data were collected by the DPC research group and covered approximately 90% of all tertiary‐care emergency hospitals in Japan. 10 This study was conducted with the approval of the local institutional review board (R4‐045), which waived the requirement for informed consent from the patients.
2.2. Inclusion and exclusion criteria
Patients with DS (International Classification of Diseases, Tenth Revision [ICD‐10] code: Q90) and associated comorbidities at the time of admission from 1073 hospitals were included in this study (N = 26,211). Of these patients, 26,195 were included in the analysis, excluding those whose principal diagnosis at the time of hospitalization was unknown.
2.3. Routes of hospital admission
In the DPC data, the route of hospitalization was selected as follows: (1) admission from home; (2) transfer from a nursing home or welfare facility; (3) transfer from a ward in another hospital or clinic; (4) birth in the hospital; (5) transfer from another ward in the hospital; or (6) others. In this study, patients admitted through (1) were categorized under “hospitalization from home,” those admitted through (2) were categorized under “hospitalization from nursing homes,” and those admitted through (3) were categorized under “hospitalization from other hospitals.” Patients admitted through (4–6) were categorized under “Others.”
2.4. Principal diagnosis
The principal diagnosis was identified using the DPC code. The details regarding the DPC codes have been described in a previous study. 9 Briefly, the DPC code consists of 14 digits, of which the first six indicate the principal diagnosis of the patient. The principal diagnosis is defined on the basis of the ICD‐10 code for each disease. In this study, the first six digits of the DPC code were used to define the precipitating diagnosis. The corresponding ICD‐10 codes are shown in Table S1.
2.5. Comorbidity of dementia
On the basis of a previous study, 11 in this study, dementia was defined according to the ICD‐10 codes as F00.x, dementia of Alzheimer's type; F03.x, dementia with unknown details; F05.1, delirium, overlapping dementia; G30.x, Alzheimer's disease; and G31.1, senile brain degeneration, not elsewhere classified. We classified dementia as dementia of Alzheimer's type (F00.x) and other dementias (F03.x, F05.1, G30.x, and G31.1) in this study. The frequency of the comorbidities of dementia of Alzheimer's type and other dementias is shown in Figure S1.
2.6. Orthopedic surgery
Falls are a serious problem in older individuals but cannot be directly evaluated using DPC data. However, because limb fractures, which are one of the main consequences of falls, can be evaluated using DPC data, we investigated the status of limb fractures in this study. A limb fracture was defined as a case in which reimbursement for surgery for the limb fracture was claimed. The evaluated surgeries performed for limb fractures are summarized in Table S2. We consulted orthopedic surgeons for advice on this definition.
2.7. Discharge destination
Except for patients who were discharged because of death, the destination of discharge in the DPC data was selected on the basis of the following: (1) discharge to home, (2) admission to a health care facility for older individuals requiring long‐term care, (3) admission to a welfare facility for older persons requiring long‐term care, (4) admission to a social welfare facility or a fee‐based nursing home, (5) admission to an integrated facility for medical and long‐term care, (6) transfer to another hospital or clinic, (7) transfer to another ward in the hospital, and (8) others. In this study, patients discharged according to (1) were categorized under “discharge to home,” those discharged according to (2–5) were categorized under “discharge to a nursing home,” those discharged according to (6) were categorized under “transfer to another hospital,” and those discharged according to (7, 8) were categorized under “Others.”
2.8. Other variables
In this study, patients' gender, age (0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years), area of residence (Hokkaido, Tohoku, Kanto, Chubu, Kinki, Chugoku/Shikoku, and Kyushu/Okinawa), and fiscal year were used as basic patient information.
2.9. Statistical analyses
We performed a descriptive epidemiological analysis by age group. First, we analyzed the admission routes by age group. In addition, we used the Cochran–Armitage trend test to identify the trends between age groups and the proportion of admissions from homes, as well as between age and the proportion of admissions from nursing homes. Age 0 years was excluded from the trend test because it included several births in the hospitals.
Second, we analyzed the principal diagnosis by age. We evaluated the diagnoses of all patients with an incidence rate of ≥1%. The incidence of the diagnosis was evaluated by age group. For each diagnosis, we further investigated the number and percentage per age group. However, data‐handling regulations prohibit the publication of fewer than 10 cases; therefore, such data were masked. As an auxiliary measure, we identified the top 10 diseases by age group (Table S3).
Third, we evaluated the number of comorbidities of dementia and surgeries performed for limb fractures in all patients. We also assessed whether there is a trend between the age of the patients and incidence rate of these diagnoses using the trend test.
Finally, we analyzed the discharge destinations of patients who were hospitalized in their homes by age. For these patients, we used the trend test to determine whether there is a trend between age and discharge to a nursing home.
We used Stata Statistical Software MP18.0 (Release 16; StataCorp LLC, College Station, TX, USA) for all statistical analyses, and the statistical significance level was set at <5%.
3. RESULTS
Table 1 shows the basic information of all patients. Of the 26,195 patients, 5195 (19.8%) were ≥20 years of age, and approximately 80% of patients were admitted from home.
TABLE 1.
Baseline characteristics of all participants.
| N = 26,195 | |
|---|---|
| Age (years) | |
| 0 | 7556 (28.8%) |
| 1–9 | 11,110 (42.4%) |
| 10–19 | 2334 (8.9%) |
| 20–29 | 1152 (4.4%) |
| 30–39 | 1050 (4.0%) |
| 40–49 | 1188 (4.5%) |
| 50–59 | 1061 (4.1%) |
| ≥60 | 744 (2.8%) |
| Male gender | 15,176 (57.9%) |
| Residential area | |
| Hokkaido | 1069 (4.1%) |
| Tohoku | 1882 (7.2%) |
| Kanto | 7878 (30.1%) |
| Chubu | 4012 (15.3%) |
| Kinki | 4392 (16.8%) |
| Chugoku/Shikoku | 2349 (9.0%) |
| Kyushu/Okinawa | 4613 (17.6%) |
| Place before admission | |
| Home | 20,727 (79.1%) |
| Nursing home | 1548 (5.9%) |
| Other hospital | 2301 (8.8%) |
| Others | 1619 (6.2%) |
| Fiscal year | |
| 2016 | 5947 (22.7%) |
| 2017 | 5421 (20.7%) |
| 2018 | 5565 (21.2%) |
| 2019 | 5269 (20.1%) |
| 2020 | 3993 (15.2%) |
Figure 1 shows the routes of admission according to the age group. Overall, 55.8%, 96.6%, 96.7%, 94.1%, 84.6%, 69.4%, 47.8%, and 28.6% of the patients with ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively, were admitted from home, indicating that the percentage of patients admitted from home decreased with increasing age (p < 0.001). By contrast, 0.5%, 0.8%, 0.6%, 3.2%, 9.0%, 25.1%, 46.4%, and 65.9% of the patients with ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively, were admitted from a nursing home, indicating that the percentage of admissions from nursing homes increased with increasing age (p < 0.001).
FIGURE 1.
Routes of admission by age group.
Table 2 shows the percentage of principal diagnoses by age group. Pneumonia was the most common primary diagnosis in patients 1–49 years of age. The incidence of aspiration pneumonia increased in patients with ages 40–49 (6.8%), 50–59 (15.0%), and 60 (27.0%) years and was the most common diagnosis in patients ≥50 years of age. The incidence of epilepsy also increased in patients ≥40 years of age (40–49 years, 4.6%; 50–59 years, 10.5%; and ≥60 years, 6.1%). Epilepsy was the fourth most common primary diagnosis in patients 40–49 and 60 years of age and the third most common primary diagnosis in those 50–59 years of age. Cataract and lens diseases were the second most common primary diagnoses in patients 30–39 (7.1%) and 40–49 (7.7%) years of age.
TABLE 2.
Major resource‐consuming diagnoses of patients with DS.
| Total (n = 26,195) | 0 years (n = 7556) | 1–9 years (n = 11,110) | 10–19 years (n = 2334) | 20–29 years (n = 1152) | 30–39 years (n = 1050) | 40–49 years (n = 1188) | 50–59 years (n = 1061) | ≥60 years (n = 744) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | n | % | n | % | n | % | n | % | n | % | n | % | |
| Congenital heart disease (excluding patent ductus arteriosus and atrial septal defect) | 3457 | 13.2 | 2123 | 28.1 | 1135 | 10.2 | 150 | 6.4 | 20 | 1.7 | 14 | 1.3 | 12 | 1.0 | ‐ | ‐ | ||
| Pneumonia | 2876 | 11.0 | 320 | 4.2 | 1749 | 15.7 | 222 | 9.5 | 112 | 9.7 | 118 | 11.2 | 131 | 11.0 | 132 | 12.4 | 92 | 12.4 |
| Acute bronchitis, acute bronchiolitis, and lower respiratory infection (others) | 1443 | 5.5 | 331 | 4.4 | 1018 | 9.2 | 60 | 2.6 | 14 | 1.2 | 11 | 1.1 | ‐ | ‐ | ‐ | |||
| Chromosome abnormality (excluding Turner syndrome and Klinefelter syndrome) | 1402 | 5.4 | 1059 | 14.0 | 164 | 1.5 | 79 | 3.4 | 28 | 2.4 | 15 | 1.4 | 19 | 1.6 | 27 | 2.5 | 11 | 1.5 |
| Disorders related to the shortened duration of pregnancy and low birth weight | 1209 | 4.6 | 1207 | 16.0 | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | |||||||
| Asthma | 851 | 3.3 | 154 | 2.0 | 673 | 6.1 | 13 | 0.6 | ‐ | ‐ | ‐ | ‐ | ‐ | |||||
| Acute leukemia | 817 | 3.1 | 63 | 0.8 | 435 | 3.9 | 212 | 9.1 | 78 | 6.8 | 21 | 2.0 | ‐ | ‐ | ‐ | |||
| Influenza and viral pneumonia | 738 | 2.8 | 129 | 1.7 | 556 | 5.0 | 25 | 1.1 | ‐ | ‐ | ‐ | ‐ | ‐ | |||||
| Virus enteritis | 733 | 2.8 | 95 | 1.3 | 458 | 4.1 | 71 | 3.0 | 48 | 4.2 | 30 | 2.9 | 17 | 1.4 | 11 | 1.0 | ‐ | |
| Patent ductus arteriosus and atrial septal defect | 729 | 2.8 | 395 | 5.2 | 299 | 2.7 | 20 | 0.9 | ‐ | ‐ | ‐ | ‐ | ‐ | |||||
| Aspiration pneumonia | 696 | 2.7 | 61 | 0.8 | 96 | 0.9 | 34 | 1.5 | 32 | 2.8 | 32 | 3.1 | 81 | 6.8 | 159 | 15.0 | 201 | 27.0 |
| Epilepsy | 596 | 2.3 | 106 | 1.4 | 143 | 1.3 | 66 | 2.8 | 35 | 3.0 | 35 | 3.3 | 55 | 4.6 | 111 | 10.5 | 45 | 6.1 |
| Pulmonary hypertension | 426 | 1.6 | 146 | 1.9 | 196 | 1.8 | 17 | 0.7 | 15 | 1.3 | 31 | 3.0 | 16 | 1.4 | ‐ | ‐ | ||
| Respiratory failure (others) | 398 | 1.5 | 85 | 1.1 | 262 | 2.4 | 29 | 1.2 | ‐ | ‐ | ‐ | ‐ | ‐ | |||||
| Otitis media with effusion, eustachitis, and eustachian tube obstruction | 360 | 1.4 | 11 | 0.2 | 287 | 2.6 | 48 | 2.1 | 12 | 1.0 | ‐ | ‐ | ‐ | ‐ | ||||
| Kidney or urinary tract infection | 340 | 1.3 | 86 | 1.1 | 87 | 0.8 | 36 | 1.5 | ‐ | 12 | 1.1 | 26 | 2.2 | 38 | 3.6 | 46 | 6.2 | |
| Upper airway inflammation | 338 | 1.3 | 73 | 1.0 | 229 | 2.1 | 26 | 1.1 | ‐ | ‐ | ‐ | ‐ | ‐ | |||||
| Cataract and lens disease | 332 | 1.3 | 8 | 0.1 | 14 | 0.1 | 16 | 0.7 | 39 | 3.4 | 74 | 7.1 | 91 | 7.7 | 72 | 6.8 | 18 | 2.4 |
| Inflammation of esophagus, stomach, duodenum, and other intestines (other benign diseases) | 325 | 1.2 | 50 | 0.7 | 127 | 1.1 | 79 | 3.4 | 23 | 2.0 | 16 | 1.5 | 20 | 1.7 | ‐ | ‐ | ||
| Heart failure | 280 | 1.1 | 36 | 0.5 | 30 | 0.3 | ‐ | 79 | 6.9 | 42 | 4.0 | 50 | 4.2 | 28 | 2.6 | 10 | 1.3 | |
| Anorectal anomaly and Hirschsprung disease | 261 | 1.0 | 199 | 2.6 | 55 | 0.5 | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ||||||
Abbreviation: DS, Down syndrome.
Figure 2 shows the frequency of comorbid dementia and the number of surgeries performed for limb fractures by age group. The comorbidity rate of dementia was 0.0%, 0.0%, 0.0%, 0.2%, 0.2%, 3.6%, 9.6%, and 20.4% in patients with ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively. The incidence of surgery for a limb fracture was 0.0%, >0.1%, 0.4%, 0.4%, 0.9%, 2.5%, 2.4%, and 3.8% in patients with ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively.
FIGURE 2.
Comorbidities of dementia and surgeries performed for limb fractures by age group.
These results indicate an increasing trend in both the rate of comorbid dementia and that of surgery for limb fractures with increasing age (p < 0.001).
Figure 3 shows the discharge destinations by age group for patients admitted from home. The percentage of patients discharged to homes was 95.4%, 98.0%, 97.3%, 93.8%, 89.4%, 82.2%, 72.6%, and 61.0% at ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively. These results suggest a decreasing trend in the percentage of patients discharged to homes with increasing age (p < 0.001). By contrast, 0.1%, 0.1%, >0.1%, 0.4%, 0.7%, 3.4%, 8.3%, and 17.4% of the patients with ages 0, 1–9, 10–19, 20–29, 30–39, 40–49, 50–59, and ≥60 years, respectively, were discharged to a nursing home. These results suggest an increasing trend in the rate of discharge to nursing homes with increasing age (p < 0.001).
FIGURE 3.
Discharge destination by age group among patients admitted from home (n = 20,727).
4. DISCUSSION
In this study, using the DPC data, we examined the principal diagnosis, frequency of dementia comorbidity, orthopedic surgeries, and admission and discharge routes of patients with DS.
Pneumonia was the most common principal diagnosis in adult patients with DS, and aspiration pneumonia was the most common principal diagnosis in patients ≥50 years of age. The frequency of dementia and the number of orthopedic surgeries performed for limb fractures tended to increase after the age of 40 years. Age‐specific admission routes and discharge destinations of patients with DS were also revealed.
4.1. Route of admission
Admissions from nursing homes increased with age. Similar results have been reported in a previous study, 12 suggesting that the living environment of patients with DS changes with age. Factors leading to this phenomenon include a decline in the caregiving ability of caregivers owing to their increasing age and bereavement. In addition, the prevalence of dementia and seizures increases with age in patients with DS. 12 Caregivers may not cope with these problems at home and are shifting the living places of patients with DS to facilities where specialized care is available. In the future, it will be important to take measures to support home care, focusing on the issues of older patients with DS, and to secure facilities that can provide comprehensive care, including medical care.
4.2. Principal diagnosis
Pneumonia was the most common principal diagnosis in patients with DS 1–49 years of age. Pneumonia is a lifelong problem in these patients, 13 and the results of this study are consistent with this assertion. Interestingly, the incidence of aspiration pneumonia increased after the age of 40 years and was the most common principal diagnosis after the age of 50 years. Respiratory syncytial virus often causes pneumonia in childhood and is problematic because of the high risk of severe disease. 13 , 14 This study suggests that the cause of pneumonia changes with age.
Two factors contribute to the increased incidence of aspiration pneumonia: dysphagia and cognitive decline. Patients with DS are more prone to dysphagia owing to impaired tongue movement. 15 Although researchers believe that dysphagia in children with DS is caused by anatomical factors and improves with growth, some studies have shown that it also persists in adulthood. 16 The risk of aspiration pneumonia increases with a decline in swallowing function associated with aging.
Furthermore, in this study, the frequency of dementia‐related complications also increased in the age group in which the rate of aspiration pneumonia increased. Control of respiratory complications and dementia is useful in patients with DS, 17 and the early detection of dementia helps reduce the risk of respiratory complications. These results suggest that the prevention of pneumonia is important in all age groups, especially in adulthood, and that the prevention of aspiration plays an important role.
4.3. Comorbidities of dementia
The prevalence of dementia increased after the age of 40 years. The prevalence of both dementia of Alzheimer's type and other dementias increased similarly. This result is consistent with that reported in previous studies showing an increased risk of Alzheimer's disease after the age of 40 years. 18 , 19 Patients with DS are histopathologically at risk for Alzheimer's disease, 3 and screening for dementia is recommended for those >40 years of age. 19 The results of this study suggest that early detection of dementia is important in patients >40 years of age with DS in Japan. However, it is difficult to assess cognitive function in patients with DS, especially with intellectual disability. 20 Therefore, family members, caregivers, and medical staff should pay particular attention to changes in the activities of daily living in patients with DS to detect cognitive decline at an early stage. 21 It may also be beneficial to pay attention to the incidence of epileptic seizures. The occurrence of seizures at the age of ≥45 years is associated with an increased risk for dementia. 3 The incidence of first seizure at the age of 40–45 years may indicate Alzheimer's disease. 22 In this study, epilepsy was one of the most common principal diagnoses in patients with DS in their 40s and 50s, suggesting that epilepsy is associated with dementia. These results suggest that patients with DS are at an increased risk of cognitive dysfunction at a younger age than the general population. Hence, in patients ≥40 years of age with epilepsy, cognitive symptoms should be considered.
4.4. Orthopedic surgery
The number of surgeries related to limb fractures increased after the age of 40 years, and hip and proximal femoral fractures were among the principal diagnoses after the age of 50 years. The prevalence of functional disability increased after the age of 40 years in patients with DS. 23 The increase in the number of fractures after the age of 40 years may reflect the increase in the number of falls associated with a decline in physical function. The average age at which hip fractures occur in the general population is in the 80s, and the associated risk factors include falls and decreased bone mineral density 24 ; hip fractures are more likely to occur at a younger age in patients with DS, suggesting that patients >40 years of age with DS, in particular, need to be more vigilant about falls. Epileptic seizures can also cause fractures in patients with DS. 25 In this study, there was no significant difference in the incidence of fractures and pneumonia in patients >40 years of age with DS with or without dementia.
However, the prevalence of dementia increased in these patients after 40 years of age, indicating the importance of preventing fractures due to wandering and falls caused by cognitive decline. Furthermore, in this study, several patients in their 30s and 40s were hospitalized for cataract and lens diseases, suggesting that vision loss is also a cause of falls and requires attention.
4.5. Discharge destination
In this study, we focused on admission from home. The proportion of discharges to other hospitals and nursing homes increased after 30 and 40 years of age, respectively. Furthermore, the proportion of patients discharged to nursing homes also increased after 40 years of age. After the age of 40 years, approximately 80% of patients with DS admitted from home were discharged to home; this proportion decreased with age. The associated factors include the burden of care at home and decline in caregivers' abilities. In addition, respiratory diseases and fractures require rehabilitation, making home discharge difficult. The rate of use of rehabilitation therapy for adult patients with DS during hospitalization for pneumonia is low 26 ; establishment of an appropriate system to address this issue may be beneficial and facilitate easier discharge to home. Cognitive decline is another factor that renders living at home difficult, and a system that supports the care of adult patients with DS and dementia is necessary.
4.6. Limitations
First, this study was validated using DPC data; hence, not all patients with DS in Japan were included. The DPC data we used cover more than 50% of all the acute‐care hospitals. In particular, the coverage rate has reached approximately 90% for the tertiary‐care emergency hospitals in Japan. 8 However, the data do not cover to non‐tertiary hospitals or community settings, which may limit the generalizability of the results.
Second, environmental factors such as patient background, family structure, and caregivers cannot be ascertained using the DPC data. Evaluating the influence of patient background on the discharge destination is important.
Third, when dementia is defined using ICD‐10 codes in DPC studies, the specificity is high, although the sensitivity may be low. 27 Therefore, the frequency of comorbid dementia may be underestimated.
Fourth, it is difficult to determine whether the admissions are related when the medical institution changes using DPC data. However, readmissions within 7 days are considered a part of the same admission episode.
4.7. Conclusions
Using the DPC data, we examined the route of admission, comorbidity of dementia, principal diagnoses, rate of orthopedic surgery, and discharge destination in patients with DS hospitalized in acute care hospitals in Japan. The most common principal diagnosis in these patients was aspiration pneumonia; hence, the prevention of pneumonia is important. Dementia and limb fractures are more common in patients in their 40s, and it is necessary to recognize that patients with DS develop dementia at a younger age than those without DS. These results suggest that care is needed to prevent pneumonia, especially aspiration pneumonia, and falls, which can lead to limb fractures in patients with DS.
AUTHOR CONTRIBUTIONS
K.Y. designed the study, analyzed the data, and drafted the manuscript. R.M. designed the study, analyzed the data, and drafted the figures. K.M. critically reviewed the manuscript and provided intellectual and conceptual advice. S.M. critically reviewed the manuscript and supervised the study. All authors read and approved the final manuscript.
CONFLICT OF INTEREST STATEMENT
K.Y, R.M., and K.M declare no conflict of interests for this article. S.M. received honoraria and research funds from Chugai Pharmaceutical Company.
ETHICS APPROVAL STATEMENT
This study was conducted with the approval of the institutional review board of the University of Occupational and Environmental Health, Japan (R4‐045), which waived the requirement for informed consent from the patients.
Supporting information
Data S1.
ACKNOWLEDGMENTS
This study was funded by a Health Labour Sciences Research Grant from the Ministry of Health, Labour, and Welfare of Japan (grant number: H30‐Policy‐Designation‐004).
Yasunami K, Matsugaki R, Muramatsu K, Matsuda S. Hospitalization of patients with Down syndrome in acute care hospitals in Japan. J Gen Fam Med. 2025;26:135–142. 10.1002/jgf2.746
DATA AVAILABILITY STATEMENT
The datasets used and/or analyses conducted during the current study are not publicly available for ethical reasons. The datasets are available from the corresponding author upon reasonable request and with ethical approval.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data S1.
Data Availability Statement
The datasets used and/or analyses conducted during the current study are not publicly available for ethical reasons. The datasets are available from the corresponding author upon reasonable request and with ethical approval.