Effect of mild hyponatremia on in-hospital falls of elderly hospitalized patients: A retrospective, cohort study.

OBJECTIVES: This study investigated the association between hyponatremia and falls in elderly hospitalized patients, focusing on mild hyponatremia as a potential risk factor. MATERIALS AND METHODS: A retrospective analysis of 16,952 patients admitted to Kochi Medical School Hospital from 2012 to 2021 was performed. Serum sodium levels were categorized, and falls during a 30-day observation period were recorded. A Cox proportional hazards model and a machine learning model were used to estimate risk and explore interactions. RESULTS: Mild hyponatremia (130-134 mEq/L) was identified as an independent risk factor for falls (hazard ratio: 1.42, 95 % confidence interval 1.16-1.74), especially in patients with higher activities of daily living. The fall prediction model showed an area under the curve (AUC) of 0.780 (95 % confidence interval 0.751-0.806). CONCLUSION: A significant association between mild hyponatremia and falls in elderly hospitalized patients was found. The findings highlight the need for targeted fall prevention and further research into the underlying mechanisms. Mild hyponatremia may serve as a clinical marker for fall risk, especially in patients with independent activities of daily living.

Effects of renin-angiotensin system inhibitor and beta-blocker use on mortality in older patients with heart failure with reduced ejection fraction in Japan.

Introduction: Guideline-directed medical therapy with renin-angiotensin system (RAS) inhibitors and beta-blockers has improved the survival of patients with heart failure (HF) and reduced left ventricular ejection fraction (HFrEF). However, it is unclear whether RAS inhibitors and beta-blockers can be administered to older patients with HF. Therefore, this study aimed to investigate the effects of beta-blockers and RAS inhibitors on the prognosis of older patients with HFrEF. Methods: Demographic, clinical, and pharmacological data from 1,061 patients with acute decompensated HF, enrolled in the Kochi Registry of Subjects with Acute Decompensated Heart Failure (Kochi YOSACOI study), were analyzed to assess their impact on mortality. Additionally, a machine learning approach was applied to complement the conventional statistical model for analysis. Patients with HFrEF (n = 314) were divided into the all-cause mortality within 2 years group (n = 80) and the survivor group (n = 234). Results: Overall, 41.1% (129/314) of the patients were aged ≥80, and 25.5% (80/314) experienced all-cause mortality within 2 years. Furthermore, 57.6% (181/314) and 79.0% (248/314) were prescribed RAS inhibitors and beta-blockers, respectively. Our analysis showed that RAS inhibitor use was associated with reduced all-cause mortality and cardiac death in patients with HFrEF of all ages (P < 0.001), and beta-blocker use had an interaction with age. Machine learning revealed that the use of beta-blockers altered the risk of mortality, with a threshold of approximately 80 years of age. Beta-blocker use was associated with lower all-cause mortality and cardiac death in patients with HFrEF aged <80 years (P < 0.001) but not in those aged ≥80 years (P = 0.319 and P = 0.246, respectively). These results suggest that beta blockers may differ in their all-cause mortality benefits according to age. Conclusions: RAS inhibitors prevented all-cause mortality and cardiac death at all ages, whereas beta-blockers had different effects depending on the patient's age. This study suggested that the choice of beta-blockers and RAS inhibitors is more important in older patients with HFrEF than in younger patients with the same condition.

Impact of areal socioeconomic status on prehospital delay of acute ischaemic stroke: retrospective cohort study from a prefecture-wide survey in Japan.

OBJECTIVES: To examine whether the Areal Deprivation Index (ADI), an indicator of the socioeconomic status of the community the patient resides in, is associated with delayed arrival at the hospital and poor outcomes in patients with acute ischaemic stroke from a prefecture-wide stroke database in Japan. DESIGN: Retrospective study. SETTING: Twenty-nine acute stroke hospitals in Kochi prefecture, Japan. PARTICIPANTS: Nine thousand and six hundred fifty-one patients with acute ischaemic stroke who were urgently hospitalised, identified using the Kochi Acute Stroke Survey of Onset registry. Capital and non-capital areas were analysed separately. PRIMARY AND SECONDARY OUTCOME MEASURES: Prehospital delay defined as hospital arrival ≥4-hour after stroke onset, poor hospital outcomes (in-hospital mortality and discharge to a nursing facility) and the opportunities of intravenous recombinant tissue plasminogen activator (rt-PA) and endovascular reperfusion therapy. RESULTS: In the overall cohort, prehospital delay was observed in 6373 (66%) patients. Among individuals residing in non-capital areas, those living in municipalities with higher ADI (more deprived) carried a significantly higher risk of prehospital delay (per one-point increase, OR (95% CI) 1.45 (1.26 to 1.66)) by multivariable logistic regression analysis. In-hospital mortality (1.45 (1.02 to 2.06)), discharge to a nursing facility (1.31 (1.03 to 1.66)), and delayed candidate arrival ≥2-hour of intravenous rt-PA (2.04 (1.30 to 3.26)) and endovascular reperfusion therapy (2.27 (1.06 to 5.00)), were more likely to be observed in the deprived areas with higher ADI. In the capital areas, postal-code-ADI was not associated with prehospital delay (0.97 (0.66 to 1.41)). CONCLUSIONS: Living in socioeconomically disadvantaged municipalities was associated with prehospital delays of acute ischaemic stroke in non-capital areas in Kochi prefecture, Japan. Poorer outcomes of those patients may be caused by delayed treatment of intravenous rt-PA and endovascular reperfusion therapy. Further studies are necessary to determine social risk factors in the capital areas. TRIAL REGISTRATION NUMBER: This article is linked to a clinical trial to UMIN000050189, No.: R000057166 and relates to its Result stage.