# Negative association of hemoglobin levels with mortality in older Japanese patients with dysphagia: a retrospective cohort study

## TL;DR

Higher hemoglobin levels in older Japanese patients with swallowing difficulties are linked to lower risk of death.

## Contribution

Demonstrates a strong inverse association between hemoglobin levels and mortality in older patients with dysphagia.

## Key findings

- Each 1 g/dL increase in hemoglobin reduced mortality risk by 14% after adjusting for covariates.
- Patients in the highest hemoglobin tertile had over twice the median survival of those in the lowest tertile.
- Subgroup analyses confirmed consistent results without significant interactions.

## Abstract

This secondary analysis aimed to examine the association between hemoglobin levels and mortality in older Japanese individuals with dysphagia.

Data from 253 patients with clinically confirmed dysphagia between January 2014 and January 2017 were analyzed. Participants were divided into three tertiles based on their hemoglobin levels (T1: 5.4–10.2 g/dL; T2: 10.2–12.0 g/dL; T3: ≥12.0 g/dL). Cox proportional hazards regression was used to evaluate mortality risk, supplemented by Kaplan–Meier survival analysis and subgroup interaction assessments.

The study included 154 female and 99 male patients, with a median age of 83 years. The cohort demonstrated a significant inverse relationship between hemoglobin levels and mortality. After full covariate adjustment, each 1 g/dL increase in hemoglobin level corresponded to a 14% mortality risk reduction (HR = 0.86, 95% CI: 0.77–0.97, P = 0.013). Compared to T1, adjusted hazard ratios for T2 and T3 were 0.53 (95% CI: 0.34–0.84, P = 0.007) and 0.48 (95% CI: 0.27–0.83, P = 0.009), respectively (P for trend = 0.005). Median survival differed significantly across tertiles: 212 days (T1), 540 days (T2), and >1463 days (T3) (P < 0.0001). Subgroup analyses confirmed the robustness without significant interactions.

Hemoglobin concentration was independently and inversely associated with mortality in older Japanese patients with dysphagia. These findings underscore the prognostic value of hemoglobin in this population.