Higher prognostic nutritional index linked with lower mortality in older Japanese patients with severe post-stroke dysphagia

A retrospective cohort study found that a higher prognostic nutritional index (PNI), calculated from serum albumin and total lymphocyte count, was associated with lower all-cause mortality among 132 older Japanese patients with severe post-stroke dysphagia who required percutaneous endoscopic gastrostomy or total parenteral nutrition. In the fully adjusted model, each one-point increase in PNI was associated with a 7% lower hazard of death (hazard ratio, or HR, 0.93; 95% confidence interval, or CI, 0.90–0.97).

The analysis used a secondary, publicly accessible dataset originally collected at Miyanomori Memorial Hospital in Sapporo, Japan. Patients entered the study between January 2014 and January 2017, had severe dysphagia and a documented history of stroke, and received either gastrostomy feeding or total parenteral nutrition. A multidisciplinary team of physicians, nurses and speech-language pathologists diagnosed dysphagia through clinical assessment and videofluoroscopic swallowing studies. Of 253 patients in the original cohort, 133 had post-stroke dysphagia; one was excluded because the lymphocyte count needed to calculate PNI was missing, leaving 132 complete cases.

The participants had a mean age of 80.7 years and standard deviation of 10.3 years; 78 were women and 54 were men. Overall, 107 patients received gastrostomy and 25 received total parenteral nutrition. Blood samples used to calculate PNI and the C-reactive protein-to-albumin ratio were collected within seven days before nutritional support began. Follow-up started when nutritional support was initiated and continued until death or the study’s conclusion on February 28, 2018. The primary endpoint was all-cause mortality.

PNI was divided into three groups: below 36.7, 36.7–42.8 and 42.8 or higher. During a median follow-up of 714 days, 61 of the 132 patients died. Observed mortality was 65.9% in the lowest PNI group, 54.5% in the middle group and 18.2% in the highest group. After adjustment for age, sex, feeding modality, severe dementia, aspiration pneumonia, ischemic heart disease and Clinical Frailty Scale score, the highest PNI group had a 75% lower mortality hazard than the lowest group (HR 0.25; 95% CI 0.10–0.60; p=0.002).

Median survival was 247 days in the lowest PNI group and 699 days in the middle group, while it had not been reached in the highest group by the maximum follow-up of 1,463 days. An analysis that did not rely on the proportional-hazards assumption showed increasing restricted mean survival time across the PNI groups. At one year, the difference between the highest and lowest groups was 134 days (95% CI 88–178), and at two years it was 333 days (95% CI 236–424). Restricted cubic spline models found no evidence of a nonlinear association, and Firth penalized Cox regression retained the inverse association between PNI and mortality.

For one-year mortality, the time-dependent area under the receiver operating characteristic curve was numerically higher for PNI alone than for the C-reactive protein-to-albumin ratio, or CAR: 0.771 versus 0.712, although the difference was not statistically significant (p=0.16). Adding PNI to a clinical model significantly improved discrimination and reclassification, with an integrated discrimination improvement of 0.055 (95% CI 0.010–0.104; p<0.001) and a continuous net reclassification improvement of 0.471 (95% CI 0.126–0.957). The clinical model included age, sex, feeding modality, severe dementia, aspiration pneumonia, ischemic heart disease and frailty.

Adding PNI improved model fit and discrimination, raising the C-index from 0.800 to 0.821 and reducing the Brier score from 0.160 to 0.145. PNI also added significant information to a model that already contained CAR (likelihood-ratio χ²=8.00; p=0.005). By contrast, CAR did not significantly improve a PNI-containing model (χ²=0.25; p=0.62), indicating that the analysis did not detect additional information from CAR once PNI was included. Bootstrap internal validation with 500 resamples showed minimal optimism, with an apparent C-index of 0.821 and an optimism-corrected C-index of 0.810.

The inverse association between PNI and mortality was consistent in subgroup analyses based on age, sex, gastrostomy status, severe dementia, aspiration pneumonia and ischemic heart disease, with no significant interactions. Results were also similar in sensitivity analyses using an alternative PNI cutoff and after excluding deaths within the first 30 days. The authors noted that albumin and lymphocyte counts are influenced by inflammation, infection, hydration, chronic illness and acute stress, so PNI should be interpreted as an integrative marker rather than a pure measure of nutrition.

The findings are limited by the selected single-center population, which included older Japanese patients with severe dysphagia: 81% received gastrostomy and 86% had a Clinical Frailty Scale score of at least 8. PNI was measured only once, and data on stroke subtype, severity, timing and lesion location were unavailable. Because cerebrovascular disease was recorded only as a binary variable, the analysis could not establish that stroke was the sole cause of dysphagia or exclude competing contributors such as dementia, neurodegeneration or deconditioning. Residual confounding also cannot be ruled out. With 61 deaths relative to the number of covariates, the estimates require cautious interpretation, and the authors state that prospective and external validation are needed before PNI can be considered for risk stratification in this population.

Subject of Research: Association of prognostic nutritional index with mortality in older adults with severe post-stroke dysphagia

Article Title: Association between prognostic nutritional index and mortality in older Japanese patients with severe post-stroke dysphagia requiring nutritional support: a retrospective cohort study

Article References: Wu, W., & Wang, J. (2026). Association between prognostic nutritional index and mortality in older Japanese patients with severe post-stroke dysphagia requiring nutritional support: a retrospective cohort study. Frontiers in Neurology, 17, Article 1902644. https://doi.org/10.3389/fneur.2026.1902644

Image Credits: AI Generated

DOI: 10.3389/fneur.2026.1902644

Keywords: prognostic nutritional index, post-stroke dysphagia, mortality, older adults, nutritional support, dysphagia, C-reactive protein, albumin, retrospective cohort, Association, between, prognostic