What is the post-stroke mortality rate discriminated by the modified Rankin Scale (mRS)?

From the Guidelines

The modified Rankin Scale (mRS) is a strong predictor of post-stroke mortality, with higher scores correlating with increased mortality risk, as evidenced by recent studies 1.

Post-Stroke Mortality and mRS Scores

Patients with mRS scores of 4-5 (indicating severe disability) have significantly higher mortality rates compared to those with scores of 0-3.

• Specifically, patients with mRS 5 (severe disability requiring constant nursing care) have approximately 50% one-year mortality,
• while those with mRS 4 (moderately severe disability, unable to walk without assistance) have roughly 25-30% one-year mortality. In contrast, patients with mRS 0-2 (no symptoms to slight disability) have much lower mortality rates, generally below 10% at one year. This mortality gradient persists across different stroke types and severity, as supported by studies such as 1 and 1.

Relationship Between mRS and Mortality

The relationship between mRS and mortality is explained by several factors:

• higher mRS scores reflect more severe neurological damage,
• increased risk of complications like pneumonia and deep vein thrombosis,
• reduced mobility leading to deconditioning, and
• often more significant underlying cardiovascular disease. Understanding this relationship helps clinicians provide more accurate prognostic information to patients and families, and appropriately target interventions to those at highest risk of poor outcomes, as highlighted in studies like 1 and 1.

Clinical Implications

Given the strong correlation between mRS scores and post-stroke mortality, clinicians should prioritize the use of mRS scores in assessing stroke patients and guiding treatment decisions.

• This includes using mRS scores to identify patients at high risk of poor outcomes and targeting interventions to improve their prognosis.
• Additionally, clinicians should be aware of the potential complications associated with higher mRS scores and take steps to prevent or manage them, as discussed in studies such as 1 and 1. By prioritizing the use of mRS scores and taking a proactive approach to managing post-stroke complications, clinicians can improve patient outcomes and reduce mortality rates.

From the Research

Post-Stroke Mortality and Modified Rankin Scale

• The modified Rankin Scale (mRS) is a widely used tool to assess the severity of stroke and predict functional outcomes 2, 3, 4.
• Studies have shown that the mRS is a reliable and valid measure of stroke severity and functional disability outcomes 3, 4.
• The mRS has been used to predict mortality and functional outcomes in stroke patients, with higher scores indicating greater disability and higher mortality rates 2, 5.

Association between mRS and Mortality

• Research has demonstrated a positive correlation between mRS scores and mortality rates, with higher mRS scores associated with higher odds of mortality 3, 5.
• A study found that for each point increase in the mRS, the odds of having higher mortality rates were 153% more than the odds of having lower mortality rates (aOR = 2.534,95% CI [1.904,3.560]) 3.
• Another study found that 95% of participants experienced a reduction in mRS after 12 months, and functional recovery was associated with age, prestroke history, and stroke severity 5.

Predictive Value of mRS

• The mRS has been shown to be a predictive tool for functional outcomes and mortality in stroke patients, with a high degree of accuracy 2, 3, 4.
• A study found that the mRS was a reliable tool for predicting functional outcomes in stroke patients, with a positive correlation between mRS scores and functional disability outcomes (rho = 0.866,95% CI [0.751,0.925]) 3.
• Another study found that the mRS was a valuable instrument for assessing the impact of new stroke treatments, with multiple types of evidence attesting to its validity and reliability 4.

Limitations and Future Directions

• While the mRS is a widely used and reliable tool, its limitations include the potential for variability in scoring and interpretation 4, 6.
• Future studies should investigate the use of repeated measures of mRS to assess functional recovery over time, as well as the development of new tools to improve the accuracy and reliability of stroke severity assessment 5, 6.