Using the Barthel Index and modified Rankin Scale as Outcome Measures for Stroke Rehabilitation Trials; A Comparison of Minimum Sample Size Requirements

The Rankin Scale and the Barthel Index are subjective, so should have no place in measuring recovery. 

I consider the Rankin scale useless, not objective except for #6, dead?

Rankin Scale and the Berthel Index ARE NOT DAMAGE DIAGNOSES, they do not give you the 3d location of your dead and damaged neurons. In my opinion, they are FUCKING WORTHLESS to getting you recovered! 

The latest here:

Using the Barthel Index and modified Rankin Scale as Outcome Measures for Stroke Rehabilitation Trials; A Comparison of Minimum Sample Size Requirements

Kris McGill, PhDa kris.mcgill.research@outlook.com ∙ Catherine Sackley, PhDb ∙ Jon Godwin, PhDc ∙ … ∙ Belen Rubio Ballester, PhDe ∙ Marian C Brady, PhDa On behalf of VISTA-Rehabilitation collaborators⁎ … Show more

Abstract

Underpowered trials risk inaccurate results. Recruitment to stroke rehabilitation randomised controlled trials (RCTs) is often a challenge. Statistical simulations offer an important opportunity to explore the adequacy of sample sizes in the context of specific outcome measures. We aimed to examine and compare the adequacy of stroke rehabilitation RCT sample sizes using the Barthel Index (BI) or modified Rankin Scale (mRS) as primary outcomes.

We conducted computer simulations using typical experimental event rates (EER) and control event rates (CER) based on individual participant data (IPD) from stroke rehabilitation RCTs. Event rates are the proportion of participants who experienced clinically relevant improvements in the RCT experimental and control groups. We examined minimum sample size requirements and estimated the number of participants required to achieve a number needed to treat within clinically acceptable boundaries for the BI and mRS.

Results 

We secured 2350 IPD (18 RCTs). For a 90% chance of statistical accuracy on the BI a rehabilitation RCT would require 273 participants per randomised group. Accurate interpretation of effect sizes would require 1000s of participants per group. Simulations for the mRS were not possible as a clinically relevant improvement was not detected when using this outcome measure. Stroke rehabilitation RCTs with large sample sizes are required for accurate interpretation of effect sizes based on the BI. The mRS lacked sensitivity to detect change and thus may be unsuitable as a primary outcome in stroke rehabilitation trials.