Clinically meaningful change: evaluation of the Rasch-built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) and the ALSFRS-R

Abstract

Objective

To investigate clinically meaningful change for ROADS and ALSFRS-R using a patient-defined approach.

Methods

Data were reviewed from participants assessed at the Emory ALS Center from 2019–2022 with two assessments using both ROADS and ALSFRS-R and a completed patient-reported global impression of change scale at the second visit. Minimal important difference (MID), or the smallest amount of change that is clinically relevant, was assessed based on patient reported impression of change for ROADS and ALSFRS-R. Minimal detectable change (MDC), the smallest amount of change exceeding the threshold for measurement error, was assessed for ROADS and ALSFRS-R using standard deviations for participants self-rated as “unchanged”.

Results

Data were included from 162 participants. For ROADS (total possible normed score = 146), MID = 5.81 and MDC = 2.83 points. For ALSFRS-R (total possible sum-score = 48), MID = 3.24 and MDC = 1.59 points. Clinically meaningful decline during the assessment period was observed in 98/162 (60.49%) participants on ROADS and 75/162 (46.30) participants on ALSFRS-R (OR = 1.63, 95% CI [1.0009, 2.66]).

Conclusions

Changes that are on average less than 5.81 points (3.98%) on the normed ROADS score or less than 3.24 points (6.75%) on the ALSFRS-R sum-score may not be clinically meaningful according to a patient-defined approach. Understanding the clinical and statistical limitations of these scales is crucial when designing and interpreting ALS research studies.

Keywords:

• Amyotrophic lateral sclerosis (ALS)
• outcome measures
• Rasch-built Overall ALS Disability Scale (ROADS)
• clinically meaningful change

This article is related to:

Do we really need to calculate a minimal important difference for ALSFRS-R?: A letter in response to ‘Clinically meaningful change: evaluation of the Rasch-built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) and the ALSFRS-R’ published in Vol. 24(3–4), pp. 311–316

Acknowledgements

The authors thank the patients and families of the Emory ALS Clinic and the staff of the Emory ALS Clinic.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Data availability statement

All study data analyses are included within this manuscript. An anonymized version of the dataset used for conduct of this study will be shared upon request to a qualified investigator with institutional review and approval.

Additional information

Funding

This study was funded by the Department of Defense under [grant W81XWH-21-1-0124] and the Department of Veterans Affairs under [grant IK2CX001595-02].