calculate_edss: Expanded Disability Status Scale (EDSS) Calculator

In cliot: Clinical Indices and Outcomes Tools

Expanded Disability Status Scale (EDSS) Calculator

Description

Calculates the EDSS score based on Kurtzke's Functional Systems Scores (FSS) and ambulation status. The scale ranges from 0.0 (normal) to 10.0 (death). Steps 0-4.5 are determined by FSS combinations, while steps 5.0-9.5 are defined primarily by impairment to ambulation.

Usage

calculate_edss(pyramidal, cerebellar, brainstem, sensory, bowel_bladder,
               visual, cerebral, ambulation_code)

Arguments

pyramidal	Numeric (0-6). Pyramidal function score.
cerebellar	Numeric (0-5). Cerebellar function score.
brainstem	Numeric (0-5). Brainstem function score.
sensory	Numeric (0-6). Sensory function score.
bowel_bladder	Numeric (0-6). Bowel and Bladder function score.
visual	Numeric (0-6). Visual function score.
cerebral	Numeric (0-5). Cerebral (Mental) function score.
ambulation_code	Numeric (0-11). Ambulation status code: 0: Unrestricted / Walks > 500m without aid. 1: Walks > 300m without aid (Step 4.5 range). 2: Walks > 200m without aid (Step 5.0 range). 3: Walks > 100m without aid (Step 5.5 range). 4: Unilateral assistance >= 100m (Step 6.0). 5: Bilateral assistance >= 20m (Step 6.5). 6: Restricted to wheelchair, can transfer/wheel self (Step 7.0). 7: Restricted to wheelchair, needs help transferring (Step 7.5). 8: Restricted to bed/chair, retains self-care (Step 8.0). 9: Restricted to bed, some effective arm use (Step 8.5). 10: Helpless bed patient, can communicate (Step 9.0). 11: Totally helpless, unable to communicate (Step 9.5).

Value

A list containing:

EDSS_Score	The calculated Expanded Disability Status Scale score.
Inputs	A record of the provided functional scores and ambulation status.

References

Kurtzke JF. Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology. 1983;33(11):1444-1452. doi:10.1212/wnl.33.11.1444

Examples

# Example 1: Mild Disability (Ambulatory)
# Pyramidal 2, others 0/1, Walks >500m
calculate_edss(2, 1, 0, 1, 0, 0, 0, 0)

# Example 2: Moderate Disability (Walking impaired)
# Pyramidal 3, Cerebellar 2, Walks 150m without aid
# Code 3 (>100m no aid) corresponds to 5.5
calculate_edss(3, 2, 1, 0, 1, 0, 0, 3)

# Example 3: Severe Disability (Wheelchair)
# Multiple high FSS, Wheelchair restricted (can transfer)
# Code 6 -> 7.0
calculate_edss(4, 3, 2, 3, 3, 1, 1, 6)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.