Landmark 284 · Research tool
Hoehn and Yahr staging scale
In short
A five-stage severity scale from a 1967 paper on onset, progression and mortality became the field's shorthand for how advanced the disease is, and is still used to describe trial groups, though rating scales have replaced it for measuring change.
- What it is
- Research tool
- Outcome
- Replaced by a better idea
- When
- 1967
- Research lane
- Trial methods & regulation
- Last checked
- 19 Oct 2026
The research record
This is the project's file for this landmark, as written and checked. Sources are listed at the end; anything not yet confirmed is marked "Not yet verified".
Who
M. M. Hoehn and M. D. Yahr, in Neurology 1967;17:427-442.
What happened
Their paper, "Parkinsonism: onset, progression and mortality", followed patients over time and grouped them by how far the disease had spread. The staging that came from it runs from stage 1 (mildest) to stage 5 (most severe). Half-stages (1.5, 2.5) and a stage 0 were added later in the widely used "modified" version.
A Movement Disorder Society Task Force reviewed the scale in 2004 (Mov Disord 19:1020-1028). It found:
- Strengths: wide use, and higher stages go with more dopamine loss on imaging.
- Weaknesses: it mixes impairment with disability, steps are not evenly spaced, and it leans heavily on balance problems, so it misses other motor features and all non-motor problems.
- Direct testing of its reliability is limited, mostly for stages 2 to 4; the half-step version has no testing at all.
- Recommendations: use the original form for describing patient groups, and report medians and ranges with non-parametric statistics; in research it is useful mainly for defining inclusion and exclusion criteria.
Why it moved us toward a cure
It gave trials a common way to say who was enrolled ("stage 2 or less", "stage 1-3"). The 2004 Task Force describes entry criteria as the scale's main research use, and the scale stayed in routine use for decades. It was too coarse to detect a drug that slows the disease; that need led to finer measures such as the MDS-UPDRS (landmark 114), a link that is my reading, not stated in the Task Force abstract.
Outcome
Superseded for measuring change, retained for describing groups. Whether it has ever served as a primary endpoint in a slowing trial: not checked.
Sources
- Hoehn & Yahr, Neurology 1967;17(5):427-442, DOI 10.1212/WNL.17.5.427, PMID 6067254
- Goetz CG et al., "Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations", Mov Disord 2004;19:1020-1028, DOI 10.1002/mds.20213, PMID 15372591 (abstract read via PubMed)
- Not yet verified: the number of patients in the 1967 study; the exact wording of each stage (not read); which later trials used it as an endpoint.
How it connects
Built on
None recorded.
Led to
- replaces MDS-UPDRS · 2008