A simple, easy to use chart for determining whether changes as assessed via the ORS qualify as reliable; that is, greater than chance, maturation, and measurement error.

1. ORS/CORS Reliable Change Chart
0
During or Post Treatment Score
5
Reliable No
Reliable
10 Deterioration Change
5 point or more
worsening from
15 pre-treatment
score
No
20 Reliable
Change
25 Reliable
Change Clinically
5 point or more Significant Change!
30 No
Reliable improvement 5 point or more
Change from pre- improvement from
treatment score pre-treatment score
35
and crossed the cutoff
score for age group
40
40 35 30 25 20 15 10 5 0
Pre-Treatment Score
Instructions: To determine if any measured change is reliable, find the point where the
initial session “Pre-Treatment Score” and the “During or Post Treatment Score” intersect.
Use cutoff scores table below to help work out if “Reliable Change” is also “Clinically
Significant Change”.
Clinical Cutoff Scores
CORS (ages 6-12)
Child (Self-reporting) 32
Carer (Reporting on child) 28
ORS (ages 13 +)
Ages 13-17 28
Ages 18 + 25
© 2012, Scott D. Miller, Ph.D.
www.scottdmiller.com