PROMIS® Score Cut Points
General guidelines for interpreting PROMIS scores have been constructed using different methods.
PROMIS scores have a mean of 50 and standard deviation (SD) of 10 in a referent population.
Score ranges that correspond to within normal limits, mild, moderate, and severe were estimated for PROMIS profile and other domains.
PROMIS scientists constructed the interpretation of PROMIS scores graph for Profile domains by reviewing the data collected in the large scale calibration testing data (Cella et al 2010, Rothrock et al 2010). They started by reviewing whether 0.5, 1.0, and 2.0 standard deviations were reasonable thresholds to use across domains. This was evaluated by looking at the percentage of participants from large scale calibration testing that would then fit into each category.
Very Low to Very High Domains
Many PROMIS domains are interpreted from very low to very high. For these domains, the mean (T=50) plus or minus one standard deviation (SD) is considered average (T=40 to 60).
- Scores +/-1.0 SD from the mean = average
- Scores +/- 1.0 to 2.0 SD from the mean = low/high
- Scores +/- more than 2.0 SD from the mean = very low/very high
The cut points or thresholds for PROMIS Global Physical and Mental score categories of excellent, very good, good, fair, and poor were constructed by 1) creating groups based upon responses to Global01 “In general, would you say your health is excellent, very good, good, fair, or poor?”, 2) calculating mean scores for each group, and 3) identifying the midpoint between two adjacent means. For example, the mean Global Mental score for “Excellent” was 61 and the mean score for “Very Good” was 51. The midpoint between these scores is 56. Cut points are:
- Global Mental: 56, 48, 40, 29
- Global Physical: 58, 50, 42, 35
See Hays, Spritzer, Thompson & Cella (2015) for more information.
Standard Setting Using Bookmarking
Researchers have adopted a method applied in educational testing to identify thresholds for levels of academic outcomes (e.g., math proficiency levels). This method, called Bookmarking, has been used to establish thresholds for severity levels (e.g., no problems, mild problems, moderate problems, severe problems) in multiple patient populations.
Severity thresholds exist for: