Comparing Versions

Users frequently need to know if a T-score from one HealthMeasure can be compared to a T-score from another HealthMeasure. That is, are these two measures on the same metric?  

Example: Can you compare a T-score from a PROMIS® Physical Function v1.2 short form with a v2.0 short form? According to the tables below, yes, you can! 

Instructions 

• Find your measurement system (PROMIS, Neuro-QoL™, NIH Toolbox®). 
• Find your respondent (adult, pediatric, parent proxy).
• Find your domain (e.g., Physical Function). 
• Review the table. The first column shows a domain name and version number (e.g., v2.0). Each domain + version number is associated with a letter (e.g., B). If two rows within a table share a letter, it means they are on the same metric and you can compare their scores. For example, in the PROMIS adult Physical Function table below, both Physical Function v1.2 and Physical Function v2.0 are assigned the letter A. This means their scores can be compared! Rows that do not share a letter cannot be compared (e.g., Pediatric Mobility v2.0 and v3.0). 
• The letter in the Comparable Scores column applies to all measures (i.e., CAT, screen-to-CAT, short form) that share a domain + version number. 
• Measures that are in different tables (e.g., PROMIS Pediatric Mobility and PROMIS Pediatric Upper Extremity) do not have comparable scores. That is, you can’t compare everything assigned an “A” across all tables. 
• If there is only one version for a given domain, it is noted below. 

The PROMIS Profiles are comprised of multiple short forms or computer adaptive tests. Each profile produces multiple scores.  

Instructions 

To determine if a domain score (e.g., Anxiety) from one version of a Profile is comparable to another version of a Profile, you need to:

1. Identify what short form or CATs are being used in your Profile measure. This information is in the PROMIS Measure Differences summaries for profile measures (Profile – Adult, Profile – Pediatric and Parent Proxy).
2. Reference the corresponding table above to determine if the scores from a short form or CAT in one Profile are comparable to the short for or CAT included in another version of a Profile.

Examples 

The PROMIS-29 v1.0, v2.0, and v2.1 all include the PROMIS SF v1.0 – Anxiety 4a. Consequently, anxiety scores between Profile versions are comparable as they are all using the same short form.

The PROMIS-29 v1.0 and v2.0 include the PROMIS SF v1.0 – Physical Function 4a. The PROMIS-29 v2.1 includes PROMIS SF v2.0 – Physical Function 4a. In the adult Physical Function table above, v1.0 and v2.0 Physical Function are both assigned an “A.” This means that their scores are comparable. Consequently, Physical Function scores from the profile measures PROMIS-29 v1.0, v2.0, and v2.1 are comparable.