HealthMeasures use standardized scores. PROMIS®, Neuro-QoLTM, ASCQ-Me® and the self-report patient-reported outcome (PRO) measures of NIH Toolbox® use a T-score metric in which 50 is the mean of a relevant reference population and 10 is the standard deviation (SD) of that population. The NIH Toolbox performance tests of cognitive, motor, and sensory function use standard scores, but not T-scores. You will find a summary of this information for each HealthMeasures system in the pages of this section of the website.
Direction of Scores
For PROMIS, Neuro-QoL, and the NIH Toolbox PRO measures, a higher T-score represents more of the concept being measured. For negatively-worded concepts like fatigue, a higher T-score represents greater fatigue and a lower T-score represents less fatigue. For positively-worded concepts like physical function, a higher T-score reflects higher (better) physical function and a lower T-score reflects lower (worse) physical function. For NIH Toolbox performance tests of cognitive, motor, and sensory function, a higher score indicates better performance. ASCQ-Me measures vary by domain.
What Scores Mean
To know what a score means, you must also know the:
- Concept being measured (see Lists of Measures in Explore Measurement Systems)
- Reference population – the population to which scores are compared to establish normative values (e.g., general population, clinical population)
- Cut points that communicate the severity level or clinical significance of a score
- Meaningful change or the meaning of change in scores among people over time
Interpretation of HealthMeasures scores can also vary by use (clinical care vs. research), sample size (large samples, small samples, individual patients), the match between respondents and reference population, the domain or concept being measured, and other factors.
Other interpretation tools include:
- G-code severity modifiers used by CMS to indicate a patient’s level of impairment, limitation, or restriction
- T-score Maps show the most likely response to items based upon a person’s T-score