HealthMeasures use standardized scores. PROMIS®, Neuro-QoL, 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.
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 know the concept being measured, the reference population (e.g., general population, clinical population) and the metric (e.g., T-score, percentile). Other ways to interpret scores include using standard setting to identify cut points that communicate the severity level or clinical significance of a score, as well as looking at meaningful change (differences in scores between people and changes 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 sample, the domain or concept being measured, and other factors.