Patient-reported outcome measures provide valuable insights into health status after neurologic disease, but their relationships with function-based outcome measures remain incompletely understood. Here we evaluate the relationship between these two classes of measure using dimensionality-reduction techniques in patients after acute stroke and examine their associated patterns of neuroanatomical injury.

Fifty-four adults with upper extremity motor deficits were serially assessed at four time points after stroke with functional outcome measures (Upper Extremity Fugl-Meyer, Barthel Index, modified Rankin Scale, Box and Blocks, 9- Hole Peg, Grip Strength) as well as patient-reported measures (PROMIS-Global Physical, Mental, and Social Health, Patient Health Questionnaire-9) of health status. At each timepoint after stroke, exploratory and confirmatory factor analysis were performed to identify and confirm the underlying factorial structure of the entire battery of outcome measures. Multivariate linear regression analysis was used to determine the amount of variance explained by clinical and demographic characteristics on extracted factors. Voxel-Based Lesion Symptom Mapping was used to examine the relationship between factors and patterns of neuroanatomical injury.

In the battery of stroke outcome measures, two factors were identified and retained, accounting for >78% of the overall variance across outcomes at every timepoint. Function-based measures loaded onto Factor 1 separately from patient-reported measures which loaded onto Factor 2. Results were consistent at each serial timepoint after stroke. Pre-stroke disability (p=0.03) and amount of damage to the corticospinal tract (p=0.001), explained significant variance in performance on Factor 1 (function-based outcomes), whereas education (p=0.01) and socioeconomic status (p=0.04) explained significant variance in performance on Factor 2 (PROMs). While function-based measures were related to injury to subcortical brain regions known to be important for motor function, patient-reported measures were related to injury to cortical brain regions including the insula and inferior parietal lobe, known to be important for affective processing and social cognition.

Two distinct factors representing function-based and patient-reported measures of health status were extracted from the study battery of stroke outcome measures scored across the first year post-stroke. Each factor was associated with injury to brain regions concordant with the content of the represented assessments. These findings emphasize the distinct behavioral elements and neuroanatomical underpinnings of function-based and patient-reported outcome measures after stroke and have potential implications for precision rehabilitation.