1 Quantity or quality? Comparing objective and subjective participation measures to predict quality of life in aging msTBI.
Authors: Cwiek Andrew P , Vervoordt Samantha , Carter Emily E , Hillary Frank G 
Published: December 2023

Objective:Community reintegration and participation have been shown to be significantly correlated to improved Quality of Life (QoL) following moderate to severe traumatic brain injury (msTBI), yet these models often come with significant levels of unaccounted variability (Pierce and Hanks, 2006). Measures for community participation frequently employ objective measures of participation, such as number of outings in a week or current employment status (Migliorini et al., 2016), which may not adequately account for lifestyle differences, especially in aging populations. Less often integrated are subjective measures of an individual’s own belongingness and autonomy within the community (Heineman et al., 2011), also referred to as their participation enfranchisement (PE). The present study examines three questions pertinent to the potential clinical value of PE. First, do measures of objective participation significantly predict an individual’s PE ratings? Second, are both types of measures equally successful predictors of QoL for aging individuals with chronic-stage msTBI. Finally, would controlling for either objective or subjective integration ratings enable neurocognitive assessments to better predict QoL post injury?Participants and Methods:41 older-adults (M= 65.32; SD= 7.51) with a history of msTBI were included (M= 12.59 years post-injury;SD= 8.29) for analysis. Subjective community integration was measured through the Participation Enfranchisement Survey. The Participation Assessment with Recombined Tools-Objective (PART-O) provided the objective measurement of participation. Quality of life was assessed through the Quality of Life after Brain Injury (QOLIBRI). An estimate of neurocognitive performance was created through the Brief Test of Adult Cognition by Telephone (BTACT), which includes six domains including: verbal-learning and memory (immediate and delayed recall), working memory (digit-span backwards), reasoning (number sequencing), semantic fluency (category fluency), and processing speed (backwards counting). Performance on the BTACT, PE ratings, and PART-O scores were included as the dependent variables in stepwise, linear regression models predicting QoL ratings to assess the differential contribution of the dependent variables and potential interaction effects.Results:While both the PART-O (f(1,39)=5.52;p=.024,n2=.124) and the PE survey (f(1,39)=14.31 ;p<.001,n2=.268) significantly predicted QoL, the addition of PE in the PART-O model resulted in significant (20.9%) reduction in unaccounted variance. Further in the model controlling for PE, PART-O no longer provides a significant (p=.15) contribution to the model estimating QoL (f(2,38)=8.41; p=.001). Performance on the BTACT correlated with PART-O (p<.0001), but not PE (p=.13) ratings. Finally, across two models controlling for BTACT performance, PE (p=.002,partial n2=.23), but not PART-O (p=.28,partial n2=.031) contributed significantly to QoL predictions. No significant interactions between PART-O, PE, and/or BTACT were observed when added to any model.Conclusions:MsTBI impacts nearly every facet of an individual’s life, and as such, improving QoL post-injury requires a broad, yet well-considered approach. The objective ratings of participation, subjective PE, BTACT performance, all independently predicted quality of life in this sample. However, after controlling for neurocognitive assessment performance, PE was shown to independently contribute to quality of life, while the PART-O ratings no longer provided significant contribution. While community integration is a vital factor to consider for long-term rehabilitation, tailoring what “integration” means to the patient may hold significant potential to improve long-term quality of life.