Although the literature on HRQOL following pediatric TBI has increased in recent years (Limond et al., 2009
; McCarthy et al., for the Children's Health After Trauma Study Group 2006
; Petersen et al., 2008
; Winthrop, 2010
), relatively little research has focused on children with mild TBI. This may be in part because of past research suggesting that children with mild TBI do not demonstrate reliable impairments in HRQOL (Limond et al., 2009
; Petersen et al., 2008
). Previous research, however, has been characterized by a variety of methodological shortcomings. Using more rigorous methods, children in the current study with mild TBI showed deficits in physical HRQOL, but not psychosocial HRQOL, when compared to children with OI. These mixed findings are consistent with the previous literature, which fails to indicate a strong relationship between injury severity and HRQOL in children with TBI (McCarthy, 2007
), and instead suggests that other mediating factors may determine HRQOL in this population.
A key goal of the current study, therefore, was to examine the relationship between PCS and HRQOL. The findings show that early postinjury PCS are a significant predictor of both physical and psychosocial HRQOL as long as 12 months postinjury, in both children with mild TBI and those with OI. Children whose parents reported more severe PCS were more likely to demonstrate lower HRQOL at both 3- and 12-month follow-up assessments. Further, the findings reflected some degree of specificity, such that only somatic PCS predicted physical HRQOL. Physical HRQOL tends to reflect bodily pain, physical functioning, and general health, so it is perhaps unsurprising that physical symptoms, but not cognitive symptoms, are related to physical HRQOL. On the other hand, both cognitive and somatic PCS had a negative relationship with psychosocial HRQOL. A possible explanation for the influence of somatic symptoms on psychosocial functioning is that children with more somatic symptoms like headaches, dizziness, and nausea may be less able to participate in rewarding activities, which results in less time spent in social interactions and has a negative influence on mood.
Thus, the findings indicate that mild TBI per se does not have a strong, persistent influence on HRQOL, but that children who experience higher levels of PCS after mild TBI are at risk for significant and lasting declines in HRQOL. This, in turn, suggests that PCS may be a potential target for improving HRQOL following pediatric mild TBI. Our previous work suggests that a substantial minority of children with mild TBI demonstrate persistent increases in PCS after mild TBI (Yeates et al., 2009
), and outcomes could be improved by identification of and intervention with this subgroup. Several psychotherapeutic interventions have been developed to reduce PCS following mild TBI in adults and these techniques could be easily adapted for use with pediatric populations. Generally, the interventions include cognitive restructuring regarding symptom etiology and severity and the graded resumption of physical activity to minimize failure experiences and lower stress (Mittenberg, Canyock, Condit, & Patton, 2001
). A review and meta-analysis by Mittenberg et al. (2001)
examined the effectiveness of interventions targeting PCS reduction following mild TBI in adults. Studies showed consistent reductions in PCS following treatment (d
.32), even following early, single session treatments. Psychoeducational interventions may also be effective. In children with mild TBI, early education can reduce PCS and overall stress at 3-month follow-up (Ponsford et al., 2001
). Future studies are needed to examine whether reduction in PCS as a function of intervention also promotes postinjury HRQOL.
Another important finding is that preinjury HRQOL was a stronger predictor of postinjury HRQOL scores than either mild TBI or PCS. For both physical and psychosocial HRQOL, preinjury ratings accounted for more variance in postinjury HRQOL than either group membership or level of PCS. These findings are in line with recent research documenting the significant influence of preinjury functioning on outcomes following mild TBI in children (Fay et al., 2010
) and imply that clinicians should carefully evaluate preinjury functioning as part of case conceptualization and treatment planning. They also emphasize the need to assess preinjury functioning as soon after an injury as possible to reduce retrospective biases and obtain more accurate estimates. Within the context of the current study, we believe that the postinjury parent ratings are valid because they were obtained shortly after the injury, minimizing demands on retrospective recall. The mild TBI and OI groups were relatively comparable on retrospective measure of preinjury functioning, suggesting that parents in the mild TBI group were able to distinguish pre- and postinjury symptoms and were not minimizing any premorbid difficulties their children might have had.
One potential limitation of this study is the use of parent report measures for the assessment of both PCS and HRQOL. This not only raises the possibility of shared rater variance, but also omits children's self-reports. Parent–child agreement regarding frequency and severity of PCS is only moderate (Ayr et al., 2009
; Gioia, Schneider, Vaughan, & Isquith, 2009
; Hajek et al., 2011
), as is parent–child agreement about HRQOL (Eiser & Morse, 2001c
; Theunissen et al., 1998
; Upton, Lawford, & Eiser, 2008
). Therefore, children's and parents’ ratings of PCS and HRQOL may provide different perspectives. Future research should include self-report measures of PCS and HRQOL, to complement the parent ratings reported here.
Another potential limitation of the study is that recruitment rates for the mild TBI and OI groups were both below 50%, and may, therefore, limit the generalizability of the results. Relatively greater attrition of children of lower SES and ethnic minority status may also have reduced generalizability. However, nonparticipants did not differ from participants demographically, SES and minority status were taken into account in data analyses, and the mixed-model analyses incorporated all available data, including that collected from children who missed later assessments. A final caveat about the study is that the findings may not necessarily be applicable to younger children and older adolescents, given the age range of the sample. Future research is needed to determine if the results generalize to those age ranges.
In sum, mild TBI appears to have a delayed impact on physical HRQOL, but no effect on psychosocial HRQOL. However, higher levels of PCS shortly after injury predict lower physical and psychosocial HRQOL up to 12-months postinjury for children with mild TBI. Moreover, the relationship is somewhat specific, such that somatic symptoms predict physical HRQOL and both somatic and cognitive symptoms predict psychosocial HRQOL. These results suggest that intervention is indicated for children who display significant PCS following mild TBI, and that such interventions may result in improvements in HRQOL in children with such injuries.