Quality of Life in Children and Adolescents Post-TBI: A Systematic Review and Meta-Analysis

Abstract

Traumatic brain injury is (TBI) a leading cause of morbidity and mortality in children and adolescents in first-world nations. Research from our team investigating adult survivors of pediatric TBI indicate that survivors of severe TBI are particularly vulnerable to global impairments, including poorer school performance, greater employment difficulties, poor quality of life (QoL), and increased risk of mental health problems. Investigation into less observable consequences, including QoL, has emerged recently as an important outcome to assess in TBI populations. The status of QoL in pediatric TBI populations is mixed, likely a reflection of the varied methodological and theoretical perspectives on QoL. AIM: This systematic study will clarify the nature of QoL in survivors of pediatric TBI, and identify predictors of QoL in this group. Of 419 articles identified, 11 studies met our inclusion criteria, and 9 were ultimately analyzed in this review. Four studies reported good QoL and 5 poor QoL. The difference between good and poor QoL was statistically significant due to TBI severity [chi-square(3)=77.38, p<0.001], timing of outcome assessment [chi-square(1)=565, p<0.001], and definition of QoL [chi-square(3)=34.73, p<0.001]. The odds of having a poor QoL increased 5.8 times (RR=1.21) when injuries were more severe. Good outcomes are contingent on milder injuries, proxy reporting, and early assessment, whereas poor outcomes reflect more severe injuries and later assessment (≤ 6 months versus ≥ 1 year post-trauma, respectively).

Introduction

T raumatic brain injury (TBI) is a leading cause of morbidity and mortality in children and adolescents in first-world nations (Yeates et al., 2002). A great deal of neuropsychological research has been conducted on observable outcomes following pediatric and adolescent TBI, focusing particularly on changes and deficits in cognition and behavior, including executive functioning (attention and inhibition), academic achievement, learning, reading, language ability, and antisocial behaviors (Anderson et al., 2005; Catroppa et al., 2008; Ewing-Cobbs et al., 2004; Muscara et al., 2008). Research from our own team investigating adult survivors of pediatric TBI reports that survivors of severe TBI are particularly vulnerable to global impairments, including poorer school performance, greater employment difficulties, poor quality of life (QoL), and increased risk of mental health problems (Anderson et al., 2010). Investigation into less observable consequences, including QoL, has emerged in recent years as an important outcome to assess in TBI populations.

Declines in health-related QoL have been documented in pediatric TBI groups, and recent research has found evidence of poor QoL in adult survivors of pediatric TBI (Cattelani et al., 1998). McCarthy and colleagues (2006) described declines in health-related QoL that were maintained over time in children following a TBI. Other recent data have suggested good health-related QoL in adult survivors (Anderson et al., 2011). It is possible that the conflicting data on good versus poor OoL may be related to the definition of QoL used in different studies.

QoL as a construct has many definitions, which generally adhere to one of three distinctive conceptualizations: (1) QoL as subjective well-being; (2) QoL as achievement; and (3) QoL as utility/health status (Dijkers, 2003,2004). Approaches employing subjective well-being define QoL as an individual determination of life satisfaction, or the cognitive and emotional reactions to life stressors, which are influenced by negative and positive affect, self-esteem, and morale (Djikers, 2004). QoL as achievement relates to the self as categorized against a standard of achievement (e.g., salary, possessions, relationships, and accomplishments; Djikers, 2004). QoL as utility/health status is also external to the individual, with judgments based on the utility of an individual to others, as judged by society's values, standards, and expectations (Dijkers, 2003). When QoL is used as an outcome, the overall value attached to QoL can vary dramatically depending on which of these three models is used.

The overwhelming majority of available health-related QoL measures subscribe to the QoL as achievement paradigm. Examples of health-related QoL measures include the Medical Outcomes Short-Form Questionnaire (SF-36; Turner-Bowker et al., 2002), General Health Questionnaire (GHQ; Goldberg, 1978), the Child Health Questionnaire (CHQ; Landgraf et al., 1996), and the Pediatric Quality of Life Inventory (PedsQL 4.0; Varni et al., 1999).

Subjective well-being is variable and is influenced by many factors, while achievement and/or utility/health status often categorize those with injury into a lower group a priori by merit of their health condition (e.g., the “unhealthy” individual achieves less and is of less utility compared to a healthy member of society). Achievement and utility ratings are often made with little regard for the internal subjective well-being of the individual and their perspective on their life. Differences in QoL outcome may also be attributable to methodological issues, such as sample characteristics, including severity of the TBI, and whether proxy reports (e.g., parent or physician) were used. Although health-related QoL and QoL defined as utility/health status may be observed by proxy (through the achievement and functional ability construct paradigm), QoL may be regarded as poorer by familial proxies, as family members often experience more distress than the injured child following a TBI (Brooks, 1991). Families also suffer from QoL impairments of their own (Koskinen, 1998), and may describe their child's QoL as poorer as a result of their own reduced state. It is possible that reflection and possible rumination of life before the trauma may bias the current perception of life for them and their family, resulting in poorer estimates of their child's QoL post-TBI. In recent years QoL has been highlighted as an important area of investigation in health policy and medical intervention, but the broad variability in methodology used to assess QoL (e.g., definitions of QoL, whether individuals or proxy reports are used, and at which time point in the recovery phase assessments are made) compromise the clarity of findings across studies, especially in pediatric TBI. This systematic review will address these various methodological issues, with the goal of clarifying the definition of QoL in survivors of pediatric TBI.

Specifically, this review will assess: (1) the nature of QoL assessed in pediatric TBI research, examining the type of QoL assessed (e.g., definition), who is assessed (individual child versus proxy and TBI severity groups), and when they are assessed (outcome time points); (2) outcome (good versus poor) QoL across studies; (3) the effect of proxy reporting on outcome statistics; and (4) classification of good versus poor QoL when all of these variables are combined (e.g., definition of QoL, the sample assessed [proxy versus individual], TBI severity, and time of QoL assessment).

Methods

Literature search

Studies were identified that provided information on QoL outcomes among survivors of pediatric TBI. Two databases (Medline and PsycINFO) were searched for articles published up to 2010 using the search criteria described below.

PsycINFO (any field)

(quality of life) and (traumatic brain injury) and (adolescent or child or pediatric). Limits: English peer-reviewed journal; pediatric (birth–12 years), neonatal (birth–1 month), infancy (1–23 months), preschool (2–5 years), school age (6–12 years), adolescence (13–17 years), human.

MEDLINE (any field)

(quality of life) and (traumatic brain injury) and (adolescent or child or pediatric) limits: Clinical trial OR randomized controlled trial (RCT) OR case report OR clinical study OR journal article; English; human; all infant (birth to 23 months), all child (0–18 years).

The literature review methodology was conducted in accordance with the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) recommendations (Stroup et al., 2000). Detailed reporting of the search process is presented in Figure 1. No contact was made with authors. Bibliography searches did not yield additional resources.

FIG. 1.

Details of the literature search process (RCT, randomized controlled trial).

Study selection criteria

Study selection for inclusion in the systematic review is provided in Figure 1. Any predictor variable was sufficient for initial inclusion, so long as the dependent variable included an assessment of QoL, as either a primary or secondary outcome.

Two stages of processing were used to ensure appropriateness of study inclusion. The first stage (stage 1 processing) assessed the articles according to information provided in the abstract, in accordance with the eligibility criteria listed below.

Eligibility criteria: Stage 1 processing

Articles were deemed eligible for further critical analysis based on satisfying the following criteria.

1. Human subjects

2. Pediatric and/or adolescent population

3. QoL as outcome measure (primary or secondary); this includes proxies (e.g., educational/vocational outcome)

4. TBI defined as closed head injury, open head injury, accidental injury

5. Clinical trial (RCT, case report, or clinical study)

6. Studies that include QoL as an outcome, but do not define the age group in the abstract

7. Study cohort included children (0–18 years) included in the study as either child only or child+adult; in instances of child+adult, the data must be stratified by age group (child versus adult)

8. Brain injury defined as a closed or open TBI

9. Full abstract available, original article, peer reviewed, English-language publication

Exclusion criteria: Stage 1 processing

1. Full abstract not available for review

2. Adult only

3. Adults after pediatric TBI (e.g., child/adolescent at injury, adult at assessment)

4. Abuse (QoL for abused children adds extra variables to QoL analysis)

5. Non-trauma-related TBI (e.g., tumor, hydrocephalus, general encephalopathy [includes bacterial and viral], stroke, birth-related trauma, genetic disorders affecting brain development and/or maturation [e.g., micro/macroencephalopathy, prematurity, agenesis of corpus callosum])

6. Validation study (e.g., measure or therapeutic program)

7. Case study

A second stage of processing was conducted on all articles satisfying stage 1, for which additional information was required to determine eligibility with regard to eligibility criteria 3 and 6.

Stage 2 processing served to determine and/or clarify the operational definitions of “quality of life” (criterion 3), and/or details regarding stratification of the sample into appropriate age groups (criterion 6). Studies were excluded from the final systematic review if they did not satisfy either criterion 3 or 6 during stage 2 processing.

Data abstraction

Articles were reviewed independently by A.D. and verified by V.A. Data were abstracted into an access database, which was designed by A.D. The following data were abstracted: participant demographics (age range and mean; number and percentage of participants per group; number and percentage of male/female participants); TBI severity (Glasgow Coma Scale score, Abbreviated Injury Score, Injury Severity Score, other); study assessment time points; independent variables; dependent variables; definition of QoL (achievement; utility/health status; subjective well being; composite); QoL as primary versus secondary outcome and outcome analysis group (child/adolescent, parent proxy, teacher proxy, doctor proxy); study main findings; effect of independent variable on QoL; QoL as “good” versus “bad”; relationship of TBI severity to QoL.

Statistical analysis

Variable methods for data analysis and presentation were used in the various studies included in the systematic review. In order to summarize results, initial statistical analysis focused on pooling and generating means, medians, and percentages of total across studies (e.g., age and sex), and reporting those pooled means and percentages derived from those studies reporting the data of interest. Raw data and percentages of the total number of studies and the total number of children with each level of TBI severity were calculated. Microsoft Access, Microsoft Excel, and SPSS software were used to perform the analyses. Initial statistical analysis generated descriptive data of both the study variables and the participant characteristics, pooled across studies. In order to determine the effect of variables of interest on QoL outcome, all variables of interest (TBI severity, proxy versus self assessment, QoL definition, and age at assessment) had pooled relative risks (RR) and odds ratios calculated, where appropriate. Chi-square and Fisher's exact test were employed where applicable. Statistical heterogeneity was calculated using the chi-square test. QoL outcome was dichotomized into “good” versus “poor,” based on the inherent classifications within each measurement scoring system.

Results

Overview

The results of the selection process are provided in Figure 1. The initial search produced 419 citations. Stage 2 processing yielded 93 potentially relevant citations. Of these, 11 studies met our inclusion criteria and were analyzed in this review (Aitken et al., 2009; Erickson et al., 2010; Fay et al., 2009; Limond et al., 2009; McCarthy et al., 2006; Mealings and Douglas, 2010; Meuli et al., 1991; Petersen et al., 2008; Souza et al., 2007; Taylor et al., 2001; Tilford et al., 2007). Table 1 describes the characteristics of the included studies, and Table 2 shows QoL measurement characteristics.

Table 1.

Study Characteristics of the Included Articles (n=11)

Reference	Age range; mean (SD); [median]	Sample size (% male)	Study type	Independent variable	Dependent variable	Study main findings	TBI severity (% total)	TBI severity index	Assessment time points
Aitken et al., 2009	5–15 years; or10.4 years (NR)	302 (68)	Cohort; prospective	Child health and health care needs	Caregiver burden	Caregivers more likely to report family burden problems when child functioning is poorer and health care needs are unmet. Improved identification and provision of services is a potentially modifiable factor that may decrease family burden after pediatric traumatic brain injury	Moderate (30.1%); moderate–severe: (24.8%); severe (45%)	AIS	Baseline within 3 weeks, median 16 days, 3 months and 12 months
Erickson et al., 2010	9–18 years; or 13.33 (2.6) years	20 (65)	Case control; observational; prospective	TBI severity and age	HRQoL: child versus adult	Children who have suffered moderate–severe TBI experience relatively poor HRQoL, particularly in the school domain. Limited convergence between informants suggests that children and parents perceive HRQoL differently, with parents reporting lower HRQoL	Moderate-severe (100%)	GCS	Minimum of 6 months post-injury
McCarthy et al., 2006	5–15 years; or 10.42 years (NR)	330 (69)	Cohort; observational; prospective	TBI severity	HRQoL	Moderate or severe TBI resulted in measurable declines in children's HRQoL after injury. Injury-related factors impacted HRQoL more than patient and family characteristics during the first year after injury	Mild (56.1%); moderate (31.2%); severe (12.7)	AIS/NISS	Baseline, 3 and 12 months
Mealings and Douglas, 2010	13–17 years; or 14.67 years (NR)	3 (100)	Case series; observational	Individual experiences in return to school	School success	Three key themes emerged from the interviews: the adolescent student's sense of self, changes the students noted; and supports the students identified. A tentative model illustrating the relationship between these areas was developed. It is anticipated that this model will assist clinicians and educators to develop a holistic picture of a student's school participation from transition to ongoing school life	Severe (100%)	GCS	Minimum 6 months post-school return
Meuli et al., 1991	5 months to 15.5 years; or 7.9 years (NR)	31 (67)	Cohort; observational; retrospective	Post-traumatic neurological findings	GOS at 7 years, child versus adult	28 patients had a “good recovery”; “moderate disability,” and “severe disability” were found in patient one each. Our results demonstrate that the long-term outcome in children with extradural hematoma is far better than that of adults regarding survival as well as quality of life. The causes may be minor traumas with fewer associated lesions and presentation with typical clinical findings, and therefore early diagnosis and treatment is possible	NR	Other^a	Mean: 7 years post-injury; range: 2 months to 17.5 years
Petersen et al., 2008	10.0 years (NR) at assessment; or 9.05 years (3.78) at injury	59 (50.8)	Cohort; observational; Prospective	Severity and demographics (time since injury)	QoL	Mild TBI resulted in no decline in the children's health outcome after injury. The cognitive screening approach proved itself to be a useful instrument for routine clinical care	Mild (100%)	GCS	Immediately post-TBI (T0); 3-month interview (T1)
Souza et al., 2007	7–11 years at assessment; or 10.7 years (1.9) 3–11 years at injury	23 (57)	Case control; prospective	Patient and parent correlates of QoL	QoL	Children with TBI report significantly reduced QoL compared to a control group in the physical, psychological, cognitive, and total score dimensions. However, TBI children with average academic performance (65%) obtained the same QoL scores as the control group	Severe (100%)	GCS	Mean: 4.1 (2.3) years post-injury; range 1–9 years post-injury
Taylor, et al., 2001	13.6–176.4 mo (1.1–14.7 years); or [120.9 mo]	13 (NR)	Prospective; RCT	Early decompressive craniectomy	Functional outcome and control of ICP	When children with TBI and sustained intracranial hypertension are treated with a combination of very early decompressive craniectomy and conventional medical management, it is more likely that ICP will be reduced, fewer episodes of intracranial hypertension will occur, and functional outcome and quality of life may be better than in children treated with medical management alone. Very early decompressive craniectomy may be indicated in the treatment of TBI	Moderate–severe (100%)	GCS	6 months
Fay et al., 2009	6–12 years at injury: moderate TBI: 9.49 (1.86) years; or severe TBI 9.77 (2.18) years	77 (68 Moderate TBI; 81 severe TBI)	Concurrent cohort; prospective	Severity of TBI	Functional deficit: neuropsychological, behavioral, academic, adaptive	Severe TBI predicted an increased likelihood of persistent deficits in all outcome domains, as well as deterioration in behavioral functioning and improvement in neuropsychological, adaptive, and academic functioning. Severe TBI also predicted a greater total number of functional deficits across domains at each occasion. However, many children with severe TBI showed no deficits from 6 months to 4 years post-injury in one or more outcome domains	Moderate (51.9%); severe (48.1%)	GCS	6 months, 1 and 4 years
Tilford et al., 2007	5–18 years	67 (62.5) at 3 months; 76 (58.5) at 6 months	Observational cohort; prospective	Treatment intensity	Quality of well-being (QWB)	The findings support the use of the QWB score with parental reports to measure preference-weighted health outcomes of children following a TBI. Information from the study can be used in economic evaluations of interventions to prevent or treat TBIs in children	Severe (100%)	GCS	3 and 6 months
Limond et al., 2009	1–13 years (injury); or5–16 years (assessment)	43 (NR)	Cohort, retrospective	Demographic and injury characteristics	HRQoL and Service Use	Parents frequently reported poor quality of life and cognitive, emotional, and behavioral problems in their children following TBI. These preliminary findings indicate that children after TBI are at risk of developing persistent clinical problems and require follow-up beyond the acute period of recovery	Mild (72%), moderate (16%), severe (12%)	GCS	1–5 years post-injury; 2.6 (3.2) years

“Classic signs” as severity index.

AIS, Abbreviated Injury Score; HRQoL, health-related quality of life; QoL, quality of life; NISS, New Injury Severity Score; GCS, Glasgow Coma Scale; QoL, quality of Life; RCT, randomized controlled trial; ICP, intracranial pressure; TBI, traumatic brain injury; NR, not reported.

Table 2.

Quality of Life Measurement Characteristics

Reference	QoL outcome: Primary versus secondary	Assessment tool	QoL defined as	QoL measured by
Aitken et al., 2009	Secondary	Peds QL	Achievement	Parental proxy
Erickson et al., 2010	Primary	Peds QL	Achievement	Parental proxy+self-report
McCarthy et al., 2006	Primary	Peds QL	Achievement	Parental proxy
Mealings and Douglas, 2010	Secondary	Composite/inference	Composite	Self-report
Meuli et al., 1991	Secondary	GOS	Composite, achievement	Physician proxy
Petersen et al., 2008	Primary	KINDL, parent	Achievement	Parental proxy
Souza et al., 2007	Primary	SARAH QoL for children and adolescents+interview with parents	Achievement, subjective well being	Parental proxy+self-report
Taylor et al., 2001	Primary	HSU	Achievement	Physician Proxy
Fay et al., 2009	Primary	Composite:^a neuropsychological, behavioral, academic function	Composite, achievement	Self-report (child-assessed); physician proxy
Tilford et al., 2007	Primary	Quality of well-being (quality-adjusted life years)	Health status	Parental proxy
Limond et al., 2009	Primary	Peds QL	Achievement	Parental proxy

Fay et al., 2009: Neuropsychological tests: WISC III, CELF-R, CNT, BNT, COWAT, CVLT, CPT-3, underlining test (subtests 2, 4, and 9), grooved pegboard. Behavioral test: CBCL. Academic tests: Word identification, writing sample, calculation subtest of WJT-A-R; adaptive: VABS.

“Composite” indicates no direct measurement; QoL inferred from other outcome measurements used as a global composite.

KINDL, German Generic Quality of Life Instrument for Children (Ravens-Sieberer and Bullinger, 1998); GOS, Glasgow Outcome Scale (Teasdale and Jennett, 1974); HSU, Health State Utility Index (Torrance et al., 1996); Peds QL, Pediatric Quality of Life Inventory (McCarthy et al., 2005); SARAH, SARAH Network QoL Questionnaire (Souza et al., 2007).

Patient characteristics and TBI severity

A total of 968 participants (parents and children/adolescents with TBI) were assessed across all studies. Of these, 123 participants (12.7%) represent self-reported answers from children and/or adolescents. Not all studies reported demographics, but of those that did 57.3% were male (Taylor et al., 2001 was excluded from the analysis), and had an average age of 11.06 years (range 5 months to 18 years at assessment; Fay et al., 2009 was excluded from the analysis). One study (Meuli et al., 1991) did not report severity characteristics of their sample. Across the remaining 10 studies, 266 (28.4%) children were classified as mild TBI, 241 (25.7%) as moderate TBI, 108 (11.6%) as moderate-to-severe TBI, and 313 (33.4%) as severe TBI. TBI severity was classified using the Glasgow Coma Scale (72.7%), Abbreviated Injury Scale (18.2%), or other means (9.1%).

Definition and measurement of quality of life

The majority of studies (n=8) assessed QoL as a primary outcome. QoL was most commonly defined as achievement (n=7). A composite definition of QoL, reflecting no a priori definition or direct measurement of QoL, was used solely in one of the studies, and as an adjunct to an achievement definition in one study. Composite QoL was seen as a global outcome, comprised of other outcome benchmarks (e.g., social skills). One study assessed health status, and one included subjective well-being.

Proxy-only measurement of QoL was used in seven studies, with one using a proxy+child measurement. One study measured child-only QoL.

Assessment time points

Times of assessment of QoL ranged from 3 months to 5 years post-TBI. Two studies (Aitken et al., 2009; McCarthy et al., 2006) included baseline assessments conducted within 3 weeks of injury (median 16 days).

Favorable versus unfavorable quality of life outcome

Four studies identified a “good” QoL outcome following pediatric TBI, and five defined QoL as “poor.” Two studies did not assess QoL outcome on a scale amenable to “good” versus “poor” quantification, and were excluded from these and further analyses (Aitken et al., 2009; Mealings and Douglas, 2010).

Of those studies outlining a “good” QoL outcome, three studies defined QoL as achievement, and one as health status (quality-adjusted life years). All four of the good-outcome assessments were proxy reports (2 by parents, and 2 by physician proxy). Upon further refinement of the good-outcome operational definition, the study by Tilford and associates (2007) was removed from the analyses, as their “good” was borderline “moderate” (quality of well-being mean score=0.58; range −1 to 0.9). With the Tilford study removed from the analyses, all remaining studies used achievement to define QoL, and all used proxy reporting (50% of studies used parental proxy, and 50% of studies used physician proxy).

Of the poor QoL outcomes, three used an achievement-only definition of QoL, and two combined achievement+other as their definition of QoL (one study used achievement+subjective well being, and one study used achievement+composite). Of those using achievement-only definitions, all assessed QoL via parent-proxy. Of the remaining two studies using achievement+other, one study assessed QoL via parent proxy, and one included child self-report measurement techniques.

Predicting QoL: The relationship between TBI severity, proxy measurements, time of assessment, and definition of QoL

The difference between good and poor QoL outcome was statistically significant as a result of TBI severity [chi-square(3)=77.38, p<0.001], the timing of outcome assessment [chi-square(1)=565, p<0.001], and definition of QoL used [chi-square(3)=34.73, p<0.001]. The difference between use of proxy assessment alone (either parent or physician) versus using a combined assessment involving proxy+individual assessments was not statistically significant [chi-square(2)=2.53, p=0.28].

The odds of having a poor QoL outcome on assessment increased by 5.8 times (RR=1.21) when injuries were of greater severity than when they were mild TBI. When an achievement-based definition of QoL was used, it was five times more likely to have a poor QoL outcome compared to other definitions of QoL. Likelihood of poor QoL increased by 7.9 times when proxy assessments (either parent or physician) were used. Odds ratios and relative risk indices could not be calculated for timing of QoL assessment (≤ 6 months versus ≥ 1 year) because of zero cells.

Key factors involved in good QoL outcome

All studies that reported a good QoL on outcome relied solely on proxy-reported, achievement-based QoL definitions.

Good QoL was identified at the acute assessment time point (≤ 6 months post-injury). When QoL was assessed at 3 and 6 months post-injury, only good QoL was reported across all studies. Of those, three studies assessed mild TBI, and one moderate-to-severe TBI. Severe TBI was not assessed in the studies reporting a good QoL on outcome.

Key factors involved in poor QoL outcomes

Poor QoL outcomes included a mix of achievement-only (n=3) and achievement+other (subjective well being and composite) definitions. The achievement-only studies (n=3) relied solely on parental proxy reports, while the achievement+other study included child self-reports.

Poor QoL on outcome was related to a later assessment time point, with all poor QoL on outcome found when QoL was assessed a minimum of 1 year post-injury (range 1–4.2 years; mean 3.2 years).

The TBI severity assessed in studies reporting poor QoL was variable, including mild (40.2%), moderate (32.4%), moderate-to-severe (4.3%), and severe (22.3%) TBI groups.

Discussion

Overall the findings suggest that QoL after pediatric TBI is poor. This statement, however, must be contextualized by the available data, which indicate that poor outcomes slightly outnumber good outcomes in the data reviewed (56% of the studies reported poor QoL). Predictors of poor QoL include more severe TBI and assessments conducted 1 year or later post-injury.

When considering severity of injury as a predictor of QoL, it is important to acknowledge the breadth of impact it may have across multiple domains, which may either directly or indirectly affect QoL. These additional severity-related variables include: (1) longer recovery time and the need for rehabilitation; (2) greater disruption of family, social, and school life; (3) greater disability in multiple domains, including language, mobility deficits, and epilepsy; and (4) possible disruption of friendship networks due to reduced cognitive and social skills. Each of these factors could impact the overall QoL following brain injury, and because greater severity of injury is more likely to be associated with a host of these problems, it is reasonable to conclude that high severity would have a greater effect on QoL than a milder injury.

Acute and subacute assessments may generate an artificial environment that is poorly relatable to overall QoL in the real-world setting. Many survivors of TBI are involved in a focused rehabilitation, recovery, and re-integration program focusing on getting them back to normal. Assessments completed at this time may reflect ongoing concerns regarding issues in the rehabilitation setting, and exclude components relevant to ongoing life experiences for the adolescent, specifically re-integration into school and social networks.

There are few data available on patient-reported QoL post-pediatric TBI, but in the few studies available (Erickson et al., 2010; Fay et al., 2009; Mealings and Douglas, 2010; Souza et al., 2007), poor QoL has been reported. It is possible that the over-reliance on proxy achievement-based QoL is biasing the literature towards a poorer outcome; indeed, studies including mild brain injuries and early assessment time points have found good QoL. By contrast, when more severe TBI and later assessment time points are used, QoL is rated as poor. The time points at which assessments of QoL are made is an important variable to consider when assessing the accuracy and validity of the QoL outcome marker. Our systematic review highlights that no poor outcomes were reported in the first 6 months after injury, and in contrast, only poor outcomes were reported at 1 year or later post-trauma. All of the good QoL data are 100% reliant on proxy reporting; it may be possible that proxies (e.g., parents or physicians) have not had enough time to properly assess the re-integration of the child/adolescent into their usual real-life world (e.g., return to school, family roles, and friendships).

QoL is not stable over time. It is important to contextualize the nature of the QoL rating in time, as it relates to the stage of their post-injury process. It is possible that assessments done too early in the post-injury period may reflect an unclear picture of the overall impact of the trauma on families and individuals, as neither have yet been exposed to the effects of real-life variables. This review highlights the finding that longer-term outcomes are related to poor QoL. It is possible that these later outcome assessments reflect the impact of time, rehabilitation, and difficulties reintegrating into the academic and social spheres.

Limitations

The review itself may be limited by the nature of the search strategies and corresponding target words used across databases. Although every attempt was made to ensure that articles relating to the construct of QoL were included, it is possible that some were missed as a result of efficiency and the breadth of database searches. Searches were limited to studies published before 2010, and this may have limited the overall number and type of studies available for review at the time of publication.

Future directions

The overwhelming majority of studies assessing QoL post TBI use an achievement-based QoL definition. It would be informative for future studies to incorporate alterative definitions of QoL to explore the effect of injury on outcome when alternate definitions are used. Additionally, few studies involve self-reports. The perspective of the individual patient and his or her experiences post-TBI would be extremely beneficial, especially as it relates to the argument over the impact of preserved versus altered self-awareness.

Methodological issues surrounding definition and time course of assessment should be controlled for in future studies, perhaps by using alternate definitions, self-reports, and longer-term outcome assessments. Ideally, repeated assessments over time would benefit not only the literature on QoL post-TBI, but would also help to identify changes in circumstances, utility and support services used, and overall conceptualization—for the individual and the family—of QoL throughout development.

Conclusions

With systematic examination of the available QoL post-pediatric TBI literature, patterns and predictors of QoL become evident: QoL is most often defined as achievement-based, health-related QoL. Good outcomes are contingent upon milder injuries, proxy reports, and early assessment time points (≤ 6 months post-injury). Poor outcomes are attributable to more severe injuries and later assessment time points (≥ 1 year post-trauma).

Footnotes

Author Disclosure Statement

No competing financial interests exist.

References

Aitken

M.E.

, McCarthy

M.L.

, Slomine

B.S.

, Ding

, Durbin

D.R.

, Jaffe

K.M.

, Paidas

C.N.

, Dorsch

A.M.

, Christensen

J.R.

, Mackenzie

E.J.

2009. Family burden after traumatic brain injury in children. Pediatrics, 123:199–206.

Anderson

V.A.

, Brown

, Newitt

2010. What contributes to quality of life in adult survivors of childhood traumatic brain injury? J. Neurotrauma, 27:1–8.

Anderson

, Brown

, Newitt

, Hoile

2011. Long-term outcome from childhood traumatic brain injury: Intellectual ability, personality, and quality of life. Neuropsychology, 25:176–184.

Anderson

, Catroppa

, Haritou

, Rosenfeld

J.V.

2005. Attentional and processing skills following traumatic brain injury in early childhood. Brain Inj., 19:699–710.

Brooks

D.N.

1991. The head-injured family. J Clin. Exper. Neuropsychol., 13:155–158.

Catroppa

, Anderson

, Rosenfeld

2008. Outcome and predictors of functional recovery 5 years following pediatric traumatic brain injury (TBI) J. Pediatr. Psychol., 33:707–718.

Cattelani

, Lombardi

, Brianti

, Mazzucchi

1998. Traumatic brain injury in childhood: intellectual, behavioural and social outcome into adulthood. Brain Inj., 12:283–296.

Djikers

M.P.

2003. Individualization in quality of life measurement: instruments and approaches. Arch. Phys. Med. Rehabil., 84,Suppl. 2:S3–S14.

Djikers

M.P.

2004. Quality of life after traumatic brain injury: A review of research approaches and findings. Arch. Phys. Med. Rehabil., 85,Suppl. 2:S21–S34.

10.

Erickson

S.J.

, Montague

E.Q.

, Gerstle

M.A.

2010. Health-related quality of life in children with moderate-to-severe traumatic brain injury. Dev. Neurorehabil., 13:175–181.

11.

Ewing-Cobbs

, Barnes

, Fletcher

J.M.

, Levin

H.S.

, Swank

P.R.

, Song

2004. Modelling of longitudinal academic achievement scores after pediatric traumatic brain injury. Dev. Neuropsychol., 25:107–133.

12.

Fay

T.B.

, Yeates

K.O.

, Shari

, Drotar

, Stancin

, Taylor

2009. Predicting longitudinal patterns of functional deficits in children with traumatic brain injury. Neurospychology, 23:271–282.

13.

Goldberg

D.P.

1978. Manual of the General Health Questionnaire. NFER Publishing: Windsor, England.

14.

Koskinen

1998. Quality of life 10 years after a very severe traumatic brain injury (TBI): the perspective of the injured and the closest relative. Brain Inj., 12:631–648.

15.

Landgraf

J.M.

, Abetz

, Ware

J.E.

1996. The CHQ User's Manual. The Health Institute, New England Medical Center: Boston.

16.

Limond

, Dorris

, McMillan

2009. Quality of life in children with acquired brain injury: parent perspectives 1–5 years after injury. Brain Inj., 23:617–622.

17.

McCarthy

, MacKenzie

, Durbin

, Aitken

, Jaffe

, Paidas

, Slomine

, Dorsch

, Berk

, Christensen

, Ding

CHAT Study Group. 2005. The Pediatric Quality of Life Inventory: An evaluation of its reliability and validity for children with traumatic brain injury. Arch. Pediatr. Med. Rehabil., 86:1901–1909.

18.

McCarthy

, MacKenzie

, Durbin

, Aitken

, Jaffe

, Paidas

, Slomine

, Dorsch

, Berk

, Christensen

, Ding

2006. Health-related quality of life during the first year after traumatic brain injury. Arch. Pediatr. Adolesc. Med., 160:252–260.

19.

Mealings

, Douglas

2010. “School's a big part of your life..”: Adolescent perspectives of their school participation following traumatic brain injury. Brain Impairment, 11:1–16.

20.

Meuli

, Sacher

, Unger

, Gobet

, Stauffer

U.G.

1991. Characteristics and prognosis of extradural hematomas in children. Eur. J. Pediatr. Surg., 1:196–198.

21.

Muscara

, Catroppa

, Anderson

2008. Social problem solving skills as a mediator between executive function and long-term social outcome following paediatric traumatic brain injury. J. Neuropsychol., 2:445–461.

22.

Petersen

, Scherwath

, Fink

, Koch

2008. Health-related quality of life and psychosocial consequences after mild traumatic brain injury in children and adolescents. Brain Inj., 22:215–221.

23.

Ravens-Sieberer

, Bullinger

1998. News from the KINDL-Questionnaire—A new version for adolescents. The 5th Annual Conference of the International Society for Quality of Life Research (ISOQOL). Quality Life Res.. 7:653.

24.

Souza

L.M.

, Braga

L.W.

, Filho

G.N.

, Dellatolas

2007. Quality-of-life: child and parent perspectives following severe traumatic brain injury. Dev. Neurorehabil., 10:35–47.

25.

Stroup

D.F.

, Berlin

J.A.

, Morton

S.C.

, Olkin

, Williamson

, Rennie

, Moher

, Becker

B.J.

, Sipe

T.A.

, Thacker

S.B.

for the Meta-analysis of Observational Studies in Epidemiology (MOOSE) Group. 2000. Meta-analysis of observational studies in epidemiology: A proposal for reporting. JAMA, 283:2008–2012.

26.

Taylor

, Butt

, Rosenfeld

, Shann

, Ditchfield

, Lewis

, Klug

, Wallace

, Henning

, Tibballs

2001. A randomized trial of very early decompressive craniectomy in children with traumatic brain injury and sustained intracranial hypertension. Childs Nerv. Syst., 17:154–162.

27.

Teasdale

, Jennett

1974. Assessment of coma and impaired consciousness. A practical scale. Lancet, 2:81–84.

28.

Tilford

J.M.

, Aitken

M.E.

, Goodman

A.C.

, Fiser

D.H.

, Killingsworth

J.B.

, Green

J.W.

, Adelson

P.D.

2007. Child health-related quality of life following neurocritical care for traumatic brain injury: an analysis of preference-weighted outcomes. Neurocrit. Care, 7:64–75.

29.

Torrance

G.W.

, Feeny

D.H.

, Furlong

W.J.

, Barr

R.D.

, Zhang

, Wang

1996. Multiattribute utility function for a comprehensive health status classification system: Health Utilities Index Mark 2. Medical Care, 34:702–722.

30.

Turner-Bowker

D.M.

, Bartley

P.J.

, Ware

J.E.

Jr . 2002. SF-36 Health Survery & “SF” bibliography, 3rd(1988–2000).QualityMetric Incorporated: Lincoln, RI.

31.

Varni

J.W.

, Seid

, Rode

C.A.

1999. The PedsQL: Measurement model for the Pediatric Quality of Life Inventory. Med. Care, 37:126–139.

32.

Yeates

K.O.

, Taylor

H.G.

, Woodrome

S.E.

, Wade

S.L.

, Stancin

, Drotar

2002. Race as a moderator of parent and family outcomes following pediatric traumatic brain injury. J. Pediatr. Psychol., 27:393–403.