In selecting outcome domains, the Pediatric CDE Workgroup sought to preserve the focus that was established by the original CDE Workgroup, consider outcomes at multiple levels, and select measures of import to stakeholders, scientists, and practitioners. Of the original CDE domains, we included global outcome, recovery of consciousness, perceived health-related quality of life, neuropsychological impairment, physical functioning, psychological status, and TBI-related symptoms. The number of domains was expanded to also include measures related to academics, daily life skills/adaptive functioning, family/environment, language and communication, social cognition, and social competence/role participation. Finally, a subset of measures that could be used with infants and toddlers was included, given their unique developmental issues. When possible, measures were identified that spanned a wide age range to avoid the need to change measures between childhood and adolescence. Spanish translations that have been standardized are noted. (The Pediatric CDE Workgroup also recognizes that other translations including Spanish exist but have not been validated.) As with the original CDE, we sought a set of measures that collectively could cover the continua from acute to long-term outcome and from mild to severe TBI. These domains are further described in .
Outcome Domains and Descriptions
Factors of importance in selecting outcome measures within the domains
Consistent with the intent of the original CDE, measures in the pediatric subset were selected to maximize the ability of clinical researchers to: 1) document the natural course of recovery after TBI; 2) enhance the prediction of later outcome; 3) measure the effects of treatment; and 4) facilitate comparisons across centers/studies.
The Pediatric CDE Workgroup divided into smaller subgroups based on interests and expertise to identify sets of measures and detailed characteristics of potential measures for each domain. Measures were identified using the following criteria: 1) sufficient representation in the scientific literature and/or widespread use among the pediatric TBI clinical and research communities in diagnosis, outcome measurement and, prediction, or treatment effectiveness; 2) evidence of sound psychometric properties including construct validity, internal consistency, sensitivity to change, test–retest reliability, and intra-/inter-rater agreement; 3) well-established normative data; 4) applicability across a range of injury severity, functional levels, and developmental levels; 5) availability in the public domain; 6) ease of administration; 7) brevity; and 8) continuity with the original CDE measures where practicable. Whenever possible, the panel considered factors that would render the measures appropriate for international use, such as the availability in different languages and validation in different ethnic groups. For measures of health-related quality of life, activity/participation, and psychological function, consideration was also given to flexibility of formats (e.g., telephone interview versus in-person administration or self versus proxy respondent). Finally, for standardized, performance-based neuropsychological measures, the availability of alternate forms to minimize practice effects was given careful consideration.
Distinguishing core, supplemental, and emerging outcome measure recommendations
In accordance with other CDE Workgroups, three tiers of CDE were recommended: Core, Supplemental, and Emerging (Miller et al., in press,
Thurmond et al., 2010
). First, well-established core measures covering outcome domains relevant to most TBI studies were included. Core measures were selected with the idea that many of these could be applied across large TBI studies, either as a comprehensive battery or in addition to other outcome measures selected by the investigator when practicable. As with all CDEs, the use of these recommended measures should be tempered by the specific study objectives, design, and target populations; they should not be viewed as prescriptive or required for inclusion in research studies. The goals of the research studies should remain paramount when selecting appropriate outcome measures.
In the second tier, supplemental measures were recommended for consideration in pediatric TBI research focusing on specific topics or populations. For example, a study in which language and communication, physical functioning, or neuropsychological outcome is of particular interest may draw upon measures from the supplemental list that target functions not tapped specifically by the core. In the third tier, emerging measures include important instruments currently under development, in the process of validation, or nearing the point of published findings with pediatric TBI. These instruments are potentially superior to some measures currently in the core and supplemental lists or examine a novel construct within a domain.
General process for selecting common data elements
Each member of the panel selected one or more outcome domains based upon interest and expertise. Subgroups of panel members developed initial lists of potential measures within each domain and provided information on the criteria detailed previously. The potential measures were discussed among the entire panel via a series of conference calls, and a more limited set of measures for each outcome domain was selected for further discussion among the panel at a face-to-face meeting in Houston in March 2010. In preparation for the meeting, all panel members assisted in composing a series of tables detailing relevant information on general administration characteristics, psychometric properties, and advantages and limitations of each of the potential measures.
As with the original CDE meeting in March 2009, the primary objective of the meeting was to further examine, refine, and limit the list of potential outcome measures using the information collected and reviewed. In accordance with other CDE working groups, a final set of measures was selected and organized into the three tiers described previously, after further discussion of the relative advantages and limitations of each measure. Selection of the final measures for each level of CDE was accomplished by Workgroup consensus. When disagreements arose regarding the selection of some measures, extensive discussion of the relevant merits and disadvantages of the measures continued (often spanning several conference calls and e-mail exchanges) until a consensus was achieved. In rare instances when the group was unable to reach consensus, more than one measure was included along with the considerations for the use of each.
Description and selection of core, supplemental, and emerging CDE
Consistent with the original CDE objective, the Pediatric CDE Workgroup sought to select a single measure (or at most a limited set of measures) that best covered each domain. Brevity, ease of administration, and purchase cost influenced the selection of Core measures, because the intent was to recommend measures that could feasibly be administered in a variety of settings and across a range of age and post-injury functional levels. Availability of tests in Spanish or other languages was also considered. Measures with established reliability and validity for children with TBI were prioritized when available for these core measures. In three cases, two “comparable” or at least widely used measures were selected (i.e., in the core measures of domains: infant and toddlers, memory, and physical functioning) because a choice could not be reasonably made between them based on psychometric properties, specifics of the domain they assess, or other important characteristics.
The rationale behind creating a set of supplemental measures was to recommend additional measures in each domain that could be considered for more in-depth outcome assessment within a certain domain or for patients at a specific functional level. Additionally, measures of psychological and/or family functioning or substance abuse were included here because of their importance, depending upon the study design, functional level, recovery phase, or target population. Other reasons for inclusion in this category included the probability of ceiling effects outside of rehabilitation populations (e.g., including the Pediatric Evaluation of Disability Inventory for children in the acute recovery phase, but the Bruininks-Oseretsky Test of Motor Proficiency-2 for children further along in their recovery), the requirement for specialized training (e.g., Language Sample, K-SADS-P/L), normative data limitations, and cost.
The third tier – emerging measures – filled existing gaps in measurement of TBI-related sequelae in children. Additionally, some of these measures may better facilitate comparison across patient groups (e.g., to allow comparison with different neurologic disease populations, inclusion of a broader age range, more comprehensive sampling of domains of function, etc.). Emerging measures require ongoing consideration to progress to becoming supplemental or core CDE measures, as evidence accumulates regarding their psychometric characteristics, normative data, and utility in pediatric TBI research.
As with the original CDE, the efforts of the Pediatric CDE Workgroup reflect a dynamic tension between the desire to maintain consistency among a stable set of measures and the desire to adopt new, improved measures as they become available. The selection of recommended outcome measures is an evolving process and recommendations may change with additional evidence and discussion regarding the current CDEs. Therefore, the Pediatric CDE Workgroup advises the reader to consult the CDE website (http://www.nindscommondataelements.org
) for any updates to this listing, particularly with respect to emerging measures.