Dagmar Timmermann

Mrs. Dagmar Timmermann


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
Nicole von SteinbüchelNicole von Steinbüchel
Nicole von Steinbüchel
Marina ZeldovichMarina Zeldovich
Marina Zeldovich
SGSven Greving
Sven Greving
LLLaiene Olabarrieta Landa
Laiene Olabarrieta Landa
UKUgne Krenz
Ugne Krenz
KCKatrin Cunitz
Katrin Cunitz
The subjective impact of the consequences of pediatric traumatic brain injury (pTBI) on different life dimensions should be assessed multidimensionally and as sensitively as possible using a disease-specific health-related quality of life (HRQoL) instrument. The development and psychometrics of the first such self-report questionnaire for children and adolescents after TBI are reported here. Focus group interviews with children, adolescents, and their parents, cognitive debriefing, item pool generation and reduction using Delphi expert panels were performed. The resulting version was psychometrically tested on 300 individuals aged 8–17 years. After item reduction based on factor analyses, differential item functioning, reliability, and validity were investigated. The final 35 items were associated with six scales (Cognition, Self, Daily Life and Autonomy, Social Relationships, Emotions, Physical Problems). Internal consistency and construct validity were satisfactory. Health-related Quality of life (HRQoL) was significantly lower in older and in female participants, as well as those with cognitive disabilities, anxiety, depression and post-concussion symptoms, than in comparative groups. The new QOLIBRI-KID/ADO is a comprehensive, multidimensional, reliable, and valid instrument, comparable in content and items to the QOLIBRI adult version. Therefore, disease-specific HRQoL can now be measured across the lifespan and may support the amelioration of treatment, care, rehabilitation, and daily life of children and adolescents after TBI.

31 December 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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FBFabian Bockhop
Fabian Bockhop
Marina ZeldovichMarina Zeldovich
Marina Zeldovich
SGSven Greving
Sven Greving
UKUgne Krenz
Ugne Krenz
KCKatrin Cunitz
Katrin Cunitz
Nicole von SteinbüchelNicole von Steinbüchel
Nicole von Steinbüchel
The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) assesses post-concussion symptoms (PCS) after traumatic brain injury (TBI). The current study examines the applicability of self-report and proxy versions of the German RPQ in adolescents (13–17 years) after TBI. We investigated reliability and validity on the total and scale score level. Construct validity was investigated by correlations with the Post-Concussion Symptoms Inventory (PCSI-SR13), Generalized Anxiety Disorder Scale 7 (GAD-7), and Patient Health Questionnaire 9 (PHQ-9) and by hypothesis testing regarding individuals’ characteristics. Intraclass correlation coefficients (ICC) assessed adolescent–proxy agreement. In total, 148 adolescents after TBI and 147 proxies completed the RPQ. Cronbach’s α (0.81–0.91) and McDonald’s ω (0.84–0.95) indicated good internal consistency. The three-factor structure outperformed the unidimensional model. The RPQ was strongly correlated with the PCSI-SR13 (self-report: r = 0.80; proxy: r = 0.75) and moderately–strongly with GAD-7 and PHQ-9 (self-report: r = 0.36, r = 0.35; proxy: r = 0.53, r = 0.62). Adolescent–proxy agreement was fair (ICC [2,1] = 0.44, CI95% [0.41, 0.47]). Overall, both self-report and proxy assessment forms of the German RPQ are suitable for application in adolescents after TBI. As proxy ratings tend to underestimate PCS, self-reports are preferable for evaluations. Only if a patient is unable to answer, a proxy should be used as a surrogate.

5 April 2024 in Children
Verified
Journal Article
Open access
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NSNicole von Steinbuechel
Nicole von Steinbuechel
Marina ZeldovichMarina Zeldovich
Marina Zeldovich
DTDagmar Timmermann
Dagmar Timmermann
UKUgne Krenz
Ugne Krenz
IKInga K. Koerte
Inga K. Koerte
KCKatrin Cunitz
Katrin Cunitz
Until recently, no disease-specific health-related quality of life (HRQoL) questionnaire existed for pediatric traumatic brain injuries (TBIs). In this revalidation study, the psychometric properties and the validity of the 35-item QOLIBRI-KID/ADO questionnaire in its final German version were examined in 300 children and adolescents. It is the first self-reported TBI-specific tool for measuring pediatric HRQoL in individuals aged between 8 and 17 years. The six-factor model fits the data adequately. The questionnaire’s internal consistency was excellent for the total score and satisfactory to excellent for the scale scores. Intraclass correlations indicated good test–retest reliability, and the measure’s construct validity was supported by the overlap between the QOLBRI-KID/ADO and the PedsQL, which measures generic HRQoL. The discriminant validity tests showed that older children and girls reported a significantly lower HRQoL than comparison groups, and this was also true of children who were anxious or depressed, or who suffered from post-concussion symptoms, replicating the results of the questionnaire’s first developmental study. Our results suggest that the QOLIBRI-KID/ADO is a reliable and valid multidimensional tool that can be used together with the adult version in clinical contexts and research to measure disease-specific HRQoL after pediatric TBI throughout a person’s life. This may help improve care, treatment, daily functioning, and HRQoL after TBI.

30 November 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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KCKatrin Cunitz
Katrin Cunitz
IHIvana Holloway
Ivana Holloway
AHAnne Harzendorf
Anne Harzendorf
SGSven Greving
Sven Greving
Marina ZeldovichMarina Zeldovich
Marina Zeldovich
NSNicole von Steinbuechel
Nicole von Steinbuechel
Pediatric health-related quality of life (HRQoL) as a measure of subjective wellbeing and functioning has received increasing attention over the past decade. HRQoL in children and adolescents following pediatric traumatic brain injury (pTBI) has been poorly studied, and performing adequate measurements in this population is challenging. This study compares child/adolescent and parent reports of HRQoL following pTBI using the newly developed Quality of Life after Brain Injury in Children and Adolescents (QOLIBRI-KID/ADO) questionnaire. Three hundred dyads of 8–17-year-old children/adolescents and their parents were included in the study. The parent–child agreement, estimated using intraclass correlation coefficients and Cohen’s κ, displayed poor to moderate concordance. Approximately two-fifths of parents (39.3%) tended to report lower HRQoL for their children/adolescents on the total QOLIBRI-KID/ADO score. At the same time, about one-fifth (21.3%) reported higher HRQoL Total scores for their children/adolescents. The best agreement for parents rating adolescents (aged 13–17 years) was found in terms of the Total score and the Cognition and Self scale scores. To date, parent-reported HRQoL has been the preferred choice in pediatric research after TBI. However, with a parent–child disagreement of approximately 60%, our results highlight the importance of considering self-reports for children/adolescents capable of answering or completing the HRQoL measures.

16 November 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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DTDagmar Timmermann
Dagmar Timmermann
UKUgne Krenz
Ugne Krenz
SSSilke Schmidt
Silke Schmidt
MLMichael Lendt
Michael Lendt
CSChristel Salewski
Christel Salewski
Nicole von SteinbüchelNicole von Steinbüchel
Nicole von Steinbüchel
Background: The assessment of the impact of pediatric traumatic brain injury (TBI) on the health-related quality of life (HRQoL) of the children and adolescents affected can be ameliorated by a disease-specific instrument. Such an instrument does not yet exist. This qualitative study investigates how children and adolescents after TBI subjectively perceive their HRQoL and whether and how this differs from the perspective of individuals without a history of TBI. Methods: Eight problem-centered interviews were conducted with 11 children and adolescents around four years after mild TBI and with eight children and adolescents around three years after moderate to severe TBI. Nine problem-centered interviews were conducted with 25 participants without a history of TBI. The interviews were recorded and transcribed verbatim. The statements were assigned to inductively and deductively derived categories relevant to the HRQoL of children and adolescents after TBI and compared with those of individuals without a history of TBI. Results: The HRQoL of children and adolescents after TBI tended to display both structural and content-related differences, independently of TBI severity, on several HRQoL dimensions, in contrast to the comparison group. For example, participants after TBI reported a broader range of negative emotions (such as worry, sadness, shame, and guilt), permanent physical impairments, felt that they were treated differently from others, and perceived cognitive limitations. Conclusions: The results of this qualitative study identified HRQoL dimensions that are relevant to children and adolescents after TBI and underlined the need for the development of a disease-specific instrument.

Verified
Journal Article
Open access
PDF file
Marina ZeldovichMarina Zeldovich
Marina Zeldovich
KCKatrin Cunitz
Katrin Cunitz
SGSven Greving
Sven Greving
Holger MuehlanHolger Muehlan
Holger Muehlan
FBFabian Bockhop
Fabian Bockhop
Nicole von SteinbüchelNicole von Steinbüchel
Nicole von Steinbüchel
Health-related quality of life (HRQOL) is an important indicator for recovery after pediatric TBI. To date, there are a few questionnaires available for assessing generic HRQOL in children and adolescents, but there are not yet any TBI-specific measures of HRQOL that are applicable to pediatric populations. The aim of the present study was to examine psychometric characteristics of the newly developed Quality of Life After Brain Injury Scale for Kids and Adolescents (QOLIBRI-KID/ADO) questionnaire capturing TBI-specific HRQOL in children and adolescents using an item response theory (IRT) framework. Children (8–12 years; n = 152) and adolescents (13–17 years; n = 148) participated in the study. The final version of the QOLIBRI-KID/ADO, comprising 35 items forming 6 scales, was investigated using the partial credit model (PCM). A scale-wise examination for unidimensionality, monotonicity, item infit and outfit, person homogeneity, and local independency was conducted. The questionnaire widely fulfilled the predefined assumptions, with a few restrictions. The newly developed QOLIBRI-KID/ADO instrument shows at least satisfactory psychometric properties according to the results of both classical test theoretical and IRT analyses. Further evidence of its applicability should be explored in the ongoing validation study by performing multidimensional IRT analyses.