Falling fertility on the left as key driver of US birth decline.

Acquired brain injury (ABI) includes any damage sustained to the brain after birth that is not caused by a congenital or perinatal condition. ABI can be categorized into traumatic brain injury (TBI), due to external causes such as traffic and sport incidents, and non-traumatic brain injury (nTBI), due to internal causes such as stroke and brain tumors. In the Netherlands, the estimated annual incidence of TBI and nTBI among those under the age of 25 is 586 and 191 per 100,000, respectively. Due to natural adaptation of the brain, approximately 70% of these young patients recover within six months after the injury. However, an estimated 30% of young patients continue to report persistent problems beyond six months; for this subgroup, multidisciplinary outpatient rehabilitation may be indicated. Studies in pediatric and young adult ABI cohorts report persistent problems across multiple domains of functioning as described by the International Classification of Functioning, Disability and Health (ICF) (e.g., body functions, activities, and participation), which can adversely affect health-related quality of life (HRQoL). HRQoL is described as a multidimensional concept, comprised of physical, functional, emotional, and social wellbeing domains which can be affected by perceived health, illness, and injury. In outpatient rehabilitation, assessing HRQoL during the first specialist consultation following referral can help identify patient-reported difficulties and support clinical and shared decision-making regarding rehabilitation goals. When HRQoL is assessed repeatedly during care, it may also support monitoring of change over time. To assess HRQoL, patient- or parent-reported outcome measures (PROMs) are often used. Several HRQoL PROMs are available, including the Quality of Life after Brain Injury (QOLIBRI), the Short Form Health Survey (SF-36), Kidscreen-27, and KINDL-R. However, the QOLIBRI and SF-36 are designed for adults, whereas Kidscreen-27 and KINDL-R are validated only up to 18 years, limiting their use across the transition from adolescence to young adulthood. Additionally, the World Health Organization (WHO) states that HRQoL instruments should be multidimensional, including at minimum physical, social and psychological (including cognitive and emotional) dimensions. The Pediatric Quality of Life Inventory™ Generic Core Scales 4.0 (PedsQL GCS) is widely used in youth (5–30 years), including in ABI populations; spans the child-to-adult transition period; and covers physical, emotional, social and school/work functioning. The PedsQL GCS has adequate validity, feasibility and reliability and is available in Dutch. It provides a 0–100 score, with lower scores indicating more diminished HRQoL. While this scale is intuitive, clinicians and families often benefit from normative benchmarks or cut-offs to interpret whether a given score reflects clinically relevant impairment relative to healthy peers. These benchmarks or cut-offs can also support communication and clinical decision-making. Moreover, when HRQoL is assessed repeatedly during care, a norm-referenced categorization may support interpretation of changes over time, particularly since minimal clinically important differences (MCIDs) for outpatient ABI populations are not well established. Using cut-off points alongside the conventional 0–100 scores may therefore facilitate an additional clinically meaningful interpretation of HRQoL outcomes.