The concept of unmet medical need (UMN) has received significant attention in the recent proposal for the revision of the pharmaceutical legislation in Europe, where it is presented as a key concept to guide pharmaceutical research and development (R&D) towards addressing gaps in underserved areas, aiming to create a more patient-centred health system (1). Beyond the European regulatory context, national health agencies are also increasingly considering the application of the UMN concept in their decision-making processes. So does the Belgian regulator, who uses the UMN concept as an eligibility criterion for the application of early access schemes such as the medical need program (2). However, translating UMN into national frameworks has raised questions about scope and relevance of this concept in different contexts (3, 4).

To address this, the Belgian Health Care Knowledge Centre (KCE) has developed the Needs Evaluations, Examination and Dissemination (NEED) framework to systematically assess unmet health-related needs (UHNs) (5). This framework provides a structured and scientifically robust methodology for identifying patient and societal needs through predefined criteria, indicators, using patient surveys, interviews with patients and experts, database analysis, and literature reviews (5). The ultimate goal of the NEED assessment is to ensure that healthcare stakeholders and policymakers integrate these findings into decision-making and priority-setting to enhance patient-centred care and healthcare innovation (5).

Although research has already been performed in identifying UHNs in adult patients, the needs of specific populations, such as the paediatric population, tend to be less frequently investigated. This is particularly striking given that, according to Eurostat in 2021, 4.4% of children reported a disability, defined as an activity limitations, due to health problems (6). The considerable differences in the pharmacokinetics and pharmacodynamics between children and adults highlight the risk of extrapolating adult data for paediatric use, risking underdosing or toxicity effects in those children (7–9).

Cancer is the primary cause of disease-related deaths among children and adolescents, with in 2022, approximately 14,000 cancer diagnoses in children in Europe, and around 2,000 deaths reported annually (10). The importance of research on children is shown in acute lymphoblast leukaemia, where the five-year survival rate spectacularly improved from 25% to 75% following multicentre trials including children, instead of extrapolating adult data for use in children (8).

The objectives of this study are (i) to identify and characterise paediatric-specific unmet health needs (UHN) criteria, (ii) to explore if these UHN criteria are already included in the existing KCE NEED framework and provide recommendations for tailoring the framework for paediatric-specific application, and (iii) to identify existing tools used to assess these needs in the paediatric population.

Haematologic malignancies were chosen for this study due to their high prevalence, accounting for more than one-third of paediatric malignancies, ensuring generalisable findings (10). The disease can occur across all paediatric age groups, allowing for insights into age-specific health needs. Its early onset and persistence throughout childhood further enable an assessment of UHNs across different developmental stages. Additionally, intensive and prolonged treatments, including chemotherapy, radiation and stem cell transplantation, lead to long-term physical, psychological, and social challenges. This broad impact makes haematologic malignancies an ideal model for studying UHNs in paediatric chronic illness.

This review identified the age-specific UHNs of paediatric haematologic malignancies patients and their families, extending beyond medicinal or therapeutic gaps covered by UMN currently used in regulatory context, categorised across health, healthcare, and social domains. For paediatric patients with haematologic malignancies, five key criteria were identified: mental health, autonomy, forgone care, social interactions, and educational continuity. Among AYAs, additional needs emerged, including age-dependent information and involvement, treatment adherence, and future perspectives. For families, information needs were universally reported. Among informal caregivers, further challenges included mental health, privacy, organization of care, family stability, social interactions, and financial stability. Siblings specifically highlighted reduced parental attention as a significant UHN.

These findings indicate that children with haematologic malignancies and their families face a wide range of UHNs that extend beyond medical treatment and often stay unaddressed. Previous research aligns with our findings, as AYAs undergoing haematopoietic stem cell transplantation have greater information and support needs related to psychological health, body image, and sexuality than adults, and they also face UHNs concerning peer relationships, education, and fertility (7–9, 59–62). In contrast, less research exists on younger children, though depression and anxiety affect 6%–15% of paediatric patients (59). The study by Kahn et al. found that approximately 25% of patients demonstrated non-adherence during oral 6-mercaptopurine treatment (63). Notably, the majority of respondents were fathers or male caregivers, and 77% of the children with acute lymphoblastic leukemia (ALL) were older than 12 years. It is important to note that adherence in this study, as well as the studies we included in our review, was measured through self-report, which likely led to an underestimation of the true prevalence of non-adherence. Furthermore, the study reported a significant association between treatment adherence and parental education level, underscoring the relevance of socio-demographic factors in adherence behavior (63). Our findings regarding UHNs of informal caregivers aligned with previous findings, especially on the importance of organisation of care, which enhances their relationship with HCPs (52).

Although the present review focused on UHNs in haematologic malignancies, our findings align with literature regarding general paediatric oncology and even in the broader paediatric setting. Specific commonalities include mental health needs, the lack of being involved in investigations and decision-making, educational discontinuity, and reduced medication adherence (26, 52, 64–66). Specifically, social isolation and mental health unmet needs can be linked to a lack of normalcy during cancer care. To address this, clinicians should pay attention to restoring a sense of normalcy and support AYA quality of life by acknowledging and reinforcing identities that extend beyond the cancer diagnosis (67). Moreover, Mack et al. highlighted that 80% of more than 200 newly diagnosed AYAs with cancer considered it important to receive correct information on their prognosis (68). In line with our results, it was described that receiving more information resulted in greater trust in the HCP and less distress (68). Additionally, in a study from Rosenberg et al, investigating 35 AYAs with cancer with an average age of 17.6 years, it was found that sexual intimacy and substance use are common among AYAs. In this study, 40% of participants reported at least 1 communication need, including fertility, safe sex and birth control (69).The challenge of forgone care is also recognized by the European Commission, which specifically identifies dental care as an UHN (6). Finally, social determinants such as household composition and income influence the distribution and severity of unmet needs, reinforcing the importance of equity-sensitive assessment approaches. Additionally, children's UHNs vary based on household composition, with higher reported needs in single-parent households and lower-income families (6). Financial stability is a well-documented UHN among parents of children with cancer, which has been consistently associated with poorer parental emotional health and reduced quality of life (70–72). Parental work disruption is widespread, regardless of income level, while treatment-related costs that fall outside of insurance or universal healthcare coverage can cause significant additional expenses (72–74). Parental divorce or separation during or after treatment was not explicitly captured in the included studies, although it may represent a critical yet under-reported determinant of family stability and paediatric patients’ health-related needs.

Extrapolation of the identified UHN to other paediatric populations should be approached with caution. In line with the generic NEED framework, the application of UHN criteria requires a prior assessment of eligibility and relevance within each disease context. The relevance and expression of individual UHN criteria may therefore differ across paediatric chronic or life-threatening conditions and cannot be assumed a priori. Accordingly, extrapolation beyond haematological malignancies should be regarded as hypothesis-generating rather than confirmatory, and the framework should be applied as a flexible analytic tool following a structured relevance assessment. A similar sensitivity consideration applies to age categorisation, as the identified UHN criteria may differ if adolescents and young adults were excluded or if age-stratified analyses were available, reflecting developmental differences across paediatric age groups. Moreover, children with solid tumours might encounter distinct or more pronounced UHN, due to tumour locations and treatments. For example, as described in literature, children suffering from central nervous brain tumours might encounter neurological, cognitive and neuropsychological deficits (75, 76). Likewise, extremity sarcomas requiring amputation can generate functional impairments, and attention must be drawn to body image concerns, as these may persist long after treatment (77–79).

One of the key needs identified in this study by both children and their families is age-appropriate information and active involvement in care. A widely recognized concept in clinical practice is shared decision-making, which empowers patients to participate in their healthcare journey, however very frequently still lacking (80–82). This approach is often supported by digital tools, providing accessible information and facilitating informed decision-making. Approximately 60% of children aged between 0 and 11 years old, and more than 80% of AYAs have access to a smartphone or computer (83, 84). In this light, digital tools could be valuable as they have the potential to address UHNs in both children as well as their families. Several studies investigate the context in which these tools can be used, comprising information needs, medication adherence, and engagement in research, and whether paediatric patients and their families are receptive to them (59, 85–87).

This study can complement existing research initiatives that map health-related needs in the general population by adapting these frameworks for the paediatric setting, thus shaping decision-making and healthcare innovation towards a more patient-centred setting. Specifically, for the KCE NEED framework, the inclusion of paediatric-specific criteria, such as age-dependent information and involvement, future perspectives, and treatment adherence, could be considered. Additionally, the broader impact on families, including siblings, could be integrated into such assessments to provide a comprehensive understanding of paediatric healthcare needs. Lastly, developmental and age-stratified dimensions should be incorporated to capture differences across childhood, adolescence, and young adulthood.

It is important to clarify the relationship between the UHN identified in this study and the concept of UMN as applied in regulatory and policy contexts. UMN is most commonly operationalized with a primary focus on therapeutic or medicinal gaps. In contrast, the findings of this review demonstrate that paediatric patients and their families experience a broader and interconnected set of health-related needs that extend beyond medical treatment alone. Accordingly, the NEED framework applied in this study is not intended to redefine UMN, but rather to offer a structured and transparent approach to identifying additional dimensions of need, including psychosocial, developmental, family-level, and system-related aspects, which may, where considered relevant by decision-makers, inform UMN assessments.

Recent years have seen a gradual shift in many healthcare policy discussions toward a more holistic understanding of patient needs, including psychological support, information provision, and shared decision-making, while medicine-oriented approaches remain central. Concurrently, the 2023 proposal for a reform of the pharmaceutical legislation highlights the concept of unmet medical needs, aiming to steer R&D toward areas with significant gaps, such as paediatric diseases (88). While this growing focus is promising, it is essential to adopt a holistic approach that extends beyond medicinal needs. Based on this study's findings, it is recommended that other health-related impacts, such as psychosocial support, educational continuity, and family well-being, are considered in decisions related to reimbursement policies, research priorities, and treatment development.

This study highlights the need for a holistic approach to address the UHNs of paediatric haematologic malignancies patients and their families, extending beyond medical treatment to include age-specific information, treatment adherence, and mental health support. Existing frameworks, such as the KCE NEED framework, should be tailored for application in the paediatric population by incorporating these paediatric-specific criteria. The increasing focus on unmet medical needs in European health policy is a unique opportunity to ensure that research priorities, reimbursement decisions, and treatment development consider broader health impacts, promoting comprehensive, patient-centred paediatric care. From a practice and policy perspective, this study shows the importance of routine implementation of identified aspects, such as providing age-appropriate information and involvement of paediatric patients and their needs in clinical and regulatory decision-making. Lastly, family criteria should be included in needs assessment, to capture family mental health, sibling outcomes, and socioeconomic strains.