Care complexity and inequities in caregiving time for undiagnosed infants and toddlers with special health care needs: a cross-sectional study in Japan

Infants and toddlers with complex medical needs often rely on consistent caregiving and health services. However, when such children remain undiagnosed, their needs may be overlooked by health and social support systems, leading to unequal access to care. This study aimed to explore how caregiving time differs according to the complexity of health care needs among children younger than 3 years of age in Japan, with particular attention to those without formal diagnoses. We conducted a cross-sectional online survey of caregivers raising children younger than 3 years of age in Japan (N = 296). Participants were categorized into three groups based on responses to the Children with Special Health Care Needs (CSHCN) Screener: more complex needs, less complex needs, and non-CSHCN. We examined the distribution and duration of caregiving activities, including medical care, rehabilitation, administrative coordination, commuting, and daily care. Twenty children were classified as having more complex needs despite lacking formal diagnoses. This group exhibited significantly higher time burdens related to rehabilitation, institutional coordination, and hospital visits than non-CSHCN, with minimal time spent on typical childrearing. The caregiving pattern revealed disparities in support and highlighted a high degree of unmet needs in the undiagnosed population. Children with complex medical needs who lack a diagnosis experience substantial caregiving burden that are often unrecognized by existing support systems. Addressing diagnostic barriers and expanding need-based support frameworks is essential for ensuring equitable caregiving conditions and child well-being.