<p><strong>Importance: </strong>Despite concerns regarding the potential deleterious physical and mental health outcomes among family members of a child with a life-threatening condition (LTC), few studies have examined empirical measures of health outcomes among these family members.</p>

<p><strong>Objectives: </strong>To examine whether mothers, fathers, sisters, and brothers of children with 1 of 4 types of pediatric LTCs have higher rates of health care encounters, diagnoses, and prescriptions compared with families of children without these conditions.</p>

<p><strong>Design, Setting, and Participants: </strong>This retrospective cohort study included US families with commercial insurance coverage from a single carrier. Children who had 1 of 4 LTCs (substantial prematurity, critical congenital heart disease, cancer, or a condition resulting in severe neurologic impairment) were identified by a diagnosis in their insurance claim data between July 1, 2015, and June 30, 2016. Each case child and their family was matched with up to 4 control children and their families based on the age of the case and control children. Data were analyzed between August 2020 and March 2021.</p>

<p><strong>Exposures: </strong>Having a child or sibling with substantial prematurity, critical congenital heart disease, cancer, or a condition resulting in severe and progressive neurologic impairment.</p>

<p><strong>Main Outcomes: </strong>Rates of occurrence of health care encounters, physical and mental health diagnoses, and physical and mental health medication prescriptions, identified from insurance claims data, were compared between case and control families using a multivariable negative binomial regression model. The statistical analysis adjusted for observed differences between case and control families and accounted for clustering at the family level.</p>

<p><strong>Results: </strong>The study included 25 528 children (6909 case children [27.1%] and 18 619 control children [72.9%]; median age, 6.0 years [IQR, 1-13 years]; 13 294 [52.1%] male), 43 357 parents (11 586 case parents [26.7%] and 31 771 control parents [73.3%]; mean [SD] age, 40.4 [8.1] years; 22 318 [51.5%] female), and 25 706 siblings (7664 case siblings [29.8%] and 18 042 control siblings [70.2%]; mean [SD] age, 12.1 [6.5] years; 13 114 [51.0%] male). Overall, case mothers had higher rates of the composite outcome of health care encounters, diagnoses, and prescriptions compared with control mothers (incident rate ratio [IRR], 1.61; 95% CI, 1.54-1.68), as did case fathers compared with control fathers (IRR, 1.55; 95% CI, 1.46-1.64). Sisters of children with LTCs had higher rates of the composite outcome compared with sisters of children without LTCs (IRR, 1.68; 95% CI, 1.55-1.82), as did brothers of children with LTCs compared with brothers of children without LTCs (IRR, 1.70; 95% CI, 1.56-1.85).</p>

<p><strong>Conclusions and Relevance: </strong>In this cohort study, mothers, fathers, sisters, and brothers who had a child or sibling with 1 of 4 types of LTCs had higher rates of health care encounters, diagnoses, and medication prescriptions compared with families who did not have a child with that condition. The findings suggest that family members of children with LTCs may experience poorer mental and physical health outcomes. Interventions for parents and siblings of children with LTCs that aim to safeguard their mental and physical well-being appear to be warranted.</p>

<p>Caring for a child with a serious or life-limiting illness presents many challenges for families and health care providers. Through that experience (and, many times, as it ends), parents are compelled to find and make meaning from their ultimate loss and the many losses along the way. In this Advocacy Case Study, we describe the experiences that led a bereaved mother to seek to harness the insights from her own family's loss to help support other families facing the challenges and complexities of a child's serious illness. Her family initially established a family foundation to advocate for palliative care. She later partnered with her family's general pediatrician and the American Academy of Pediatrics to educate providers and bring parent voices to health care provider discussions. This work eventually led to the development of the Courageous Parents Network, a nonprofit focused on making these parent and provider voices widely available to families and providers through a Web-based collection of videos, blogs, podcasts, and printable guides. Through these insights, the organization addresses feelings of isolation, anxiety, and grief. In addition, these voices illustrate the power and benefits of the growing acceptance of pediatric palliative care practices. Important lessons learned through these efforts include: (1) the power of stories for validation, healing, and understanding; (2) opportunity to extend the reach of pediatric palliative care through provider education and skill-building; (3) critical importance of the parent-provider advocacy collaboration; and (4) necessity of market testing and continuous improvement.</p>