CONTEXT.: The death of a child from cancer affects the entire family. Little is known about the long-term psychosocial outcomes of bereaved siblings.

OBJECTIVES: To describe: 1) the prevalence of risky health behaviors, psychological distress, and social support among bereaved siblings; and 2) potentially modifiable factors associated with poor outcomes.

METHODS: Bereaved siblings were eligible for this dual-center, cross-sectional, survey-based study if they were 16 years old or older and their parents had enrolled in one of three prior studies about caring for children with cancer at the end of life. Linear regression models identified associations between personal perspectives before, during, and after the family's cancer experience and outcomes (health behaviors, psychological distress, and social support).

RESULTS: Fifty-eight siblings completed surveys (62% response rate). They were approximately 12 years bereaved, with a mean age of 26 years at the time of the survey (SD=7.8). Anxiety, depression, and illicit substance use increased during the year following their brother/sister's death, but then returned to baseline. Siblings who reported dissatisfaction with communication, poor preparation for death, missed opportunities to say "goodbye," and/or a perceived negative impact of the cancer experience on relationships tended to have higher distress and lower social support scores (P<0.001-0.031). Almost all siblings reported their loss still affected them; half stated the experience impacted current educational and career goals.

CONCLUSION: How siblings experience the death of a child with cancer may impact their long-term psychosocial well-being. Sibling-directed communication and concurrent supportive care during the cancer experience and the year following sibling death may mitigate poor long-term outcomes.