Impact of Cystic Fibrosis on Unaffected Siblings: A Systematic Review

To conduct a systematic review of the evidence to determine the impact of cystic fibrosis (CF) on unaffected siblings. We searched MEDLINE (Ovid interface, from 1946); EMBASE (Ovid interface, from 1946); CINAHL (EBSCO interface); Academic Search Complete (EBSCO interface); Psych Info (EBSCO interface); ProQuest Theses' and Dissertation's (ProQuest); British Index of Nursing (ProQuest); Web of Science (ISI, Web of Knowledge portal); PubMed (PubMed NCBI); BASE (Bielefeld Academic Research Engine); Scopus; EThOS (e-theses online service); Open Grey; and Cochrane Library. Contents pages of the Journal of Cystic Fibrosis, June 2002-April 2017 were hand searched to identify further eligible studies. Reference lists of eligible articles and relevant review papers were screened. Inclusion criteria were full studies published after 1989 in English focusing on the impact of cystic fibrosis on unaffected siblings. In total, 13 papers, 4 PhD theses and 1 MSc thesis were included in the review. Four themes were identified; family functioning, psychosocial impact, knowledge of CF, and condition-specific differences. Most studies are old and may not accurately represent the impact of CF on unaffected siblings following changes to health care provision including newborn bloodspot screening and the advent of CF transmembrane regulator modulator therapies. Further work is needed directly with siblings rather than using mothers as proxies to determine effect of age, sex, and disease trajectory on unaffected siblings' experiences.