BACKGROUND: Researchers report difficulties in conducting research with children and young people (CYP) with life-limiting conditions (LLC) or life-threatening illnesses (LTI) and their families. Recruitment is challenged by barriers including ethical, logistical and clinical considerations. AIM: To explore how children and young people (aged 0-25 years) with life-limiting conditions or life-threatening illnesses and their families were identified, invited and consented to research published in the last 5 years. DESIGN: Systematic review. DATA SOURCES: Medline, PsycINFO, Web of Science, Sciences Citation Index, SCOPUS were searched for original English language research published between 2009-2014, recruiting children and young people with life-limiting conditions or life-threatening illness and their families. RESULTS: Two-hundred and fifteen studies; 152 qualitative, 54 quantitative, 9 mixed methods were included. Limited recruitment information but a range of strategies and difficulties were provided. The proportion of eligible participants from those screened could not be calculated in 80% of studies. Recruitment rates could not be calculated in 77%. Thirty-one per cent of studies recruited less than 50% of eligible participants. Reasons given for non-invitation included missing clinical or contact data, or clinician judgements of participant unsuitability. Reasons for non-participation included lack of interest and participants’ perceptions of potential burdens. CONCLUSIONS: All stages of recruitment were under reported. Transparency in reporting of participant identification, invitation and consent is needed to enable researchers to understand research implications, bias risk and to whom results apply. Research is needed to explore why consenting participants decide to take part or not and their experiences of research recruitment
