Background Multiple complex needs (MCN) is one of a number of terms used to describe people facing co-occurring issues of homelessness, substance misuse, offending, and mental ill-health. When considered in isolation, homelessness, substance misuse, mental ill-health and offending, each contribute to high mortality rates; however, when co-occurring this effect is amplified. A large amount of the mortality research to date within MCN populations has been epidemiological. Despite acknowledge of the benefits of conducting research withindividuals rather than on, there is limited involvement of peer research methods in current studies exploring mortality and MCN. This research aimed to explore the perspectives of people with lived experience of MCN and professionals who support them on the perceived reasons underlying high mortality rates among people with MCN.

Methods Using peer research methods, three focus group discussions (21 participants) were conducted within the North East of England to explore the perspectives of people with MCN, frontline staff, and managers/commissioners.

Results Findings from this study provide valuable perspectives of people with MCN and those that provide them with support on what may be perceived factors underlying premature mortality. Mental ill-health and substance misuse (often co-occurring dual diagnosis) were perceived as influencing premature mortality among MCN groups. Perceptions of opportunities for identify people at-risk included critical life events (e.g. bereavement, relationship breakdown) and transitions (e.g. release from prison, completion of drug treatment). Early prevention, particularly supporting young people experiencing adverse childhood experiences was also highlighted as a priority.

Conclusion High mortality in MCN groups may be reduced by addressing dual diagnosis, providing more support at critical life events, and investing in early prevention efforts. The novelty of this study is it has shown the value of listening to and conducting research with individuals with experience of MCN. It enabled an exploration of an issue that directly affects their community and supported understanding of the personal perspective of a handful of people with MCN and their carers on what may have informed premature mortality among their networks, as well as identifying perceived avenues for possible preventive interventions within the local region. Furthermore, the insights specific to opportunities for service provision take into consideration the intricate nature of MCN and improve service access and navigation.