Table 1 Keyword search strategy for electronic databases

Lived experience

(exp lived experience) OR (expert by experience) OR (exp substance abuse) OR (intravenous/) OR (exp substance related disorders) OR (exp vulnerable populations) OR (exp prison*) OR (exp homeless persons) OR (homelessness) OR (exp sex workers) OR (exp drug users) OR (exp prostitution)

(Research) involvement

(research involvement) OR co-research* OR (Patient and Public Involvement) OR PPI OR (research engagement) OR engaging OR (research participation) OR (collaboration)

Palliative care

(palliative care) OR palliative* OR (palliative medicine) OR (end of life) OR (end-of-life) OR EOL