Study selection

Studies of any intervention to promote access to, or uptake of, screening or monitoring for any physical health condition where participants were aged 18 years and over with a diagnosis of SMI (psychosis or bipolar disorder however diagnosed) were eligible. Uptake of screening was the main outcome of interest. Patient-related outcomes were not an inclusion criteria, but were included in the online supplementary tables following the review of the studies, to provide important additional information and give a rounded picture of the effectiveness of the interventions. The UK National Screening Committee defines screening as a ‘public health service in which members of a defined population…are asked a question or offered a test, to identify those individuals who are more likely to be helped than harmed by further tests or treatment to reduce the risk of a disease or its complications’.²² ‘Monitoring’ was defined in a Cochrane²³ review as a means ‘to obtain information which can then be acted on to treat or prevent a physical health problem’. We included any intervention described as promoting either screening or monitoring; for clarity the term ‘screening’ is used throughout. Only studies reported in English were included.

In line with the realist approach to literature synthesis,¹⁹ an inclusive approach was taken and intervention studies of any design were eligible as long as the full text was published in a peer-reviewed journal. We also excluded intervention studies to improve physical health in people with SMI which may involve screening, but where uptake or access to screening was not a main outcome and service evaluations or audits which considered screening, but did not test any intervention.

The protocol is published on the International Prospective Register of Systematic Reviews (PROSPERO) database.²⁴ The search strategy (online supplementary appendix 1) was informed by published, related systematic reviews^{8 17 20} and was checked by a specialist health librarian at the University of West London (Marc Forster, PhD). Searching was conducted in December 2016.

bmjopen-2017-019412supp001.pdf

MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, PsychINFO, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness. Reference chaining of identified studies was also conducted. No date restrictions were applied.