Lambert, Katie, Chu, Simon ORCID: 0000-0001-8921-4942, Duffy, Chris, Hartley, Victoria, Baker, Alison and Ireland, Jane Louise ORCID: 0000-0002-5117-5930 (2018) The prevalence of constant supportive observations in a high, medium and low secure service. BJPsych Bulletin . ISSN 2056-4708