What is the impact of psychiatric decision units on mental health crisis care pathways? Protocol for an interrupted time series analysis with a synthetic control study

Abstract

Background The UK mental health system is stretched to breaking point. Individuals presenting with mental health problems wait longer at the ED than those presenting with physical concerns and finding a bed when needed is difficult – 91% of psychiatric wards are operating at above the recommended occupancy rate. To address the pressure, a new type of facility – psychiatric decision units (also known as mental health decision units) – have been introduced in some areas. These are short-stay facilities, available upon referral, targeted to help individuals who may be able to avoid an inpatient admission or lengthy ED visit. To advance knowledge about the effectiveness of this service for this purpose, we will examine the effect of the service on the mental health crisis care pathway over a 4-year time period; the 2 years proceeding and following the introduction of the service. We use aggregate service level data of key indicators of the performance of this pathway. Methods Data from four mental health Trusts in England will be analysed using an interrupted time series (ITS) design with the primary outcomes of the rate of (i) ED psychiatric presentations and (ii) voluntary admissions to mental health wards. This will be supplemented with a synthetic control study with the same primary outcomes, in which a comparable control group is generated for each outcome using a donor pool of suitable National Health Service Trusts in England. The methods are well suited to an evaluation of an intervention at a service delivery level targeting population-level health outcome and the randomisation or ‘trialability’ of the intervention is limited. The synthetic control study controls for national trends over time, increasing our confidence in the results. The study has been designed and will be carried out with the involvement of service users and carers. Discussion This will be the first formal evaluation of psychiatric decision units in England. The analysis will provide estimates of the effect of the decision units on a number of important service use indicators, providing much-needed information for those designing service pathways. Trial registration primary registry: isrctn.com Identifying number: ISRCTN77588384 Link: Date of registration in primary registry: 27/02/2020. Primary sponsor St George’s, University of London, Cramner Road, Tooting, SW17 ORE. Primary contact: Joe Montebello.

The psychiatric decision unit as an emerging model in mental health crisis care: a national survey in England

“…A national funded study is currently underway which includes a synthetic control study and interrupted time series study (Goldsmith et al . 2020) to address priority (i), a cohort study to address priority (ii), qualitative interviews with both staff and service users to address priority (iii), an economic evaluation to address point (iv), and a synthesis of data across these investigations to address the final priority (v). Further research priorities include exploring the experiences of carers of service users admitted to PDUs and further national mapping studies of short‐stay crisis units, particularly in the United States where PES units are more well‐established, to understand more about these units and their variation.…”

“…There are five priorities for future research: (i) examine the effects of PDUs on service parameters, patient flows, and trust-wide targets, (ii) identify changes in service use following a service user's first stay on a decision unit, (iii) explore service users' experiences of PDUs and other forms of crisis care from a qualitative perspective, (iv) understand the comparative costs of alternative models of crisis care, and (v) understand the optimal configuration of a PDU. A national funded study is currently underway which includes a synthetic control study and interrupted time series study (Goldsmith et al 2020) to address priority (i), a cohort study to address priority (ii), qualitative interviews with both staff and service users to address priority (iii), an economic evaluation to address point (iv), and a synthesis of data across these investigations to address the final priority (v). Further research priorities include exploring the experiences of carers of service users admitted to PDUs and further national mapping studies of short-stay crisis units, particularly in the United States where PES units are more well-established, to understand more about these units and their variation.…”

“…Within this context, Psychiatric Decision Units (PDUs) are emerging as an operational strategy to reduce the pressure on the ED and psychiatric inpatient wards. The units, also known as Psychiatric Emergency Services or Crisis Stabilization Units, have been introduced in the United States (Zeller et al 2014), Luxembourg (Damsa et al 2005), Australia (Braitberg et al 2018), Singapore (San Thinn et al 2015), and the United Kingdom (Goldsmith et al 2020;Trethewey et al 2019).…”

Impact of changes in community psychiatric service provision on mental health presentations to the emergency department

“…In Australia, the introduction of a specialised behavioural assessment unit (BAU) facilitated more timely and direct access to a mental health clinician, reduced use of restrictive interventions and decreased ED LOS [14]. A large multicentre study is ongoing at present in the UK to evaluate the impact of PDUs, with a particular focus on ED LOS and inpatient psychiatric admission outcomes [45]. To the authors' knowledge, such units are not available in Ireland.…”

Evaluating mental health decision units in acute care pathways (DECISION): a quasi-experimental, qualitative and health economic evaluation

“…There were a small number of deviations from the methods described in the published protocol, 60 primarily arising from the use of reduced datasets where availability was limited in WPs 2 and 3 (ITS and SC study). This resulted in a reduced set of outcomes in some sites in some WPs.…”