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

The effect of psychiatric decision unit services on inpatient admissions and mental health presentations in emergency departments: an interrupted time series analysis from two cities and one rural area in England

AIMS

High-quality evidence is lacking for the impact on healthcare utilisation of short-stay alternatives to psychiatric inpatient services for people experiencing acute and/or complex mental health crises (known in England as psychiatric decision units [PDUs]). We assessed the extent to which changes in psychiatric hospital and emergency department (ED) activity were explained by implementation of PDUs in England using a quasi-experimental approach.

METHODS

We conducted an interrupted time series (ITS) analysis of weekly aggregated data pre- and post-PDU implementation in one rural and two urban sites using segmented regression, adjusting for temporal and seasonal trends. Primary outcomes were changes in the number of voluntary inpatient admissions to (acute) adult psychiatric wards and number of ED adult mental health-related attendances in the 24 months post-PDU implementation compared to that in the 24 months pre-PDU implementation.

RESULTS

The two PDUs (one urban and one rural) with longer (average) stays and high staff-to-patient ratios observed post-PDU decreases in the pattern of weekly voluntary psychiatric admissions relative to pre-PDU trend (Rural: -0.45%/week, 95% confidence interval [CI] = -0.78%, -0.12%; Urban: -0.49%/week, 95% CI = -0.73%, -0.25%); PDU implementation in each was associated with an estimated 35-38% reduction in total voluntary admissions in the post-PDU period. The (urban) PDU with the highest throughput, lowest staff-to-patient ratio and shortest average stay observed a 20% (-20.4%, CI = -29.7%, -10.0%) level reduction in mental health-related ED attendances post-PDU, although there was little impact on long-term trend. Pooled analyses across sites indicated a significant reduction in the number of voluntary admissions following PDU implementation (-16.6%, 95% CI = -23.9%, -8.5%) but no significant (long-term) trend change (-0.20%/week, 95% CI = -0.74%, 0.34%) and no short- (-2.8%, 95% CI = -19.3%, 17.0%) or long-term (0.08%/week, 95% CI = -0.13, 0.28%) effects on mental health-related ED attendances. Findings were largely unchanged in secondary (ITS) analyses that considered the introduction of other service initiatives in the study period.

CONCLUSIONS

The introduction of PDUs was associated with an immediate reduction of voluntary psychiatric inpatient admissions. The extent to which PDUs change long-term trends of voluntary psychiatric admissions or impact on psychiatric presentations at ED may be linked to their configuration. PDUs with a large capacity, short length of stay and low staff-to-patient ratio can positively impact ED mental health presentations, while PDUs with longer length of stay and higher staff-to-patient ratios have potential to reduce voluntary psychiatric admissions over an extended period. Taken as a whole, our analyses suggest that when establishing a PDU, consideration of the primary crisis-care need that underlies the creation of the unit is key.

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

Background

People experiencing mental health crises in the community often present to emergency departments and are admitted to a psychiatric hospital. Because of the demands on emergency department and inpatient care, psychiatric decision units have emerged to provide a more suitable environment for assessment and signposting to appropriate care.

Objectives

The study aimed to ascertain the structure and activities of psychiatric decision units in England and to provide an evidence base for their effectiveness, costs and benefits, and optimal configuration.

Design

This was a mixed-methods study comprising survey, systematic review, interrupted time series, synthetic control study, cohort study, qualitative interview study and health economic evaluation, using a critical interpretive synthesis approach.

Setting

The study took place in four mental health National Health Service trusts with psychiatric decision units, and six acute hospital National Health Service trusts where emergency departments referred to psychiatric decision units in each mental health trust.

Participants

Participants in the cohort study (n = 2110) were first-time referrals to psychiatric decision units for two 5-month periods from 1 October 2018 and 1 October 2019, respectively. Participants in the qualitative study were first-time referrals to psychiatric decision units recruited within 1 month of discharge (n = 39), members of psychiatric decision unit clinical teams (n = 15) and clinicians referring to psychiatric decision units (n = 19).

Outcomes

Primary mental health outcome in the interrupted time series and cohort study was informal psychiatric hospital admission, and in the synthetic control any psychiatric hospital admission; primary emergency department outcome in the interrupted time series and synthetic control was mental health attendance at emergency department. Data for the interrupted time series and cohort study were extracted from electronic patient record in mental health and acute trusts; data for the synthetic control study were obtained through NHS Digital from Hospital Episode Statistics admitted patient care for psychiatric admissions and Hospital Episode Statistics Accident and Emergency for emergency department attendances. The health economic evaluation used data from all studies. Relevant databases were searched for controlled or comparison group studies of hospital-based mental health assessments permitting overnight stays of a maximum of 1 week that measured adult acute psychiatric admissions and/or mental health presentations at emergency department. Selection, data extraction and quality rating of studies were double assessed. Narrative synthesis of included studies was undertaken and meta-analyses were performed where sufficient studies reported outcomes.

Results

Psychiatric decision units have the potential to reduce informal psychiatric admissions, mental health presentations and wait times at emergency department. Cost savings are largely marginal and do not offset the cost of units. First-time referrals to psychiatric decision units use more inpatient and community care and less emergency department-based liaison psychiatry in the months following the first visit. Psychiatric decision units work best when configured to reduce either informal psychiatric admissions (longer length of stay, higher staff-to-patient ratio, use of psychosocial interventions), resulting in improved quality of crisis care or demand on the emergency department (higher capacity, shorter length of stay). To function well, psychiatric decision units should be integrated into the crisis care pathway alongside a range of community-based support.

Limitations

The availability and quality of data imposed limitations on the reliability of some analyses.

Future work

Psychiatric decision units should not be commissioned with an expectation of short-term financial return on investment but, if appropriately configured, they can provide better quality of care for people in crisis who would not benefit from acute admission or reduce pressure on emergency department.

Study registration

The systematic review was registered on the International Prospective Register of Systematic Reviews as CRD42019151043.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (NIHR award ref: 17/49/70) and is published in full in Health and Social Care Delivery Research; Vol. 11, No. 25. See the NIHR Funding and Awards website for further award information.

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

Psychiatric decision units have been developed in many countries internationally to address the pressure on inpatient services and dissatisfactory, long waits people in mental health crisis can experience in emergency departments. Research into these units lags behind their development, as they are implemented by healthcare providers to address these problems. This is the first-ever national survey to identify their prevalence, structure, activities, and contextual setting within health services, in order to provide a robust basis for future research. The response rate was high (94%), and six PDUs in England were identified. The results indicated that PDUs open 24/7, accept only voluntary patients, provide recliner chairs for sleeping rather than beds, and limit stays to 12-72 hours. PDUs are predominantly staffed by senior, qualified mental health nurses and healthcare assistants, with psychiatry input. Staff:patient ratios are high (1:2.1 during the day shift). Differences in PDU structure and activities (including referral pathway, length of stay, and staff:patient ratios) were identified, suggesting the optimal configuration for PDUs has not yet been established. Further research into the efficacy of this innovation is needed; PDUs potentially have a role in an integrated crisis care pathway which provides a variety of care options to service users.

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

Background

The reconfiguration of many Irish stand-alone psychiatric units has led to many patients in acute mental health need now being assessed in emergency departments (EDs). This has implications for ED resources and raises questions about appropriate assessment location for this group.

Aims

This report aims to examine the impact of removal of a direct community access point for patients in acute mental health need on ED presentations in a Dublin hospital.

Methods

We examined data on ED referrals to psychiatry over 5 years: 12 months before the service change, and four subsequent 12-month periods. We compared numbers referred, mode of referral, average ED length of stay, proportion with no physical issue requiring psychiatric assessment only, and numbers who did not wait for psychiatry assessment.

Results

In the year directly after the service change, referrals to psychiatry from ED increased by 200%, remaining at this level for the subsequent 3 years. Of these, 32.5% were referred by a GP—more than a threefold increase in numbers from the previous year, with both numbers remaining similarly elevated over subsequent years. In the year after the service change, 52.1% of total ED to psychiatry presented solely for mental health reasons—nearly a fourfold increase in cases from the previous year, and remained high.

Conclusions

Removing a direct community access point for this group resulted in a substantial increase in ED presentations, many of which did not have physical needs. This study has implications for future policy to address the needs of this group, especially in light of the pandemic.