Collaborative critical care prediction and resource planning during the COVID-19 pandemic using computer simulation modelling: future urgent planning lessons.

In March 2020, epidemiological modelling of COVID-19 predicted overwhelming demand on healthcare resources, yet data that emerged painted a different picture. Our management science health systems team at the University of Strathclyde collaborated with one NHS organisation to contextualise national policy and predict local resource needs before the pandemic took hold. Using action research, we combined organisational expertise, local and international data, and healthcare systems expertise to create a discrete event simulation model that predicted concurrent resource use over the first 10 weeks of the pandemic with realistic estimates of uncertainty. This allowed the organisation to create an effective strategy for resource planning. Had they followed national guidance, the costs would have been unwieldy and futile. Our decentralised approach delivered valuable information in a timely manner. This case study is unique in healthcare literature and serves as an example of successful methodology for similar crises.

Impact of visitation and cohorting policies to shield residents from covid-19 spread in care homes: an agent-based model.

BACKGROUND: This study examines the impact of visitation and cohorting policies as well as the care home population size upon the spread of COVID-19 and the risk of outbreak occurrence in this setting. METHODS: Agent-based modelling RESULTS: The likelihood of the presence of an outbreak in a care home is associated with the care home population size. Cohorting of residents and staff into smaller, self-contained units reduces the spread of COVID-19. Restricting the number of visitors to the care home to shield its residents does not significantly impact the cumulative number of infected residents and risk of outbreak occurrence in most scenarios. Only when the community prevalence where staff live is considerably lower than the prevalence where visitors live (the former prevalence is less than or equal to 30% of the latter), relaxing visitation increases predicted infections much more significantly than it does in other scenarios. Maintaining a low infection probability per resident-visitor contact helps reduce the effect of allowing more visitors into care homes. CONCLUSIONS: Our model predictions suggest that cohorting is effective in controlling the spread of COVID-19 in care homes. However, according to predictions shielding residents in care homes is not as effective as predicted in a number of studies that have modelled shielding of vulnerable population in the wider communities.

Evaluating intervention strategies in controlling coronavirus disease 2019 (COVID-19) spread in care homes: An agent-based model.

BACKGROUND: Care homes are vulnerable to widespread transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) with poor outcomes for staff and residents. Infection control interventions in care homes need to not only be effective in containing the spread of coronavirus disease 2019 (COVID-19) but also feasible to implement in this special setting which is both a healthcare institution and a home. METHODS: We developed an agent-based model that simulates the transmission dynamics of COVID-19 via contacts between individuals, including residents, staff members, and visitors in a care home setting. We explored a representative care home in Scotland in our base case and explore other care home setups in an uncertainty analysis. We evaluated the effectiveness of a range of intervention strategies in controlling the spread of COVID-19. RESULTS: In the presence of the reference interventions that have been implemented in many care homes, including testing of new admissions, isolation of symptomatic residents, and restricted public visiting, routine testing of staff appears to be the most effective and practical approach. Routine testing of residents is no more effective as a reference strategy while routine testing of both staff and residents only shows a negligible additive effect. Modeling results are very sensitive to transmission probability per contact, but the qualitative finding is robust to varying parameter values in our uncertainty analysis. CONCLUSIONS: Our model predictions suggest that routine testing should target staff in care homes in conjunction with adherence to strict hand hygiene and using personal protective equipment to reduce risk of transmission per contact.

Requesting spinal MRIs effectively from primary care referrals.

OBJECTIVE: To define if MRI scans can accurately be requested based on information provided in the primary care referral and, therefore, streamline the patient journey. The demand for outpatient spinal appointments significantly exceeds our services' ability to provide efficient, high-quality patient care. Currently, magnetic resonance imaging (MRI) of the spine is requested following first consultation. METHODS: During routine vetting of primary care referral letters, three consultant spinal surgeons recorded how likely they thought each patient would be to have an MRI scan. Following the first consultation with the spinal service, the notes of each patient were reviewed to see if an MRI was requested. We measured the positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity of ordering MRI scans based on primary care referral letters. RESULTS: 149 patients were included [101 females, 48 males, mean age 49 (16-87)]. There were 125 routine, 21 urgent, and 3 'urgent-suspected cancer' referrals. The PPV of ordering MRIs before first consultation was 84%, NPV was 56% with the sensitivity and specificity being 82 and 59%, respectively. Ordering MRIs during initial vetting could shorten the patient journey with potential socioeconomic benefits. CONCLUSIONS: MRI scans can be effectively ordered based on the information provided by the primary care referral letter. Requesting MRI scans early in the patient journey can save considerable time, improve care, and deliver cost savings. These slides can be retrieved under Electronic Supplementary Material.

Modeling the critical care pathway for cardiothoracic surgery.

The west of Scotland heart and lung center based at the Golden Jubilee National Hospital houses all adult cardiothoracic surgery for the region. Increased demand for scheduled patients and fluctuations in emergency referrals resulted in increasing waiting times and patient cancellations. The main issue was limited resources, which was aggravated by the stochastic nature of the length of stay (LOS) and arrival of patients. Discrete event simulation (DES) was used to assess if an enhanced schedule was sufficient, or more radical changes, such as capacity or other resource reallocations should be considered in order to solve the problem. Patients were divided into six types depending on their condition and LOS at the different stages of the process. The simulation model portrayed each patient type's pathway with sufficient detail. Patient LOS figures were analyzed and distributions were formed from historical data, which were then used in the simulation. The model proved successful as it showed figures that were close to actual observations. Acquiring results and knowing exactly when and what caused a cancellation was another strong point of the model. The results demonstrated that the bottleneck in the system was related to the use of High Dependency Unit (HDU) beds, which were the recovery beds used by most patients. Enhancing the schedule by leveling out the daily arrival of patients to HDUs reduced patient cancellations by 20%. However, coupling this technique with minor capacity reallocations resulted in more than 60% drop in cancellations.

Cost comparison of orthopaedic fracture pathways using discrete event simulation in a Glasgow hospital.

OBJECTIVE: Healthcare faces the continual challenge of improving outcome while aiming to reduce cost. The aim of this study was to determine the micro cost differences of the Glasgow non-operative trauma virtual pathway in comparison to a traditional pathway. DESIGN: Discrete event simulation was used to model and analyse cost and resource utilisation with an activity-based costing approach. Data for a full comparison before the process change was unavailable so we used a modelling approach, comparing a virtual fracture clinic (VFC) with a simulated traditional fracture clinic (TFC). SETTING: The orthopaedic unit VFC pathway pioneered at Glasgow Royal Infirmary has attracted significant attention and interest and is the focus of this cost study. OUTCOME MEASURES: Our study focused exclusively on patients with non-operative trauma attending emergency department or the minor injuries unit and the subsequent step in the patient pathway. Retrospective studies of patient outcomes as a result of the protocol introductions for specific injuries are presented in association with activity costs from the models. RESULTS: Patients are satisfied with the new pathway, the information provided and the outcome of their injuries (Evidence Level IV). There was a 65% reduction in the number of first outpatient face-to-face (f2f) attendances in orthopaedics. In the VFC pathway, the resources required per day were significantly lower for all staff groups (p≤0.001). The overall cost per patient of the VFC pathway was £22.84 (95% CI 21.74 to 23.92) per patient compared with £36.81 (95% CI 35.65 to 37.97) for the TFC pathway. CONCLUSIONS: Our results give a clearer picture of the cost comparison of the virtual pathway over a wholly traditional f2f clinic system. The use of simulation-based stochastic costings in healthcare economic analysis has been limited to date, but this study provides evidence for adoption of this method as a basis for its application in other healthcare settings.

A relational understanding of sibling experiences of children with rare life-limiting conditions: findings from a qualitative study.

Mucopolysaccharidoses (MPS) and Batten disease are rare life-limiting conditions (LLCs) characterised by progressive and permanent physical and cognitive decline. The impact of such conditions on families, and notably on siblings, has not yet been described or documented. This paper presents data from a UK-wide study that sought to understand the family experience of supporting a child with the rare degenerative LLCs of MPS and Batten disease. The aim of this paper is to report sibling experiences related to these rare degenerative and progressive conditions, in order to inform the future development of supportive interventions. Eight siblings of children with MPS (n = 7) and Batten Disease (n = 1) participated in semi-structured qualitative interviews. A card sort technique was utilised to support and engage the children. Siblings are clearly impacted emotionally, pragmatically and relationally by the ill health of another child in the family. The data indicate four key themes which demonstrate impacts on siblings: perceptions of the condition and its symptoms, impact on daily life, emotional consequences and ways of coping. Siblings often had considerable knowledge of the condition and took on important roles in symptom management. However, these experiences were in the context of managing relationships within the family (often protecting parents from an awareness of how much they knew) and relationships at school (including distraction from learning and being bullied by peers). The data highlight how sibling experiences are generated through a combination of negative disability discourses and support through peers and family members. The data indicate how these features shift as a consequence of witnessing the advancement of their brother's or sister's condition and the emotional sequelae of disease progression. Exploration of siblings' experiences of living with such rare progressive and degenerative LLCs suggest the focus of interventions to support this group should address their emotional health and ways to overcome isolation and build connections with other siblings who share their unique experiences. Critically, the data suggest that sibling support should be cognisant of the trajectory of the illness as well as the family, school and peer relational contexts that siblings inhabit.

Achieving safe conception in HIV-discordant couples: the potential role of oral preexposure prophylaxis (PrEP) in the United States.

Approximately half of HIV-discordant heterosexual couples in the United States want children. Oral antiretroviral preexposure prophylaxis, if effective in reducing heterosexual HIV transmission, might be an option for discordant couples wanting to conceive. Couples should receive services to ensure they enter pregnancy in optimal health and receive education about all conception methods that reduce the risk of HIV transmission. In considering whether preexposure prophylaxis is indicated, the question is whether it contributes to lowering risk in couples who have decided to conceive despite known risks. If preexposure prophylaxis is used, precautions similar to those in the current heterosexual preexposure prophylaxis trials would be recommended, and the unknown risks of preexposure prophylaxis used during conception and early fetal development should be considered. Anecdotal reports suggest that oral preexposure prophylaxis use is already occurring. It is time to have open discussions of when and how preexposure prophylaxis might be indicated for HIV-discordant couples attempting conception.

Challenging symptom profiles of life-limiting conditions in children: a survey of care professionals and families.

This paper reports on data from the initial phase of a UK-wide study exploring life-limiting conditions (LLCs) in children where, because of their rarity, little is understood regarding the significant symptom challenges of families and care professionals who support them. In this initial phase, care professionals (n=43) and families (n=16) completed a survey to identify which rare LLCs present symptom challenges and which individual symptoms prove difficult to manage. Findings led to the prioritization of mucopolysaccharidoses, Batten Disease and leukodystrophy. Care professionals' rationales for selecting these conditions included the presence of symptoms that are very difficult to manage, a requirement for additional clinical evidence to support symptom management, and the progressive nature of these diseases where symptoms frequently change and are difficult to predict. Families identified symptoms such as behavioural difficulties, visual impairments and communication impairments as those being most difficult to manage and having most impact on quality of life for children and families.

Regulation of cell survival in the developing thalamus: an in vitro analysis.

There is evidence that developing thalamic cells become dependent for their survival on the integrity of their afferent and/or efferent connections, which may provide required levels of neural activity and/or essential neurotrophic factors. These connections develop in the second half of gestation in mice and, during this time (embryonic days 17-19), isolated thalamic cells either grown as explants or dissociated from each other lose their ability to survive. Here we show that the loss of viability of explants, but not of dissociated cells, is delayed if the cultures are treated with depolarizing stimuli. The survival of dissociated thalamic cells is promoted by culture medium conditioned by thalamic explants grown with depolarizing stimuli, indicating that the effect of depolarization involves trophic factors released by thalamic cells. This survival promoting effect is found prenatally, but not postnatally, and is prevented by the neurotrophin blocker K252a. Culture medium conditioned by cortex also promotes the survival of thalamic cells and this effect does occur postnatally. These findings suggest that diffusible factors, possibly members of the neurotrophin family, and depolarizing stimuli regulate thalamic cell survival before birth, but trophic support from cortex becomes crucial after birth. This culture model may provide a means of investigating the mechanisms of thalamic cell survival during development.

Layer-specific thalamocortical innervation in organotypic cultures is prevented by substances that alter neural activity.

Cortical layer IV is the major target of thalamocortical axons and many previous studies have shown that the development of this layer-specific innervation can be modelled in vitro by organotypic cocultures of thalamus and cortex. The mechanisms causing thalamic axons to terminate in layer IV are unknown. We used these in vitro models to test the possibility that neural activity plays a part in this termination process by adding substances that raise or lower levels of neural activity to the cocultures. We found that addition of tetrodotoxin or 2-amino-5-phosphonovalerate, to block activity, or potassium, to raise it, all interfered with termination in layer IV. These findings suggest that termination in layer IV requires neural activity at an appropriate level in the thalamocortical system. They also add support to recent findings that show that the importance of neural activity in development may extend to an earlier period than thought previously, to include the correct targeting of axons as well as the later refinement of connections.