Process modelling of NHS cardiovascular waiting lists in response to the COVID-19 pandemic.

OBJECTIVE: To model the referral, diagnostic and treatment pathway for cardiovascular disease (CVD) in the English National Health Service (NHS) to provide commissioners and managers with a methodology to optimise patient flow and reduce waiting lists. STUDY DESIGN: A systems dynamics approach modelling the CVD healthcare system in England. The model is designed to capture current and predict future states of waiting lists. SETTING: Routinely collected, publicly available data streams of primary and secondary care, sourced from NHS Digital, NHS England, the Office of National Statistics and StatsWales. DATA COLLECTION AND EXTRACTION METHODS: The data used to train and validate the model were routinely collected and publicly available data. It was extracted and implemented in the model using the PySD package in python. RESULTS: NHS cardiovascular waiting lists in England have increased by over 40% compared with pre- COVID-19 levels. The rise in waiting lists was primarily due to restrictions in referrals from primary care, creating a bottleneck postpandemic. Predictive models show increasing point capacities within the system may paradoxically worsen downstream flow. While there is no simple rate-limiting step, the intervention that would most improve patient flow would be to increase consultant outpatient appointments. CONCLUSIONS: The increase in NHS CVD waiting lists in England can be captured using a systems dynamics approach, as can the future state of waiting lists in the presence of further shocks/interventions. It is important for those planning services to use such a systems-oriented approach because the feed-forward and feedback nature of patient flow through referral, diagnostics and treatment leads to counterintuitive effects of interventions designed to reduce waiting lists.

Aortic stenosis post-COVID-19: a mathematical model on waiting lists and mortality.

OBJECTIVES: To provide estimates for how different treatment pathways for the management of severe aortic stenosis (AS) may affect National Health Service (NHS) England waiting list duration and associated mortality. DESIGN: We constructed a mathematical model of the excess waiting list and found the closed-form analytic solution to that model. From published data, we calculated estimates for how the strategies listed under Interventions may affect the time to clear the backlog of patients waiting for treatment and the associated waiting list mortality. SETTING: The NHS in England. PARTICIPANTS: Estimated patients with AS in England. INTERVENTIONS: (1) Increasing the capacity for the treatment of severe AS, (2) converting proportions of cases from surgery to transcatheter aortic valve implantation and (3) a combination of these two. RESULTS: In a capacitated system, clearing the backlog by returning to pre-COVID-19 capacity is not possible. A conversion rate of 50% would clear the backlog within 666 (533-848) days with 1419 (597-2189) deaths while waiting during this time. A 20% capacity increase would require 535 (434-666) days, with an associated mortality of 1172 (466-1859). A combination of converting 40% cases and increasing capacity by 20% would clear the backlog within a year (343 (281-410) days) with 784 (292-1324) deaths while awaiting treatment. CONCLUSION: A strategy change to the management of severe AS is required to reduce the NHS backlog and waiting list deaths during the post-COVID-19 'recovery' period. However, plausible adaptations will still incur a substantial wait to treatment and many hundreds dying while waiting.

Long-term trends in the epidemiology of cardiovascular diseases in the UK: insights from the British Heart Foundation statistical compendium.

The British Heart Foundation's (BHF) annual statistical compendium is a comprehensive source of accessible epidemiological data in relation to cardiovascular disease (CVD) in the UK. Using datasets with multiple years of data from the compendium we have analysed trends in mortality, morbidity, and treatment for CVD within the UK. CVD mortality in the UK has consistently declined over recent decades, from 1045 deaths per 100 000 in 1969, shortly after the BHF was founded, to 255 per 100 000 in 2019. Despite this remarkable improvement, inequalities in CVD mortality persist in the UK nations, for example in 2019 the death rate in Scotland was 326 deaths per 100 000 compared with 246 per 100 000 in England. Improvements in CVD mortality have been paralleled by increased use of primary prevention medications (anti-hypertensives and statins) and interventional procedures. In recent years, progress in mortality outcomes has stalled, probably due to a combination of factors including a rise in risk factors such as obesity and diabetes. In terms of morbidity, CVD remains a significant burden in the UK, accounting for at least 1.18 million hospital admissions and reflects the enormous economic burden of CVD, estimated at £19bn in the UK. Our results highlight the importance of accessible and comprehensive statistics in relation to the burden of CVD and the value of the BHF's annual compendium in drawing out conclusions and opportunities for future research. One key area is to improve the data on which estimation of prevalence is based. There is also a need for ongoing work to better understand the root causes of disparity between socio-economic groups in relation to CVD. One important way to address this will be to improve the consistency of reporting of CVD health data across all nations of the UK. Understanding the causes will inform UK healthcare planning in addition to providing analytical insights that will be applicable in other countries.

Learning from the design and development of the NHS Safety Thermometer.

QUALITY ISSUE: Research indicates that 10% of patients are harmed by healthcare but data that can be used in real time to improve safety are not routinely available. INITIAL ASSESSMENT: We identified the need for a prospective safety measurement system that healthcare professionals can use to improve safety locally, regionally and nationally. CHOICE OF SOLUTION: We designed, developed and implemented a national tool, named the NHS Safety Thermometer (NHS ST) with the goal of measuring the prevalence of harm from pressure ulcers, falls, urinary tract infection in patients with catheters and venous thromboembolism on one day each month for all NHS patients. IMPLEMENTATION: The NHS ST survey instrument was developed in a learning collaborative involving 161 organizations (e.g. hospitals and other delivery organizations) using a Plan, Do, Study, Act method. EVALUATION: Testing of operational definitions, technical capability and use were conducted and feedback systems were established by site coordinators in each participating organization. During the 17-month pilot, site coordinators reported a total of 73,651 patient entries. LESSONS LEARNED: It is feasible to obtain national data through standardized reporting by site coordinators at the point of care. Some caution is required in interpreting data and work is required locally to ensure data collection systems are robust and data collectors were trained. Sampling is an important strategy to optimize efficiency and reduce the burden of measurement.

What is the relationship between free flow and pressure flow studies in women?

INTRODUCTION AND HYPOTHESIS: The relationship between free flow (FFS) and pressure flow (PFS) voiding studies remains uncertain and the effect of a urethral catheter on flow rates has not been determined. The relationship between residuals obtained at FF and PFS has yet to be established. METHODS: This was a prospective cohort study based on 474 consecutive women undergoing cystometry using different sized urethral catheters at different centres. FFS and PFS data were compared for different conditions and the relationship of residuals analysed for FFS and PFS. The null hypothesis was that urethral catheters do not produce an alteration in maximum flow rates for PFS and FF studies. RESULTS: Urethral catheterisation results in lower flow rates (p < 0.01) and this finding is confirmed when flows are corrected for voided volume (p < 0.01). FFS and PFS maximum flow rates are lower in women with DO than USI (p < 0.01). A 6-F urethral catheter does not have a significantly greater effect than a 4.5-F urethral catheter. A mathematical model can be applied to transform FFS to PFS flow rates and vice versa. There was no significant difference between the mean residuals of the two groups (FFS vs PFS-two-tailed t = 0.54, p = 0.59). Positive residuals in FFS showed a good association with positive residuals in the PFS (r = 0.53, p < 0.01) CONCLUSIONS: Urethral catheterisation results in lower maximum flow rates. The relationship can be compared mathematically. The null hypothesis can be rejected.

Is a practice incremental shuttle walk test really necessary?

The incremental and endurance shuttle walking tests (ISWT and ESWT) are measures of exercise tolerance commonly used in pulmonary rehabilitation (PR). A practice ISWT is advocated but often omitted by PR centres. We aimed to investigate the effect of such an omission within a clinical PR service. Between October 2002 and October 2008, 392 patients attending PR completed a practice ISWT and an ISWT. Results showed that patients walked significantly further on ISWT compared to practice ISWT (p ≤ 0.001). A significant difference in ESWT level was found between those calculated from practice ISWT and those calculated from ISWT (p ≤ .001). Despite a visual trend towards a negative relationship between distance walked at baseline (practice ISWT) and magnitude of the difference between the two walks, this did not meet statistical significance (p = 0.409). Absence of a practice ISWT could lead to possible clinical misjudgements.