A Bayesian multivariate factor analysis model for causal inference using time-series observational data on mixed outcomes

Assessing the impact of an intervention by using time-series observational data on multiple units and outcomes is a frequent problem in many fields of scientific research. Here, we propose a novel Bayesian multivariate factor analysis model for estimating intervention effects in such settings and develop an efficient Markov chain Monte Carlo algorithm to sample from the high-dimensional and nontractable posterior of interest. The proposed method is one of the few that can simultaneously deal with outcomes of mixed type (continuous, binomial, count), increase efficiency in the estimates of the causal effects by jointly modeling multiple outcomes affected by the intervention, and easily provide uncertainty quantification for all causal estimands of interest. Using the proposed approach, we evaluate the impact that Local Tracing Partnerships had on the effectiveness of England's Test and Trace programme for COVID-19.

Evaluating the impact of clinical screening by a hospital pharmacy team on the homecare prescription service

Introduction

The homecare prescription service delivers medicines initiated by hospital prescribers directly to patients. The Trust utilises homecare services for approximately 4,000 patients spanning a range of specialities. Historically, homecare prescriptions were directly sent to the homecare company by clinicians and hospital pharmacy received payment invoices. In response to published professional standards for homecare1, the hospital pharmacy clinical screening process was introduced to ensure the safe use of medicines and to reduce wastage.

Aim

To evaluate the impact on pharmacy clinical screening on the homecare prescription service by: Identifying query types and measuring the error rate; and, measuring query resolution times and the delay in prescription processing.

Methods

The data collection was conducted over a 6-month period commencing November 2021 at a teaching NHS Trust. The sample included 100% of homecare prescriptions received by the hospital pharmacy department. Pharmacy technicians involved in the processing of payment invoices recorded the number of received prescriptions. During the clinical screening process, pharmacists involved in the identification of queries or errors relating to homecare prescription documented the presenting issue, any action taken, and the outcome on a purposefully created data collection form. The data was entered into Excel and analysed descriptively. This service evaluation did not require ethical approval.

Results

In total, 4,580 homecare prescriptions were clinically screened by the pharmacy team. Most prescriptions had no issues; 2.5% (n=114) had a query raised. Of these queries, 47% (n=54) necessitated clarification from prescribers without subsequent prescription amendments; 14% (n=16) required new blood tests; 13% (n=15) required prescription amendments; 8% (n=9) resulted in prescriptions being returned and not reissued; and 18% (n=20) had no documented outcome. A lack of recent in-range blood test results accounted for 39% (n=45) of queries. Data were collected during the Covid-19 pandemic, potentially impacting on patients’ ability to obtain blood tests every 3-6 months, depending on indication, to comply with Trust policy.2 Dosage enquiries accounted for 26% (n=30) of queries; most arose from discrepancies between the prescription and the most recent clinic letter. The prescribing error rate was low: 1% (n=40) of prescriptions had an error identified during the evaluation. Time from clinical screening to resolution of the raised issue was documented on 82% of (n=93) forms. Of these queries, 50% (n=46) were resolved within 3 working days, 45% (n=42) took up to 14 days, and 5% (n=5) over 14 days.

Discussion/Conclusion

The introduction of hospital pharmacy clinical screening of homecare prescriptions reduced prescription errors and increased safety of the service by ensuring patients had required monitoring and appropriate medicine doses. However, the project identified that clinical screening added additional processing time for those prescriptions with discrepancies, therefore potentially leading to delays in patients receiving their medications. Further work is planned to improve clarity of clinical letters and create a more robust process in achieving timely query resolutions. The main strength of the project was the relatively large sample size and prolonged data collection period. Limitations included accuracy of the recorded data on the enquiry forms for data analysis.

References

1. Royal Pharmaceutical Society (RPS). Professional Standards for Homecare Services in England. [internet] Royal Pharmaceutical Society; 2013 [cited 2022 May 20]. Available from: https://www.rpharms.com/Portals/0/RPS%20document%20library/Open%20access/Professional%20standards/Professional%20standards%20for%20Homecare%20services/homecare-standards-final-sept-13.pdf

2. Hull University Teaching Hospitals NHS Trust. SOP 16.2-Management of low and medium tech homecare paper prescriptions. Hull; Hull University Teaching Hospitals NHS Trust; 2022 [cited 2022 May 20].

Household transmission of COVID-19 cases associated with SARS-CoV-2 delta variant (B.1.617.2): national case-control study

BACKGROUND

The SARS-CoV-2 Delta variant (B.1.617.2), first detected in India, has rapidly become the dominant variant in England. Early reports suggest this variant has an increased growth rate suggesting increased transmissibility. This study indirectly assessed differences in transmissibility between the emergent Delta variant compared to the previously dominant Alpha variant (B.1.1.7).

METHODS

A matched case-control study was conducted to estimate the odds of household transmission (≥ 2 cases within 14 days) for Delta variant index cases compared with Alpha cases. Cases were derived from national surveillance data (March to June 2021). One-to-two matching was undertaken on geographical location of residence, time period of testing and property type, and a multivariable conditional logistic regression model was used for analysis.

FINDINGS

In total 5,976 genomically sequenced index cases in household clusters were matched to 11,952 sporadic index cases (single case within a household). 43.3% (n=2,586) of cases in household clusters were confirmed Delta variant compared to 40.4% (n= 4,824) of sporadic cases. The odds ratio of household transmission was 1.70 among Delta variant cases (95% CI 1.48-1.95, p <0.001) compared to Alpha cases after adjusting for age, sex, ethnicity, index of multiple deprivation (IMD), number of household contacts and vaccination status of index case.

INTERPRETATION

We found evidence of increased household transmission of SARS-CoV-2 Delta variant, potentially explaining its success at displacing Alpha variant as the dominant strain in England. With the Delta variant now having been detected in many countries worldwide, the understanding of the transmissibility of this variant is important for informing infection prevention and control policies internationally.

Chemical characterisation of aerosols emitted by electronic cigarettes using thermal desorption-gas chromatography-time of flight mass spectrometry

A non-targeted analytical method, using thermal desorption-gas chromatography-time of flight mass spectrometry, to detect, identify and semi-quantify volatile and semi-volatile organic constituents of e-cigarette aerosols is presented. A heart-cutting process with a Deans Switch has been applied to avoid saturation of the mass analyser by high-abundance bulk components. Between 30 and 90 compounds were detected in four aerosol samples generated by e-cigarettes, depending on the added flavourings. The method analyses in a single 80mL, 3-second puff, GC-amenable compounds with volatilities ranging between those of propane (C3) and octacosane (C28) and abundance greater than approximately 5ng. Method sensitivity is suitable for the application of thresholds of toxicological concern for product assessment at an exposure threshold of 1.5μg per day. The method is compatible with the high-throughput screening of GC-amenable compounds in e-cigarette aerosols.

Prognostic significance of endoluminal ultrasound defined tumor volume (EDTV) in patients diagnosed with esophageal cancer

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Background: The aim of this study was to assess the prognostic significance of endoluminal ultrasound defined tumour volume (EDTV) in patients diagnosed with esophageal cancer. The hypothesis was that tumour volume is a better predictor of outcome than tumour length. Methods: One hundred and seventy-four consecutive patients (median age 64y, 128 m) underwent both CT and specialist EUS, and the maximum potential tumour cylinder volume (EDTV) was calculated using the formula πr2L (cylinder volume), where r = tumour thickness (cm) and L = total length of disease, including the position and level of both the primary tumour and proximal and distal lymph nodes (cm). All patients received stage directed multidisciplinary treatment [surgery 104 patients (80 neoadjuvant chemotherapy), definitive chemoradiotherapy 54 patients, and palliative therapy alone 16 patients]. The primary measure of outcome was survival. Results: Survival was related to EUS T (p=0.013), EUS N (p=0.001), EUS M1a stage (p=0.004), EUS disease length (p=0.001), and EDTV (all patients <25cm3, p=0.001, surgical patients <40cm3, p=0.036). Forward conditional multivariate analysis revealed 3 factors to be associated with survival; EUS N stage (HR= 1.646, 95% CI 1.041 to 2.602, p=0.033), EUS M1a stage (HR= 2.702, 95% CI 1.069 to 6.830, p=0.036), and EDTV (HR= 2.702, 95% CI 1.069 to 6.830, p=0.025). Conclusions: EDTV emerged as a new and important prognostic indicator for patients diagnosed with esophageal cancer.

No significant financial relationships to disclose.

Prognostic significance of the endoluminal ultrasound defined lymph node metastasis count in esophageal cancer

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Background: TNM histopathological staging system for esophageal cancer is controversial, and will soon be revised to account for the relative burden of the number of lymph node metastases. The aim of this study was to assess the prognostic significance of endoluminal ultrasound (EUS) defined lymph node metastasis count (eLNMC) in patients with esophageal cancer. Methods: Two hundred and sixty-seven consecutive patients (median age 63 yr, 187 m) underwent EUS followed by stage directed multidisciplinary treatment [183 esophagectomy (92 neoadjuvant chemotherapy), 79 definitive chemoradiotherapy, and 5 palliative therapy]. The eLMNC was subdivided into four groups (0, 1, 2 to 4, >4) and the primary measure of outcome was survival. Results: Survival was related to EUS T stage (p<0.0001), EUS N stage (p<0.0001), EUS tumour length (p<0.0001), and the eLNMC (p<0.0001). Multivariable analysis revealed EUS tumour length (HR 1.071, 95% CI 1.008 to 1.138, p=0.027) and eLNMC (HR 1.302, 95% CI 1.133 to 1.496, p<0.0001) to be significantly and independently associated with survival. Median and 2 year survival for patients with 0, 1, 2 to 4, and >4 lymph node metastases were: 44 months and 71%; 36 months and 59%; 24 months and 50%; and 17 months and 32% respectively. Conclusions: The eLNMC was an important and significant prognostic indicator in patients with esophageal cancer, which should in future be reported and used to revise the perceived radiological stage, in order to inform stage directed multimodal therapy.

No significant financial relationships to disclose.

Injecting quality into the health care building process

This article, which draws on material from a study undertaken by Rawlinson Kelly Whittlestone (RKW) for the King Edwards' Hospital Fund for London, explores the interrelationships between quality in health buildings and the health building process. It describes the new context for quality improvements in the UK, and attempts to define health building quality from a variety of differing perspectives. It also describes some of the lessons learned and threats to quality from the last 25 years of new health buildings in the UK. Decision points which can compromise quality during the health building process are highlighted. Prerequisites for ensuring that quality is both safeguarded and injected into the health building process are identified and discussed.

Oxygen and suction in hospital wards: how many outlets?

Current DHSS guidance assumes a close link between patient dependency and the number of oxygen and suction outlets required. Research now puts a question mark against this assumption, reports Dr Carole Rawlinson, of the Medical Architecture Research Unit, Polytechnic of North London.