Automatic coding of nearly 2 million hospitalisation events to ICD-10 in the China Kadoorie Biobank

Introduction Using linkage to the Chinese National Health Insurance (HI) system, we identified disease outcomes from a prospective cohort study of 512,000 middle-aged Chinese adults. Mandarin free-text diagnosis data were supplied by over 30 different agencies across 10 areas, often without an accompanying International Classification of Diseases 10th revision (ICD-10) code. Objectives and Approach To facilitate a genome-wide association study (GWAS) of all our genotyped participants, we needed to code as many of our 2.02 million hospitalisation events as possible. We developed software to assign ICD-10 codes to unique disease descriptions and stored the coded diagnoses in an internal corpus. The software used an interface which allowed clinicians to select and code disease descriptions individually, or collectively using Chinese keywords. All coded disease descriptions were subsequently validated by an independent Mandarin-speaking clinician. All new events with descriptions which matched exactly those already in the corpus were automatically coded to ICD-10. Results By the end of 2016, there were 2,021,352 hospitalisation events coded to ICD-10. 436,702 (21.6%) were automatically assigned codes where disease descriptions corresponded to those in the Chinese version of the ICD-10 codebook. A further 1,084,197 (53.6%) were coded by a clinician using our standardisation software; all disease descriptions linked to 200 or more events were included. Finally, a remaining 454,237 (22.5%) events were given the ICD-10 codes supplied by the health insurance agency (after cleaning). In total, 97.7% of all health insurance events were coded to ICD-10. Overall, over 17,000 unique disease descriptions have been clinically classified. Conclusion/Implications Automatic coding of hospitalisation events to ICD-10 has enabled our study to investigate a greater range of diseases and use GWAS to detect novel genetic variants. We are now well positioned to test semantic matching and machine learning strategies for coding of the remaining 46,216 (2.3%) uncoded events

Advances in optical sensing of explosive vapours

This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under agreement no 284747, and the EPSRC under EP/K503940/1, EP/K503162/1, and EP/N509759/1. IDWS acknowledges a Royal Society Wolfson Research Merit Award.Optical techniques for the detection of explosives are receiving increasing interest due to potentially fast responding, highly-sensitive systems. Conjugated polymers are suitable probe materials for this application since their fluorescence is quenched by electronegative materials including explosives. This can be used to make a sensor for explosive vapour, which can then give chemical information to help identify explosive devices, and complements other approaches such as metal detectors and ground penetrating radar. Whilst the principle has been known for some time, its practical implementation requires considerable development of instrumentation and materials, including preconcentration materials. This paper reports our current efforts to address these challenges, with particular emphasis on humanitarian demining and looking towards application in Improvised Explosive Device (IED) detection.Publisher PD

A portable, low-cost system for optical explosive detection based on a CMOS camera

Humanitarian demining requires a variety of methods and instrumentation for effective mine clearance, since a wide range of materials are used in mine manufacturing. However, landmines release vapours over time that can be detected, for example, by sniffer dogs. Optical sensor systems are especially suited to this application due to the potential for lightweight, portable, low-cost systems that nevertheless have fast response times and ppb-level sensitivity to explosive vapours. In this paper we present a system for detection based on a low-cost Raspberry Pi platform with an integrated CMOS camera. The conjugated polymers Super Yellow and Polyfluorene are excited by an LED, and the quenching effect by DNB vapour is monitored by the camera to indicate the presence of explosives. The system shows potential as a user friendly, lightweight platform for explosive vapour sensing.Publisher PD

Ormosil-coated conjugated polymers for the detection of explosives in aqueous environments

This project has received funding from the TIRAMISU project, funded by the European Commission’s Seventh Framework Programme (FP7/2007-2013) under grant agreement 284747, and the Engineering and Physical Sciences Research Council under grants EP/K503940/1, EP/K503162/1, EP/N509759/1. IDWS acknowledges a Royal Society Wolfson Research Merit Award. The research data supporting this publication can be accessed at http://dx.doi.org/10.17630/3875a099-bb75-4ae1-82e5-0b98b6b7ebc6.A fluorescence-based sensor for detecting explosives, based on a conjugated polymer coated with an ormosil layer, has been developed for use in aqueous environments. The conjugated polymer Super Yellow was spin-coated onto glass substrates prior to a further spin-coating of an MTEOS/TFP-TMOS-based ormosil film, giving an inexpensive, solution-based barrier material for ruggedization of the polymer to an aqueous environment. The sensors showed good sensitivity to 2,4-DNT in the aqueous phase at micromolar and millimolar concentrations, and also showed good recovery of fluorescence when the explosive was removed.PostprintPeer reviewe

MTHFR and risk of stroke and heart disease in a low-folate population: a prospective study of 156 000 Chinese adults

Background The relevance of folic acid for stroke prevention in low-folate populations such as in China is uncertain. Genetic studies of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, which increases plasma homocysteine (tHcy) levels, could clarify the causal relevance of elevated tHcy levels for stroke, ischaemic heart disease (IHD) and other diseases in populations without folic acid fortification. Methods In the prospective China Kadoorie Biobank, 156 253 participants were genotyped for MTHFR and 12 240 developed a stroke during the 12-year follow-up. Logistic regression was used to estimate region-specific odds ratios (ORs) for total stroke and stroke types, IHD and other diseases comparing TT genotype for MTHFR C677T (two thymine alleles at position 677 of MTHFR C677T polymorphism) vs CC (two cytosine alleles) after adjustment for age and sex, and these were combined using inverse-variance weighting. Results Overall, 21% of participants had TT genotypes, but this varied from 5% to 41% across the 10 study regions. Individuals with TT genotypes had 13% (adjusted OR 1.13, 95% CI 1.09–1.17) higher risks of any stroke [with a 2-fold stronger association with intracerebral haemorrhage (1.24, 1.17–1.32) than for ischaemic stroke (1.11, 1.07–1.15)] than the reference CC genotype. In contrast, MTHFR C677T was unrelated to risk of IHD or any other non-vascular diseases, including cancer, diabetes and chronic obstructive lung disease. Conclusions In Chinese adults, the MTHFR C677T polymorphism was associated with higher risks of stroke. The findings warrant corroboration by further trials of folic acid and implementation of mandatory folic acid fortification programmes for stroke prevention in low-folate populations

Heterogeneity in the diagnosis and prognosis of ischemic stroke subtypes: 9-year follow-up of 22,000 cases in Chinese adults

Background: Reliable classification of ischemic stroke (IS) etiological subtypes is required in research and clinical practice, but the predictive properties of these subtypes in population studies with incomplete investigations are poorly understood. Aims: To compare the prognosis of etiologically classified IS subtypes and use machine learning (ML) to classify incompletely investigated IS cases. Methods: In a 9-year follow-up of a prospective study of 512,726 Chinese adults, 22,216 incident IS cases, confirmed by clinical adjudication of medical records, were assigned subtypes using a modified Causative Classification System for Ischemic Stroke (CCS) (large artery atherosclerosis (LAA), small artery occlusion (SAO), cardioaortic embolism (CE), or undetermined etiology) and classified by CCS as “evident,” “probable,” or “possible” IS cases. For incompletely investigated IS cases where CCS yielded an undetermined etiology, an ML model was developed to predict IS subtypes from baseline risk factors and screening for cardioaortic sources of embolism. The 5-year risks of subsequent stroke and all-cause mortality (measured using cumulative incidence functions and 1 minus Kaplan–Meier estimates, respectively) for the ML-predicted IS subtypes were compared with etiologically classified IS subtypes. Results: Among 7443 IS subtypes with evident or probable etiology, 66% had SAO, 32% had LAA, and 2% had CE, but proportions of SAO-to-LAA cases varied by regions in China. CE had the highest rates of subsequent stroke and mortality (43.5% and 40.7%), followed by LAA (43.2% and 17.4%) and SAO (38.1% and 11.1%), respectively. ML provided classifications for cases with undetermined etiology and incomplete clinical data (24% of all IS cases; n = 5276), with area under the curves (AUC) of 0.99 (0.99–1.00) for CE, 0.67 (0.64–0.70) for LAA, and 0.70 (0.67–0.73) for SAO for unseen cases. ML-predicted IS subtypes yielded comparable subsequent stroke and all-cause mortality rates to the etiologically classified IS subtypes. Conclusion: This study highlighted substantial heterogeneity in prognosis of IS subtypes and utility of ML approaches for classification of IS cases with incomplete clinical investigations

Chronic Hepatitis B Virus Infection and Risk of Stroke Types: A Prospective Cohort Study of 500 000 Chinese Adults

BACKGROUND: Stroke is a leading cause of mortality and permanent disability in China, with large and unexplained geographic variations in rates of different stroke types. Chronic hepatitis B virus infection is prevalent among Chinese adults and may play a role in stroke cause. // METHODS: The prospective China Kadoorie Biobank included >500 000 adults aged 30 to 79 years who were recruited from 10 (5 urban and 5 rural) geographically diverse areas of China from 2004 to 2008, with determination of hepatitis B surface antigen (HBsAg) positivity at baseline. During 11 years of follow-up, a total of 59 117 incident stroke cases occurred, including 11 318 intracerebral hemorrhage (ICH), 49 971 ischemic stroke, 995 subarachnoid hemorrhage, and 3036 other/unspecified stroke. Cox regression models were used to estimate adjusted hazard ratios (HRs) for risk of stroke types associated with HBsAg positivity. In a subset of 17 833 participants, liver enzymes and lipids levels were measured and compared by HBsAg status. // RESULTS: Overall, 3.0% of participants were positive for HBsAg. HBsAg positivity was associated with an increased risk of ICH (adjusted HR, 1.29 [95% CI, 1.16–1.44]), similarly for fatal (n=5982; adjusted HR, 1.36 [95% CI, 1.16–1.59]) and nonfatal (n=5336; adjusted HR, 1.23 [95% CI, 1.06–1.44]) ICH. There were no significant associations of HBsAg positivity with risks of ischemic stroke (adjusted HR, 0.97 [95% CI, 0.92–1.03]), subarachnoid hemorrhage (adjusted HR, 0.87 [95% CI, 0.57–1.33]), or other/unspecified stroke (adjusted HR, 1.12 [95% CI, 0.89–1.42]). Compared with HBsAg-negative counterparts, HBsAg-positive individuals had lower lipid and albumin levels and higher liver enzyme levels. After adjustment for liver enzymes and albumin, the association with ICH from HBsAg positivity attenuated to 1.15 (0.90–1.48), suggesting possible mediation by abnormal liver function. // CONCLUSIONS: Among Chinese adults, chronic hepatitis B virus infection is associated with an increased risk of ICH but not other stroke types, which may be mediated through liver dysfunction and altered lipid metabolism

What might make nurses stay? A protocol for discrete choice experiments to understand NHS nurses’ preferences at early-career and late-career stages

Introduction: Like many countries, England has a national shortage of registered nurses. Employers strive to retain existing staff, to ease supply pressures. Disproportionate numbers of nurses leave the National Health Services (NHS) both early in their careers, and later, as they near retirement age. Research is needed to understand the job preferences of early-career and late-career nurses working in the NHS, so tailored policies can be developed to better retain these two groups.Methods and analysis: We will collect job preference data for early-career and late-career NHS nurses, respectively using two separate discrete choice experiments (DCEs). Findings from the literature, focus groups, academic experts and stakeholder discussions will be used to identify and select the DCE attributes (ie, job features) and levels. We will generate an orthogonal, fractional factorial design using the experimental software Ngene. The DCEs will be administered through online surveys distributed by the regulator Nursing and Midwifery Council. For each group, we expect to achieve a final sample of 2500 registered NHS nurses working in England. For early-career nurses, eligible participants will be registered nurses who graduated in the preceding 5 years (ie, 2019–2023). Eligible participants for the late-career survey will be registered nurses aged 55 years and above. We will use conditional and mixed logit models to analyse the data. Specifically, study 1 will estimate the job preferences of early-career nurses and the possible trade-offs. Study 2 will estimate the retirement preferences of late-career NHS nurses and the potential trade-offs.Ethics and dissemination: The research protocol was reviewed and approved by the host research organisation Ethics Committees Research Governance (University of Southampton, number 80610) (https://www.southampton.ac.uk/about/governance/regulations-policies/policies/ethics). The results will be disseminated via conference presentations, publications in peer-reviewed journals and annual reports to key stakeholders, the Department of Health and Social Care, and NHS England/Improvement retention leaders.Registration details: Registration on OSF http://doi.org/10.17605/OSF.IO/RDN9G