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Dr John Dennis

Dr John Dennis

Senior Independent Research Fellow

 07734 940921

 RILD Building 

 

University of Exeter Medical School, RILD Building, RD&E Hospital Wonford, Barrack Road, Exeter, EX2 5DW, UK

Overview

John is an Senior Independent Research Fellow, funded by a UKRI E3 Independent Research Fellowship.

John’s research focuses on developing a personalised or ‘precision’ approach to drug therapy in type 2 diabetes, a condition for which there are many different drug options but little guidance to help clinicians and patients choose between them. John is applying data science and advanced statistical methods to better understand the benefits and risks of each drug option, and to develop a decision aid to help health professionals choose the best drug for their individual patients.

John is also developing a more general methodological framework for precision medicine research combining data from UK routine primary care (CPRD) and randomised clinical trials.

He completed his PhD in Medical Statistics under Professor William Henley, Dr Beverley Shields and Professor Andrew Hattersley. He was awarded runner-up in the Diabetes UK Type 2 Diabetes Research Prize in 2017 and won the Diabetes UK Lily Clinical Science Poster Award in 2015. Prior to joining the Diabetes team at Exeter, John trained at the London School of Hygiene & Tropical Medicine and worked as an epidemiological researcher in the financial services industry, specialising in longevity modelling.

Qualifications

  • PhD Medical Statistics University of Exeter
  • MSc London School of Hygiene and Tropical Medicine
  • BSc (Hons) University of Nottingham

Funding

UKRI E3 Independent Research Fellowship (2019-2023)

Grants

  • "Understanding the association between diabetes and severity of COVID-19 infection." PI with 9 co-applicants. Diabetes UK Grant £65,418.30 awarded May 2020.
  • BHF-Turing Cardiovascular Data Science Award. £110,000 awarded Sept 2019. Co-PI with S. Vollmer (Turing Institute), plus 5 other co-applicants: 'Precision medicine in type 2 diabetes: developing and testing a decision support tool for primary care to optimise the selection of glucose-lowering therapy.'
  • NIHR Development Funding Scheme (DFS). £50,000 awarded February 2018. Co-applicant with A Hattersley (PI), plus 10 other co-applicants: "Developing a working platform for a treatment selection algorithm for glucose lowering in Type 2 diabetes”

 

Links

Research group links

Research

Research interests

  • Precision treatment in type 2 diabetes
  • Diabetes and COVID-19
  • Clinical prediction models
  • Synthesis of evidence from observational and trial datasets
  • Methods to strengthen inference from routine clinical practice databases

Research projects

Precision medicine in type 2 diabetes (Funding: MRC, BHF)

Understanding the association between diabetes and severity of COVID-19 infection (Funding: Diabetes UK)

Publications

Journal articles

Mateen BA, Wilde H, Dennis JM, Duncan A, Thomas NJ, McGovern AP, Denaxas S, Keeling MJ, Vollmer SJ (In Press). A geotemporal survey of hospital bed saturation across England during the first wave of the COVID-19 Pandemic.  Abstract.
Dennis J, Jones A, Shields B, Hattersley A (In Press). Comparison of causal forest and regression-based approaches to evaluate treatment effect heterogeneity: an application for type 2 diabetes precision medicine. BMC Medical Informatics and Decision Making Abstract.
Dennis JM, Young KG, McGovern AP, Mateen BA, Vollmer SJ, Simpson MD, Henley WE, Holman RR, Sattar N, Pearson ER, et al (In Press). Derivation and validation of a type 2 diabetes treatment selection algorithm for SGLT2-inhibitor and DPP4-inhibitor therapies based on glucose-lowering efficacy: cohort study using trial and routine clinical data.  Abstract.
Lynam A, McDonald T, Hill A, Dennis J, Oram R, Pearson E, Weedon M, Hattersley A, Owen K, Shields B, et al (In Press). Development and validation of multivariable clinical diagnostic models to identify type 1 diabetes requiring rapid insulin therapy in adults aged 18 to 50. BMJ Open
Dennis J, Shields B, Jones A, Pearson E, Hattersley A, Henley W (In Press). Evaluating associations between the benefits and risks of drug therapy in type 2 diabetes: a joint modelling approach. Clinical Epidemiology
Thomas NJ, McGovern A, Young KG, Sharp SA, Weedon MN, Hattersley AT, Dennis J, Jones AG (In Press). Identifying type 1 and 2 diabetes in population level data: assessing the accuracy of published approaches.  Abstract.
Dennis JM, McGovern AP, Vollmer SJ, Mateen BA (In Press). Improving COVID-19 critical care mortality over time in England: a national cohort study, March to June 2020.  Abstract.
Dennis J, Henley W, Weedon M, Lonergan M, Rodgers L, Jones A, Hamilton W, Sattar N, Janmohamed S, Holman R, et al (In Press). Sex and BMI alter the benefits and risks of sulfonylureas and thiazolidinediones in type 2 diabetes: a framework for evaluating stratification using routine clinical and individual trial data. Diabetes Care
Dennis J, Henley W, McGovern A, Farmer A, Sattar N, Holman R, Pearson E, Hattersley A, Shields B, Jones AG, et al (In Press). Time trends in prescribing of type 2 diabetes drugs, glycemic response and risk factors: a retrospective analysis of primary care data, 2010-2017 Running title: Prescribing and patient outcomes in type 2 diabetes. Diabetes, Obesity and Metabolism
McGovern A, Shields B, Hattersley A, Pearson E, Jones AG (In Press). What to do with diabetes therapies when HbA1c lowering is inadequate: add, switch, or continue? a MASTERMIND study. BMC Medicine
Young KG, McGovern AP, Barroso I, Hattersley AT, Jones AG, Shields BM, Thomas NJ, Dennis JM (2023). Correction to: the impact of population-level HbA1c screening on reducing diabetes diagnostic delay in middle-aged adults: a UK Biobank analysis. Diabetologia, 66(8). Author URL.
Young KG, McGovern AP, Barroso I, Hattersley AT, Jones AG, Shields BM, Thomas NJ, Dennis JM (2023). HbA1c screening for the diagnosis of diabetes. Reply to Brož J, Brabec M, Krollová P et al [letter]. Diabetologia, 66(8), 1578-1579. Author URL.
Locke JM, Dusatkova P, Colclough K, Hughes AE, Dennis JM, Shields B, Flanagan SE, Shepherd MH, Dempster EL, Hattersley AT, et al (2022). Association of birthweight and penetrance of diabetes in individuals with HNF4A-MODY: a cohort study. Diabetologia, 65(1), 246-249. Author URL.
Thygesen JH, Tomlinson C, Hollings S, Mizani MA, Handy A, Akbari A, Banerjee A, Cooper J, Lai AG, Li K, et al (2022). COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records. The Lancet Digital Health, 4(7), e542-e557. Abstract.
Nair ATN, Wesolowska-Andersen A, Brorsson C, Rajendrakumar AL, Hapca S, Gan S, Dawed AY, Donnelly LA, McCrimmon R, Doney ASF, et al (2022). Heterogeneity in phenotype, disease progression and drug response in type 2 diabetes. Nat Med, 28(5), 982-988. Abstract.  Author URL.
Shields BM, Dennis JM, Angwin CD, Warren F, Henley WE, Farmer AJ, Sattar N, Holman RR, Jones AG, Pearson ER, et al (2022). Patient stratification for determining optimal second-line and third-line therapy for type 2 diabetes: the TriMaster study. Nature Medicine, 29(2), 376-383.
Young KG, McGovern AP, Barroso I, Hattersley AT, Jones AG, Shields BM, Thomas NJ, Dennis JM (2022). The impact of population-level HbA1c screening on reducing diabetes diagnostic delay in middle-aged adults: a UK Biobank analysis. Diabetologia, 66(2), 300-309. Abstract.
Wilde H, Dennis JM, McGovern AP, Vollmer SJ, Mateen BA (2021). A national retrospective study of the association between serious operational problems and COVID-19 specific intensive care mortality risk. PLOS ONE, 16(7), e0255377-e0255377. Abstract.
Rodgers LR, Hill AV, Dennis JM, Craig Z, May B, Hattersley AT, McDonald TJ, Andrews RC, Jones A, Shields BM, et al (2021). Choice of HbA1c threshold for identifying individuals at high risk of type 2 diabetes and implications for diabetes prevention programmes: a cohort study. BMC Medicine, 19(1). Abstract.
Thomas NJ, Dennis JM, Sharp SA, Kaur A, Misra S, Walkey HC, Johnston DG, Oliver NS, Hagopian WA, Weedon MN, et al (2021). Correction to: DR15-DQ6 remains dominantly protective against type 1 diabetes throughout the first five decades of life. Diabetologia, 65(1), 258-258.
Thomas NJ, Dennis JM, Sharp SA, Kaur A, Misra S, Walkey HC, Johnston DG, Oliver NS, Hagopian WA, Weedon MN, et al (2021). DR15-DQ6 remains dominantly protective against type 1 diabetes throughout the first five decades of life. Diabetologia, 64(10), 2258-2265. Abstract.  Author URL.
Cefalu WT, Andersen DK, Arreaza-Rubín G, Pin CL, Sato S, Verchere CB, Woo M, Rosenblum ND, Symposium planning committee, moderators, and speakers:, Rosenblum N, et al (2021). Heterogeneity of Diabetes: β-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes Abstract.  Author URL.
Mateen BA, Wilde H, Dennis JM, Duncan A, Thomas N, McGovern A, Denaxas S, Keeling M, Vollmer S (2021). Hospital bed capacity and usage across secondary healthcare providers in England during the first wave of the COVID-19 pandemic: a descriptive analysis. BMJ Open, 11(1), e042945-e042945. Abstract.
Dennis JM, McGovern AP, Vollmer SJ, Mateen BA (2021). Improving Survival of Critical Care Patients with Coronavirus Disease 2019 in England: a National Cohort Study, March to June 2020. Crit Care Med, 49(2), 209-214. Abstract.  Author URL.
Wilde H, Mellan T, Hawryluk I, Dennis JM, Denaxas S, Pagel C, Duncan A, Bhatt S, Flaxman S, Mateen BA, et al (2021). The association between mechanical ventilator compatible bed occupancy and mortality risk in intensive care patients with COVID-19: a national retrospective cohort study. BMC Med, 19(1). Abstract.  Author URL.
McGovern AP, Thomas NJ, Vollmer SJ, Hattersley AT, Mateen BA, Dennis JM (2021). The disproportionate excess mortality risk of COVID-19 in younger people with diabetes warrants vaccination prioritisation. Diabetologia, 64(5), 1184-1186. Author URL.
Dennis JM, McGovern AP, Thomas NJ, Wilde H, Vollmer SJ, Mateen BA (2021). Trends in 28-Day Mortality of Critical Care Patients with Coronavirus Disease 2019 in the United Kingdom: a National Cohort Study, March 2020 to January 2021. Crit Care Med, 49(11), 1895-1900. Abstract.  Author URL.
Lynam AL, Dennis JM, Owen KR, Oram RA, Jones AG, Shields BM, Ferrat LA (2020). Logistic regression has similar performance to optimised machine learning algorithms in a clinical setting: application to the discrimination between type 1 and type 2 diabetes in young adults. Diagnostic and Prognostic Research, 4(1). Abstract.
Dennis JM (2020). Precision Medicine in Type 2 Diabetes: Using Individualized Prediction Models to Optimize Selection of Treatment. Diabetes, 69(10), 2075-2085. Abstract.
Rodgers LR, Dennis JM, Shields BM, Mounce L, Fisher I, Hattersley AT, Henley WE (2020). Prior event rate ratio adjustment produced estimates consistent with randomized trial: a diabetes case study. Journal of Clinical Epidemiology, 122, 78-86.
McGovern AP, Hogg M, Shields BM, Sattar NA, Holman RR, Pearson ER, Hattersley AT, Jones AG, Dennis JM (2020). Risk factors for genital infections in people initiating SGLT2 inhibitors and their impact on discontinuation. BMJ Open Diabetes Research & Care, 8(1), e001238-e001238. Abstract.
Donnelly LA, Dennis JM, Coleman RL, Sattar N, Hattersley AT, Holman RR, Pearson ER (2020). Risk of Anemia with Metformin Use in Type 2 Diabetes: a MASTERMIND Study. Diabetes Care, 43(10), 2493-2499. Abstract.
Jones AG, Shields BM, Dennis JM, Hattersley AT, McDonald TJ, Thomas NJ (2020). The challenge of diagnosing type 1 diabetes in older adults. Diabet Med, 37(10), 1781-1782. Author URL.
Dennis JM, Mateen BA, Sonabend R, Thomas NJ, Patel KA, Hattersley AT, Denaxas S, McGovern AP, Vollmer SJ (2020). Type 2 Diabetes and COVID-19–Related Mortality in the Critical Care Setting: a National Cohort Study in England, March–July 2020. Diabetes Care, 44(1), 50-57. Abstract.
Dennis JM, Shields BM, Henley WE, Jones AG, Hattersley AT (2019). Clusters provide a better holistic view of type 2 diabetes than simple clinical features - Authors' reply. Lancet Diabetes Endocrinol, 7(9). Author URL.
Dennis J, Shields B, Henley W, Jones A, Hattersley A (2019). Disease progression and treatment response in data-driven subgroups of type 2 diabetes compared to models based on simple clinical features: an evaluation using clinical trial data. Lancet Diabetes and Endocrinology
Dennis J, Shields B, Hill A, Knight B, McDonald T, Rodgers L, Weedon M, Henley W, Sattar N, Holman R, et al (2018). Precision medicine in Type 2 diabetes: Clinical markers of insulin resistance are associated with altered short- and long-term glycemic response to DPP-4 inhibitor therapy. Diabetes Care
Curtis HJ, Dennis JM, Shields BM, Walker AJ, Bacon S, Hattersley AT, Jones AG, Goldacre B (2018). Time trends and geographical variation in prescribing of drugs for diabetes in England from 1998 to 2017. Diabetes Obes Metab, 20(9), 2159-2168. Abstract.  Author URL.
Harris JD, Little CJL, Dennis JM, Patteson MW (2017). Heart rate turbulence after ventricular premature beats in healthy Doberman pinschers and those with dilated cardiomyopathy. J Vet Cardiol, 19(5), 421-432. Abstract.  Author URL.
Dennis J, Crayford T (2015). Parliamentary privilege—mortality in members of the Houses of Parliament compared with the UK general population: retrospective cohort analysis, 1945-2011. BMJ, h6563-h6563.

Conferences

Young KG, McGovern AP, Hopkins R, Raya D, Sattar NA, Holman RR, Pearson ER, Hattersley AT, Jones AG, Shields BM, et al (2022). Precision medicine in type 2 diabetes: integrating trial and real-world evidence can provide accurate estimates of heart failure benefit when initiating SGLT2-inhibitors.  Author URL.
Cefalu WT, Andersen DK, Arreaza-Rubín G, Pin CL, Sato S, Verchere CB, Woo M, Rosenblum ND, Cefalu W, Dhara C, et al (2021). Heterogeneity of Diabetes: β-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases.  Abstract.
McGovern AP, Thomas NJ, Vollmer SJ, Hattersley AT, Mateen BA, Dennis JM (2021). In younger people with diabetes the disproportionate additional covid-19 mortality risk of covid-19 warrants vaccination prioritisation.  Author URL.
Young KG, Dennis JM, Thomas NJ, Jones AG, McGovern A, Shields BM, Barroso I, Hattersley AT (2021). Participants with undiagnosed diabetes in UK Biobank wait on average two years to receive a diagnosis, and simple clinical features are associated with diagnosis delays.  Author URL.
Dennis JM, Donnelly LA, Henley WE, Jones AG, McGovern AP, Sattar N, Holman RR, Pearson ER, Hattersley AT, Shields BM, et al (2020). Development of a decision aid for primary care to predict the best glucose-lowering treatment after metformin for people with type 2 diabetes.  Author URL.
Ferrat LA, Dennis JM, Owen KR, Oram RA, Jones AG, Shields BM, Lynam AL (2020). Early development of insulinopenia in Black African men with dysglycaemia.  Author URL.
Mcgovern AP, Dennis JM, Shields BM, Hattersley AT, Jones AG (2020). Predictors of genital mycotic infections with SGLT2 inhibitors.  Author URL.
Donnelly LA, Dennis JM, Coleman RL, Hattersley AT, Holman RR, Sattar N, Pearson ER (2020). Risk of anaemia with metformin use: a MASTERMIND study.  Author URL.
McGovern AP, Dennis JM, Shields BM, Pearson ER, Hattersley AT, Jones AG (2020). Should you intensify therapy? a simple tool to quantify the chance of meeting HbA1c targets without adding medication.  Author URL.
Dennis JM, Henley W, Jones A, McGovern A, Pearson E, Hattersley A, Shields B, Consortium MASTERMIND (2019). Precision medicine in type 2 diabetes: harnessing individual-level trial data alongside routine care records to identify predictors of response to SGLT2 inhibitors and DPP4 inhibitors.  Author URL.
Dennis JM, Shields BM, Henley WE, Jones AG, Hattersley AT (2019). Using trial data to test the proposed 5 novel subgroups of diabetes from Ahlqvist et al. derived from cluster analysis: simple clinical measures markedly outperform the 5 subgroups to predict drug response and diabetes progression.  Author URL.
McGovern AP, Dennis JM, Shields BM, Hattersley AT, Pearson ER, Jones AG (2019). What to do when a new medication does not lower HbA1c: Add, switch or continue? a MASTERMIND study.  Author URL.
Dennis JM, Henley WE, Weedon MN, Rodgers LR, Jones AG, Pearson ER, Hattersley AT, Shields BM (2018). Are the new drugs better? Changing UK prescribing of Type 2 diabetes medications and effects on HbA1c and weight, 2010 to 2016.  Author URL.
Kimmitt RA, Dennis JM, Weedon M, Rodgers LR, Jones AG, Pearson ER, Hattersley AT, Oram RA, Shields BM (2018). Higher estimated glomerular filtration rate (eGFR) is associated with improved glycaemic response to sodium-glucose co-transporter-2 (SGLT2) inhibitors in patients with Type 2 diabetes and normal renal function: a MASTERMIND study.  Author URL.
Dennis JM, Shields BM, Henley WE, Jones AG, Hattersley AT (2018). Trial data show the proposed 5 diabetes subgroups from cluster analysis do predict drug response and diabetes progression but simple clinical measures are stronger predictors.  Author URL.
Dennis JM, Henley WE, Weedon MN, Lonergan M, Rodgers LR, Jones AG, Sattar NA, Holman RR, Pearson ER, Hattersley AT, et al (2017). A calculator to predict durability of HbA(1c) response with DPP4 inhibitors, sulfonylureas and thiazolidinediones: a MASTERMIND precision medicine study.  Author URL.
Dennis JM, Shields BM, Henley WE, Knight BA, McDonald TJ, Hill AV, Weedon MN, Rodgers LR, Hattersley AT, Jones AG, et al (2017). Clinical markers of insulin resistance predict reduced glycaemic response with DPP4-inhibitors: a MASTERMIND stratified medicine study.  Author URL.
Dennis JM, Henley WE, Weedon M, Lonergan M, Jones AG, Sattar N, Holman RR, Pearson ER, Hattersley AT, Shields BM, et al (2017). Development of an online risk calculator to predict durability of good glycaemic control with sulfonylurea and thiazolidinedione therapy: a MASTERMIND stratified medicine study.  Author URL.
Shields BM, Dennis JM, Henley W, Weedon M, Lonergan M, Rodgers L, Jones AG, Holman RR, Pearson ER, Hattersley AT, et al (2016). Personalising therapy in type 2 diabetes: the effect of BMI and sex on glycaemic response and side effects to sulphonylureas and thiazolidinediones.  Author URL.
Dennis JM, Henley WE, Weedon MN, Lonergan M, Rodgers LR, Jones AG, Holman RR, Pearson ER, Hattersley AT, Shields BM, et al (2016). Personalizing Therapy in Type 2 Diabetes: the Effect of BMI and Gender on Response and Side Effects to Sulfonylureas and Thiazolidinediones.  Author URL.
Dennis JM, Hattersley AT, Henley WE, Jones AG, Pearson ER, Shields BM (2016). Stratification using gender and body mass index (BMI) can predict side-effect risk in people with Type 2 diabetes initiating thiazolidinediones but not sulphonylureas: a MASTERMIND study.  Author URL.
Dennis JM, Hattersley AT, Weedon M, Angwin C, Rodgers L, Pearson ER, Henley WE, Shields BM (2015). Development of oedema is associated with an improved glycaemic response in patients initiating thiazolidinediones: a MASTERMIND study.  Author URL.
Dennis JM, Hattersley AT, Weedon M, Angwin CD, Rodgers L, Pearson ER, Henley WE, Shields BM (2015). Patients who develop oedema on initiating thiazolidinedione therapy have an improved glycaemic response: a MASTERMIND study.  Author URL.


John_Dennis Details from cache as at 2023-09-22 20:46:36

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External Engagement and Impact

Awards

  • Poster prize runner-up. Statistical analysis of multi-outcome data conference, 2017
  • Diabetes UK Type 2 diabetes research award runner-up. Diabetes UK professional conference, 2017
  • Diabetes UK Lily Clinical Science Poster Award, Diabetes UK professional conference, 2015

Committee/panel activities

Diabetes UK Clinical Studies Group 1: Causes of diabetes (2018-date)


Competitively funded studentships and postdoctoral fellowships

UKRI E3 Independent Research Fellowship (2019-2023)


Invited lectures

  • “Precision Medicine in Type 2 Diabetes—Using Individualized Prediction Models to Optimize Selection of Treatment” ADA Diabetes Symposium—Unraveling the Heterogeneity in Type 2 Diabetes, 2020
  • “Is defining subtypes the best way to individualise care in Type 2 diabetes?” Diabetes UK Professional conference Hot Topics, Liverpool, 2019
  • “Can we use clinical features to stratify type 2 diabetes treatment?” GoDARTs Symposium Precision Medicine in Diabetes, Pitlochry, Scotland, 2018
  • “Developing a treatment selection algorithm for second-line therapy” MASTERMIND 5 year report: Industry Partners and Stakeholders meeting, London, 2018

Media Coverage

Oct 2020: Death Rates Have Dropped for Seriously Ill Covid Patients

Dec 2015: New perk for MPs: longer life

Teaching

Supervision / Group

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