Professor Karla Hemming PhD

Professor Karla Hemming

Department of Applied Health Sciences
Professor of Biostatistics

Contact details

Address
Public Health, Epidemiology and Biostatistics
Department of Applied Health Sciences
College of Medicine and Health
University of Birmingham
Edgbaston
Birmingham, B15 2TT

Karla is a Professor of Biostatistics in the Department of Applied Health Sciences, University of Birmingham, UK. Karla’s research interests include how to design cluster and stepped-wedge trials so as to maximise their statistical efficiency and minimise their risk of bias; how to model time and treatment effect heterogeneity in longitudinal cluster trials; and the ethical issues surrounding these pragmatic trial designs, such as ethical oversight and consent. Karla has recently led the CONSORT extension for the stepped-wedge cluster randomised trial.

Teaching

Teaching Programmes

MBChB Year 2 Integrated Problems (statistics)

Master in Public Health (ESRM and Advanced Statistics)

Postgraduate supervision

Karla supervises PhD students in all aspects of the methodology of cluster randomised trials and the interpretation of statistical findings in RCTs. This includes both quantitative and qualitative projects.

Research

Research and reporting methods for the stepped wedge cluster randomised controlled trial

The stepped‐wedge cluster randomised trial (SW‐CRT) is a novel research study design that  is increasingly being used in the evaluation of service delivery type interventions. Recent systematic reviews have demonstrated that use of this study design is clearly on the increase. In the early history of cluster randomised trials it was not unusual to see trial results which were published without allowing for the clustering, and so results which were overly precise. Because the SW‐CRT is a new study design, it is possible that the analysis and reporting of these trials are not adequately reported. Reporting guidelines specific to SWCRTs do not exist, but here we recommend some minor additions or modifications that can be made to the cluster consort guidelines until specific guidelines for SW‐CRTs are formalised. 

One day work shop: Stepped wedge cluster RCT Roadshow 
For information on upcoming dates please contact Karla: k.hemming@bham.ac.uk  

Collaborators: Karla works with an international group of people all interested and actively researching into the stepped wedge design.
This includes: Monica Taljaard, Associate Professor, Epidemiology and Community Medicine University of Ottawa http://www.ohri.ca/profile/mtaljaard and Terry Haines, Monash University http://www.med.monash.edu.au/physio/staff/haines.html

Publications

Highlight publications

Hemming, K, Thompson, J, Hooper, RL, Ukoumunne, OC, Li, F, Caille, A, Kahan, BC, Leyrat, C, Grayling, MJ, Mohammed, NI, Thompson, JA, Giraudeau, B, Turner, EL, Watson, S, Goulão, B, Kasza, J, Forbes, AB, Copas, AJ & Taljaard, M 2025, 'Guidelines for the content of statistical analysis plans in clinical trials: protocol for an extension to cluster randomized trials', Trials, vol. 26, 72. https://doi.org/10.1186/s13063-025-08756-3

Thompson, JY, Shaw, J, Watson, S, Wang, Y, Robinson, C, Taljaard, M & Hemming, K 2025, 'Review of the quality of reporting of statistical analysis plans for cluster randomized trials', Journal of Clinical Epidemiology. https://doi.org/10.1016/j.jclinepi.2025.111726

McKenzie, JE, Taljaard, M, Hemming, K, Arnup, SJ, Giraudeau, B, Eldridge, S, Hooper, R, Kahan, BC, Li, T, Moher, D, Turner, EL, Grimshaw, JM & Forbes, AB 2025, 'Reporting of cluster randomised crossover trials: extension of the CONSORT 2010 statement with explanation and elaboration', BMJ (Clinical research ed.), vol. 388, e080472. https://doi.org/10.1136/bmj-2024-080472

Hemming, K, Thompson, JY, Taljaard, M, Watson, SI, Kasza, J, Thompson, JA, Kahan, BC & Copas, AJ 2024, 'Re-analysis of data from cluster randomised trials to explore the impact of model choice on estimates of odds ratios: study protocol', Trials, vol. 25, no. 1, 818. https://doi.org/10.1186/s13063-024-08653-1

Hemming, K, Copas, A, Forbes, A & Kasza, J 2024, 'What type of cluster randomized trial for which setting?', Journal of epidemiology and population health, vol. 72, no. 1, 202195. https://doi.org/10.1016/j.jeph.2024.202195

Recent publications

Article

Kudrna, L, Yates, J, Alidu, L, Hemming, K, Quinn, L, Schmidtke, KA, Jones, J, Al-Khudairy, L, Jolly, K, Bird, P, Campbell, N, Bharatan, I, Latuszynska, A, Currie, G & Lilford, R 2025, 'A Mixed-Methods Cluster Randomised Waitlist-Controlled Trial of a Goal-Based Behaviour Change Intervention Implemented in Workplaces', International Journal of Environmental Research and Public Health, vol. 22, no. 3, 398. https://doi.org/10.3390/ijerph22030398

MacArthur, C, Bick, D, Salmon, V, Jones, E, Hay-smith, J, Bishop, J, Gkini, E, Hemming, K, Webb, S, Pearson, M, Coleman, T, Terry, R, Edwards, E, Frawley, H, Oborn, E & Dean, S 2025, 'Antenatal pelvic floor muscle exercise intervention led by midwives in England to reduce postnatal urinary incontinence: APPEAL feasibility and pilot randomised controlled cluster trial', BMJ open, vol. 15, no. 1, e091248. https://doi.org/10.1136/bmjopen-2024-091248

Dickinson-Craig, E, Turbat, T, Hemming, K, Pope, F, Bartington, S, Anjaa, S, Davaa, S, Day, R, Boldbaatar, D, Ochir, C, Warburton, D, Thomas, GN, Badarch, J & Manaseki-Holland, S 2025, 'Improving Air Quality and Childhood Respiratory Health in Mongolia: The Impact of the Raw Coal Ban and COVID-19 Restrictions—An Interrupted Time-Series Analysis', Atmosphere, vol. 16, no. 1, 46. https://doi.org/10.3390/atmos16010046

Williams, EV, Goranitis, I, Oppong, R, Perry, SJ, Devall, AJ, Martin, JT, Mammoliti, K-M, Beeson, LE, Sindhu, KN, Galadanci, H, Al-beity, FA, Qureshi, Z, Hofmeyr, GJ, Moran, N, Fawcus, S, Mandondo, S, Middleton, L, Hemming, K, Oladapo, OT, Gallos, ID, Coomarasamy, A & Roberts, TE 2024, 'A cost-effectiveness analysis of early detection and bundled treatment of postpartum haemorrhage alongside the E-MOTIVE trial', Nature Medicine. https://doi.org/10.1038/s41591-024-03069-5

Schmidtke, KA, Kudrna, L, Quinn, L, Bird, P, Hemming, K, Venable, Z & Lilford, R 2024, 'Cluster randomised evaluation of a training intervention to increase the use of statistical process control charts for hospitals in England: making data count', BMJ Quality & Safety. https://doi.org/10.1136/bmjqs-2024-017094

Hemming, K, Kudrna, L, Watson, S, Taljaard, M, Greenfield, S, Goulao, B & Lilford, R 2024, 'Interpretation of statistical findings in randomised trials: a survey of statisticians using thematic analysis of open-ended questions', BMC Medical Research Methodology, vol. 24, no. 1, 256. https://doi.org/10.1186/s12874-024-02366-4

Quinn, L, Martin, J, Asamane, E, Manaseki-Holland, S, Lilford, RJ, Traore, L, Thompson, J, Watson, SI & Hemming, K 2024, 'Statistical analysis plan for cluster randomised trial to evaluate a community-level complementary food safety and hygiene and nutrition intervention in Mali: the MaaCiwara study', Trials, vol. 25, no. 1, 483. https://doi.org/10.1186/s13063-024-08328-x

Hemming, K, Melo, P, Luo, R, Taljaard, M & Coomarasamy, A 2023, 'A re‐analysis of 150 women's health trials to investigate how the Bayesian approach may offer a solution to the misinterpretation of statistical findings', BJOG: An International Journal of Obstetrics & Gynaecology. https://doi.org/10.1111/1471-0528.17570

Al-Khudairy, L, Akram, Y, Watson, SI, Kudrna, L, Hofman, J, Nightingale, M, Alidu, L, Rudge, A, Rawdin, C, Ghosh, I, Mason, F, Perera, C, Wright, J, Boachie, J, Hemming, K, Vlaev, I, Russell, S & Lilford, RJ 2023, 'Evaluation of an organisational-level monetary incentive to promote the health and wellbeing of workers in small and medium-sized enterprises: a mixed-methods cluster randomised controlled trial', PLOS Global Public Health, vol. 3, no. 7, e0001381. https://doi.org/10.1371/journal.pgph.0001381

Dickinson-Craig, E, Badarch, J, Bartington, S, Hemming, K, Thayakaran, R, Day, R, Pope, F, Chuluunbaatar, B, Boldbaatar, D, Ochir, C, Warburton, D, Thomas, GN & Manaseki-Holland, S 2023, 'Impact assessment of a raw coal ban on maternal and child health outcomes in Ulaanbaatar: a protocol for an interrupted time series study', BMJ open, vol. 13, no. 4, e061723. https://doi.org/10.1136/bmjopen-2022-061723

Hemming, K & Taljaard, M 2023, 'Key considerations for designing, conducting and analysing a cluster randomized trial', International Journal of Epidemiology, pp. 1-11. https://doi.org/10.1093/ije/dyad064

Martin, J, Middleton, L & Hemming, K 2023, 'Minimisation for the design of parallel cluster-randomised trials: An evaluation of balance in cluster-level covariates and numbers of clusters allocated to each arm', Clinical Trials, vol. 20, no. 2, pp. 111–120. https://doi.org/10.1177/17407745221149104

Watson, S, Girling, A & Hemming, K 2023, 'Optimal Study Designs for Cluster Randomised Trials: An Overview of Methods and Results', Statistical methods in medical research. , pp. 1-23. https://doi.org/10.1177/09622802231202379

Review article

Thompson, J, Watson, SI, Middleton, L & Hemming, K 2025, 'Estimating relative risks and risk differences in randomised controlled trials: a systematic review of current practice', Trials, vol. 26, 1. https://doi.org/10.1186/s13063-024-08690-w

Goldstein, CE, Marouf, Y, Johri, M, Shaw, JF, Sergeant, A, Nicholls, SG, Althabe, F, Ferrand, RA, van der Graaf, R, Hemming, K, Mbuagbaw, L, Treweek, S, Welch, VA, Weijer, C & Taljaard, M 2024, 'Systematic scoping review of cluster randomised trials conducted exclusively in low-income and middle-income countries between 2017 and 2022', BMJ open, vol. 14, no. 9, e087724. https://doi.org/10.1136/bmjopen-2024-087724

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