Browse research from the School of Nursing and Midwifery.

Follow


Submissions from 2021

PDF

The impact of COVID-19 on the wellbeing of the UK nursing and midwifery workforce during the first pandemic wave: a longitudinal survey study, Bridie Kent

PDF

A Systematic Review and Narrative Synthesis of the Effectiveness of Peer- versus Faculty-led Simulation for Clinical Skills Acquisition in Undergraduate Student Nurses., Graham Williamson, Daniel Clarke, and Andrea Stebbings

PDF

Barriers and facilitators to hepatitis C screening and treatment for people with lived experience of homelessness: A mixed‐methods systematic review, Martha Paisi, Neeltje Crombag, Lorna Burns, Annick Bogaerts, Lyndsey Withers, Laura Bates, Daniel Crowley, Robert Witton, and Jill Shawe

PDF

Parents’ experiences with a sick or injured child during the COVID-19 lockdown: an online survey in the Netherlands, Chantal D. Tan, Eveline K. Lutgert, Sarah Neill, Rachel Carter, Ray B. Jones, Jade Chynoweth, Dorine M. Borensztajn, Monica Lakhanpaul, and Henriette A. Moll

PDF

Preconception and Diabetes Information (PADI) App for Women with Pregestational Diabetes: a Feasibility and Acceptability Study, Chidiebere H. Nwolise, Nicola Carey, and Jill Shawe

PDF

Seeing lockdown through the eyes of children from around the world: Reflecting on a children's artwork project, S Neill, MJ Foster, M Al-Motlaq, B Carter, T O'Sullivan, A Quaye, M Majamanda, K Abdullah, IK Hallstrom, C English, A Vickers, I Coyne, E Adama, and E Morelius

PDF

Factors Influencing Oral Health Behaviours, Access and Provision of Dental Care for Autistic Children and Adolescents in Countries with a Very High Human Development Index: Protocol for a Mixed Methods Systematic Review, Sarah Neill, Jo Erwin, Martha Paisi, Robert Witton, Lorna Burns, I Vassallo, Abigail Nelder, Jemma Facenfield, Urshla Devalia, and T Vassallo

PDF

Awareness and attitudes towards sustainability and climate change amongst students and educators in nursing: A systematic integrative review protocol, Jennie Aronsson, Andy Nichols, Paul Warwick, and Marie Elf

PDF

How COVID-19 has affected staffing models in intensive care: a qualitative study examining alternative staffing models (SEISMIC), Ruth Endacott, Susie Pearce, Pamela Rae, Annette Richardson, Suzanne Bench, and Natalie Pattison

PDF

Intergenerational language practices, linguistic capital and place: the case of Greek-Cypriot Migrant Families in the UK, Gina Kallis and Richard Yarwood

PDF

Exploring Interventions to Improve the Oral Health and Related Health Behaviours of Adults Experiencing Severe and Multiple Disadvantage: Protocol for a Qualitative Study with Stakeholders, Emma C. Joyes, Laura J. McGowan, Emma A. Adams, Martha Paisi, Martin Burrows, Hosein Shabaninejad, Fiona Beyer, Kate Haddow, Aishah Coyte, David Landes, Suzanne Moffatt, Richard G. Watt, Falko F. Sniehotta, Clare Bambra, Dawn Craig, Eileen Kaner, and Sheena E. Ramsay

PDF

Investigating the Effectiveness and Acceptability of Oral Health and Related Health Behaviour Interventions in Adults with Severe and Multiple Disadvantage: Protocol for a Mixed-Methods Systematic Review, Laura J. McGowan, Emma C. Joyes, Emma A. Adams, Aishah Coyte, Richard Gavin, Catherine Richmond, Hosein Shabaninejad, Fiona Beyer, Angela Broadbridge, Kevin Dobson, David Landes, Suzanne Moffatt, Richard G. Watt, Falko F. Sniehotta, Ruth Freeman, Martha Paisi, Clare Bambra, Dawn Craig, Eileen Kaner, and Sheena E. Ramsay

PDF

Bone turnover in pregnancy, measured by urinary CTX, is influenced by vitamin D supplementation and is associated with maternal bone health: findings from the Maternal Vitamin D Osteoporosis Study (MAVIDOS) trial, Elizabeth M. Curtis, Camille Parsons, Kate Maslin, Stefania D'angelo, Rebecca J. Moon, Sarah R. Crozier, Fatma Gossiel, Nicholas J. Bishop, Stephen H. Kennedy, Aris T. Papageorghiou, Robert Fraser, Saurabh V. Gandhi, Ann Prentice, Hazel M. Inskip, Keith M. Godfrey, Inez Schoenmakers, M. Kassim Javaid, Richard Eastell, Cyrus Cooper, Nicholas C. Harvey, N. K. Arden, A. Carr, M. Clynes, E. M. Dennison, M. Z. Mughal, and S. J. Woolford

PDF

ExMed: An AI Tool for Experimenting Explainable AI Techniques on Medical Data Analytics, Marcin Kapcia, Hassan Eshkiki, Jamie Duell, Xiuyi Fan, Shangming Zhou, and Benjamin Mora

PDF

Position statement of the international network for child and family centered care: Child and family centred care during the COVID19 pandemic, Mohammad Al-Motlaq, Sarah Neill, Mandie Jane Foster, Imelda Coyne, Davina Houghton, Charlotte Angelhoff, Malin Rising-Holmström, and Maureen Majamanda

PDF

User-Centered Design of Companion Robot Pets Involving Care Home Resident-Robot Interactions and Focus Groups With Residents, Staff, and Family: Qualitative Study, Hannah Louise Bradwell, Katie Edwards, Deborah Shenton, Rhona Winnington, Serge Thill, and Ray B. Jones

PDF

Where are the children? An autoethnography of deception in dementia in an acute hospital, G Hodge

PDF

Mining Primary Care Electronic Health Records for Automatic Disease Phenotyping: A Transparent Machine Learning Framework, Fabiola Fernández-Gutiérrez, Jonathan I. Kennedy, Roxanne Cooksey, Mark Atkinson, Ernest Choy, Sinead Brophy, Lin Huo, and Shang Ming Zhou

PDF

Designing a nurse-led assessment and care planning intervention to support frail older people in primary care: An e-Delphi study, Helen Lyndon, Jos M. Latour, Jonathan Marsden, and Bridie Kent

PDF

GlacierMap: a virtual opportunity to explore the Andes’ vanishing glaciers, Caroline Clason, Sally Rangecroft, Gina Kallis, Shaun Lewin, and Tom Mullier

PDF

Does a Nursing Associate Programme Team Work and Leadership Module Make a Difference to Student Nursing Associate Self-reported Leadership Skills? A Mixed-methods Study, Graham Williamson, Beverley Maund, and Sandy Knowles

PDF

Identifying Prenatal and Postnatal Determinants of Infant Growth: A Structural Equation Modelling Based Cohort Analysis, Kelly Morgan, Shang Ming Zhou, Rebecca Hill, Ronan A. Lyons, Shantini Paranjothy, and Sinead T. Brophy

PDF

Authors’ Response to Peer Reviews of “Technologies to Support Assessment of Movement During Video Consultations: Exploratory Study”, RB Jones, S Hubble, L Taylor, H Gunn, A Logan, T Rowland, H Bradwell, LJ Connolly, K Algie, K Anil, B Halliday, S Houston, R Dennett, S Chatfield, S Buckingham, and J Freeman

PDF

Technologies to Support Assessment of Movement During Video Consultations: Exploratory Study, RB Jones, S Hubble, L Taylor, H Gunn, A Logan, T Rowland, H Bradwell, LJ Connolly, K Algie, K Anil, B Halliday, S Houston, R Dennett, S Chatfield, S Buckingham, and J Freeman

PDF

Digital technologies for monitoring and improving treatment adherence in children and adolescents with asthma: A scoping review of randomised controlled trials, Madison Milne-Ives, Ching Lam, and Edward Meinert

PDF

Preterm births in South-West England before and during the COVID-19 pandemic: An audit of retrospective data, Kate Maslin, Roisin McKeon-Carter, Joanne Hosking, Lauren Stockley, Clara Southby, Jill Shawe, and Jos M. Latour

PDF

Are we prepared for change? The need for evidence on healthcare practitioner readiness for current and future trends in abortion provision in the UK, Rebecca S. French, Jill Shawe, Melissa J. Palmer, Jennifer Reiter, and Kaye Wellings

PDF

Being the father of a preterm-born child: Contemporary research and recommendations for NICU staff, Franco Baldoni, Gina Ancora, and Jos M. Latour

PDF

Frontline experiences and perceptions of Urgent Dental Care centre staff in England during the COVID-19 pandemic: a qualitative study, Anastasios Plessas, Martha Paisi, Rebecca Baines, Hannah Wheat, Maria Bernardes Delgado, Ian Mills, and Robert Witton

PDF

Design recommendations for socially assistive robots for health and social care based on a large scale analysis of stakeholder positions, Hannah Louise Bradwell, Noury GE Aguiar, Katie Jane Edwards, Rhona Winnington, Serge Thill, and Ray B. Jones

PDF

Paediatric Residents and Fellows Ethics (PERFEct) survey: Perceptions of European trainees regarding ethical dilemmas, Boer MC den, A. Zanin, J. M. Latour, and J. Brierley

PDF

Caring for a sick or injured child during the COVID‐19 pandemic lockdown in 2020 in the UK: An online survey of parents' experiences, Sarah Neill, Rachel Carter, Ray Jones, Damian Roland, Natasha Bayes, Alison Tavaré, Joanne Hughes, Tracy Turner, Jade Chynoweth, Chantal Tan, Henriette Moll, and Monica Lakhanpaul

PDF

Family-Centered Care at Pediatric Cardiac Intensive Care Units in Germany and the Relationship with Parent and Infant Well-Being: A Study Protocol, Hannah Ferentzi, Ralph C.A. Rippe, Jos M. Latour, Stephan Schubert, Alona Girch, MJ Stocker, Constanze Pfitzer, Joachim Photiadis, Eugen Sandica, Felix Berger, and Katharina R.L. Schmitt

PDF

The experience and psychological impact of a sharps injury on a nursing student population in the UK, Kevin Hambridge, Ruth Endacott, and Andrew Nichols

PDF

Morphology of socially assistive robots for health and social care: A reflection on 24 months of research with anthropomorphic, zoomorphic and mechanomorphic devices, Hannah L. Bradwell, Rhona Winnington, Serge Thill, and Ray B. Jones

PDF

Impact of different visiting policies on family satisfaction in two Spanish ICUs before and during COVID-19, Emilio Rodriguez-Ruiz, Maitane Campelo-Izquierdo, Ana Estany-Gestal, Antonio Rodríguez-Núñez, and Jos M. Latour

PDF

Future solutions to improve comfort during radiotherapy: patient & radiation therapist interviews, S Goldsworthy, S Palmer, J Latour, H McNair, and M Cramp

PDF

Safety and acceptability of a natural-language AI assistant to deliver clinical follow-up to cataract surgery patients: Proposal for a pragmatic evaluation, Pennington N. de, Guy Mole, Ernest Lim, Madison Milne-Ives, Eduardo Normando, Kanmin Xue, and Edward Meinert

PDF

A Comparison of Explanations Given by Explainable Artificial Intelligence Methods on Analysing Electronic Health Records, Jamie Duell, Xiuyi Fan, Bruce Burnett, Gert Aarts, and Shang Ming Zhou

PDF

Need for recovery and physician well-being in emergency departments: national survey findings, Laura Cottey, Tom Roberts, Blair Graham, Daniel Horner, Jos M. Latour, Doyo Enki, Mark D. Lyttle, and Kara N. Stevens

PDF

Interventions to prevent aspiration in older adults with dysphagia living in nursing homes: a scoping review, Shen Chen, Bridie Kent, and Yan Cui

PDF

Maternal ethnicity and the prevalence of British pregnancies affected by neural tube defects, Jordana N. Peake, Rachel L. Knowles, Jill Shawe, Judith Rankin, and Andrew J. Copp

PDF

Phase Angle and Bio-Impedance Values during the First Year after Delivery in Women with Previous Excessive Gestational Weight Gain: Innovative Data from the Belgian INTER-ACT Study, Margriet Bijlholt, Kate Maslin, Lieveke Ameye, Jill Shawe, Annick Bogaerts, and Roland Devlieger

PDF

Pregnancy remains, infant remains, or the corpse of a child? The incoherent governance of the dead foetal body in England, A Middlemiss

PDF

The meaning of confidence from the perspective of older people living with frailty: a conceptual void within intermediate care services, Frazer Underwood, Jos M. Latour, and Bridie Kent

PDF

Return on investment of a model of access combining triage with initial management: an economic analysis, David A. Snowdon, Katherine E. Harding, Nicholas F. Taylor, Sandra G. Leggat, Bridie Kent, Annie K. Lewis, and Jennifer J. Watts

PDF

The impact of digital educational interventions to support parents caring for acutely ill children at home and factors that affect their use: systematic review protocol, Madison Milne-Ives, Sarah Neill, and Edward Meinert

PDF

Evaluation of a neonatal resuscitation training programme for healthcare professionals in Zanzibar, Tanzania: A pre-post intervention study, Xiang Ding, Li Wang, Mwinyi I. Msellem, Yaojia Hu, Jun Qiu, Shiying Liu, Mi Zhang, Lihui Zhu, and Jos M. Latour

PDF

Measuring family-centred care practices in adult ICUs: the EMPATHIC-F questionnaire, E Rodriguez-Ruiz, Maitane Campelo-Izquierdo, MM Rodríguez, Ana Estany-Gestal, AB Hortas, Rodríguez-Calvo M Sol, Antonio Rodríguez-Núñez, and Jos M. Latour

PDF

Concept libraries for automatic electronic health record based phenotyping: A review., ZA Almowil, S-M Zhou, and S Brophy

PDF

Authors’ Response to Peer Reviews of “Machine Learning for Risk Group Identification and User Data Collection in a Herpes Simplex Virus Patient Registry: Algorithm Development and Validation Study”, S Surodina, C Lam, S Grbich, M Milne-Ives, Velthoven M van, and E Meinert

PDF

Machine Learning for Risk Group Identification and User Data Collection in a Herpes Simplex Virus Patient Registry: Algorithm Development and Validation Study, S Surodina, C Lam, S Grbich, M Milne-Ives, Velthoven M van, and E Meinert

PDF

Distributed Ledger Infrastructure to Verify adverse Event Reporting (DeLIVER): Proposal for a proof-of-concept study, Madison Milne-Ives, Najib Rehman, Raja Sharif, and Edward Meinert

PDF

The Contribution of Registered Dietitians in the Management of Hyperemesis Gravidarum in the United Kingdom, Kate Maslin, Hazel A. Billson, Caitlin R. Dean, and Julie Abayomi

PDF

Singapore’s Health outcomes After Critical illness in Kids: A study protocol exploring health outcomes of families six-months after critical illness, Pei Fen Poh, Jan Hau Lee, Joseph C. Manning, Matthew C. Carey, Rehena Sultana, and Jos M. Latour

PDF

Chapter 6: Evaluation. 6.1: Plymouth University, G Williamson, A Kane, and J Bunce

File

Learning From Pre-Hospital Journeys: Uncertain Illness Trajectories For Young Children With Serious Infectious Illness, S Neill, D Roland, B Carter, L Riches, N Bayes, J Hughes, L Bray, S Palmer-Hill, ED Carrol, J O'Donnell, and P Pandey

PDF

How to do and report survey studies robustly: a helpful mnemonic SURVEY, Jos M. Latour and Lyvonne N. Tume

PDF

Development of a Secure Website to Facilitate Information Sharing in Families at High Risk of Bowel Cancer—The Familyweb Study, Selina Goodman, Heather Skirton, Leigh Jackson, and Ray B. Jones

PDF

User-Centered Design of Companion Robot Pets Involving Care Home Resident-Robot Interactions and Focus Groups With Residents, Staff, and Family: Qualitative Study (Preprint), HL Bradwell, K Edwards, D Shenton, R Winnington, S Thill, and RB Jones

PDF

Acupuncture as a Complementary Therapy for Cancer Care: Acceptability and Preferences of Patients and Informal Caregivers, Laura Tack, Tessa Lefebvre, Virginie Blieck, Lieselot Cool, Hans Pottel, KV Eygen, Sofie Derijcke, Philippe Vergauwe, Patricia Schofield, Rebecca Chandler, Pauline Lane, Tom Boterberg, and Philip R. Debruyne

PDF

The Greta Thunberg effect: student nurses’ attitudes to the climate crisis, J Richardson, J Aronsson, D Clarke, and J Grose

PDF

Neurally adjusted ventilator assist (NAVA) in infants with acute respiratory failure: a literature scoping review, Julia Harris, Shane M. Tibby, Ruth Endacott, and Jos M. Latour

PDF

Person-Centered Health Promotion: Learning from 10 Years of Practice within Long Term Conditions, John Downey, Saul Bloxham, Ben Jane, Joseph D. Layden, and Sam Vaughan

PDF

Smartphone Applications Designed to Improve Older People’s Chronic Pain Management: An Integrated Systematic Review, Margaret Dunham, Antonio Bonacaro, Patricia Schofield, Liz Bacon, Fotios Spyridonis, and Hadi Mehrpouya

PDF

A Multi-Faceted Strategy for Evidence Translation Reduces Healthcare Waiting Time: A Mixed Methods Study Using the RE-AIM Framework, Katherine E. Harding, Annie K. Lewis, David A. Snowdon, Bridie Kent, and Nicholas F. Taylor

PDF

Copper IUD continuation, unwanted effects and cost consequences at 1 year in users aged under 30 – a secondary analysis of the EURAS-IUD study, Hannat Akintomide, Nataliya Brima, Diana J. Mansour, and Jill Shawe

PDF

Oral care experiences of palliative care patients, their relatives and healthcare professionals: A qualitative study, Delgado M. Bernardes, Jos Latour, Helen Neilens, and Sarah Griffiths

PDF

The effectiveness and usability of online, group-based interventions for people with severe obesity: Systematic review protocol, Madison Milne-Ives, Dawn Swancutt, Lorna Burns, Jonathan Pinkney, Mark Tarrant, Raff Calitri, Arunangsu Chatterjee, and Edward Meinert

PDF

Comparison between centralised and decentralised supply chain of autologous CAR-T therapies: a UK case study based on discrete event simulation, Ching Lam, Edward Meinert, Aidong Yang, and C Zhanfeng

PDF

Exploring the cost of eLearning within the field of health professions education: Scoping Review, Edward Meinert, S Reeves, Jessie Eerens, Christina Banks, Stephen Maloney, George Rivers, Dragan Ilic, Kieran Walsh, A Majeez, and Josip Car

PDF

P0082 / #337: BARRIERS TO DELIVERING ENTERAL NUTRITION IN PICUS: A SURVEY AND NEW QUALITY IMPROVEMENT TOOL, L Tume, R Eveleens, S Verbruggen, G Harrison, JM Latour, and F Valla

PDF

Collaborative Learning in Practice: videos to prepare students and staff, G Williamson, A Kane, D clarke, C Jamison, J bunce, C McDowall, and H Plowright

PDF

Identifying the health care–initiated and self-initiated interventions used by women for the management of rectal emptying difficulty secondary to obstructive defecation: a scoping review protocol, Sharon Eustice, Alison James, Ruth Endacott, and Bridie Kent

PDF

The use of Breast Milk Fortifier in Preterm Infants by paediatric dietitians in the UK, Sophie Jupe and Kate Maslin

PDF

Behaviour change practices in exercise referral schemes: developing realist programme theory of implementation, John Downey, Katie Shearn, Nicola Brown, Ross Wadey, and Jeff Breckon

PDF

Fertility and digital technology: narratives of using smartphone app ‘Natural Cycles’ while trying to conceive, Pippa Grenfell, Nerissa Tilouche, Jill Shawe, and Rebecca S. French

PDF

Implementing online patient feedback in a ‘special measures’ acute hospital: A case study using Normalisation Process Theory, Rebecca Baines, Frazer Underwood, Kim O’Keeffe, Jessica Saunders, and Ray B. Jones

PDF

Is there an association between drug use and oral health conditions?, Martha Paisi, Robert Witton, and Anastasios Plessas

PDF

Older Patients’ Views of Oral Health Care and Factors which Facilitate or Obstruct Regular Access to Dental Care-Services: A Qualitative Systematic Review, Alexander R. Legge, Jos M. Latour, and Mona Nasser

PDF

Participant views and experiences of sexual health research: The Contraception Choices online trial, Julia V. Bailey, Kirsty F. Bennett, Anasztazia Gubijev, Jill Shawe, and Judith Stephenson

File

Prioritising Design Features for Companion Robots Aimed at Older Adults: Stakeholder Survey Ranking Results, Hannah Bradwell, Rhona Winnington, Serge Thill, and Ray B. Jones

PDF

Type-1 OWA Operators in Aggregating Multiple Sources of Uncertain Information: Properties and Real-World Applications in Integrated Diagnosis, Shang Ming Zhou, Lin Huo, Francisco Chiclana, Robert I. John, and Jonathan M. Garibaldi

PDF

What is the global prevalence of dental healthcare needs and unmet dental needs among adolescents?, Martha Paisi, Robert Witton, Philip Radford, and Anastasios Plessas

PDF

Where next for the design, delivery, and evaluation of community-based physical activity prescription? Emerging lessons from the United Kingdom, E. J. Oliver, B. Buckley, C. J. Dodd-Reynolds, J. Downey, C. Hanson, H. Henderson, J. Hawkins, J. Steele, M. Wade, and P. M. Watson

Submissions from 2020

PDF

(Not) talking about fertility: the role of digital technologies and health services in helping plan pregnancy. A qualitative study, Rebecca S. French, Jill Shawe, Nerissa Tilouche, Sarah Earle, and Pippa Grenfell

PDF

Is there an association between oral health-related quality of life and Alzheimer's disease?, Anastasios Plessas and Martha Paisi

PDF

The Effectiveness and Usability of Online, Group-Based Interventions for People With Severe Obesity: Protocol for a Systematic Review (Preprint), M Milne-Ives, D Swancutt, L Burns, J Pinkney, M Tarrant, R Calitri, A Chatterjee, and E Meinert

PDF

Developing a blockchain-based supply chain system for advanced therapies: study protocol, Edward Meinert, Ching Lam, and Velthoven M van

PDF

Developing and testing a nurse-led intervention to support bereavement in relatives in the intensive care (BRIC study): a protocol of a pre-post intervention study, Mol MMC van, Sebastian Wagener, Jos M. Latour, Paul A. Boelen, Peter E. Spronk, Uil CA den, and Judith A.C. Rietjens

PDF

Ethical perceptions towards real-world use of companion robots with older people and people with dementia: survey opinions among younger adults, Hannah L. Bradwell, Rhona Winnington, Serge Thill, and Ray B. Jones

PDF

The Physical Activity Wearables in the Police Force (PAW-Force) study: acceptability and impact, SA Buckingham, K Morrissey, AJ Williams, L Price, and J Harrison

PDF

Barriers and facilitators to dental care access among asylum seekers and refugees in highly developed countries: a systematic review, Martha Paisi, Rebecca Baines, Lorna Burns, Anastasios Plessas, Philip Radford, Jill Shawe, and Robert Witton

PDF

External Use of Mirabilite Combined with Lactulose Improves Postoperative Gastrointestinal Mobility among Older Patients Undergoing Abdominal Surgery, Wenyan Pan, Shining Cai, Jos M. Latour, Ming Zhong, Minzhi Lv, Jingjing Li, X Zhang, and Y Zhang

PDF

‘How to recognize if your child is seriously ill’ during COVID-19 lockdown: An evaluation of parents’ confidence and health-seeking behaviors, Emma Lim, Ravi D. Mistry, Alexandra Battersby, Kerry Dockerty, Aaron Koshy, Michelle N. Chopra, Matthew C. Carey, and Jos M. Latour

PDF

Searching for individual determinants of probabilistic cueing in large-scale immersive virtual environments, Rory Baxter and Alastair D. Smith

PDF

Need for recovery amongst emergency physicians in the UK and Ireland: a cross-sectional survey, Laura Cottey, Tom Roberts, Blair Graham, Daniel Horner, Kara Nicola Stevens, Doyo Enki, Mark David Lyttle, and Jos Latour

PDF

An interactive website to aid young women’s choice of contraception: feasibility and efficacy RCT, J Stephenson, JV Bailey, A Blandford, N Brima, A Copas, P D’Souza, A Gubijev, R Hunter, J Shawe, G Rait, and S Oliver

PDF

Cross-cultural adaptation of children´s environmental health questionnaires for nursing students in England, Cristina Álvarez-García, Carmen Álvarez-Nieto, Rachel Carter, Janet Kelsey, Sebastián Sanz-Martos, and I López-Medinaa

PDF

Interventions demonstrate potential to promote patient comfort during radiotherapy, S Goldsworthy, S Palmer, JM Latour, H McNair, and M Cramp