Sexual Violence PSP Protocol

Contents

Abstract

Background

Approximately one in 10 people in the UK have experienced some form of sexual violence since the age of 16. Sexual violence is known to have short-term and long-term impact on individual’s physical and mental health. There are many unanswered questions about sexual violence.

Objectives

  1. To develop a protocol to work with adult survivors of sexual violence and healthcare professionals that have supported this population, to identify uncertainties associated with sexual violence.
  2. To agree by consensus a top ten list of sexual violence uncertainties.
  3. To disseminate prioritised uncertainties to researchers and funders to promote work answering the uncertainties stakeholders consider most important.

Methods

A Sexual Violence Priority Setting Partnership (SVPSP) has been established to gather research uncertainties. The transparent methodology advocated by the James Lind Alliance will be followed. A stakeholder Steering Group will support the SVPSP including dissemination of the survey to survivors and healthcare professionals, whereby important questions associated with sexual violence will be collected. Following removal of duplications, uncertainties will be collated and checked against existing evidence. All unresolved uncertainties will be circulated to stakeholders in a second survey where they will be ranked by importance. At a final workshop, information will be distilled to generate a top ten list of uncertainties.

Results

By following the protocol outlined in this paper a prioritised list of uncertainties will be identified which will be inform the sexual violence research agenda.

Conclusions

Research targeted to address priorities identified by a range of stakeholders is imperative. This project will inform policymakers and research funding bodies of what really matters to these groups.

Background

Sexual violence implies any form of unwanted sexual activity, that is not consented to1. Across London, Metropolitan Police data from 2015 showed women were more susceptible to sexual violence than men, with 87% of reported sexual abuse cases involving female survivors2. For the year ending March 2018, the Crime Survey for England and Wales (CSEW) records 150,732 cases of sexual offences1.

According to the Sexual Violence Research Initiative, sexual violence is an under-researched area and the interventions available to survivors of sexual abuse are not always centred around their needs3. Research is necessary to identify the needs of survivors, and subsequently ensure these recovery needs receive the appropriate attention. It is crucial that survivors themselves and those working with survivors are at the centre of such initiatives and help to shape guidelines, services and future research. The under-researched area of sexual violence would therefore benefit from identifying priority questions for future research.

One potential explanation for why research in the area of sexual violence has not received more investment is the widespread under-reporting of cases of sexual violence4. The Crime Survey for England and Wales reported five in six sexual assault victims as not reporting to the police4. Barriers to reporting sexual violence include shame, guilt, embarrassment, concerns surrounding confidentiality, fears of stigma, desire to protect friends and family and fear of not being believed 5,6,7,8,9,10. Crucially, additional factors such as gender identity11, ethnicity12 and disabilities13 also play additional roles in the issue of under-reporting.

For male survivors of sexual violence, myths that males cannot be sexually abused14 and feelings of threatened masculinity15 can contribute to their hesitance in issuing a report. Subsequently, male survivors can be seen as a ‘seldom heard’ and underrepresented group within sexual violence research. LGBTQ+ survivors are another ‘seldom heard’ group who can experience additional barriers reporting sexual violence and accessing support, such as gender binary services, fear of lack of understanding by professionals, whether they are “out” and fears of information being “leaked” and negative feelings towards specific body parts.11 Many BAME groups also experience additional challenges to disclosing sexual violence and seeking support. For example, sexual violence reporting rates within British South Asian communities are thought to be particularly low; some suggested explanations are lack of understanding of available services and lack of culturally appropriate services.16 Sex workers, despite experiencing high levels of sexual violence, are another group who can be difficult to reach within sexual violence research and who also experience barriers to reporting sexual violence and when seeking support 17,18. Disabled survivors are another underrepresented group in sexual violence research who also face additional difficulties and have additional support needs when reporting and disclosing sexual violence, including an increased fear of not being believed.13,19. Older people are yet another sub-group of society who experience sexual violence and can experience additional barriers in recalling and therefore disclosing incidents20.

These multifaceted barriers to reporting sexual violence in various sub-groups of survivors represent a hindrance to early interventions that could buffer some of the known impacts of abuse on physical and mental health. The physical effects of sexual abuse, ranging from immediate to lifetime, include but are not limited to: sexually transmitted infections,21 pregnancy and abortions,22 abrasions, lacerations and bruising,23 self-harm,24 gynaecological problems,25 gastrointestinal problems, 22 disruptions in sleeping patterns,26 obesity,27 chronic pain and fatigue.23 Often these physical symptoms are medically unexplained symptoms (MUS), and there is a lack of research around MUS and sexual violence 28. Evidence suggests that there might be considerable barriers to the access and successful completion of certain medical treatments addressing the medical sequelae of sexual violence29. There is also extensive evidence that sexual violence survivors are at increased risk of a wide range of mental health difficulties and psychological consequences, such as: depression, anxiety, symptoms of Post-Traumatic Stress Disorder, suicide attempts, eating disorders, alcohol and drug use, impulsive behaviours, difficulties developing and maintain emotional relationships, personality disorders and psychotic disorders 30,31. Research has also revealed that there is a high prevalence of pre-existing mental health complaints in those attending SARC’s32.

There is however a relative paucity of research on the efficacy of psychosocial interventions addressing the health of sexual violence survivors. The identification of more effective and acceptable interventions might represent a pressing priority in the light of emerging evidence suggesting that sexual violence survivors may not respond as well to usual treatments that are routinely available for treating mental health complaints commonly reported by trauma survivors. For example, one study reported that depressed individuals who had experienced sexual abuse did not respond as well to CBT for depression than those who have not experienced sexual abuse33. There was also higher levels of hospitalisation and relapse at two-year follow-up for the group that had previously experienced sexual abuse 33.

Additionally, a systematic review revealed a lack of studies where survivors voiced their own experiences around support and interventions, and that there were few targeted interventions specifically for sexual violence survivors 41. The review made recommendations for survivors to be the prime focus in order to develop effective interventions and stated that important unanswered questions around interventions for the physical and psychological consequences of sexual violence remain28.The provision of high quality support for sexual violence survivors is a NHS priority. NHS England has recently issued a strategic direction for the care of survivors of sexual violence being implemented in the following years18. This document was inspired by previous complaints of inconsistent quality of care in interventions, as well as disoriented and confusing options of care available for survivors31. The identification of uncertainties around the support and recovery needs of sexual violence survivors is therefore timely and urgently needed in order to drive service improvements, national guidelines and future research.

The aim of the Sexual Violence Priority Setting Partnership (SVPSP) is to bring survivors and healthcare professionals together to identify uncertainties about the best way to support people who have experienced sexual violence and to prioritise, by consensus, a top ten list of these uncertainties for research purposes. Survivors includes those individuals who self-identify as a person with lived experience of sexual violence. Hereon in, survivors and healthcare professionals will be referred to as the “key stakeholders”. This top ten list of uncertainties will be publicised widely with targeted dissemination to researchers and research funders in order to promote future research addressing the questions that key stakeholders consider to be most important. The James Lind Alliance (JLA), which is hosted by the National Institute for Health Research, were responsible for originally setting up the PSP process and will be facilitating the SVPSP process.

Methods

The scope of the Sexual violence PSP was defined at the outset as the health and social care needs of adults (18 and over) that have experienced sexual violence, in childhood and/or adulthood. The needs and systems of service provisions for children exposed to sexual violence are likely to be distinct and will deserve separate consideration in a future PSP. All forms of sexual violence and abuse, including penetrative and non-penetrative, would be considered in scope. Responses will be gathered from survivors who currently live in the UK or who have experienced sexual violence in the UK or abroad, and from health and social care professionals who have currently or previous experience of working directly with survivors in the UK. This UK focus is due to the results from this work being used to inform future UK research.

The SVPSP will exclude from its scope any survey responses: regarding the prevention of sexual violence (including risk/protective factors); the specifics of the criminal justice component in response to sexual violence incidents (however responses regarding the effects and impact e.g. psychological and emotional of this component and process will be included); focussing on prevalence of sexual violence; focussing on the perpetrators of sexual violence; received from individuals who are not survivors, or a health and social care professional with direct experience of working with survivors.

Unlike previous PSP’s, the SVPSP will also exclude survey responses from purely family members/supporters/loved ones of survivors. This complex decision has been made based on multiple factors raised and discussed during the first SG meeting. For example, often survivors do not disclose their experiences to anyone at all and this was felt to be especially true for ‘seldom-heard’ groups, such as males, sex workers and ethnic minorities. It was further suggested that the inclusion of family members/supporters may negatively effect the diversity the SVPSP is intending to capture in the survey. Moreover, it was strongly felt that due to this being the first PSP focussing on sexual violence and giving a voice to survivors in research, the focus should remain on the survivors themselves. The SVPSP does however acknowledge the importance of family members/supporters/loved ones, to many survivors and acknowledges the effect such experiences can have on these individuals.

The SVPSP protocol follows the JLA’s methodology, as outlined in their Guidebook35. The JLA will also facilitate each step of the SVPSP process, ensuring transparent methods are used that are reflective of the JLA ethos.

Step 1: Identification and invitation of steering group members and partners

Various organisations from across the UK representing and advocating for key stakeholders have committed to support the SVPSP as partners. The partners invited to join the PSP have experience and knowledge of sexual violence, as organisations that represent the views of survivors and clinicians. Partners include charities, support groups or professional organisations involved in helping survivors (see Appendix 2). Partners will be involved in promoting the work of the PSP to their network and encourage involvement of survivors and clinicians.

A steering group of eleven members: four survivor representatives; three survivor/clinical representatives and four clinical representatives, has also been convened. Care has been taken to recruit a diverse SG who will oversee the SVPSP activity and ensure it represents balanced perspectives. The steering group signed a “Terms of Reference” form and a “Declaration of Interests” form.

An important consideration of the PSP is to involve ‘seldom heard’ and underrepresented groups in sexual violence research in the PSP. This is important as it will allow uncertainties around the specific support needs of different groups to be considered when sexual violence research priorities are identified. One strategy that has been used to help achieve this aim is to ensure the partners and steering group have a wide and inclusive representation. They will therefore be better placed to advise on ways to advertise the survey that will have a broad reach as well as make their own, otherwise ‘seldom heard’ networks aware of the survey.

Step 2: Awareness raising

National awareness will be raised about the SVPSP through various platforms including social media (Twitter and Facebook). The purpose of awareness raising activities is to present the SVPSP to a wider audience, which should lead to support and participation in the SVPSP by as many as diverse a group of survivors and professionals as possible.

Step 3: Identifying evidence uncertainties

The SVPSP will collect uncertainties about sexual violence through surveys. The surveys will predominantly be electronic due to practical considerations. This electronic format will allow the survey to be shared widely across social media platforms by ourselves, the partners and the steering group. If possible (considering the current COVID-19 situation) paper copies of the survey may be considered for ‘seldom heard’ groups, particularly if they have been underrepresented in the online survey responses.

It is estimated the survey will be open for three months in the first instance. Responses to the survey will be on the agenda for review at each SG meeting. Based on this, a decision will be made on how long to keep the survey open. The diversity of the responders will be monitored throughout the period the survey is open. Attention will be paid to groups responding to the survey and one strategy may be to keep the survey open longer for underrepresented groups, such as male survivors and people from BAME communities. It is important to have these procedures in place to gain representative and diverse survey responses.

Self-report methods of data collection promote honesty. People responding to the survey will remain anonymous. Information will be asked regarding whether they are a survivor and/or professional, age (over 18), area and country of residence, gender and ethnicity. If the respondee is a professional, they will be asked to provide some further details regarding their professional background, this is to allow monitoring of representation from different disciplines. This information will allow the diversity of responses to be monitored. If they would like to be informed of the subsequent surveys and study findings, they will be advised to send an email with their preferred contact details to sexualviolencePSP@manchester.ac.uk. This process ensures personal details remain separate from the survey data. Effective management of this confidential information is crucial, the team will adhere to the principles of GDPR.

Due the sensitivity of this subject matter, we will take the following course of action to support all individuals maintain psychological wellbeing throughout the process of the SVPSP and to reduce and minimise distress where possible:

- Provide emergency numbers
- Provide links to advisory/signpost support websites
- Safeguarding
- Trigger warnings

Step 4: Refining questions and uncertainties

Analysis will begin in parallel with the survey once initial responses have been submitted. The raw submitted questions will start to be categorised and questions that are not within scope will be removed. Responses that are not questions will also be removed. Subsequent questions can then be “tested” to see if these fit within these categories, or whether new ones are emerging. “Saturation” will also be monitored, i.e. when no new questions are coming from the survey, it will be closed. The survey may also close due to resource constraints prior to reaching ‘saturation’.

Final list of research questions will then be categorised into summary (indicative) questions by multiple individuals including sense checking by SG members to avoid any bias. The JLA Advisor will also support this stage. The research questions should be easy to understand whilst still reflecting the original raw submitted questions. Following this each indicative question needs to be verified as a ‘true uncertainty’. In order to do this, searches will be undertaken for systematic reviews and guidelines that may have addressed the uncertainties, these searches may be partially done in advance of or parallel to data collection. All systematic reviews will be less than 3 years old, in accordance with JLA guidelines.

A JLA Question Verification Form will then be completed and published to describe and account for the evidence checking. The relevant source(s) of verification will be cited for each verified uncertainty. During this stage, uncertainties from research recommendations will also be recorded and added to the list of indicative questions for prioritisation. By identifying true research uncertainties, the PSP will ensure that it identifies questions not previously considered by other research thereby contributing novel findings to the sexual violence research sphere.

The SVPSP will reveal questions that have been previously answered by research but are still being asked by the public. This may provide an insight into whether the questions have been satisfactorily answered or whether the research findings are accessible enough to the wider public. Following JLA’s recommendations, these “answerable questions” will also be recorded, as they may be useful to inform future awareness-raising exercises and education programmes.

Step 5: Prioritisation – interim survey

The list of verified evidence uncertainties will then go into an interim survey for stakeholders to complete. The survey will again be publicised with the help of the SG. The survey will be open for one-two months, but as with the initial survey, the SG will review and monitor this. This survey will ask respondents (survivors and professionals) to pick the questions they believe are the Top 10 most important from the list of verified uncertainties.

Once the interim survey is closed these responses will be collated and analysed. The SG will look at the ranking based on both survivors and professionals, this is to ensure that their scores are given equal weighting. It may also reveal questions that are particularly important to one, but not the other. The most highly ranked questions overall will be taken to the final stage (the workshop). This is anticipated to be approximately 25- 30 questions.

Step 6: Final Priority Setting – Final Workshop

Fifteen to thirty survivor and professional representatives will then be invited to the final workshop. All attendees will participate as equals. Efforts will be made to have a representative and diverse group of attendees. Workshop attendees may be selected through various methods including through partner organisations, SG networks and social media. The workshop will be facilitated and run by three JLA advisors to ensure fairness, accountability and transparency. The JLA advisors will use an adapted Nominal Group Technique, this prevents one person from dominating discussions and encourages all members to participate.

At the end of the workshop there will be a list of Top 10 priorities agreed, these will be published on the JLA website, along with the other questions discussed and ranked at the workshop.

At the final workshop there will be a distress protocol in place for all those attending. The distress protocol will be developed in collaboration with survivor members of the SG; it will build on procedures already employed by the Project Leads for consultations activities with trauma survivors as part of other projects (e.g. use of ‘breakout rooms’ with access to professionally qualified staff or fellow suitably trained survivors), aTop 10 nd will cover appropriate measures to support workshop attendees that may feel upset as a result of the topics discussed during the final prioritisation activities. All attenders will be briefed ahead of the event regarding the potential emotional impact that some of the topics considered at the workshop may have and will be reminded that they are free to discontinue their involvement at any point should they wish to. There will also be a ‘wellbeing’ contact made within the next 24 hours after the workshop has ended, to all attendees. This would provide opportunities to all attenders to discuss any issues that may have arisen following the workshop and will enable the project team to signpost any distressed individual to appropriate sources of support.

Results

The Top 10 priorities of the SVPSP will be disseminated widely to researchers and research funders in the field of sexual violence. Avenues for dissemination will include social media updates, professional conferences and publication in an academic journal. The purpose of wide dissemination will be to ensure that future research resource can prioritise questions, which survivors and professionals in the field of sexual violence, consider to be the most important. This will enable the PSP’s goal of facilitating evidence-based care, for survivors of sexual violence.

Discussion

The SVPSP allows for the exploration of uncertainties that key stakeholders, survivors and health professionals working with survivors, themselves consider to be the most important. It is of utmost importance that seldom heard groups are represented in the SVPSP and multiple strategies are employed to enable this. Narrowing down the unanswered questions (uncertainties), into a Top 10 list agreed upon as the most important questions by a representative group of key stakeholders is critical, to facilitating effective and informed care, for survivors of sexual violence.

This is a good time for the SVPSP to be undertaken since NHS England have addressed the strategic direction for care of sexual violence survivors34. The prioritised list of questions will be used to inform research funders on the areas of care of sexual violence survivors, that are agreed upon, to be most important. This process will support future research on management and care and of survivors of sexual violence will target areas which survivors feel are most important.

References

1 NHS. Help after rape and sexual assault.
https://www.nhs.uk/live-well/sexual-health/help-after-rape-and-sexual-assault/
Accessed 5 July 2019.

2 MBARC. The London Sexual Violence Needs Assessment (2016 for MOPAC & NHS England (London).
https://www.london.gov.uk/sites/default/files/sexual_violence_needs_assessment_report_2016.pdf
Accessed 5 July 2019.

3 Sexual Violence Research Initiative (2019) FAQ.
https://www.svri.org/faq
Accessed 25 August 2019.

4 Office for National Statistics.
Sexual offences in England and Wales: year ending March 2017.
https://www.ons.gov.uk/peoplepopulationandcommunity/crimeandjustice/articles/sexualoffencesinenglandandwales/yearendingmarch2017#sexual-offences-recorded-by-the-police
Accessed 12 September 2019

5 Stern V. Stern review of rape reporting in England and Wales. London: Home Office. 2010.

6 Hohl K, Stanko EA. Complaints of rape and the criminal justice system: Fresh evidence on the attrition problem in England and Wales. European journal of criminology. 2015 May;12(3):324-41.

7Myhill A, Allen J. Rape and sexual assault of women: the extent and nature of the problem. London, England: Home Office; 2002 Mar.

8 Binder RL. Why women don't report sexual assault. The Journal of clinical psychiatry. 1981 Nov.

9Miller AK, Canales EJ, Amacker AM, Backstrom TL, Gidycz CA. Stigma-threat motivated nondisclosure of sexual assault and sexual revictimization: A prospective analysis. Psychology of Women Quarterly. 2011 Mar;35(1):119-28.

10Aakvaag HF, Thoresen S, Wentzel-Larsen T, Dyb G, Røysamb E, Olff M. Broken and guilty since it happened: A population study of trauma-related shame and guilt after violence and sexual abuse. Journal of affective disorders. 2016 Nov 1;204:16-23.

11Harvey S, Mitchell M, Keeble J, McNaughton Nicholls C, Rahim N. Barriers faced by lesbian, gay, bisexual and transgender people in accessing domestic abuse, stalking, harassment and sexual violence services. Cardiff: Welsh Government. 2014 Jun 4.

12Harrison K, Gill AK. Breaking down barriers: Recommendations for improving sexual abuse reporting rates in British South Asian communities. The British Journal of Criminology. 2018 Feb 15;58(2):273-90.

13Bartlett H, Mears E. Sexual violence against people with disabilities: data collection and barriers to disclosure. 2011

14 Hammond, L., Ioannou, M., & Fewster, M. Perceptions of male rape and sexual assault in a male sample from the United Kingdom: Barriers to reporting and the impacts of victimization. Journal of Investigative Psychology and Offender Profiling. 2016; 14:133-149. doi: 10.1002/jip.1462

15 Sable, M.R., Danis, F., Mauzy, D.L., & Gallagher, S.K. “Barriers to Reporting Sexual Assault for Women and Men: Perspectives of College Students”. Journal of American College Health. 2006; 55-157-162. Doi: 10.3200/jach.55.3.157-162.

16 Harrison K, Gill AK. Breaking down barriers: Recommendations for improving sexual abuse reporting rates in British South Asian communities. The British Journal of Criminology. 2018 Feb 15;58(2):273-90.

17 Deering KN, Amin A, Shoveller J, Nesbitt A, Garcia-Moreno C, Duff P, Argento E, Shannon K. A systematic review of the correlates of violence against sex workers. American journal of public health. 2014 May;104(5):e42-54.

18 Manning, D, Majeed-Ariss R. & White C. (2020). Sex workers reporting rape: Understanding their vulnerabilities to improve their care. The characteristics of sex workers who attend Saint Marys Sexual Assault Referral Centre. [published online ahead of print October 8, 2020]. Journal of Forensic & Legal Medicine. DOI/10.1016/j.jflm.2020.102068

19 Majeed-Ariss R, Rodriguez PM. & White C. (In Press). Identifying the prevalence of learning disabilities amongst adults attending Saint Marys Sexual Assault Referral Centre in 2017. Journal of Applied Research in Intellectual Disabilities.

20 Lee J, Majeed-Ariss R, Pedersen A, Yusuf F. & White C. Sexually Assaulted older women attending a U.K. Sexual Assault Referral Centre for a Forensic Medical Examination. [published online ahead of print August 20, 2019]. Journal of Forensic & Legal Medicine. DOI:10.1016/j.jflm.2019.101859

21Allsworth JE, Anand M, Redding CA, Peipert JF. Physical and sexual violence and incident sexually transmitted infections. Journal of Women's Health. 2009 Apr 1;18(4):529-34.

22 Jina R, Thomas LS. Health consequences of sexual violence against women. Best Practice & Research Clinical Obstetrics & Gynaecology. 2013 Feb 1;27(1):15-26.

23 Alempijevic D, Savic S, Pavlekic S, Jecmenica D. Severity of injuries among sexual assault victims. Journal of forensic and legal medicine. 2007 Jul 1;14(5):266-9.

24 Campbell L, Keegan A, Cybulska B, Forster G. Prevalence of mental health problems and deliberate self-harm in complainants of sexual violence. Journal of Forensic and Legal Medicine. 2007 Feb 1;14(2):75-8.

25 Eby KK, Campbell JC, Sullivan CM, Davidson WS. Health effects of experiences of sexual violence for women with abusive partners. Health care for women international. 1995 Nov 1;16(6):563-76.

26 Steine IM, Harvey AG, Krystal JH, Milde AM, Grønli J, Bjorvatn B, Nordhus IH, Eid J, Pallesen S. Sleep disturbances in sexual abuse victims: A systematic review. Sleep Medicine Reviews. 2012 Feb 1;16(1):15-25.

27 Paras ML, Murad MH, Chen LP, Goranson EN, Sattler AL, Colbenson KM, Elamin MB, Seime RJ, Prokop LJ, Zirakzadeh A. Sexual abuse and lifetime diagnosis of somatic disorders: a systematic review and meta-analysis. Jama. 2009 Aug 5;302(5):550-61.

28 Nelson S, Baldwin N, Taylor J. Mental health problems and medically unexplained physical symptoms in adult survivors of childhood sexual abuse: an integrative literature review. Journal of psychiatric and mental health nursing. 2012 Apr;19(3):211-20.

29 Schopper, D. Responding to the needs of survivors of sexual violence: Do we know what works? International review of the red cross. 2014; 96: 585-600. Doi: 10.1017/s1816383114000460

30 Chen LP, Murad MH, Paras ML, Colbenson KM, Sattler AL, Goranson EN, Elamin MB, Seime RJ, Shinozaki G, Prokop LJ, Zirakzadeh A. Sexual abuse and lifetime diagnosis of psychiatric disorders: systematic review and meta-analysis. InMayo clinic proceedings 2010 Jul 1 (Vol. 85, No. 7, pp. 618-629). Elsevier.

31Yuan NP, Koss MP, Stone M. The psychological consequences of sexual trauma. Retrieved September. 2006 Sep;27:2007.

32 Manning, D, Majeed-Ariss R, Mattison M. & White C. (2019). The high prevalence of pre-existing mental health complaints in clients attending Saint Mary’s Sexual Assault Repferral Centre: implications for initial management and engagement with the Independent Sexual Violence Advisor Service at the Centre. Journal of Forensic and Legal Medicine. 61, 102-107. DOI:10.1016/j.jflm.2018.12.001

33 Barbe RP, Bridge JA, Birmaher B, Kolko DJ, Brent DA. Lifetime history of sexual abuse, clinical presentation, and outcome in a clinical trial for adolescent depression. The Journal of clinical psychiatry. 2004 Jan.

34 NHS England. STRATEGIC DIRECTION FOR SEXUAL ASSAULT AND ABUSE SERVICES. Lifelong care for victims and survivors: 2018 – 2023.
https://www.england.nhs.uk/wp-content/uploads/2018/04/strategic-direction-sexual-assault-and-abuse-services.pdf Accessed 25 August 2019.

35 James Lind Alliance. The James Lind Alliance Guidebook, Version 8 2018.
http://www.jla.nihr.ac.uk/jla-guidebook/ Accessed 9 August 2019