Table A1.

Summary and characteristics of included studies.

Paper	Country	Specialty	Overview of Included Studies	Evidence of Records/Storage
Group A. Prescribed Action—Electronic
den Hollander and Mars. [21] 2017	South Africa	Burn care.	Referring doctors were required to telephone the burns specialist, answer a referral questionnaire about the case and send photographs of the burn wounds before a decision was made on acceptance of the referral or providing ongoing management advice. The photographs were taken and sent by smartphone using MMS or WhatsApp. The completed questionnaire, with photographs, were entered into a database which was reviewed for the study.	Evidence of record keeping and storage. Reported transfer of data from mobile phones to electronic versions of patient notes or departmental records. Transfer was done manually to a password protected database. Retrospective study from a database where messages and photos were deleted from the consultant’s phone.
Joshi et al. [22] 2018	India	Neurosurgical referral service.	Examined the use of WhatsApp for a neurosurgical referral service. Use of WhatsApp was extended from a purely intra-departmental informal communication to a formal tertiary referral service for Neurosurgical referrals. The pros and cons of deploying such a system were discussed and important concerns highlighted.	Evidence of both record keeping and storage. Reported the transfer of data from mobile phones to electronic versions of patient notes or departmental records. Transfer was done manually to a departmental secure computer. Messages remained on the phone and apparently ‘backed up’, with no explanation of how and no mention of subsequent deletion of messages. A retrospective study where information was accessed from WhatsApp messages stored on the users’ mobile phones.
Group B. Prescribed Action—Paper Based
Johnston et al. [27] 2015	UK	Communication in emergency surgical teams.	Evaluated implementation of a WhatsApp messaging service within emergency surgical teams. A prospective mixed-methods study. All emergency surgery team members used WhatsApp for communication for 19 weeks. Examined response times, communication types, and safety events.	Reported on both record keeping and storage. Temporarily stored messages on the phone for 1 week. Downloaded and kept a hard copy record but did not explain how? Benefits were a record of communication for training purposes.
Nardo et al. [28] 2016	Italy	Patient surgical management.	Examined use of WhatsApp between two distant elective surgery teams to verify if WhatsApp improved patient care, while preserving their privacy and enhanced learning.	Reported on both record keeping and storage. Temporarily stored messages on the phone for 1 week before deleting messages off mobile phones. Downloaded and kept a hard copy record, but did not describe how? Applied the same protocol as Johnston et al.
Siegal et al. [29] 2016	Israel	Otolaryngology.	Experience and practices governing the usage of WhatsApp for mobile health purposes in a national cohort of practicing otolaryngologists.	Reported on both record keeping and storage by ‘downloading’ of a hard copy/script for record keeping before deleting data from ‘participant devices’ after a defined period but the method was not described.
Group C. Prescribed Action—Uncertain electronic or paper based
Wani et al. [31] 2013	Saudi Arabia	Plastic and reconstructive surgery.	An assessment of the efficacy of smartphone and its WhatsApp application as a communication method amongst the staff of plastic and reconstructive surgery section at tertiary care health facility. WhatsApp was used for various aspects of patient management.	Reported keeping records, but it was not clear from descriptions if this was done electronically or was paper based. The chat conversations were photographed as screenshots for saving in the medical record, but it was not clear if and how the screenshots were stored, but it seems unlikely they were printed as it was reported that WhatsApp conversations could not be printed.
Ellanti et al. [32] 2017	UK	Orthopaedic Surgery.	Analysis of WhatsApp communication between non-consultant members of an orthopaedic team over a six-month period. A specific “orthopaedic group” was created on WhatsApp, which included all the non-consultant orthopaedic team.	Reported only on record keeping. Reported deleting messages off mobile phones after a 6 month period and although no mention was made of formal storage or record keeping this was inferred from the descriptions in the paper.
Martinez et al. [35] 2018	South Africa	Paediatric burn care.	Reviewed use of WhatsApp to facilitate paediatric burn injury consultations to a regional burn centre. A retrospective review of all WhatsApp consultations over an 18 month period. Assessed the impact in terms of reductions in admissions and clinic visits, a cost analysis plus analysis of feedback from those health practitioners regularly using the service.	Evidence of storage only. Reported keeping records, but it was not clear if it was done electronically or was paper based. Reported deleting messages off mobile phones. The importance of record keeping, and storage was noted, but no details were provided on how this was done.
Neogi et al. [24] 2020	India	Interinstitutional patient transfer.	Use of WhatsApp to facilitate transfer of paediatric patients, including neonates, from paediatric department of one hospital (which does not have paediatric surgical support) to a tertiary care hospital. The WhatsApp group included the consultants and residents of the concerned department from both the hospitals. Patient details, investigations were initially uploaded on the group. The case was assessed on the messenger and the transfer coordinated.	Reported on both record keeping and storage but it was not clear if this was done electronically or was paper based. Kept an analogue or digital record, and then periodically deleted messages off mobile phones or gained consent and archived.
Group D. Inaction—ePHI remains on mobile phones
Gulacti et al. [33] 2016	Turkey	Communication between consulting and emergency physicians.	Evaluated WhatsApp messenger usage for communication between consulting and emergency physicians. A retrospective, observational study conducted in the emergency department of a tertiary care university hospital.	Reported only on record keeping and that information stored on the users’ mobile phone constituted a medical record. Retrospective study of WhatsApp messages stored on the phone with no mention of subsequent deletion of messages.
Sidhoum et al. [34] 2016	France	Surgical team communication.	Experiences and results over nearly three years of the use of WhatsApp in the plastic surgery team in CHU Amiens. Transmitted patient information included text, photos, and video, with the patient’s agreement to share with other team members.	Reported only on record keeping where information stored on the users’ mobile phone constituted a medical record. Retrospective study of messages stored on the phone with no mention of subsequent deletion of messages.
Ganasegeran et al. [5] 2017	Malaysia	Use in clinical practice.	A preliminary study. Aim was to investigate perceived benefits, if any, of WhatsApp use across general medical and emergency teams during clinical practice.	Reported on both record keeping and storage and that information stored on the users’ mobile phone constituted a medical record. Benefits of this were a record of communication for audit purposes. Mentioned concerns of messages stored on users’ phones.
Mars and Scott. [23] 2017	South Africa	Dermatology and burn management.	Describes two ‘‘spontaneous’’ WhatsApp-based telemedicine services in dermatology and burn management. For dermatology, doctors at rural referring hospitals take photographs of skin lesions and send them to dermatologists together with a brief text message history. For the burns service, admissions now require completion of a preadmission questionnaire and submission of photographs of the burn sent by WhatsApp, with the decision transmitted by text message.	Reported on both record keeping and storage. In the dermatology service, some messages were stored on the consultant’s phone, no central depository. In the burns service: some messages deleted from the phones.
Pandian et al. [25] 2014	India	Maxillofacial surgery.	Description of a protocol using WhatsApp for communication between postgraduate trainees and senior maxillofacial surgeons. Electronic transmission of clinical images for remote consultation was done using WhatsApp in the maxillofacial unit.	Reported on both record keeping and storage. Messages stored on the phone as a digital record for future reference such that “lost X-rays are a thing of the past”.
Group E. Uncertain
Williams and Kovarik. [30] 2018	Botswana	Dermatology care.	The use of WhatsApp for dermatology care and a description as to how this application can be easily adapted and integrated into clinical practice in resource-limited settings to improve patient outcomes.	Mentioned but did not report evidence of record keeping or storage of WhatsApp message content. A reported drawback was the inability to save data centrally or integrate WhatsApp consultations into a patient’s medical record.
Dungarwalla et al. [26] 2019	UK	Oral and maxillofacial surgery.	Investigation of the use of WhatsApp among oral and maxillofacial surgery junior trainees at a level one trauma centre in London. Additionally included a review of existing studies.	Mentioned but did not report evidence of record keeping or storage. A retrospective study where information was accessed from WhatsApp messages stored on the users’ mobile phones with no mention of subsequent deletion of messages. Stated that “records constitute a pillar of good clinical practice and governance”, but reported difficulties with transferring consults to patient records when using the departmental mobile phone.