Original Research

Retrospective audit of anaesthesia practices in a new Bariatric unit in a Johannesburg academic hospital

Harshal J. Mistry, Shafeeqa Mayet, Tahlia Jeggo, Zainub Jooma

Received: 22 Apr. 2026; Accepted: 25 June 2026; Published: 22 Sept. 2026

Copyright: © 2026. The Authors. Licensee: AOSIS.
This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).

Abstract

Background: Obesity is a significant issue in South Africa, where 27% of the population is considered obese and this is estimated to increase. Bariatric surgery is currently offered at four public institutions in South Africa. There is limited literature on the anaesthetic practice in bariatric surgery in South Africa.

Aim: To describe perioperative anaesthetic practices for bariatric surgery.

Setting: Helen Joseph Hospital.

Methods: This was a retrospective, descriptive study that included all bariatric cases performed from 01 January 2022 to 30 June 2024. The data collection sheet was designed in accordance with the perioperative recommendations of the Enhanced Recovery After Surgery (ERAS) Society for Bariatric Surgery. Pre-, intra- and postoperative variables were reviewed. Outcomes were descriptively described.

Results: Forty-three patients met the inclusion criteria; 90% were female, with a median age of 45 years and a median body mass index of 59 kg/m². Although all patients met the prerequisites for surgery, only 65% achieved the recommended preoperative weight loss. Opioid-sparing analgesia and multimodal postoperative nausea and vomiting (PONV) prophylaxis were administered to 55% and 78% of patients, respectively. Postoperative prophylactic oxygen was provided to 86% of patients. PONV was the most common complication (16.3%), and overall mortality was 7%.

Conclusion: This was the first public-sector audit of bariatric surgery in South Africa analysing current anaesthetic practice. Intraoperative practices had higher compliance with ERAS guidance, and postoperative practices had the lowest compliance. Multidisciplinary involvement for context-specific guidance will ensure standardised care for these patients throughout the perioperative period.

Contribution: The study provides insight into current anaesthesia practices for bariatric surgery at a single centre in South Africa. It highlights areas for improvement to align practice with international guidelines.

Keywords: bariatric surgery; obesity; perioperative outcomes; opioid sparing; enhanced recovery after surgery; anaesthesia.

Introduction

Obesity is a significant issue in South Africa, where 27% of the population is considered obese.¹ It is estimated that this will increase to 30% by 2030.² Bariatric surgery is considered an effective long-term treatment for patients with a body mass index (BMI) ≥ 40 kg/m² or ≥ 35 kg/m² in the presence of comorbidities.^3,4 Bariatric surgery is being performed more regularly and is currently offered at four public institutions in South Africa: three in Gauteng and one in the Western Cape.⁵ Helen Joseph Hospital (HJH) initiated its bariatric surgery service in January 2022.

There are several guidelines that exist addressing aspects of bariatric surgical care. The International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), in conjunction with the American Society for Metabolic and Bariatric Surgery (AMBS), specifically address BMI thresholds and comorbidity indications.⁴ The Clinical Practice Guidelines of the Association for Endoscopic Surgery (EAES) on bariatric surgery focus primarily on the surgical process and have very limited anaesthetic detail.⁵ The Enhanced Recovery After Surgery (ERAS) Society released updated consensus-based guidelines for the care of bariatric patients in 2021. These guidelines are more comprehensive and encompass the pre-, intra- and postoperative period and were used in this study.⁶

Preoperatively, ERAS emphasises the involvement of a multidisciplinary team, patient education and counselling to optimise patients prior to surgery. Intraoperatively, a multimodal opioid-sparing analgesic approach, goal-directed fluid therapy, depth of anaesthesia monitoring in conjunction with intravenous anaesthesia techniques, lung-protective ventilation, neuromuscular blockade monitoring and postoperative nausea and vomiting (PONV) prophylaxis are discussed. Postoperatively, the focus is on the removal of unnecessary drains and tubes, nutritional support, thromboprophylaxis and oxygen supplementation.

There is limited literature on anaesthetic practice in bariatric surgery in South Africa.⁷ At HJH, there is no institutional protocol for anaesthesia in bariatric surgery. This study was developed with the ERAS consensus recommendations in mind and seeks to assess whether current practices at HJH align with international standards.

This study aimed to describe the perioperative management of patients presenting for bariatric surgery at HJH. The primary objectives of this study were to describe the patient profile, preoperative workup, intraoperative anaesthetic practices and postoperative course. The secondary objective was to determine whether the current practice aligns with the recommended ERAS practice guidance.

Research methods and design

This was a retrospective, descriptive study that included all bariatric cases performed at HJH from 01 January 2022 to 30 June 2024. As this was a retrospective study, informed consent was not obtained.

Helen Joseph Hospital is a tertiary public hospital affiliated with the University of the Witwatersrand. The hospital conducted its first bariatric surgery in January 2022, and to date, 47 bariatric surgeries have been performed. The bariatric theatre team consisted of three surgeons and five anaesthetists with experience in bariatric surgery. All patients considered for surgery were assessed at the preoperative anaesthesia clinic. This was considered mandatory for a complete workup.

The sample size was determined by the number of bariatric surgeries performed during the study period. Patients who were not assessed at the preoperative anaesthesia clinic were excluded as the preoperative component of the ERAS pathway constituted significant missing data. All other patients undergoing bariatric surgery during the study period were included.

Each patient was risk-stratified and counselled regarding the surgical procedure at the preoperative anaesthesia clinic. Following risk stratification, patients were referred to the relevant specialists for optimisation and reassessed thereafter. Comorbidities and further counselling regarding the procedure were provided. Different anaesthetic registrars and anaesthetic consultants manage the clinic, resulting in heterogeneity in the investigations requested and the counselling provided.

A non-probability convenience sampling method was employed using medical records available from the bariatric surgery database. The database included preoperative clinic notes, anaesthetic charts and patient files.

The data collection sheet was designed based on the perioperative recommendations of the ERAS Society for Bariatric Surgery.⁶ The data collection tool was peer-reviewed by five consultant anaesthetists experienced in bariatric surgery to ensure practical application and content validity (Online Appendix 1). Data were captured using a structured Google Form by the primary investigator (HJM).

Preoperative, intraoperative and postoperative variables were reviewed. Preoperative data consisted of patient demographics and factors related to their anaesthetic risk profile. Airway management, ventilation strategies (lung-protective ventilation: tidal volume (TV) 6 mL – 8 mL based on ideal body weight, positive end expiratory pressure (PEEP) 5 cm – 10 cm H₂O) and drugs administered for neuromuscular blockade, analgesia, PONV prophylaxis and maintenance of anaesthesia were noted in the intraoperative data. Complications, destination after surgery, oxygen supplementation and outcome were collected during the postoperative period.

The ERAS audit list included preoperative, intraoperative and postoperative categories, with all strong recommendations listed in the guideline assessed for institutional compliance.⁶ Each patient record was then compared to the recommendations. The strong and weak recommendations are tabulated in Table 1.⁶

Outcomes were predominantly descriptive. Continuous data were described numerically using the median and interquartile range. Categorical data (nominal and ordinal) were reported numerically as counts and percentages. A Fisher’s exact test was conducted to assess associations among morphine administration, the presence of nausea and vomiting, and the need for supplemental oxygen as an exploratory analysis. A p-value < 0.05 was considered statistically significant.

Ethical considerations

Ethical clearance to conduct this study was obtained from the University of the Witwatersrand and Human Research Ethics Committee (No. MED24-08-553).

Results

Forty-seven patients had undergone bariatric surgery during the study period; four were excluded as they did not attend the preoperative clinic. The final sample size included 43 patient records.

Table 2 summarises the preoperative data.

Weight loss was achieved through dietary strategies, but no standard exercise plan was implemented. A specific weight-loss target was not set, contrary to the guideline recommendation of 5% – 10%, but the percentage of weight loss was recorded at the follow-up visit. The average weight loss achieved was 6.7%. There was heterogeneity in patient referrals to the bariatrics programme; all patients were referred to the surgical department, but by a variety of referees, namely, orthopaedics, internal medicine and other specialities.

Nearly all patients (97.6%, n = 42) underwent blood tests, a chest X-ray and an electrocardiogram. Other standard procedures included lung function tests (72.1%, n = 31) and referrals to dietitians (72.1%, n = 31). Referrals to endocrinologists (20.9%, n = 9) and for liver ultrasounds (18.6%, n = 8) were less common.

Table 3 summarises the intraoperative data.

South African Society of Anaesthesiologists standard monitoring was used on all patients. No patient needed a central venous catheter. Guideline recommendations of 6 mL/kg – 8 mL/kg of ideal body weight for TV could not be analysed because heights were not recorded on the charts and this data was missing for all patients. The mean duration of surgery was 150 min (interquartile range 108–198 min).

The most common two-drug combination for opioids was: remifentanil + fentanyl, n = 10 (23.2%), remifentanil + morphine, n = 10 (23.2%). The most common three-drug combination of opioids was remifentanil + fentanyl + morphine, n = 6 (14.0%). The median intraoperative dose of morphine was 3.5 mg (interquartile range 1 mg – 10 mg).

As a result of the unanticipated utilisation of morphine, an exploratory analysis for any association between the administration of morphine and the occurrence of PONV and the need for postoperative oxygen supplementation was conducted. This was not one of the primary outcomes of the study. There were very few patients on whom the statistical analysis was conducted, so these results should be interpreted with caution, and further studies are needed to better delineate the effects of morphine in this patient cohort. No statistically significant association was found between the administration of morphine and either PONV or need for oxygen supplementation (Table 4).

Patients were sent to the ward, high-care or intensive care unit (ICU), depending on their obesity surgery risk mortality score (OS-MRS).⁸ The score was calculated at the preoperative clinic assessment. Patients who scored 0–1 (predicted postoperative mortality of 0.3%) were sent to the ward. Those who were at moderate risk, scoring 2–3 (predicted postoperative mortality of 1.7%), were sent to high care. Patients who were high risk 4–5 (predicted postoperative mortality of 3.2%) were sent to the ICU.

Patients generally had favourable outcomes in the early postoperative period, with n = 28 (65.1%) experiencing uncomplicated recoveries during their hospital stay. The majority of complications were minor, and most included PONV (n = 7, 16.3%). Four patients reported pain; no other complications were noted. Serious events occurred less frequently, including venous thromboembolism (VTE) (n = 2, 4.7%), a case of intraoperative awareness (n = 1, 2.3%) (target-controlled infusion [TCI], neuromuscular blocking agent used, and depth of anaesthesia monitoring used) and an anastomotic leak (n = 1, 2.3%). The majority of patients required some form of postoperative oxygen support (n = 37, 86.0%).

Three patients died postoperatively. On further exploration, the OS-MRS were determined for those who demised. One patient developed VTE, with subsequent disseminated intravascular coagulopathy and renal failure (OS-MRS:4), this patient also had the highest BMI of the cohort at 70.45 kg/m². A second patient died of unknown causes (OS-MRS:3), and the third patient died from an anastomotic leak (OS-MRS:3).

Table 5 summarises the audit of current practice with recommended guidelines. As a result of the study design, many pertinent postoperative ERAS recommendations could not be assessed. This study was limited to the perioperative and early postoperative period. Consequently, long-term ERAS outcomes such as nutritional status, prolonged opioid use, functional recovery and weight-loss sustainability could not be evaluated, as this was not documented in the patients’ records and presumably not done.

Discussion

This study aimed to evaluate current perioperative practices in a bariatric unit in a South African public-sector setting and to determine whether these practices align with the ERAS recommendations. The main finding was that preoperatively, patients had a significantly higher BMI than the global average. There was also heterogeneity in current practices compared with the ERAS protocol. Preoperatively, there was high compliance with patient optimisation. However, intraoperatively, while there was high compliance with airway management, PONV prophylaxis and neuromuscular blockade, adherence to opioid-sparing analgesia, neuromuscular blockade monitoring, and depth-of-analgesia monitoring was suboptimal during total intravenous anaesthesia (TIVA)/TCI. The mortality rate was 6.9%, higher than global averages.⁹ Other complications, such as PONV, were lower than those reported internationally.¹⁰ There was a paucity of data pertaining to postoperative recommendations.

Preoperative findings

Preoperatively, all patients met the criteria for bariatric surgery. According to the South African Society for Surgery, Obesity and Metabolism guidelines, patients may be referred for surgical management only after assessment by a specialist weight management service.¹¹ Patients who meet the criteria for bariatric surgery are individuals who fit the following criteria: individuals without any clinical or psychological contraindications; patients with a BMI above 40 kg/m²; patients with a BMI above 35 kg/m² with comorbid disease where conventional treatment has failed; and patients with a BMI > 30 kg/m² with poorly controlled diabetes mellitus.¹² In our study, the median BMI was 59, and based on this criterion alone, all patients qualified for surgery.

This figure is significantly higher than the global average for patients presenting for bariatric surgery.⁹ Since 2014, the IFSO has produced an annual report detailing all bariatric surgeries submitted to a global registry. In its 2024 report, which marked the eighth yearly publication, results from 5 million surgeries performed in 19 countries worldwide were tabulated. South Africa had the highest BMI for males at 47.7, based on 362 surgeries performed in 2024 (across both public and private settings).⁹ This contrasts with the global average BMI of 40 kg/m² – 45 kg/m². However, in keeping with international trends, our cohort was over 90% female.⁹

Specialist services included in our cohort were a dietitian and a psychologist to aid weight loss, but these were provided in only 72% of cases. All patients achieved some weight loss; the average was 6.7% of their initial weight. However, only 65.1% achieved the 5% – 10% preoperative weight loss, which ERAS recommends.⁶

Surgical optimisation encompasses education and counselling, smoking cessation, alcohol abstinence and preoperative weight loss. Preoperative education was well provided by the surgical team and the psychologists. This was not formally assessed in terms of patient understanding.

During the audit, it was found that specific preoperative recommendations were suboptimal in accordance with ERAS guidelines.⁶ Improved outcomes and adherence to the ERAS protocol have been observed in other lower- and middle-income countries that adopt a multidisciplinary team approach.^13,14 In a study published in Brazil by Chaim et al.,¹³ the adoption of a multidisciplinary team approach in the preoperative period resulted in greater weight loss, reversal of patient comorbidities and fewer postoperative complications. Currently at HJH, all units involved in bariatric surgery operate in isolation: dietetics, surgery, endocrinology, psychology and anaesthesia. A holistic multidisciplinary approach for patients at HJH may improve perioperative outcomes.

Intraoperatively

Airway management was ubiquitously performed via endotracheal intubation. This is in keeping with ERAS guidelines, as these patients are at an increased risk of aspiration due to surgical and patient factors.¹⁵ However, ERAS recommendations advocate ramping the patient to improve laryngeal view and oxygenation on induction⁶; this was done in only 30.2% of patients. The low implementation of a ramped-up position in the cohort may reflect limited access to ramping pillow devices, a lack of bariatric airway protocols, and variability in familiarity with bariatric airway optimisation techniques. Neuromuscular blockade was used in 95% of patients; however, train-of-four (TOF) monitoring was performed in only one patient. The guidelines recommend deep neuromuscular blockade intraoperatively, but this was not monitored. This is problematic, as the protocol advocates objective neuromuscular monitoring, in which a TOF > 0.9 is achieved before extubation.⁶ Residual neuromuscular blockade increases the risk of airway obstruction and pulmonary complications.⁶ The low utilisation of TOF monitoring observed in our study likely reflects a combination of equipment limitations, gaps in training, absence of a standardised anaesthetic protocol and reliance on subjective clinical assessment rather than objective neuromuscular monitoring.

In terms of analgesia, ERAS recommendations strongly suggest multimodal analgesia incorporating non-opioid agents, such as non-steroidal anti-inflammatories (NSAIDs), acetaminophen and regional techniques to minimise opioid side effects and improve recovery.⁶ Common adjuncts include lignocaine, dexmedetomidine, ketamine and magnesium sulphate.⁶ Opioids should only be administered as a rescue protocol at the lowest effective dose and should be short-acting agents like fentanyl.⁶ In our study, patients received at least one opioid, the most common opioid being remifentanil (76.7%; n = 33/43), followed by fentanyl (60.5%; n = 26/43), and morphine (44.2%; n = 19/43). Importantly, 55% of the patients had opioid-sparing regimes. These regimens consisted of ERAS-recommended drugs. A multimodal approach was used in most patients. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, was administered to 34 patients (79.1%). Lignocaine was used in 36 patients (83.7%). An alpha-2 agonist, dexmedetomidine, was used in 32 patients (74.4%). Paracetamol was administered in 31 patients (72.1%), whereas NSAIDs were used less frequently, in 10 patients (23.2%).

Specific analgesic vary by institution. In a systematic review looking at the efficacy of non-opioid analgesics and adjuvants in multimodal analgesia for reducing postoperative opioid consumption and complications in obesity, it was found that the use of dexmedetomidine, ketamine, lignocaine, magnesium and gabapentin significantly reduced the use of postoperative opioids, PONV and length of hospital stay.¹⁶ In a speciality bariatric hospital in Hong Kong, a protocol was instituted enlisting opioid-sparing analgesia strategies.¹⁷ Preoperatively, paracetamol and pregabalin were given. After induction, a dexmedetomidine infusion using lean body weight and fentanyl was administered. Maintenance included a dexmedetomidine infusion, a ketamine bolus, parecoxib, tramadol and local infiltration of the wound. Postoperative analgesia included paracetamol, etoricoxib and pregabalin. Rescue analgesia was pethidine. The study noted, however, that 46% of patients required pethidine in the postoperative period.¹⁷

Opioid minimisation has been shown to reduce PONV, improve recovery times and shorten hospital stays.⁶ Notably, all of the patients in the study received at least one opioid. Morphine was administered to 44.2% of patients. Morphine is not recommended as a first-line treatment in bariatric surgery because of the risk of respiratory and gastrointestinal complications, slower recovery, and a higher potential for long-term opioid dependence.¹⁸ In this study population, 18% of the group were diagnosed with obstructive sleep apnoea (OSA), and the majority had significant risk factors for OSA. Therefore, the use of morphine can be problematic because of the risk of respiratory depression.¹⁹

The significant use of morphine in these patients could be attributed to the lack of analgesia protocols in the unit and the limited availability of drugs. However, morphine has been used safely after bariatric surgery. In a prospective randomised controlled study, the use of morphine in an intrathecal route using 0.3 mg added to bupivacaine 0.5%, with a multimodal analgesic plan, was reported to be effective in reducing postoperative pain scores in patients who underwent bariatric surgery.²⁰ There were no statistically significant respiratory depression or respiratory complications secondary to opioid use found in this study.

The ERAS guidelines for bariatric surgery recommend multimodal prophylaxis against PONV. All patients should receive two or more antiemetics, including a steroid and a serotonin receptor antagonist, and consider a third agent in patients who have a very high risk for PONV. The Apfel score can be inadequate for guiding practitioners in determining which patients are at very high risk.²¹ There was a high adherence to this recommendation in this study, with 78% of patients receiving at least two agents. Monotherapy was used in 25.6% of patients.

In a prospective study that analysed more than 8000 patients, it was found that patients who were at very high risk for PONV were more likely to be younger, female and undergoing laparoscopic sleeve gastrectomy with moderate to severe pain postoperatively.²² Recommended additional agents include a neurokinin-1 receptor antagonist or a transdermal scopolamine patch.⁶ Neither of these agents is available at HJH.

Target-controlled infusion was used in 72.1% of patients; however, the model used was not noted. Only 58.1% were monitored for depth of anaesthesia. There was one case of postoperative awareness, which may be attributable to the above. The use of TCI should be standardised, as the incidence of PONV has been shown to decrease in propofol-based TCI regimes.²³ Target-controlled infusion has been well corroborated in the benefits of PONV in this population; however, in a systematic review and meta-analysis, there was no difference in postoperative pain scores, postoperative opioid use and perioperative complications compared to their volatile counterparts.²⁴ However, as a result of the altered pharmacodynamics in obese individuals, the need for accurate dosing and the potential for infusion interruptions, it should be mandatory that depth of anaesthesia monitoring be used to minimise the risk of awareness.²⁵

There are no specific ERAS protocols for the use of TIVA/TCI in bariatric surgery, nor does it mandate its use over volatile anaesthesia.⁶ However, it indirectly supports the use of TIVA/TCI to prevent PONV. In the demographic of obese individuals, the Eleveld model for propofol should be used as it has the strongest validation across BMI ranges.²⁶ This model has been shown to accurately estimate the clearance in obese patients, which is essential for precise dosing in this population.²⁷ When the Eleveld model is unavailable, the Marsh or Schneider method can be used. The input weight should be the adjusted body weight for the Marsh model or fat-free mass for the Schneider model.²⁸ These models should be used in conjunction with depth of anaesthesia monitoring to reduce the risk of under- or overdosing.²⁸ Unfortunately, in our cohort, the model and weight used for the patients were not recorded.

Postoperatively

Postoperative care, according to the ERAS guidelines, includes early oral intake, diet progression protocol, vitamin and mineral supplementation, nutritional monitoring, pharmacological and mechanical thromboprophylaxis, and early mobilisation. As our study examined only immediate postoperative complications and outcomes, we did not assess these aspects of postoperative care. The long-term efficacy of the procedure was also not investigated, namely, long-term weight loss, effect on comorbid diseases and long-term complications.

The mortality in this group was almost 7%. In 2024, the IFSO reported overall mortality rates after bariatric surgery ranging from 0% to 0.25% globally. South Africa had a mortality rate of 0.25% (1 in 394 cases).⁹ The risk factors for higher mortality include age above 65 years, BMI > 60 kg/m², severe comorbidities, revisional bariatric surgery and delayed recognition of complications such as anastomotic leak or pulmonary embolism.^29,30 Of the patients who died, high BMI, VTE and anastomotic leak were contributing factors. These deaths emphasise the requirement for vigilant postoperative monitoring, strict thromboprophylaxis and early recognition of surgical complications, which can be challenging in this cohort. The disproportionately high mortality rate in our cohort reinforces the need for strengthened preoperative optimisation and postoperative care measures that must form part of future bariatric surgery programmes.

Limitations

Several limitations of our study need to be acknowledged. This was a retrospective audit, and the analysis depended on the completeness and accuracy of the records. There may be poor documentation of certain practices and under-reporting of side effects such as PONV. Some eligible patients had to be excluded because no preoperative clinic information was available, potentially introducing selection bias. As this study was conducted as an audit rather than a formal quality improvement project, many relevant stakeholders were not engaged in the review, progression and analysis of the process, thereby limiting multidisciplinary insight. The small sample size reflects the single bariatric unit in which the study was conducted, and caution should be exercised when generalising these results to larger or differently resourced centres. Lastly, compliance with ERAS recommendations was assessed using retrospective data rather than direct observation, and patient-centred postoperative efficacy was not analysed, making it difficult to determine the intervention’s long-term clinical impact.

Conclusion

This was, to our knowledge, the first public-sector audit of bariatric surgery in South Africa, analysing current practice. The patients in this study have a higher BMI and overall higher mortality than international standards. Multidisciplinary input was limited. Standardised analgesia protocols were lacking, but the majority of patients had opioid-sparing strategies and a multimodal analgesic approach. Intraoperative practices had higher compliance with ERAS guidance, whereas postoperative practices had the lowest compliance. Multidisciplinary involvement for context-specific guidance will ensure standardised care for these patients throughout the perioperative period.

Future recommendations

Future endeavours include establishing an institution-specific ERAS protocol that involves multidisciplinary coordination among anaesthesia, surgery, nursing staff, dietitians, psychology and physiotherapy. This would allow a standardised framework for perioperative management. Once this protocol is implemented, a reaudit should be conducted to assess improvements in compliance and ensure continuity of changes in practice. Lastly, there should be ongoing evaluation analysing the efficacy of the procedure in terms of sustained weight loss, reversal of organ dysfunction and long-term complications in addition to immediate complications and mortality. The incorporation of weight-loss drugs into the optimisation has not yet been delineated. The criteria for bariatric surgery may change over time, considering the advancement of care for obese patients.

Acknowledgements

Peter Kamerman, PhD (University of the Witwatersrand), BSc Hons, is acknowledged for his invaluable assistance with biostatistical analysis.

The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article. The author, Zainub Jooma, serve as an editorial board member of this journal. The peer review process for this submission was handled independently, and the author had no involvement in the editorial decision-making process for this article. The author has no other competing interests to declare.

Harshal J. Mistry: Conceptualisation, Data curation, Formal analysis, Methodology, Writing – original draft. Shafeeqa Mayet: Conceptualisation, Methodology, Supervision, Writing – review & editing. Tahlia Jeggo: Conceptualisation, Methodology, Supervision, Writing – review & editing. Zainub Jooma: Methodology, Supervision, Writing – review & editing. All authors reviewed the article, contributed to the discussion of results, approved the final version for submission and publication, and take responsibility for the integrity of its findings.

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Data sharing is not applicable to this article as no new data were created or analysed in this study.

The views and opinions expressed in this article are those of the authors and are the product of professional research. It does not necessarily reflect the official policy or position of any affiliated institution, funder, agency or that of the publisher. The authors are responsible for this article’s results, findings and content.

References