The impact of self-isolation on psychological wellbeing and how to reduce it: a systematic review
King’s College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK
NIHR Health Protection Research Unit in Emergency Preparedness and Response, London, UK
UK Health Security Agency, Chief Scientific Officer’s Group, UK
*Corresponding author: Alex F Martin. Department of Psychological Medicine, King’s College London, Weston Education Centre, Cutcombe Road, London, SE5 9RJ, UK. Email: alex.f.martin@kcl.ac.ukAbstract
Self-isolation is a public health measure used to prevent the spread of infection, and which can have an impact on the psychological wellbeing of those going through it. It is likely that self-isolation will be used to contain future outbreaks of infectious disease. We synthesised evidence on the impact of home self-isolation on psychological wellbeing of the general public during the COVID-19 pandemic.
This systematic review was registered on PROSPERO (CRD42022378140). We searched Medline, PsycINFO, Web of Science, Embase, and grey literature (01 January 2020 to 13 December 2022). Our definition of wellbeing included adverse mental health outcomes and adaptive wellbeing. Studies that investigated isolation in managed facilities, children, and healthcare workers were excluded. We followed PRISMA and synthesis without meta-analysis (SWiM) guidelines. We extracted data on the impact of self-isolation on wellbeing, and factors associated with and interventions targeting wellbeing during self-isolation.
We included 36 studies (most were cross sectional, two were longitudinal cohort studies, three assessed interventions, and five were qualitative). The mode quality rating was ‘high-risk’. Depressive and anxiety symptoms were most investigated. Evidence for an impact of self-isolation on wellbeing was often inconsistent in quantitative studies, although qualitative studies consistently reported a negative impact on wellbeing. However, people with pre-existing mental and physical health needs consistently reported increased symptoms of mental ill health during self-isolation. Studies reported modifiable stressors that have been reported in previous infectious disease contexts, such as inadequate support, poor coping strategies, inadequate and conflicting information, and the importance of regular contact from trusted healthcare professionals. However, interventions targeting psychological wellbeing were rare and evaluative studies of these had high or very high risk of bias.
When implementing self-isolation directives, public health officials should prioritise support for more vulnerable individuals who have pre-existing mental or physical health needs, lack support, or who are facing significant life stressors. Clinicians can play a key role in identifying and supporting those most at risk. Focus should be directed toward interventions that address loneliness, worries, and misinformation, whilst monitoring and identifying individuals in need of additional support.
Article notes
Competing Interest Statement
LES, RA, and GJR were participants of the UK Scientific Advisory Group for Emergencies or its subgroups. GJR advised the UK Office for National Statistics on its work relating self isolation, papers relating to this work were considered as part of the review. All authors co-authored papers that were considered during the review process. RA is an employee of the UK Health Security Agency. AFM, SKB, RD, MVS, and NG report no competing interests.
Funding Statement
This study was funded by the Research England Policy Support Fund 2022-23 (from the allocation to Kings College London). AFM, LES, SKB, RA and GJR are supported by the National Institute for Health and Care Research Health Protection Research Unit (NIHR HPRU) in Emergency Preparedness and Response, a partnership between the UK Health Security Agency, Kings College London and the University of East Anglia. The views expressed are those of the authors and not necessarily those of the NIHR, UKHSA or the Department of Health and Social Care.
Introduction
To minimise the spread of infection and protect the public, several containment measures have been used in infectious disease outbreaks, including isolation (the separation of those who are ill from those who are well) and quarantine (the separation of those at risk of developing an illness from those who are well). During the COVID-19 pandemic, there was a substantial focus among public health practitioners across the world on the use of these strategies (hereafter self-isolation) 1
Self-isolation can be a time of upheaval and concern with potential impacts on the psychological wellbeing of those going through it. For example, isolation may lead to fears about illness progression, or worries about financial loss and caretaking responsibilities. Psychological wellbeing (hereafter wellbeing) encompasses both adverse mental health outcomes, such as symptoms and disorders, and adaptive outcomes, such as resilience and flourishing. In February 2020, Brooks and colleagues published a rapid review of studies that assessed the psychological impact of quarantine.2 The findings indicated that quarantine was associated with adverse wellbeing outcomes in nearly all contexts, with some evidence that these effects could be long-lasting. A subsequent meta-analysis found that the odds of depressive, anxiety, and stress related disorders was more than double for people who self-isolated compared to those who had not.3 The study also reported an increased risk for some broader wellbeing outcomes, such as insomnia and substance use. All the studies included in these reviews were conducted before the COVID-19 pandemic.
The COVID-19 pandemic led to a proliferation of studies on wellbeing and its associated factors. For example, pre-existing mental health disorders, loneliness, worry, and a lack of access to resources and support were all identified as risk factors for poorer mental health during the pandemic.4–6 Conversely, an editorial published during the early stages of the pandemic reported that isolation could have a positive ‘downstream’ impact on wellbeing through, for example, increased health behaviours such as physical activity and healthy eating.7 During the pandemic, many studies investigated the impact on wellbeing of ‘lockdown’ measures. Lockdown, in contrast to self-isolation, involved population-wide ‘stay-at-home’ or ‘mass quarantine’ orders, where people were required to stay at home except for essential activities and exercise. What is less clear is how self-isolation specifically impacted wellbeing, given that this containment measure has the potential for a greater impact on specific aspects of mental health, such as social stigma and anxiety related to the likelihood of infection or the development of symptoms.2,3
A recent review of 25 studies carried out globally found that testing followed by self-isolation was an important public health mitigation measure to reduce transmission during the COVID-19 pandemic.8 It is likely that home-based self-isolation will be used in future outbreaks of infectious disease, as it was during the UK public health response to the 2022 mpox outbreak.9 Reducing the burden of self-isolation on those affected remains a scientific and policy priority.
This systematic review appraises:
- The impact of self-isolation on wellbeing during or following the COVID-19 pandemic.
- Factors associated with wellbeing outcomes during or following self-isolation.
- The effectiveness of interventions designed to improve wellbeing during or following self-isolation.
Methods
This systematic literature review was carried out in accordance with the Cochrane Collaboration guidelines for the conduct of systematic reviews,10 and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA; see Appendix 1).11,12 The protocol was prospectively registered on PROSPERO (CRD42022378140).
Search strategy and selection criteria
A systematic search was conducted of studies published between 01 January 2020 and 13 December 2022. We searched six databases (Medline, PsycInfo, Web of Science, Embase, PsyArXiv, medRxiv). The search strategy included terms for COVID-19, isolation and quarantine (combined with NOT social isolation), and wellbeing. The search was also used for a separate systematic review exploring adherence to self-isolation,13 screening was performed in parallel up to full-text screening. We searched five grey literature databases, relevant UK agencies and organisations, Google, and made direct inquiries with UK Government agencies. A full description of the search is reported in Appendix 2.
The search was piloted, and the reviewing team (AFM, LES, SKB, MVS, RD, and GJR) reviewed a training set of 300 studies. Discrepancies were discussed until agreement on included studies was attained. Piloting led to some revisions and clarifications of the protocol (Appendix 3). Then, reviewers independently screened citations, meeting weekly to reach agreement on queries and discrepancies.
Studies were included if they used original data to investigate the impact of self-isolation on wellbeing during the COVID-19 pandemic. Self-isolation was defined as: anyone advised (directly or by widely disseminated public health guidance) to avoid contact with others because they were known or suspected to have COVID-19 or because they were suspected to be incubating COVID-19. Wellbeing was broadly defined, including adverse mental health outcomes and adaptive characteristics. We included adults who self-isolated at home and excluded children, healthcare workers, and those in managed isolation facilities or in a hospital. For aim 1, quantitative studies had to use a design that allowed attribution of the impact of self-isolation on wellbeing, for example, through use of a comparison to a control group. For aim 2, factors associated with wellbeing had to be directly related to, or occur during, the self-isolation period. For example, studies investigating the impact of a change in the national containment rules after the isolation period but before the study was carried out were excluded. For this aim, studies were included that compared home to isolation in a managed facility. Grey literature was only included if it investigated the effectiveness of an intervention, to ensure only the most rigorous non-peer-reviewed studies were included and because of the dearth of peer-reviewed data on this specific topic. If it was unclear whether a study met the inclusion criteria, the corresponding author was contacted, and the study was excluded if no response was received.
Data Analysis
Data were extracted by one reviewer (AFM for quantitative studies and SKB for qualitative studies) using a piloted, standardised table. All studies were discussed with at least one other reviewer (AFM, LES or GJR). Extracted data included: study characteristics (design, methods, sampling, demographics); isolation characteristics (reason, duration, context); and wellbeing characteristics (measures, impact, associated factors, interventions). We reported the most rigorous analysis conducted in each study, for example, multivariable analysis over unadjusted analysis.
Study quality assessment was performed by one reviewer (AFM for quantitative studies and SKB for qualitative studies), all studies were discussed with at least one other reviewer (AFM, LES or GJR). For quantitative studies, we used the Risk of Bias in Non-randomized Studies for Exposure (ROBINS-E) and Interventions (ROBINS-I).14,15 ROBINS assessments are specific to a reported result rather than a study. Consequently, studies that reported a result for aim 1 and 2 received two risk of bias scores. Each result was categorised as low risk, some concerns, high risk, or very high risk based on the tool’s algorithm.
We used the Critical Appraisal Skills Programme (CASP) checklist for qualitative studies,16 but reworded the item ‘how valuable is the research?’ to ‘do the authors discuss the value of the research in terms of implications and contribution to literature?’ to allow yes/no responses in line with the other items and to give each study an overall quality score percentage. Scores were out of ten, reported as a percentage, with higher scores indicating better quality. Risk of bias tools are reported in Appendix 4.
Quantitative data were synthesised narratively, following SWiM guidelines.17 No meta-analysis was planned due to expected heterogeneity in study design, outcomes, and associated factors. Qualitative data were synthesised using meta-ethnography, following eMERGe guidelines.18 A description of the synthesis of results for each aim is reported in Appendix 5.
Role of the funding source
The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.
Results
The search identified 15,275 citations (Figure 1). Thirty-six studies were included, all of which were identified through database searches.19–54
Study characteristics
Most of the studies were conducted in Europe,19,23,26,30,34,36–39,41,45,47,50,52,53 Asia,22,24,28,29,33 and South Asia.20,31,46,48,49 The rest were in Africa,21,40,42,43 East Asia,32,35,54 South America,27,44 North America,25 and one study was multi-continent.51 Most studies were cross-sectional in design,19–23,25,27,29,30,32,34,36,37,39–45,47,49–51,53,54 two were longitudinal,35,46 three were interventions,24,31,48 and five were qualitative.26,28,33,38,52 Sample sizes ranged from 14 to 18,146. One study included only older adults,22 all other studies included adults aged 18 years and over.
Studies often reported on more than one wellbeing outcome. The most reported outcomes were anxiety symptoms,19,24,27,31,35,36,39,40,42–45,47,48,50,51,54 depressive symptoms,19,27,31,32,35,36,39,40,42–45,48–51 and general psychological symptoms.19,20,25,27,30,31,34,37,39,43,46,48 Only three quantitative studies reported adaptive wellbeing outcomes.31,46,48 Reasons for self-isolation were COVID-19 infection,21,24,26,28,29,31,33,35,37,40,41,43,45,47–49 suspected infection,42 close contact with an infected person,30,36,39,52,54 or a combination of these.19,20,22,23,25,27,32,34,38,44,50,51,53 One study did not report a reason.46
Ten studies were carried out during national/regional lockdown measures,20,23,27,29,41,42,45,46,49,50 two were not,25,39 two were mixed,36,51. Twenty-two studies did not report lockdown context, all but one19 related to aims 2 and 3.21,22,24,26,28,30–35,37,38,40,43,44,47,48,52–54
Study characteristics are reported in Table 1.
Aim 1: The impact of self-isolation on psychological wellbeing
Associations between self-isolation and wellbeing were reported in 11 quantitative studies, several of which reported more than one wellbeing outcome. The most reported outcomes were anxiety symptoms,27,36,39,42,46,50,51 depressive symptoms,27,36,39,42,50,51 general psychological symptoms,19,20,25,27,46 post-traumatic stress disorder (PTSD),23,50 and stress related symptoms (Table 2).36,50 Several other outcomes were reported by only one study, such as loneliness and substance use, which are not synthesised here but can be found in the full extraction tables (Appendix 6). Evidence was inconsistent; grouping by lockdown context did not alter the pattern of results. Risk of bias is summarised and then the outcomes reported in the highest number of studies are discussed first.
In the risk of bias assessments, no quantitative findings were low risk. Five findings had some concerns,19,23,27,39,50 five were high risk,20,36,42,46,51, and one was very high risk.25 Only one of the four qualitative studies scored more than 40% on the quality appraisal tool,52 and even the higher-quality study was at substantial risk of bias due to the authors’ analysis using an a priori framework based on ‘areas of interest’. The risk of bias summaries are reported in Appendix 7.
For anxiety and depressive symptoms, most studies found no evidence of an effect of self-isolation, (27,36,39,42,46 and 36,39,42,50 respectively) while two reported worse symptoms in those who had self-isolated (50,51 and 27,51 respectively). Limiting findings to studies at lowest risk of bias (some concerns),27,39,50 did not change the pattern of findings.
For general psychological symptoms, three studies found no evidence for an association with self-isolation.19,27,39 Two studies that reported worse general psychological symptoms in those who had self-isolated were carried out under rapidly changing societal contexts.20,25 Limiting findings to studies at lowest risk of bias (some concerns),19,27,39 suggested no evidence for an effect of self-isolation.
Studies on PTSD symptoms consistently reported a positive association with self-isolation, both were large population cohort studies early in the pandemic, and both had some concerns of bias.23,50 Two studies found no evidence for an association between self-isolation and with stress, also early in the pandemic, at high risk and some concerns of bias respectively.36,50
Evidence for an impact of self-isolation on psychological symptoms was more consistent in qualitative studies, (Table 3). Participants also described feeling lonely,26,28,33 sad,26,28 angry and frustrated,26,52 bored,28,33,38,52 and afraid.33,52 They also reported negative impacts on their family relationships.26,38 In contrast, some also reported self-isolation to be relaxing and providing more time with family.28,38
Aim 2: Factors associated with psychological wellbeing during or following self-isolation
Factors associated with wellbeing were reported in 20 quantitative studies, several of which investigated associations with more than one factor (Table 4). The most reported factors were related to self-isolation,19,21,32,34,35,37,40,44,45,49,51 demographics,21,30,32,42,44,47 mental and physical health,21,32,37,47,54 and COVID-19 symptoms.21,37,43 Several factors or outcomes were reported by only one study, such as the time of year or loneliness, which are not reported here but can be found in the full extraction tables (Appendix 6). Evidence was often inconsistent. A general narrative summary is provided here; full details are in Appendix 8.
In risk of bias assessments, no findings were at low risk, one had some concerns,35 and most findings were at high,21,30,32,41,42,44,45,49,51,53 or very high risk of bias.19,22,29,34,37,40,43,47,54; (Appendix 7). Limiting findings to some concerns of bias or high risk of bias did not alter the interpretation of the findings for aim 2.
Factors related to self-isolation were reported in eleven studies. COVID-19 stressors, such as changes in daily life, worries about infection and job security, and a lack of support during self-isolation were consistently associated with higher levels of general psychological, depressive, and anxiety symptoms.32,37,44 Depressive and anxiety symptoms were found to be lower at the end of self-isolation compared to the start 35 and a longer period of self-isolation was associated with lower sleep problems at the end of the isolation period.21 Self-isolation at home rather than a hotel was associated with lower PTSD symptoms,40,49 but not anxiety symptoms.40,45,51
Factors related to demographics were reported in six studies. There was no evidence found for living alone to be associated with wellbeing symptoms.30,32 There was inconsistent evidence for an association between age or gender with any wellbeing symptoms.21,30,32,42,44,47
Factors related to mental or physical health were reported in five studies, all of which reported associations with wellbeing outcomes including psychological burden,37 depressive and anxiety symptoms,32,47,54 and insomnia.21 Low levels of coping strategies were associated with psychological burden,37 and anxiety symptoms.54
Factors related to COVID-19 were reported in three studies, including higher viral load and more severe symptoms.21,37,43 Both these factors were associated with an increase in general psychological symptoms.37,43 Whereas no evidence was found for an association with depressive or anxiety symptoms, or insomnia.21,43
Qualitative findings largely supported the associations identified in the quantitative findings (Table 3). Other factors which participants perceived to increase the negative wellbeing impacts of self-isolation included fears around COVID-19,26,33,38,52 financial difficulties,26,33 stigma,38,52 exposure to excessive media coverage of COVID-19,33 and conflicting guidance on how to isolate and symptom prognosis.26,38,52 Factors which participants perceived to reduce the negative impact of self-isolation on wellbeing included social support,26,28,33,38,52 coping strategies such as making plans for after isolation, keeping a regular routine, spirituality, and self-care,28,33,52,38 and receiving reliable information about COVID-19 from healthcare professionals.28 In addition, some people also reported a positive impact on their wellbeing, such as having more time to spend with family and to relax, which allowed them to refocus and appreciate what they had.26,38,52
Qualitative findings also indicated that the same factor could have a positive or negative impact on wellbeing, depending on the person’s individual context. For example, having children,26,28 or uncertainties around symptoms and duration.26,33,38
Aim 3: Interventions to improve psychological wellbeing during self-isolation
Three studies investigated the effect of an intervention on wellbeing. 24,31,48 One study tested a telenursing intervention, reporting a greater reduction in anxiety symptoms from pre-test to post-test in the intervention group compared to the control group. 24 Two studies tested yogic meditation interventions, reporting a decrease in depressive and general psychological symptoms, and insomnia, and an increase in adaptive wellbeing, at the end of the intervention period compared to the start (Table 5). 31,48 Both meditation intervention studies were conducted in the same hospital, using the same outcomes and similar interventions, but at least partially different participants. Study quality was problematic for all interventions, which rated as high risk, 24 or very high risk (Appendix 7). 31,48
Discussion
This systematic review summarises the literature on self-isolation and psychological wellbeing during the COVID-19 pandemic. Overall, there was considerable heterogeneity in wellbeing outcomes and isolation contexts reported in the studies. Most studies were cross-sectional, survey based, and at high or very high risk of bias. Quantitative evidence for an association between self-isolation and wellbeing was inconsistent, although some clear associations emerged for specific outcomes such as increased PTSD symptoms. Qualitative evidence showed a more consistent negative impact of self-isolation. Stressors, including pre-existing health needs and low levels of support, were consistently associated with worse wellbeing outcomes. Intervention studies were rare and at high or very high risk of bias.
Quantitative studies largely reported psychopathology symptom scales, which may explain the discrepancy between their findings and those of qualitative studies. These scales rarely assessed broader aspects of wellbeing such as worry, stigma, and somatic pain that could lead to behavioural changes like obsessive protective behaviours lasting far beyond the period of self-isolation, as found in other infectious disease contexts. 26,38,55,56 These broader aspects of wellbeing, and others such as frustration and agitation, may also have broader consequences, including lowering trust in governments and reducing adherence to mitigation measures. 57,58 Future research should consider wellbeing beyond psychopathology symptoms to better characterise the impact of self-isolation on wellbeing, whilst also continuing to focus on identifying groups with symptom levels suggestive of a treatment need.
One exception was PTSD symptoms, which were consistently higher in people who were currently or previously in self-isolation. 23,50 This is consistent with a previous review that found increased levels of PTSD symptoms in quarantined individuals across all contexts, including different infectious diseases and different groups such as parents, the general population, and healthcare workers. 2 Additionally, home isolation was consistently associated with reduced PTSD symptoms compared to isolation in a managed facility. 40,49 These results suggest that home isolation should be prioritised to reduce the risk of PTSD symptoms during self-isolation.
Self-isolation was found to associate with wellbeing differently, depending on individual factors and context. There was good evidence that people with greater mental and physical health needs, 26,29,32,37,44,47,54 who experienced COVID-related stressors including inadequate support, 26,32,33,37,38,44,52 and had reduced coping strategies, 37,53,54 were most at risk of adverse outcomes. As found during COVID-19 lockdowns, 59,60 parents and carers were more at risk, especially when there was conflict between childcare and work. 26 However, the presence of children could also reduce stress and helped some parents to cope. 28 This complexity mirrors the intricacies observed in prior studies, which found that factors such as the number and age of the children could exert different risk or protective effects. 61,62 Future research should focus on identifying the subpopulations most at risk of adverse wellbeing outcomes during self-isolation and developing and evaluating targeted public health interventions to support these groups, including providing practical support and promoting coping strategies to those who need it.
Few studies investigating the effect of interventions on wellbeing during self-isolation were identified. All three studies reported a supposed impact of the intervention on most wellbeing outcomes, 24,31,48 but several non-intervention studies also found that people generally experienced a reduction of symptoms over the course of isolation21,35 This suggests that two of the intervention studies, which lacked control groups, may have overestimated the effect of the intervention. Nevertheless, the study that used a control group found a greater reduction in anxiety at the end of the intervention (i.e. at follow-up) in those who received daily tele-nursing. 24 Qualitative studies highlighted modifiable stressors that have been consistently reported in previous infectious disease and disaster contexts, such as inadequate and conflicting information, 55,63,64 leading to heightened fears of disease progression and extended isolation. 65,66 Together, these findings suggest that high-quality intervention studies should be prioritised to better understand how to mitigate the impact of self-isolation on wellbeing. Emphasis should be placed on interventions targeting loneliness and misinformation, for example, through regular contact with healthcare professionals, whilst monitoring and identifying individuals who may require additional support.
Strengths and limitations
To our knowledge, this is the first review to explore the relationship between self-isolation and psychological wellbeing during the COVID-19 pandemic. Strengths include a pre-registered protocol, no geographical or language limitations, comprehensive risk of bias assessments, a robust process for agreement, and adherence to PRISMA, SWiM, and eMERGe guidelines. Limitations of the studies were the inconsistent use of the terms ‘isolation’ and ‘quarantine’, which could have led to the exclusion of relevant research, and the high risk of bias in many studies. Limitations of the review were that we were unable to formally analyse publication bias and did not examine heterogeneity in study design in the synthesis, which limits our confidence in the certainty of the evidence presented. Human error may have resulted in missed studies.
Implications and conclusions
Self-isolation impacts psychological wellbeing, particularly for PTSD symptoms. Self-isolating at home may reduce this risk, but more and better-quality evidence is needed. A significant limitation of the research base is its over reliance on psychopathology symptom questionnaires, which may miss the substantial impact of self-isolation on broader aspects of wellbeing, such as frustration or stigma. Ignoring these impacts can mean that potential downstream effects such as trust in government and reduced adherence to mitigation measures are overlooked. Public health officials should make it a priority to support vulnerable individuals with pre-existing health conditions, lack of support, or significant life stressors when implementing self-isolation directives in the future. Clinicians and healthcare workers can play a key role in identifying and supporting those most at risk. Interventions should focus on addressing loneliness, worries, and misinformation, and monitoring and identifying individuals who need additional support.
Contributors
AFM, LES, SKB, and GJR conceptualised the study. AFM ran the systematic searches and curated the data. AFM, LES, SKB, RD, MVS and GJR screened citations. AFM and SKB completed data extraction and risk of bias ratings. AFM wrote the original draft. LES, SKB, RD, MVS, RA, NG, and GJR reviewed, edited, and approved the final manuscript. All authors were involved in the scientific processes leading up to the writing of the manuscript and contributed to reviewing the papers, the interpretation of the findings, and the critical evaluation of the final version of the manuscript. All authors had full access to the data and accept responsibility to submit for publication. LES and AFM are guarantors. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted.
Declaration of interests
LES, RA, and GJR were participants of the UK’s Scientific Advisory Group for Emergencies or its subgroups. GJR advised the UK’s Office for National Statistics on its work relating self-isolation – papers relating to this work were considered as part of the review. All authors co-authored papers that were considered during the review process. RA is an employee of the UK Health Security Agency. AFM, SKB, RD, MVS, and NG report no competing interests.
Data sharing
No novel data were collected as part of this study. All data are already publicly available.
Supporting information
Data Availability
No novel data were collected as part of this study. All data are already publicly available.
Acknowledgements
This study was funded by the Research England Policy Support Fund 2022-23 (from the allocation to King’s College London). AFM, LES, SKB, RA and GJR are supported by the National Institute for Health and Care Research Health Protection Research Unit (NIHR HPRU) in Emergency Preparedness and Response, a partnership between the UK Health Security Agency, King’s College London and the University of East Anglia. The views expressed are those of the authors and not necessarily those of the NIHR, UKHSA or the Department of Health and Social Care. For the purpose of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising.
AI statement
During the preparation of this work, AI-assisted technologies were used in the writing process to improve readability and language of the work. AI was not used to produce scientific insights, analyse or interpret data, or draw scientific conclusions. Application of AI was performed with human oversight and control. The authors reviewed and edited the content, and are responsible and accountable for the originality, accuracy, and integrity of the work.
Ethics
All data used were in the public domain, therefore ethical approval was not required.