Sexual and reproductive health information and service needs and preferences of adolescents and young adults in Sri Lanka: a systematic review

Abstract

Background

Sexual and reproductive health is a key component of young people’s right to health during their development years. However, in the health policies of many low-to-middle-income countries such as Sri Lanka, sexual and reproductive healthcare is primarily conceptualised and implemented through the lens of family planning, which has resulted in a lack of awareness about the diverse sexual and reproductive health needs of the growing adolescent and young adult demographic. Therefore, this study aims synthesise and analyse the evidence on the sexual and reproductive health information and services needs and preferences of young people in Sri Lanka.

Methods

A systematic review of quantitative, qualitative, and mixed-methods studies on the sexual and reproductive health information and services needs of young people aged 10–24 years was carried out according to the ‘Preferred Reporting Items for Systematic Reviews and Meta-Analysis’ guidelines. Electronic searches were conducted in Ovid Medline, Ovid Embase, Ovid Global Health, and Ovid PsycInfo, for peer reviewed articles. Two authors conducted the full text screening, data extraction, and quality assessment independently. Data were extracted and analysed thematically.

Results

The database search yielded 1198 results, of which 16 papers met the inclusion criteria and were included in the review. Overall, young people face multiple barriers relating to availability, accessibility, and quality when accessing formal youth friendly sexual and reproductive health services. Some of these barriers included embarrassment, fear of stigma, and lack of knowledge about available services. Our findings indicate that young women preferred to receive sexual and reproductive health information from their mothers, while young men preferred to seek information from their peers. In contrast, young people in included studies were less likely to prefer more formal sources of information and care, such as resources at their schools (teachers and the school curriculum), and trained healthcare providers.

Conclusions

Potential strategies to improve sexual and reproductive health information and services in Sri Lanka to better meet the needs of young people include the education of parents and teachers, increased partnerships with young people to develop effective healthcare interventions, and tailored promotion of available youth-friendly resources. More research is needed on how sexual and reproductive health needs vary between young people from different socio-demographic groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-025-24324-5.

Background

Sexual and reproductive health (SRH) becomes increasingly important from adolescence, yet young people from low-to-middle-income countries (LMICs) often lack information about SRH and access to related health care. This diverges from international standards recognising non-discriminatory access to SRH information and services as a fundamental aspect of the right to health [1–4]. Adolescence and early adulthood (defined as 10–19 and 20–24 years of age, respectively by the World Health Organization (WHO) [5]) are critical developmental periods characterised by biological, cognitive, social, and emotional changes, often including the initiation of intimate partnerships and/or sexual activity [6]. It is important that young people’s right to access SRH care is recognised and upheld so they can independently make informed, safe, and voluntary decisions to protect their health and wellbeing and express their sexuality in a healthy, positive, and safe manner [4, 6–9]. When young people’s SRH information and service needs are not met, consequences can include adverse health and social outcomes that can reduce quality of life for the individual, their family, and the wider community [10–12]. Examples of such harms include physical and mental risks associated with unintended pregnancies, increased vulnerability to sexual coercion and violence, and exposure to sexually transmissible infections (STIs) [10, 11, 12]. The importance of addressing and preventing these risks is acknowledged and emphasised in the ‘United Nations 2030 Sustainable Development Goals’ (SDGs) goal 3.7 (ensure universal access to SRH healthcare services), and goal 5.6 (ensure universal access to SRH and reproductive rights), which prioritise addressing the SRH needs of young people [13, 14].

However, there is still a gap in knowledge about the SRH information and service needs of young people living in South Asian countries, such as Sri Lanka [6, 15, 16]. Currently, Sri Lanka is experiencing a major shift in its age structure associated with a youth bulge [17]. In the coming decades, the number of young people in Sri Lanka is predicted to increase by over 10%, from 4.7 million in 2012 to 5.2 million by 2032 [18]. Additionally, more young adults are delaying marriage to pursue their higher-education and careers [19]. Despite this, Sri Lanka’s current national SRH policies and services primarily focus on maternal care and family planning for married couples [20]. For example, the Sri Lanka Family Health Bureau’s principal national health survey, collects and analyses population level data to generate indicators which inform programs, policies, and services on areas of reproductive, maternal, newborn, child, adolescent, and youth health [21]. Furthermore, most community clinics and hospitals in Sri Lanka focus on maternal care in the context of SRH [20]. However, when it comes to the SRH of young people who are out of school, the Family Health Bureau only investigates the information and service needs of married couples who want to practice spacing between their children [21]. As a result, there is a lack of knowledge at the government level of what services and information sources are required to address the diverse SRH needs and preferences of both married and unmarried young people in Sri Lanka [21]. Without this knowledge, there is limited foundation to develop effective, appropriate, and evidence-based SRH healthcare initiatives which empower all young people to take control of, and freely make decisions about, their SRH wellbeing - key aspects of their right to health [13, 14].

In Sri Lanka, the dearth of knowledge about adolescent and young adult SRH information and service needs has been identified as an urgent national policy and research concern [20], and is becoming as a central feature in recent development plans aimed at improving the wellbeing of young people (e.g. ‘Sri Lanka National Strategic Plan on Adolescent and Youth Health’ (2018–2025)) [22]. To inform and guide future research and evidence-based policy making that promote youth SRH, a synthesis of what is already known about the SRH resource needs of young people is vital. To date, there has been no study that systematically consolidated evidence on the topic. To fill this knowledge gap, the aim of this systematic review is to synthesise existing data on the SRH information and service needs and preferences of adolescents and young adults in Sri Lanka.

Methods

Study design

This systematic review of published literature on the SRH information and service needs and preferences of adolescents and young adults in Sri Lanka is conducted according to the ‘Preferred Reporting Items for Systematic Reviews and Meta-Analyses’ (PRISMA) guidelines [23] and based on a registered protocol (ID: CRD42023411549) [24].

Search strategy

In January 2024, electronic searches were conducted across four databases (Ovid Medline, Ovid Embase, Ovid Global Health, and Ovid PsycInfo). After an initial search for articles in OVID Medline and Embase, an analysis of the text words included in the title and abstract, and of the index terms used to describe these articles, was conducted. A second search using identified key words and subject index terms was then undertaken from database inception to January 2024 across all four databases. As the four databases are hosted on the same interface (OVID), one search strategy was remapped onto all four databases. This search strategy used a combination of subject headings and free text terms addressing the three domains of (1) population (adolescents and young adults living in Sri Lanka), (2) outcome (SRH information and service needs), and (3) seven SRH topics (sexual behaviour, reproductive health, menstrual health, sexuality, pregnancy, STIs, and contraception) which were identified as most relevant to youth SRH promotion, research, and care in Sri Lanka and the broader South Asia region, based on a prior exploratory search of the literature by the research team. The search strategy applied to the four databases can be found in Additional File 1. The reference lists of the articles included in the systematic review were then hand-searched and cross-checked to identify any relevant studies not captured through the database search.

Eligibility criteria

All studies meeting the following eligibility criteria were included in the review: written in English; included a study population of adolescents and young adults (young men and women aged between 10 and 24 years as defined by the WHO [9]) living in Sri Lanka; observational studies reporting on information and service needs and preferences relating to any of the seven SRH topics detailed above; and published from 1968, the year that the Sri Lanka Family Health Bureau, a pivotal government initiative that signified an increased recognition and inclusion of reproductive and sexual health within Sri Lanka’s policy sphere, was founded [25]. Research on people living in Sri Lanka temporarily (e.g. tourists and international students), and studies where the data for participants aged between 10 and 24 years could not be disaggregated from other age groups, were excluded.

Data extraction

Citations retrieved from searches were uploaded into Covidence (www.covidence.org) [26], where duplicates were removed. Each title and abstract was screened for eligibility by two independent reviewers (from a team of three reviewers: MW, CM, SM). Any conflicts during the title and abstract screening were discussed and resolved by the whole research team.

MW and CM then independently extracted the following data: Author, date of publication, type of study, research design, research study setting, participants sex, sample size, participants response rate, sampling method, participant age range, data collection method/tool, SRH topics assessed, socio-demographic data, key findings, significant determinants, author recommendations, and study limitations. Outcomes about SRH information and service needs and preferences were extracted. After extraction, the study team compared findings and resolved any discrepancies in interpretation or extraction through discussion. Finally, extracted data were exported to a spreadsheet for analysis.

Quality assessment

The quality of quantitative, qualitative, and mixed-method articles was assessed using the ‘KMET Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields’ (KMET) [27]. There were 14 criteria for quantitative data (of which four were excluded as they related to clinical trials), and 10 criteria for qualitative data. The lowest score which could be allocated was 0.0 (very poor quality) and the highest was 1.0 (very high quality). MW and CM independently conducted a KMET quality assessment of each included study. Differences were resolved by discussion and consensus among members of the research team. All studies that met the predefined eligibility criteria were included in the systematic review, regardless of their methodological quality rating.

Data analysis

Thematic analysis was used to synthesise qualitative and quantitative findings relating to the SRH information and service needs and preferences of adolescents and young adults in Sri Lanka.

The team conducted a hybrid inductive-and-deductive thematic analysis [28]. Themes identified in the wider literature were listed in a codebook and used as guidelines to deductively code, analyse, and present data extracted from studies in this review [28]. Through the iterative process of coding these findings, themes were also developed inductively and added to the codebook. All quantitative data were synthesised and analysed in a narrative and reported in relation to variables examined. These descriptive interpretations of the quantitative data were integrated with the data extracted from qualitative studies according to the thematic framework [29].

Findings relating to SRH service needs and preferences were thematically analysed according to the ‘Availability, Accessibility, Acceptability and Quality’ (AAAQ) framework [30]. The AAAQ guidelines stipulate that: there should be a sufficient number of high-quality and diverse health services (availability); that all individuals should be able to access health services without discrimination due to physical, social, financial, information, and administrative barriers (accessibility); that health services should adhere to the cultural beliefs and values of the societies within which they function (acceptability); and that health services should provide a consistently high standard of care (quality) [30].

Results

The search yielded a total of 1,133 studies. After applying the exclusion criteria, 16 studies were analysed for this systematic review [Figure 1]. Due to the heterogeneity among studies in terms of SRH topics investigated, data collection tools, analytical methods, and key findings, meta-analysis was not possible. These studies comprise data collected from 19,563 participants aged 10 to 24 years – 19,531 participants from 15 studies that collected quantitative data, and 32 participants from 3 studies that included qualitative data. Eight of the 16 studies focused on assessment of information and service needs as the primary objective [34, 35, 37, 41–44, 46]. See Tables 1, 2 and 3 for a summary of the characteristics and key findings from each study. Supplementary Files 2 and 3 include a detailed overview of study characteristics and their quality assessments according to the KMET criteria. Findings from low-quality studies were critically analysed and interpreted through discussions among authors about how methodological weaknesses and potential biases may have influenced the reporting of results.

Fig. 1.

Flow chart showing the process of study selection according to PRISMA guidelines [23]

Table 1.

Characteristics of quantitative studies and main findings

Quantitative Studies
Author (year of publication)	Study objectives	Study design	Participant characteristics & Region of Sri Lanka	Study findings about sexual and reproductive health information sources	Study findings about sexual and reproductive health services	Recommendations to improve sexual and reproductive health information sources and services	Quality score
Wilkes, Schicor, Rea, Silva & Aponso (1988) [31]	Assess the health risks, support systems, and sources of health information for a population of Sri Lankan adolescents.	Cross-sectional survey	Sample size: n = 282 Sex of participants: 166 females and 116 males Age range: 14-23 years Region of Sri Lanka: Urban and Rural	1) More than half of participants wanted more information about birth control. 2) Friends and teachers were most frequently used information sources. 3) Parents and books/films were least used information sources.	N/A	N/A	0.55
Illangasekera & Nugegoda (1996) [32]	Examine the knowledge and perceptions about AIDS among adolescent school girls.	Cross-sectional survey	Sample size: n = 361 Gender of participants: 361 girls and 0 boys Age range: 15-20 years Region of Sri Lanka: Urban and Rural	1) Mass media was most important source of information about AIDS. 2) Parents were poor sources of information about AIDS. 3) Half of participants received information about AIDS from teachers and school curriculum.	N/A	1) Mass media utilised in future for AIDS education. 2) School based AIDS education should be expanded to teach more about prevention.	0.55
Perera & Reece (2006) [33]	Examine the sexual behaviours and condom use patterns of young adults in Sri Lanka to determine factors associated with sexual activity and sexual risk taking.	Cross-sectional survey	Sample size: n = 3,134 Sex of participants: 1760 females and 1374 males Age range: 18-20 years Region of Sri Lanka: Urban and Rural	1) Most participants learned about sexual health during secondary level science or zoology classes. 2) Males were more likely to attend out-of-school government and non-government sexual health education programs compared to females. 3) Most females picked their mothers, and most males picked their peers, as first person they go to for sexual health information.	1) Females found it more difficult to access condoms compared to males.	1) Youth preferences to get SRH information from non-professional sources is a structural problem which must be addressed when developing school education programs. 2) Increased youth involvement in planning, implementation, and evaluation of SRH education programs to ensure they are responsive to changing cultural and social norms.	0.75
Fernando, Perera, Fernando, Gunawardana & Østbye (2009) [34]	Investigate the prevalence of sexual experiences among school age adolescents and assess demographic and behavioural correlates of sexual experience.	Cross-sectional survey	Sample size: n = 2385 Sex of participants: 1281 females and 1104 males Age range: Around 18 years Region of Sri Lanka: Urban and Rural	1) Around half of participants sought advice about sexual health problems from their peers. 2) Peers and doctors were the first choice for sexual health advice for males. 3) Mothers were the first choice for sexual health advice for more than half of female participants.	1) Half of participants knew counselling services were provided at their school. Less than a fifth reported ever using such services.	1) Empower teachers and parents with knowledge to provide sexual health advice and care for young people. 2) Periodic evaluation and updating of SRH educational interventions.	0.80
Chandraratne & Gunawardena (2011) [35]	To determine the prevalence of pre-menstrual syndromes, factors associated with it, and its influence on daily life in adolescents.	Cross-sectional survey	Sample size: n = 598 Gender of participants: 598 girls and 0 boys Age range: 13-16 years Region of Sri Lanka: Urban	1) Most participants discussed any pre-menstrual symptoms with their mothers followed by friends. 2) A quarter of participants used print materials (e.g. textbooks and magazines) to gain information about pre-menstrual symptoms. 3) Very few participants went to teachers to get information.	1) Less than a tenth of participants who experienced pre-menstrual symptoms had received necessary treatment. 2) Most girls used homemade remedies as opposed to prescription medicine.	1) Improve role of healthcare providers to discuss adolescent reproductive health problems and provide effective interventions. 2) Utilise mothers to disseminate information about menstrual problems and treatments. 3) Train teachers to address sensitive SRH topics to gain confidence of adolescents. 4) Expand SRH school curriculum to teach young people about menstrual health related problems.	0.80
Wijesiri & Suresh (2013) [36]	Assessing the knowledge of and attitudes towards dysmenorrhea in adolescent girls	Cross-sectional survey	Sample size: n = 200 gender of participants: 200 girls and 0 boys Age range: 17-18 years Region of Sri Lanka: Urban	1) Most girls received information about menstrual pain management from their mothers. Some turned to their friends or sisters for information. 2) Very few girls got information about menstrual pain management from healthcare providers, mass media, teachers, and their fathers.	1) Home remedies (e.g. yoga) and over-the-counter pain relief medication were used by more than half of participants to deal with menstrual pain. 2) Reasons why participants did not go to healthcare providers: they believed menstrual pain was natural, they thought the pain would disappear after marriage, and they were embarrassed.	1) Expansion of school SRH curriculum to include following menstrual health topics: abnormal symptoms of menstruation, the normal menstrual cycle, dysmenorrhea, and available menstrual health services. 2) Educating mothers about adolescent reproductive health problems.	0.65
Fernando, Gunawardena & Weerasinghe (2014) [37]	Describe personal and family attributes of pregnant teenagers in Sri Lanka.	Cross-sectional survey	Sample size: n = 510 Sex of participants: 510 females and 0 males Age range: 13-19 years Region of Sri Lanka: Urban and Rural	1) Around quarter of participants felt they had freedom to discuss puberty and their sexuality with their family. 2) Less than a fifth of participants felt they could discuss their love life with their family.	N/A	1) Programs to strengthen parenting skills are necessary to prevent teenage pregnancies. 2) Public Health Midwifes should provide services/information to prevent unplanned pregnancies among married/co-habiting teenagers.	0.70
Rajapaksa-Hewageegana, Salway, Piercy, Samarage (2014) [38]	Increase understanding of the context within which teenage pregnancy occurs in Sri Lanka	Cross-sectional survey	Sample size: n = 600 (of which this systematic review will analyse the findings relating to the 450 pregnant female teenagers as the ages of the 150 males cannot be disaggregated) Sex of participants: 450 females and 150 males Age range: Females: 14-19 years Males: 18-37 years Region of Sri Lanka: Rural	1) Most female participants went to their mother or friends for information about puberty. Few sought information from schools/teachers. 2) Less than a fifth of female participants discussed their sexual relationships and how girls became pregnant with their friends.	1) Pregnant teenager’s husband/partner was most common source of support, followed by their mother, and finally their father.	1) Ensure pregnant teenagers have contraceptive information and accessible services to delay second pregnancy. 2) Public Health Midwifes should educate pregnant teenagers and their families about pregnancy prevention and contraception.	0.80
Rajapaksa-Hewageegana, Piercy, Salway & Samarage (2015) [39]	Examining the SRH knowledge, attitudes and behaviours of school going adolescents in Sri Lanka.	Cross-sectional survey	Sample size: n = 2020 Sex of participants: 1499 females and 521 males Age range: 16-19 years Region of Sri Lanka: Urban and Rural	1) Participants discussed sexual concerns with parents, friends, and siblings. 2) Participants preferred it if they could get SRH information from healthcare providers. 3) Almost half of females discussed sexual health concerns with their mothers. 4) Friends and sibling were most common SRH information sources for males. 5) Over one third of the males and almost one fifth of the females had no-one to discuss sexual health with. 6) Very few participants would go to their teacher for SRH information.	N/A	1) The school SRH curriculum must be updated and reformed through the collaboration of key stakeholders including policy makers, parents, and adolescents.	0.60
Kandauda, Bandara, Tennakoon & Gunathilake (2020) [40]	To describe the impact of menstruation on day-to-day activities from the perspective of school girls.	Cross-sectional survey	Sample size: n = 1064 Gender of participants: 1064 girls and 0 boys Age range: 14-16 years Region of Sri Lanka: Urban	1) Around 10% of participants received education about menstrual health. 2) All participants had discussed some menstrual health problems with at least one other person. 3) Most participants went to their friends, followed by their parents, for information about their menstrual health. 4) Few participants went to a school counsellor or healthcare provider for information.	1) Almost all participants brought over-the-counter pain relief without proper consultation with a healthcare provider to alleviate menstruation pain/symptoms.	1) The SRH school curriculum should be expanded to provide information and raise awareness about the physiological impact of menstruation to prepare young girls.	0.55
Batagalla & Manathunge (2020) [41]	To assess the risk behaviours and vulnerabilities towards sexually transmitted infections and HIV among youth attending ‘Youth Corps Centres’ in the Western Province.	Cross-sectional survey	Sample size: n = 404 Sex of participants: 182 females and 222 males Age range: Mean age was 17.9 years, and all participants were under the age of 20 years. Region of Sri Lanka: Urban and Rural	1) Majority of participants believed SRH information was important. 2) The internet, followed by healthcare workers, teachers, and then electronic media were most commonly used information sources. 3) Participants deemed information lectures as most effective and preferred way to receive information. This was followed by digital media, social media, and lastly parents.	1) More than a third of participants did not know where to buy condoms. 2) SRH services were under-utilised by participants due to the following reasons: lack of knowledge about available services, fear of stigma, embarrassment, and inconvenient opening hours of service centres.	1) Ensure that youth are informed about reliable, accurate, and updated SRH information websites 2) Utilise social media to promote sexual health services among young people. 3) Engage youth in developing methods to promote SRH services. 4) Promote services by assuring youth that there is no stigma at SRH service centres.	0.60
Agampodi et al. (2021) [42]	Describe the hidden burden associated with biological and psychosocial factors and utilisation patterns of pre-conceptual services among pregnant adolescents in rural Sri Lanka.	Prospective cohort study	Sample size: n = 254 Sex of participants: 254 females and 0 males Age range: 15-19 years Region of Sri Lanka: Rural	N/A	1) Despite being freely available, contraceptive use, pre-and-post-conceptional folic acid use, and attendance to pre-conceptional educational sessions were low among adolescent females compared to older females in the study.	1) Targeted SRH campaigns for school dropouts in rural areas should be considered. 2) Assessments relating to awareness, availability, accessibility, and acceptability are vital to understanding the underlying root causes as to why freely available family planning services are under-utilised.	0.70
Mataraarachchi, Pathirana, Buddhika & Vithana (2023) [43]	To assess SRH topics discussed between mother and daughters, barriers to communication, and association of SRH communication among Sinhala adolescent girls.	Cross-sectional survey	Sample size: n= 810 Gender of participants: 810 girls and 0 boys Age range: 14-19 years Region of Sri Lanka: Urban and rural	1) Around half of the girls viewed their mothers as useful sources of information 2) Over 80% of girls believed that talking to their mothers about their SRH topics will protect them from sexual harm in the future. 3) More than 70% of girls were satisfied with their mothers’ answers to their SRH questions. Particularly girls over 15 years of age, and those from high-income families 4) Girls mostly discussed abstinence (keeping body limits), menstrual health, protection from sexual violence, and relationships/marriage with their mothers. The least discussed topics were sexuality, sexually transmissible infections, pregnancy, and contraception. 5) Major barriers experienced by girls when seeking SRH information from their mothers was fear of judgement and cultural stigma surrounding SRH topics.	N/A	1) Implementation of parent-oriented interventions and awareness campaigns to improve the knowledge, reshape negative attitudes, and enhance communication skills of mothers when discussing SRH topics with their daughters.	0.90

Table 2.

Characteristics of qualitative studies and main findings

Qualitative Studies
Author (year of publication)	Study objectives	Study design and analysis techniques	Participant characteristics & Region of Sri Lanka	Study findings about sexual and reproductive health information sources	Study findings about sexual and reproductive health services	Recommendations to improve sexual and reproductive health information sources and services	Quality score
Agampodi, Agampodi & UKD (2008) [44]	Explore the perceived reproductive health problems, health seeking behaviours, knowledge about available services, and barriers to accessing such services among adolescents in Sri Lanka.	Focus-group discussions	Sample size: n = 32 Sex of participants: 19 females and 13 males Age range: 17-19 years Region of Sri Lanka: Urban	1) Majority of participants identified friends/peers as first choice for advice/information. 2) Females went to their mother for advice on minor problems. 3) Most participants did not trust their teachers as information sources. 4) Participants believed vital information was deliberately made unavailable to them by their parents and teachers.	1) Knowledge on available services was very poor among adolescents. 2) None of the males knew that they could access required services from Public Health Midwifes or Ministry of Health clinics. 3) Lack of available services, lack of self-confidence and shyness, and negative attitudes among members of society were barriers inhibiting access to services.	1) Expand existing maternal and child healthcare centred public health services to include youth friendly clinics where health personnel are trained to provide care tailored to needs of young people. 2) School teachers should be trained to conduct lessons on sensitive SRH topics to gain adolescent confidence.	0.65

Table 3.

Characteristics of mixed method studies and main findings

Mixed Method Studies
Author (year of publication)	Study objectives	Study design and analysis techniques	Participant characteristics & Region of Sri Lanka	Study findings about sexual and reproductive health information sources	Study findings about sexual and reproductive health services	Recommendations to improve sexual and reproductive health information sources and services	Quality score
De Silva, Karunathilake & Perera (2009) [45]	Understand the level of sexual awareness, the pattern of behaviour, and the causes behind the vulnerability experienced by adolescents and youths in the changing socio-economic and cultural environment in Sri Lanka.	Quantitative: Cross-sectional survey Qualitative: Focus-group discussions	Sample size: Quantitative: n= 4004 Qualitative: Does not state number of participants Sex of participants: 1362 females and 1258 males Age range: 10-24 years Region of Sri Lanka: Urban and Rural	1) Although they had learned about reproductive health at school, 15-to 17-year-olds did not have a sound understanding of sexuality. 2) Students who were unmarried or lived in urban and rural areas of Sri Lanka received better-quality reproductive health education through the formal schooling system compared to young people who lived in estate sectors and were married. 3) More than half of married and unmarried males aged between 18-24 years got information about sexual health from their peers.	N/A	1) SRH education programs should be provided to out-of-school adolescents.	Quant Score: 0.55 Qual Score: 0.45
Fernando, Gunawardena, Senarath, Weerasinghe, Senevirathne, Senanayake, Galwaduge, De Silva & Lokubalasooriya (2013) [46]	Compare personal and family characteristics of pregnant teenagers in three districts of Sri Lanka and identify patterns in their field health service utilisation.	Quantitative: Cross-sectional survey Qualitative: in-depth interviews (one-on-one and focus-group discussions)	Sample size: Quantitative: n= 589 Qualitative: Does not state number of participants Gender of participants: 589 girls and 0 boys Age range: 14-20 years Region of Sri Lanka: Urban and Rural	1) In both urban and rural Sri Lanka, Public Health Midwives were the first healthcare providers contacted to discuss pregnancy related concerns.	1) There were no apparent social barriers for participants to attend antenatal care in rural or urban Sri Lanka.	1) A district-based approach should be taken improve services provided within the public health system to prevent teenage pregnancies.	Quant Score: 0.65 Qual Score: 0.50

Recruitment method and participant characteristics

Eight studies were school-based and collected data from high-school students (grades 9–13) [31–36, 39, 40]. Four studies were population-based and recruited participants from local youth and sports clubs [44] or used data from public maternity service registries [38, 46] and administrative records [45]. Additionally, four community-based studies recruited participants from youth corps centres [41] and Public Health Midwives (PHMs) registries [37, 42, 43]. PHMs provide maternity and child healthcare within an allocated geographic area encompassing around 3,000 to 5,000 people, using a regularly updated register detailing the contact information of all young women of reproductive age and families with children younger than five years [47]. Additional information on the characteristics of the studies included in this systematic review is provided in Table 4.

Table 4.

Pooled study findings. (total studies n = 16)

Study Characteristics	Number of Studies n (% of total studies)	Study Citations
Sexual and Reproductive Health Topic
Sexual Health	9 (56.3)	[31][32][33][34][39][41][43][45][46]
Sexually Transmissible Infections	6 (37.5)	[31][32][33][39][41][43]
Contraceptives	6 (37.5)	[31][33][38][39][41][43]
Menstrual Health	5 (31.3)	[35][36][40][42[43]
Pregnancy	5 (31.3)	[37][38][42][43][46]
Reproductive Health	4 (25.0)	[39][43][44][45]
Study Design
Cross Sectional Survey	14 (87.5)	[31][32][33][34][35][36][37][38][39][40] [41][43][45][46]
Prospective Cohort Study	1 (6.3)	[42]
Focus Group Discussions	2 (12.5)	[44][45]
In-Depth Interviews	1 (6.3)	[46]
Publication Year
1968–1999	2 (12.5)	[31][32]
2000–2009	4 (25.0)	[33][34][44][45]
2010–2019	6 (37.5)	[35][36][37][38][39][46]
2020–2023	4 (25.0)	[40][41][42][43]
Data Collection Tool Language
Sinhalese	10 (62.5)	[31][33][34][36][38][39][42][43][44][46]
Tamil	3 (18.8)	[38][39][42]
English	1 (6.3)	[39]
Location of Study
Central Sri Lanka	10 (62.5)	[31][35][36][37][38][39][40][42][46]
East Sri Lanka	2 (12.5)	[37][46]
West Sri Lanka	3 (18.8)	[41][43][44]
South Sri Lanka	1 (6.3)	[34]
North Sri Lanka	0 (0.0)
Island Wide	2 (12.5)	[33][45]
Participant Recruitment Strategy
Cluster Sampling	5 (31.3)	[33][34][35][43][45]
Simple Random Sampling	3 (18.8)	[39][40][41]
Convenience Sampling	2 (12.5)	[36][44]
Purposive Sampling	2 (12.5)	[37][46]
Stratified Sampling	1 (6.3)	[38]
No Sampling Method Mentioned	3 (18.8)	[31][32][42]

The SRH information and service needs and preferences for both young women and men were reported in eight studies [31, 33, 34, 38, 39, 41, 44, 45], while the other eight studies included only young women [32, 35–37, 40, 42, 43, 46]. Eleven studies focused on unmarried participants [31–36, 39–41, 43, 44], while five studies included both married and unmarried participants [37, 38, 42, 45, 46]. Of the 12 studies reporting the ethnicity of participants, 11 had a Sinhalese majority [31, 32, 34–36, 38, 39, 41–43, 46], and one study had a distribution between multiple ethnicities (52.9% Sinhalese, 30% Tamil, and 17% Muslim) [37].

Quality assessment of studies

The quality of the 16 studies were diverse with KMET scores ranging between 0.45 and 0.90 for quantitative studies and 0.45 to 0.65 for qualitative studies (Additional files 2 and 3).

Information and service needs and preferences of adolescents and young adults in Sri Lanka

Information sources

The most commonly reported sources of information relating to topics of menstrual health, sexual health, pregnancy, and reproductive health were parents, peers, schools, and mass/digital/educational media resources. There were no data on the sources used by young people to get information on contraception and STIs.

Parents

Mothers were the most common information source for young women when it came to their sexual health [33–35, 39] and reproductive health [44]. In comparison, very few young men turned to either of their parents for SRH information [33, 34, 39]. Due to cultural taboos relating to pregnancy and sex among young people (such as negative attitudes towards pre-marital sex [44]), even young women found it difficult to discuss some SRH topics with their mothers [37, 44]. For example, a study conducted in urban and rural Sri Lanka found that pregnant teenagers felt limited freedom to talk about their romantic relationships and their sexuality with their family [37]. In four studies, it was found that young women also chose their mothers as their main source of information for questions relating to puberty, menstruation symptoms, and menstrual pain management [35, 36, 38, 43].

Peers

Peers were found to be the primary source of information on sexual health for young men [31, 33, 39, 44, 45], and were also a commonly used source of information by young women [33–35, 39, 44]. One study conducted in urban and rural Sri Lanka found that young people were more likely to discuss culturally taboo topics (e.g. genitalia function) with their peers as opposed to teachers, parents, or healthcare providers, who are deemed to be authority figures [45]. That being said, one study reported that young men were more likely to discuss only minor sexual health problems as opposed to major and more personal sexual health concerns with their peers, as they were afraid of being marginalised or bullied [44]. This reservation when discussing personal matters was also seen among pregnant teenagers; few participants in a study of this population conducted in rural Sri Lanka said they talked about sexual relationships and pregnancy with their friends [38].

Schools/teachers

In five out of 16 studies, students reported that they did not trust their teachers as SRH information sources [34–36, 40, 44]. For example, it was found in four studies that many young women did not go to their teacher for information on menstrual health problems [35, 36, 40, 44]. This was because some girls were afraid that if they told teachers about their menstruation symptoms, the school principal and senior teachers would find out, and they would be discriminated against at school [44]. Furthermore, while some students knew about SRH counselling services available at their school, very few had ever used such services due to the lack of encouragement and support from their school [34].

While most students did not go to their teachers to get SRH advice, four studies found that many young people still relied on the general reproductive health lessons they received as part of the school curriculum as an important source of information [32, 33, 42, 45]. In two studies, students described learning about reproductive health during senior level science or zoology classes [32, 33].

Young people who had dropped out of high-school early (generally due to pregnancy or marriage), who lived in the rural estate sectors of Sri Lanka, and who had not yet started their senior high-school education (younger than grade 11), had received none to very little reproductive health education through the formal education system. Therefore, these students had a significantly lower level of knowledge about this topic compared to students who had a higher level and better quality high-school education [42, 45]. This reflects that reproductive health classes were provided to senior high-school students through specialist classes. Some studies also identified gaps in the school-based reproductive health curriculum and its implementation [40, 44]. For example, students stated that important SRH information was deliberately withheld from them by their teachers, and that they should have received necessary education about puberty from their schools at a younger age [44]. Furthermore, it was reported that only a few young women had received any form of awareness-raising training from their schools about menstrual health problems/disorders [40].

Mass, digital, and educational media

Three of the 16 studies explored how SRH information was acquired by young people through mass media, digital media, and educational media sources [32, 35, 41]. Over time, the media sources used by young people to get SRH information has changed. A 1996 study reported that young people used mass media sources such as newspapers, televisions, magazines, and radio to get general information on Acquired Immunodeficiency Syndrome (AIDS) [32]. However, two more recent studies (2011 and 2020) found that digital and educational media sources, such as textbooks, journals, lectures, and the internet, were commonly used by young people to source the SRH information they required [35, 41].

Assessments of availability, accessibility, acceptability, and quality of sexual and reproductive health services for young people

Overall, ten of the 16 studies had collected data on the availability, accessibility, acceptability, and quality of SRH services for young people in Sri Lanka [33–36, 38, 40–42, 44, 46]. These findings are described below.

Availability

The availability of SRH services was investigated in one qualitative study in urban and rural Sri Lanka [44]. This study found that young men felt excluded by healthcare providers as there were many initiatives to promote the SRH of young women; in contrast, young men did not have specialised services or trained/knowledgeable healthcare providers with whom they could discuss their SRH concerns [44].

Acceptability

None of the 16 studies in this review examined the acceptability of SRH services.

Accessibility

Three studies reported on the barriers that young people faced when accessing SRH services [41, 42, 44]. One major barrier was that young people were unaware of ‘youth friendly clinics’ in government hospitals, which provided free services such as pre-conception education and contraception advice [41, 42, 44]. Furthermore, the accessibility of SRH services was hindered by factors such as shyness or lack of self-confidence, fear of stigma, inconvenient opening times, the costs associated with using services, lack of single-sex services (e.g. male only clinics), and the lack of privacy at youth clinics that were usually held at congested and busy locations where child and maternity clinics were operating [41, 44].

Two studies found that young women did not use formal medical services to manage menstruation symptoms because they were embarrassed to discuss menstruation with healthcare providers, as it was considered a highly personal and secretive topic [35, 36]. Therefore, even if their symptoms were severe, most young women would use alternate therapies and Ayurvedic or homemade remedies such as hot fermentation, yoga, coriander water, and Siddhalepa (Ayurveda herbal balm) [35, 36]. Some participants also used pain relief such as paracetamol, which could be brought over the counter without consulting with a healthcare provider [35, 36, 40].

Quality

Five of 16 studies reported on the quality of SRH services available for young people [34–36, 39, 44]. The quality of these services was perceived to be low by young people, as healthcare providers were not providing the necessary information and treatments [35, 46]. For example, a study in urban and rural Sri Lanka found that most teenagers who had visited public healthcare services had not received the information they wanted on sexual relationships, contraception methods, or the adverse effects of teenage pregnancy [46]. Furthermore, very few young women reported being asked about concerns regarding their menstrual cycle when they were undergoing examinations and receiving treatment for an illness [35].

Recommendations to improve sexual and reproductive health information sources and services for young people

Across the 16 studies, 15 included recommendations on how SRH information sources and services could be improved to better meet young people’s needs and align with their preferences.

Education and Raising awareness amongst parents

In five of the 16 studies, recommendations described how future SRH policy interventions should focus on improving the skills of mothers so that they can become a reliable and trustworthy information source for their daughters [33–36, 43]. Four studies emphasised the importance of community-based training programs to equip parents, particularly mothers, with knowledge on different SRH problems experienced by young people [33, 34, 36, 43]. For example, one study recommended ‘parent-oriented interventions’ with skill-building sessions and awareness-raising campaigns; these could reshape the attitudes and enhance the knowledge and communication skills of mothers, so they can engage in meaningful and sensitive SRH conversations with their daughters [43]. Furthermore, it was recommended that healthcare providers in urban and rural Sri Lanka should utilise mothers to disseminate information to young women about menstrual health problems and appropriate treatments [35].

Upskilling teachers and updating the sexual and reproductive health curriculum

Another policy recommendation was to train teachers on diverse SRH areas impacting young people. Four studies emphasised the importance of training teachers to address sensitive SRH topics to gain the confidence of adolescents [34, 35, 39, 44]. For example, a study in urban Sri Lanka outlined the importance of a collaborative partnership between healthcare providers and teachers, where knowledge on SRH concepts and teaching methods could be provided to teachers through formal and ongoing interprofessional training programs [39].

Two studies also suggested that updating SRH school curricula may be important as the high levels of educational coverage across Sri Lanka provides an ideal infrastructure through which SRH information could be disseminated systematically to all young people [35, 39]. Five of the 16 studies included recommendations to expand existing reproductive health curricula taught at schools to a wider range of SRH topics to effectively provide the necessary information to all adolescents as a preventative care initiative [34, 36, 39, 40, 45]. Examples of topics that could be added to the SRH school curriculum included contraception [39], the physical and psychological effects of menstruation [36, 40], dysmenorrhea [36], predictors (cultural and environmental) and adverse effects of risky sexual behaviours [34, 45], and the avenues through which adolescents can get accurate sexual health advice [34].

Along with improving the SRH curriculum, three studies conducted in both urban and rural Sri Lanka highlighted the importance of increasing the educational attainment of young people; this would ensure they can access accurate and reliable SRH information taught during the senior years of high school [32, 42, 46]. That being said, a study on rural Sri Lanka argued that age-appropriate SRH courses should also be taught to younger year levels [38]. Furthermore, two studies recommended educational programs for out-of-school adolescents [42, 45].

Expanding and developing youth friendly sexual and reproductive health services

Four of the 16 studies included recommendations on how to improve the availability of SRH services for young people [39, 42, 44, 46]. These studies detailed how existing community health, maternity care, and family planning infrastructures and frameworks such as Public Health Inspectors, Public Health Midwives, and the previously successful ‘Safe Motherhood Initiative’ should be expanded to integrate SRH services and develop facilities specifically designed for young people [39, 42, 44, 46]. In a study on urban and rural Sri Lanka, it was argued that such an initiative would require a systematic and sustained partnership between different government sectors (health, education, and social welfare) [39]. Three studies detailed how services targeting young people should focus on geographical and ethnic disparities [42], couples who are living together but are not married [42], the strengthening of mechanisms for the early identification of SRH health problems [42], the SRH information and service needs of adolescent boys and young men [44], and the needs of sexually active youth (e.g. provision of information to enable informed decision making and increased access to contraceptives) [39]. Two studies deemed it important that young people, policy makers, teachers, and parents are involved in the planning, implementation, and rigorous evaluation of SRH services and information sources to ensure that they are responsive to the changing needs of young populations in Sri Lanka [33, 39].

Promoting sexual and reproductive health information sources and services available for young people

Four studies in urban and rural Sri Lanka included recommendations on how mass/social media should be used in an innovative manner to spread awareness about available SRH information sources and services to young people [31, 32, 41, 42]. However, one study warned that extra precaution should be taken to ensure that young people are directed to reliable online sources and that information provided on the internet should be accurate and up to date [41].

Discussion

This systematic review found that young people in Sri Lanka preferred informal SRH information sources, such as peers (for young men) or mothers (for young women), over formal sources such as schools/teachers and trained healthcare providers. This likely reflects the diverse barriers to formal SRH information and services documented in this review, including the fear of judgement, the common practice of withholding SRH information from young people, and a shortage of accessible and inclusive youth friendly SRH clinics.

Sexual and reproductive health information sources

When it comes to information about sexual health, however, young women were at times reluctant to go to their mothers for information as they feared that they would be misunderstood [37, 44]. This aligns with previous research in low-and-middle-income countries that found communications about SRH between mothers and their daughters are mostly limited to reproductive development (e.g. menarche), as young women are actively encouraged to practise chastity and abstain from pre-marital sex [48–51]. Parents may perceive sexual health to be an inappropriate or embarrassing topic to discuss with their children [48–51].

The fear of being bullied or ostracised also discouraged some young people from discussing personal SRH experiences with their peers [38, 44], similar to findings of research conducted with young people in Sub-Saharan Africa and the Pacific Islands [52–54]. These studies found that young people are uncomfortable discussing STIs, pregnancy, sexual experiences, and contraception use with peers due to fear of teasing and judgement related to gossip and rumours [52–54]. According to Byron (2016), the level of intimacy in conversations among peers about sexual health topics depends on the levels of established trust and care between the individuals [55]. As none of the studies in this review included an analysis on the nature of the relationships between peers/friends, it is not possible to ascertain whether the likelihood of discussing SRH experiences varied depending on the different relationship dynamics [56].

School teachers were perceived to be an untrustworthy source of advice and information when delivering SRH lessons and answering students’ questions or concerns [34–36, 40, 44]. Previous research on school teachers in Sri Lanka, as well as other low-to-middle-income countries [57, 58], has found that teachers may feel uncomfortable and ill-equipped to run SRH classes as they lack adequate training on the concepts, examples, and terminology they can use when explaining these topics to young people [59]. Further, external influences such as religious and cultural norms and values may also inhibit the open discussion of SRH topics between teachers and students in the classroom [48, 57, 58, 60, 61]. For example, other studies found that teachers may have reservations about educating students on topics such as contraceptive use as they believe that this information might encourage and promote sexual activity among youth [60–62]. Additionally, school-based administrative factors such as the lack of training for teachers about SRH topics, along with the lower priority and limited funds allocated to SRH education compared to other academic subjects, may also limit the scope and effectiveness of SRH classes provided at schools [59, 62, 63].

When comparing the findings of a study published in 1996 [32] to the findings of studies published in 2011 [35] and 2020 [41], we found that the way young people acquire information about SRH topics has changed from passively receiving general information from mass media sources, to actively searching through written, audio, and visual educational and digital media resources to find the information they need [32, 35, 41]. These findings are consistent with previous research that found young people prefer to use anonymous sources that provide information in different formats (text and illustrations), such as websites (which can be accessed anonymously), and printed media such as books and magazines [64, 65].

Sexual and reproductive health services

This review identifies a range of barriers that inhibit young people in Sri Lanka from accessing available formal SRH services. For example, there are no clinics that primarily focus on and specialise in the needs of unmarried young men [44]. This finding aligns with a study in India that also found that young unmarried men are rarely the targeted demographic of SRH services and initiatives [66].

Furthermore, we found that some young people perceived healthcare workers to be untrustworthy information sources as they withheld SRH advice [35, 46]. These results are corroborated by existing literature on how cultural norms and community beliefs inform social barriers such as embarrassment and shyness, which inhibit open discussion between healthcare workers and young people [67, 68]. For example, Dawson et al. (2012) had found that healthcare workers in urban Sri Lanka felt uncomfortable and reluctant providing information about modern contraceptives, instead opting to promote abstinence to young people [62].

Policy, program, and clinical practice implications

The findings of this review suggest that the SRH information sources and services available for young people in Sri Lanka could be improved through interwoven initiatives targeting one or more of the following categories: training, expansion, and promotion. Efforts to improve the quality and accessibility of SRH information and services could extend beyond formal care avenues to also include informal and digital/online resources that young people prefer.

Training

Previous studies have shown that awareness-raising efforts aimed at community members and care providers can effectively combat misinformation and stereotypes surrounding youth SRH needs in LMICs [59, 62, 63]. This notion is supported by studies in this review, which recommend providing education and training programs for parents and teachers [33–36, 39, 44]. According to the United Nations Educational, Scientific and Cultural Organization’s (UNESCO) ‘International Technical Guidance on Sexuality Education’ (2018), ongoing professional development opportunities may help teachers in Sri Lankan schools enhance their theoretical knowledge, thereby building confidence and capability in delivering engaging SRH classes [69]. Furthermore, such training may also support teachers in separating their personal beliefs from their students’ health needs, encouraging a more open and comprehensive approach to teaching sexuality lessons [69]. On the other hand, SRH education for parents may be delivered through workshops led by grassroot NGOS, religious organisations, or community-oriented groups. During these sessions, parents could be provided with the opportunity to engage in open discussions to dismantle any myths and misconceptions relating to SRH topics [70, 71].

Expansion

Interventions relating to SRH care provision could be co-designed in a manner that centres the voices of the very population they aim to serve, Sri Lanka’s youth. This was echoed across the studies in this review [39, 42, 44, 46]. According to the United Nations Population Fund (UNFPA), NGOs in Sri Lanka could uplift diverse youth groups with the technical and financial support needed to come together and advocate for their SRH rights at the community and national level [72]. Meaningful inclusion of young people in the design and delivery of formal SRH services may require close collaboration between NGOs, government organisations, and youth themselves. This partnership could prioritise young people’s perspectives and lived experiences in identifying their needs, co-developing solutions to fill resource gaps, and offering continuous feedback as health services are designed and implemented [73, 74].

Promotion

Finally, to increase awareness of available SRH information sources and services, youth-friendly SRH information sources and services could be promoted across online platforms (e.g. social media), so that young people know what is readily at their disposal [31, 32, 41, 42]. Young people generally have a high level of technology competency and frequently use the internet to search for health-related information, particularly when it comes to sensitive topics such as their sexual health [75]. Therefore, it is essential that young people have access to reliable and well-credentialed online resources. By having an increased online presence, formal healthcare services may be able to reach more young people and provide them with trustworthy SRH information and guidance [75].

Together, the education of parents and teachers, centralisation of young people’s voices in the development of accessible and high-quality services and information sources, and extensive promotion of available SRH resources, could form a foundation for comprehensive and effective SRH initiatives that meet the evolving needs of young people in Sri Lanka.

Strengths and limitations of systematic review

A thorough search was conducted across five databases for qualitative, quantitative, and mixed method studies. This review includes research from urban and rural communities across Sri Lanka. Moreover, to ensure replicability and to avoid bias, the data extraction and quality assessment process was independently conducted by two researchers using the KMET guidelines [28]. This review also has some limitations. As the database search was conducted in English, studies in Sinhalese or other local languages are not included. Additionally, studies not indexed by the databases might have been missed, as a grey literature search was not conducted. Another limitation of this study was the research team’s inability to access 15 studies to assess eligibility, as they were not digitised or because attempts to contact the authors for access were unsuccessful. Two of the qualitative studies included in this review were assessed as ‘low quality’ based on the KMET criteria [27]. Despite their methodological limitations, these studies were included in this systematic review as they met the predefined eligibility criteria and provided valuable insights into the SRH information and service needs of young people in Sri Lanka. To mitigate any reporting bias, the findings from these studies were critically analysed taking their methodological limitations into consideration, and results were interpreted with caution. Additionally, we ensured that the findings from these studies aligned with the results from high-quality studies included in this review. Due to the absence of research on sexual orientation and gender diverse groups of people in Sri Lanka, this review does not report on the SRH information and service needs of LGBTQ + communities.

Future research

The findings of this review indicate a gap in understanding how SRH information and service needs and preferences vary between different demographic groups. This could be a fruitful avenue for future research to support equitable access. Further, focused research within diverse communities holds potential to better understand the complexity and nuances of the SRH information and service needs and preferences of young people, acknowledging there is no one-size fits all prescription to meet these needs. For example, studies need to be conducted with young people who are completing their higher education/vocational training, gender and sexually diverse people, and youth from different ethnic and religious backgrounds. The findings of this systematic review, alongside data from future research, can inform detailed and targeted policies, initiatives, and programs which ensure SRH for all young people.

Conclusion

This review suggests that in the absence of adequate formal sources of care (education at schools and youth friendly health services), young people are turning to informal sources such as their mothers and peers for SRH information and care. It also identified many barriers inhibiting young people’s access to formal SRH services such as embarrassment to discuss topics such as menstrual health, inconvenient opening hours, lack of awareness about youth SRH clinics, costs of services, limited number of clinics specialising in the needs of young men, and gaps in the SRH information provided by healthcare providers. The findings of this study can be used alongside future research looking into the specific needs of diverse groups of young people to inform education programs, public health policies, and clinical health practices. Such initiatives will be central to improving SRH information sources and services, to ensure that they meet the needs of adolescents and young adults in Sri Lanka and other low-and-middle-income countries.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

SRH

Sexual and reproductive health

LMICs

Low-to-middle income countries

WHO

World Health Organization

STI

Sexually transmissible infections

SDGs

United Nations Sustainable Development Goals (2030)

PRISMA

Preferred Reporting Items for Systematic Reviews and Meta-Analyses

KMET

KMET standard quality assessment criteria for evaluating primary research papers from a variety of fields

AAAQ

Availability, accessibility, acceptability and quality framework

AIDS

Acquired immunodeficiency syndrome

LGBTQ+

Lesbian, gay, bisexual, transgender and queer +

PHMs

Public Health Midwifes

UNESCO

United Nations Educational, Scientific and Cultural Organization

UNFPA

United Nations Population Fund

Author contributions

JF, SM, JS, NRH, and MW contributed to the design of this study. MW and LR designed the database search strategies, and the search was run by MW. Titles and abstracts were searched by MW, CM, and SM. Full text screening, data extraction, and quality assessment was conducted by MW and CM. JF, SM, JS, NRH, MW, CM, LR, and KV contributed to the interpretation of the systematic review findings, the development of the manuscript, and the approval of the final version.

Funding

MW and CM are supported by the Australian Government Research Training Program (RTP) Scholarship. JF is supported by the Finkel Professorial Fellowship which is funded by the Finkel Family Foundation.

Data availability

Data sharing is not applicable to this article as no datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.