Article Text

Original research
A qualitative study exploring experiences of the safetxt digital health intervention to reduce sexually transmitted infections in young people in the UK
  1. Sima Berendes1,
  2. Anasztazia Gubijev1,
  3. Rebecca French2,
  4. Ford Colin Ian Hickson2,
  5. Caroline Free1
  1. 1Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
  2. 2Department of Public Health, Environments & Society, London School of Hygiene and Tropical Medicine, London, UK
  1. Correspondence to Dr Sima Berendes; Sima.Berendes{at}


Objectives People aged 16–24 are more likely than other age groups to acquire sexually transmitted infections (STI). Safetxt was a randomised controlled trial of a theory-based digital health intervention to reduce STIs among 16–24 year-old people in the UK. We report results of qualitative research regarding participants’ perceptions and experiences of the intervention and trial participation.

Design Qualitative thematic analysis following a critical realist paradigm of written open feedback comments provided in the 12-month follow-up questionnaire and semistructured interviews.

Setting Safetxt trial participants were recruited from UK sexual health clinics.

Participants Trial inclusion criteria: people aged 16–24 diagnosed with or treated for chlamydia, gonorrhoea or non-specific urethritis. Optional open feedback provided by 3526 of 6248 safetxt participants at 12 months and interviews with a purposive sample of 18 participants after the trial.

Results We summarise and report results in seven broad themes. According to recipients, the safetxt intervention increased awareness of the importance of avoiding STIs and ways to prevent them. Participants reported improved confidence, agency, sexual well-being and communication about sexual health with partners, friends and family. Recipients attributed increased condom use, increased STI testing after (rather than before) sex with new partners, and more confident partner notification to the intervention. Recipients described a reduced sense of isolation and stigma in having an STI. Control group participants reported that having had an STI and receiving control texts asking them to report any changes in contact details acted as reminders to use condoms and get tested. We also summarise participant recommendations for future interventions and studies.

Conclusions While control group participants reported precautionary behaviours were ‘triggered’ by trial participation, intervention recipients reported additional benefits of the intervention in increasing precautionary behaviours and in broader aspects of sexual health such as confidence, communication, emotional well-being and agency.

Trial registration ISRCTN registry ISRCTN64390461.

  • public health
  • qualitative research
  • telemedicine
  • sexual health
  • infectious diseases
  • young people

Data availability statement

Data are available on reasonable request. Deidentified data collected as part of the randomised controlled trial will be made available via the data sharing portal FreeBIRD after publication of the primary and secondary analyses as outlined in the Data sharing statement of the trial publication Free et al (2022). Part of the study materials and anonymised extracts of the interview study conducted after trial completion, have been included in online supplemental files of this article. Sharing of further anonymised qualitative data extracts on reasonable request would have to be in line with data protection laws and subject to appropriate ethics committee approval.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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  • Qualitative research has an important role in gaining greater in-depth insight and complementing data of randomised controlled trials, especially if there are unanticipated results, as in the case of the safetxt trial.

  • Two sexual and reproductive health researchers not involved in the design and implementation of the safetxt trial, independently analysed 3526 open feedback comments from trial participants and conducted 18 semistructured interviews.

  • Obtaining results from different sources, including qualitative data from the open feedback comments and interviews reported here, in addition to the quantitative trial data allowed for triangulation of results.

  • Limitations are that many of these optional open feedback comments were only brief, and that we had to end the interview study slightly earlier due to the COVID-19 pandemic.


Sexual and reproductive health is defined by WHO as ‘a state of physical, emotional, mental and social well-being in relation to all aspects of sexuality and reproduction, not merely absence of disease, dysfunction or infirmity'.1 In terms of sexually transmitted infections (STIs), younger people aged 16–24 bear the heaviest burden of chlamydia and gonorrhoea with long-term adverse health effects including ectopic pregnancy and subfertility.2–4 Inequalities in sexual health persist; STIs are positively associated with lower educational levels and living in more deprived areas.2 5–7 High STI rates among young people also reflect broader aspects of poor sexual health, such as lack of knowledge, skills or confidence in how to carry out safer sex behaviours and how to communicate with partners about sex and desired precautions.8

We developed the safetxt intervention delivered by text message to reduce STI infection by increasing condom use, partner notification and STI testing before sex with new partners.9 The intervention development was informed by behaviour change theory,9 including the ‘capability, opportunity and motivation model of behaviour’ (COM).10 This model is incorporated into the comprehensive ‘behaviour change wheel’ model, which aims to capture the full range of intervention functions involved in behaviour change; these include education, persuasion, environmental restructuring (encouraging people to change their environment to support the behaviour), training and enablement. Each intervention function can be implemented by a wide range of evidence-based behaviour change techniques.11 In the case of sexual behaviour, knowledge, skills, beliefs, self-efficacy, and social and interpersonal influences have important effects on COM.8 12 Our intervention aimed to influence these factors to reduce sexual risk behaviour and encourage STI preventive behaviour.

The intervention text messages were developed based on the content of effective face-to-face safer sex interventions targeting condom use,13–15 the factors known to influence safer sex behaviours16 and the views of over 200 people aged 16–24 collected in focus groups, a questionnaire and qualitative interviews.9 The latter included telephone interviews conducted with 16 young people 2–3 weeks after enrolling in a feasibility trial in 2013.17 The findings were used to adapt the intervention.

Intervention text messages were sent with decreasing frequency over the period of 12 months (online supplemental file 1).18 Our randomised controlled trial to establish the effects of the intervention on STI, condom use, partner notification and STI testing before sex with new partners was conducted among 6250 people aged 16–24 diagnosed at UK sexual health clinics with chlamydia, gonorrhoea or non-specific urethritis.19 20 Control group participants received a monthly untailored text message asking for information about changes in postal or email addresses. The safetxt intervention did not reduce STIs, there were slightly more infections in the intervention group with 22.2% (693/3123) versus 20.3% (633/3125) in the control group (OR 1.13, 95% CI 0.98 to 1.31).19 20 There were some increases in self-reported precautionary behaviours such as condom use at last sex, OR 1.14, 95% CI 1.01 to 1.28.19 20 Although our intervention did not target sexual partnerships, we assessed at 1-year follow-up the proportion of people who had two or more partners since joining the trial and found that it was slightly higher in the intervention vs control group (56.9% vs 54.8%, OR 1.11, 95% CI 1.00 to 1.24). This result, however, was not statistically significant (p=0.06) but could have contributed to the unexpected trial outcome. Other quantitative results, including on intermediate outcomes, did not clarify either, why a statistically significant effect was shown for the condom use outcome, but not for the biologic trial outcome.19 20

To shed further light on this, we analysed and triangulated qualitative data from two sources, including open feedback from the last follow-up questionnaires at the end of the trial (at 12 months)20 and semistructured interviews conducted after 12 months. In this paper, we present and discuss qualitative data on participant perceptions of the safetxt intervention and of 12 months trial participation with a view to exploring for whom, how and why the intervention worked or not and what improvements could be made in the future.


We conducted qualitative research (as part of a mixed-methods approach integrated through an advanced intervention framework with embedded methods and narrative staged reporting21) including the analysis of open feedback comments collected in the 12-month questionnaire20 of the safetxt trial and semistructured qualitative interviews with participants after completing their involvement in the trial. The research team members are mixed-methods researchers within the areas of sexual and reproductive health. During the research, we followed a ‘critical realist’ (CR) paradigm,22 23 as in terms of ontology, epistemology and methodology we position ourselves in the middle of a continuum between positivism, naïve realism and objectivism23–25 on the one hand and interpretivism, relativism and constructionism23 24 on the other. According to CR, there is a reality that exists independent of our thoughts about it, and while we can become more confident about what exists by observing, existence itself is not dependent on observation. CR also sees the social world as layered, complex and an open system and characterised by change. CRs often try to answer the question ‘what works for whom, when and why?’ and are typically pragmatic in their approach to methodology and methods.23 26

Below, we provide details on the two data sources used for our qualitative analysis.

Data source 1: free-text comments

The final page of the 12-month questionnaire given to all trial participants (who had provided written informed consent on enrolment) included an open-ended question: ‘Did anything good or bad happen as a result of being involved in the study or receiving the text messages? Please describe’. This question was followed by a blank space that participants had the option of completing themselves.

Two researchers (AG and SB), who had not been involved in the design, implementation and quantitative evaluation of the intervention, independently coded the free-text comments and categorised data by theme, using Excel 2019 and NVivo v.12 respectively. AG and SB initially took a purposive sample of 12% (n=390) of free-text comments. They ensured that participants from different gender and sexuality groups were represented (by adding random samples of comments from each group) and included all comments from participants reporting that someone else had read their messages or reporting partner violence. This was to ensure that the feedback from participants who might have experienced unforeseen intervention side effects was coded in detail. AG and SB then independently coded these comments inductively line-by-line, considering all content (almost all of it was relevant to our research question). They then collated codes into potential themes and compared these to check for consistency of analysis and to reduce the risk of imposing own assumptions and predefined theories onto participants’ narratives. Subsequently, AG and SB independently analysed all remaining free-text comments, thereby adding newly generated themes, reviewing and naming themes. AG and SB then compared their findings again (which were consistent) and discussed them within the team. The findings were compared with data from the semi-structured interviews (data source 2).

Data source 2: semistructured interviews

We purposively recruited from safetxt participants based on trial allocation and sociodemographic characteristics (age, sexuality, ethnicity, index of multiple deprivation) to encompass a variety of experiences. Eligible were participants who indicated during trial follow-up that they agreed to be contacted for further research. We sent text messages about the interview study to those who had recently (<6 months) completed trial follow-up. AG and SB then approached and provided verbal and written information to those who were interested in the study.

After receiving written informed consent, SB and AG conducted interviews by video conferencing (including Teams, Zoom or WhatsApp) or telephone. We initially focused on the recruitment of intervention participants and found that after 14 interviews data saturation for key themes relevant to our research question regarding the intervention had been reached (based on reflective notes, concurrent data analysis, triangulation with results of open feedback analysis and team discussions). After completing four interviews with control group participants, we had to stop study activities due to the COVID-19 pandemic and related personal circumstances and were unable to resume the work at a later stage as funding could not be extended.

Interviews lasted between 30 and 90 min (average about 60 min). The interviewers (AG and SB, both female) introduced themselves as public health researchers who had not been involved in the design of the safetxt trial. Both kept reflective journals throughout the research process and engaged in self-reflexivity not only during interviews, but also during analysis to recognise and avoid imposing own assumptions and predefined theories onto participants’ narratives.

The interviews followed a semistructured topic guide, which aimed to explore participants’ experiences regarding trial participation, whether or not they had been able to carry out the behaviours targeted by the intervention, and (for those from the intervention group) the intervention and how and why the messages did or did not help. We first explored which intervention messages participants recalled without being prompted. We then showed, sent or read to participants some of the messages and asked which, if any, they found particularly helpful or not. We also asked participants to make suggestions for improvements of the interventions. (Topic guides and example intervention messages in online supplemental file 2). New topics not included in the guide were further explored during subsequent interviews. These topics and summaries of reflective field notes were also discussed with RF and/or CF during team meetings.

After completing the interviews, participants were offered a £20 voucher as a thank you for their time.


Interviews were audiorecorded, transcribed verbatim by a professional transcription service (bound to a confidentiality agreement), and reviewed for anonymity and accuracy of transcription by SB and AG, while listening to the audiorecordings. This was also part of the first step of the thematic analysis approach that we used, including (1) familiarising ourselves with the data, (2) generating initial codes, (3) searching for themes, (4) defining and naming themes and (5) producing the report.27 This process was iterative as analyses were conducted alongside data collection. During the early stages, SB and AG first independently developed thematic codes from the same four interview transcripts, two of which were also coded by RF, to ensure consistency of coding. Thereafter, SB and AG independently coded their interview transcripts and categorised data by theme using NVivo v.12 and Microsoft Word 2019, respectively. At the later stages of thematic analysis, Microsoft Word 2019 was used to integrate and triangulate themes developed by both researchers from both data sources, based on comparisons and team discussions. During analysis meetings with the research team, results from open feedback comments (source 1) and interviews (source 2) were triangulated with quantitative trial data (including primary, secondary and intermediate outcomes)19 20 and data from telephone interviews conducted as part of the 2013 feasibility trial 2–3 weeks after starting messages17 looking for consistencies and inconsistencies across the different data sources and searching for deviant cases.

Patient and public involvement

Patients and members of the public were involved in all phases of the safetxt intervention development and trial, including part of the qualitative components of the safetxt evaluation reported here. Prior to development of the safetxt intervention, possible safer sex interventions were discussed with young people in five discussion groups (25 participants). Subsequently, patients who participated in formal focus group discussions, helped to design the content of the intervention,9 and a patient representative was included in the trial steering committee. In addition, 14 patient representatives from the King’s College Hospital Sexual and Reproductive Health user group helped design the patient information, consent and follow-up procedures and all trial questionnaires, including the open feedback question. Due to time restrictions, we did not seek help from patients for the design and pilot-testing of the interview topic guides, but instead gained input from four young colleagues. After the interviews, most participants indicated that they would be happy to help with the dissemination of results once published.


Fifty-six per cent (n=3526/6248, intervention: n=1745, control: n=1781) of participants provided comments in the open feedback section of the 12-month questionnaire, 72% of those who completed a 12-month questionnaire (table 1). Participants across all sociodemographic backgrounds provided open feedback comments, and the characteristics of respondents were similar to the characteristics of safetxt trial participants.19

Table 1

Characteristics of open feedback respondents (N=3526)

About 27% (intervention: 24%, control: 29%) of those who provided open feedback on whether anything good or bad had happened (see the Methods section for exact question) merely stated ‘no’, ‘n/a’, ‘don’t know’, ‘nothing’, ‘neutral’, ‘no difference’ or a brief statement saying either they were unsure or did not notice any change as a result of participating in the study, for example, ‘I carried on as usual, nothing good or bad happened’. A further 3% of comments from control group participants merely stated that they were in the control group or did not receive any intervention messages or similar. The remaining free text comments (intervention: 76%, control: 70%) provided another free text response (beyond the aforementioned statements) that was generally mostly only a few sentences long, with some participants providing longer feedback (8% of intervention and 5% of control group comments were >50 words long).

We completed 18 interviews between February and May 2020. Respondent characteristics are in table 2. Open feedback was overwhelmingly positive both about the intervention text messages and being in the trial. Many intervention and control group participants commented on the usefulness and convenience of having an STI test kit sent to their home for primary outcome assessment. Intervention group participants commented positively on the tone of the intervention text messages finding them friendly, reassuring, helpful and written in a non-judgmental manner. Participants also found that mobile phone delivery was a trusted, appropriate and convenient way to access information. Conversely, a few people in open feedback had concerns about keeping their messages private or reported that messages were annoying and many in both, the intervention and control arm, indicated that there was no change and nothing good or bad had happened as a result of being in the study.

Table 2

Characteristics of interviewees (N=18)

Findings from open feedback and the interviews were consistent, but interviews allowed to gain greater insight into themes that had had been generated during analysis of open feedback comments. Results from both sources are summarised by major theme below with example quotes provided in box 1 (intervention group) and box 2 (control group).

Box 1

Intervention group extracts illustrating themes

Taking part in the study and general comments

‘Sexual health is something we need to be talking to each other about…, I think this study needs to be a regular thing and be sent to everyone thank you so much for all your help :)’ (23, WSM, OF)

Knowledge and awareness of safer sex

‘I learnt a lot more about STI’s etc which I didn’t know beforehand.’ (18, MSM, OF)

‘It educated me on other things I wasn't aware of and it was very nice to know I had support on my phone.’ (24, WSM, OF)

‘All of the texts were really useful, most of it was stuff I didn’t know already(…)I think having the STI has made me a bit paranoid and the study’s made me a bit more aware of what I can do to avoid getting them again.’ (21, WSM, I)

Confidence, agency, well-being and communication

‘It was helpful, made me rethink how important safe sex is. How much risk we put ourselves in, as well as difficult situations. I put my health first rather than pleasing others or being irresponsible. You enjoy it more when you control the controllable and prevent any problems for the future.’ (23, WSM, OF)

‘In regards to new partners, I felt more confident in asking them about their sexual health, which in turn helped me.’ (19, MSW, OF)

‘Making sure you know your rights and like. making sure that you agreed to it, not like where like it’s fun and games and that and then they come onto you, like you have to say yes.’ (21, WSM, I)

‘Spoken about it when I was at uni whenever I got a text with my housemates. It has also made me speak more openly about it with my current partner - as like an ice-breaker.’ (20, WSM, OF)

‘I feel positive about my life and my sex life.’ (17, WSM, OF)

‘My attitude towards sexual health changed to the better… I respect my body more.’ (21, WSM, OF)

‘Since the study I've been more aware of being safe especially with new partners and being fully open with them about the topic instead of being shy/embarrassed. It’s normalised the idea of being open with talking about safe sex.’ (20, WSM, OF)

‘The study has made more aware of being safe when having sex. The texts were friendly and comforting. The study gave me the confidence to engage in a new sexual relationship with a new partner without worrying about unwanted consequences.’ (17, WSM, OF)

Change in condom use

‘I think the main thing I do now differently is I definitely check them a lot more before I use them… my boyfriend… he just wants to get it done but I just say, ‘No, I want to check them,’ so I will, I’ll check the tip, I’ll check the packaging to make sure there’s no holes in it, there’s no tears…’ (18, WSM, I).

‘My partner asked if we can ditch the condom, but I didn’t know how to say to him I don't want to. So I just nonchalantly showed him the message, pretending I just got a message and the message happened to be about condoms.’ (22, WSM, OF)

‘The texts were a reminder to take better care of myself, something to refer to if I felt reckless. Whilst having sexual contact with someone they slipped their penis inside me for a few seconds without a condom+I made him stop due to the risks whereas previously I wouldn’t have objected.' (23, WSM, OF)

‘Although I, myself did not use protection due to only being with my long term partner. This study has helped me pass on vital info to my friends to make sure they stay safe when sleeping with multiple people.’ (18, WSM, OF)

‘I now have regular texts and have only not had sexual intercourse without a condom once, which was as a result of me and my partner both having alcohol. (21, WSM, OF)

‘No, not much has changed in regards to me because I like to, I consider myself quite a safe person so I do wear protection where I can.’ (26, MSM, I)

‘I have been better at using a condom—but this may be just because of getting chlamydia last year, not because of the texts.’ (18, WSM, intervention, OF)

‘I look back now and I realise that it definitely was a form of definitely like some sort of self-harming, of like I was just, the only way, you know, I’d have (unprotected) sex with so many people, to make myself feel bad about myself almost.(…)I just didn’t really care, I had no self-respect, I didn’t really care about myself, my body really, … so I think the study definitely made me realise that’ (23, WSM, I)

Effects on partner notification

‘I think I would have gone a very different way about doing it (notifying partner), I think I would have sort of hid it away and taken, it would have taken me a lot longer to do it because I would have been embarrassed, but the text messages, like I said, they really do make you realise that you’re not the only one in this situation, so…’ (18, WSM, I)

‘I think there was one ….that made me realise that actually it’s normal to not want to tell someone, and it’s normal to feel really uncomfortable about it, but actually I need to tell them, and(…)the texts inspired me to reach out to my friends, and then my friends help me create a message that I then sent to people, so yeah.’ (23, WSM, I)

‘The text study was really helpful and insightful it helped me to be able to tell my sexual partner that I had been given a positive result for chlamydia and it helped me understand how to speak to him and tell him.’ (23, WSM, intervention, OF)

‘I think where it gives examples of how to tell, I think that helps, because … you don’t really know how to put it, or how to start it, … a lot of people are actually quite embarrassed or they’re scared of what the other person might say or they just don’t know what to say so some people actually leave it, which is how other people get infected’ (20, WSM, I)

‘I remember thinking like ‘oh this is so annoying that I got it now and not like on the day when I actually had to like tell them’.(…)Because I was thinking ‘oh I’ve really like gone through all that like internal stress of being like how do I tell him?’ and all that stuff like before and like telling him and then getting the text after.’(25, WSM, I)

Increased STI testing

‘I’d say the text messages made me get checked more often but I would have got checked anyway, but probably not as much as I did without the text messages. (21, WSMW, I)

‘I got tested sooner after having had unprotected sex than I probably would have done had I not received a safer sex message text.’ (21, WSM, OF)

‘…the texts definitely were probably part of it, but I think just sort of the maturity side of it, and sort of getting in a better frame of mind where I could ask somebody, after I had sex with them, when were you last tested, because I really didn’t want to get it again.’ (21, WSM, I)

Reduction of isolation and stigma

‘…very helpful to feel less like you were the only one.’ (21, MSW, OF)

‘it was just reassuring to know that it wasn’t just me getting them…’ (21, WSM, I)

‘I think having regular texts written in the way that they were, it’s really sort of like reassuring that you’re not alone.(…)I’m not ashamed of my sexual health anymore, I don’t think, I think before I was, I sort of thought that STIs were something to be ashamed of, but now definitely I know that they are more common than I thought they were, and they can be treated, easier than I thought they could be as well.’ (18, WSM, I)

‘Good for reminding you to keep getting tested and removes the stigma.’ (24, WSM, OF)

‘Thanks to studies like these, there is less shame relating to STI testing so I received the help I needed to get right away.’ (23 years, WSM, OF)

‘…when you have that sort of thought at the back of your mind that it could go wrong, what if it does go wrong, I’m scared, it’s, you feel sort of alone, but then with the text messages it really did help me sort of come out of that corner… I think it’s … the way they were worded, it wasn’t sort of, they weren’t ordering me to do anything, they weren’t demanding us to do anything, they were just suggesting, they were just informing, and I think that’s a lot better than being sort of too firm with things.’ (18, WSM, I).

‘…the stigma is still very much there so it’s so easy to feel like ‘oh I’m the only one, I can’t tell anyone, I don’t want people to think… because it could be one time but people assume just you’re very promiscuous to get an STI… So I think it’s really good… it’s not just the physical treatment of it in regards to your body but like the mental treatment of it. It’s like it’s a common bacterial infection, just saying the word common makes people feel less alone so it could help their emotional wellbeing as well.’ (26, MSM, I)

Information in parenthesis: Age at interview or, in case of open feedback, age at enrolment, gender and sexual orientation, data source; I, interview; OF, open feedback.

Box 2

Control group extracts illustrating perceived impact of having a sexually transmitted infection and trial participation

‘I'm very happy to have participated and hope that you get some conclusive results.’ (24, MSM, OF)

‘I have been a lot more insistent of using condoms during sex. This could have been due to contracting chlamydia last summer which was treated and not wanting to get it again. I was part of the placebo group in the study but still got a text every month or so to keep my details updated. This made me thought of the study so could have reminded me anyway.’ (21, WSM, OF)

‘I guess I’ve been more inclined to use condoms and have less unprotected sex as a screening was always in the back of my mind.’ (24, MSM, OF)

‘Made me more aware of my sexual health by receiving the texts, it was almost like a reminder as sometimes sexual health can be at the back of your mind whereas when receiving the texts it was like a reminder and kept it at the forefront of your mind’ (18, WSM, OF)

‘…receiving these texts made me feel good about taking steps towards being more aware and a part of something bigger that helped me be a better adult (18, MSM, OF)

‘I didn't receive many messages. However, I became more conscious of my sexual health. I take precautions when I remember although, I haven't always used anything. I have been more conscious of sleeping with new people I don't know that well and have avoided this. (19, WSM, OF)

‘I was sort of more wary about who I slept with, it’s like I didn’t sleep with as many people that I was before, I don’t know if that was just because of my age or if… I don’t know.(…) Like I went through a bit of a rough patch when I was younger and I feel like that sort of did include sleeping around a bit more and then I came out of it(…) and I was more like, I didn’t want to just sleep with anyone, I was sort of more picky.(…)

I feel like it did play a little role [joining the study), like agreeing to be part of the safetxt I think was like a turning point as well in its own right. (21, WSM, I)

‘Through the whole process of being diagnosed with an STI has made me consider my life choices. … I am reluctant to have a ‘one-night stand’ as I have previously experienced the consequences of unprotected sex with unfamiliar people. Overall, I have thought more about my actions, not so much as a result of the texts I receive, but instead because of what has happened with my health.’ (19, MSW, OF)

‘I was made far more aware of how unsafe I was being, when in the past I would make more decisions in the moment which were unsafe and unthoughtful about the consequences. Having regular texts made me far more conscious about safe sex—it was a great reminder; as it is easy to forget.’ (19, WSM, OF)

‘… I was in the group that didn’t receive texts about safe sex, however just being involved in the study and completing the questionnaires gave me a greater awareness of the benefits of practicing safe sex even after the shock from my initial diagnosis wore off… (18, WSM, OF)

‘Made me more cautious of who to sleep with. Due to constant reminders.’ (19, MSW, OF)

‘The only kind of messages I was receiving were the ones about confirming my address and contact information. In spite of that, I was still more aware to be cautious and ask people if they were getting tested etc.’ (19, MSM, OF)

‘Has made me think to not have unprotected sex with a new person. I also feel happier…not having to feel embarrassed if I did have an STI.’ (18, MSW, OF)

‘If I hadn't been part of the study I would not think to get tested as often…. or think to ask about whether my partner has been tested recently.’ (22, WSM, OF)

‘I felt that having the message helped in reminding me to continue having tests at the clinic when & if needed.’ (19, MSWM, OF)

‘It made me feel like I was not alone with getting an STI.’ (19, WSMW, OF)

‘Receiving the text messages could be upsetting as they would remind me of the shame and stigma of contracting an STI.… Being part of the study made me feel less alone but it didn't make me feel less ashamed. It would have been good to have received texts with support or info…’ (24, WSM, OF)

Information in parenthesis: Age at interview or, in case of open feedback, age at enrolment, gender and sexual orientation, data source; I, interview; OF, open feedback.

Knowledge and awareness of safer sex

Intervention group participants reported the messages were ‘clear’, ‘concise’ and ‘informative’. Participants reported impact on their general knowledge of practising safer sex including new ways to protect themselves, how STIs are contracted, the risks and consequences of unprotected sex and the need to go for regular testing. Some participants appreciated intervention messages as a ‘proper’ source of information with links to trustworthy internet sites that clarified which information from other less reliable sources was correct. A few participants in the open feedback reported messages only said things they already knew.

Many intervention participants, but also some control group participants, reported increased awareness of the importance of safer sex behaviours. Control group participants were ‘indirectly’ reminded of safer sex importance, because the regular texts reminded them their previous STI and/or because trial participation raised their awareness and motivation. This greater awareness reportedly influenced some intervention and control group participants in being more ‘careful’ in their choice of sexual partners and/or having less casual sex.

Confidence, agency, well-being and communication

Intervention group participants reported an increased confidence and agency in asserting their needs, for example, greater agency in only having sex when they wanted to. Some participants reported benefits in their sexual well-being such as, ‘feeling positive’ about their sex lives, respecting their body more or greater sexual pleasure through feeling more in control of their sex lives.

In both the intervention and control group, sexual health was reported to be a ‘difficult’ and a ‘taboo’ subject to talk about. Sharing intervention text messages with partners, friends, housemates and siblings was a catalyst for facilitating open and honest dialogues about sexual health and helped many participants feel less embarrassed raising the topic. Showing partners messages was also used to reinforce requests to use condoms. One person reported the intervention gave them the confidence to start a new relationship after their STI.

Changes in condom use

Many intervention, but also some control group respondents reported having been ‘more cautious’ after receiving messages and that texts were good reminders to use condoms. Several participants explicitly reported increased condom use especially with casual or new partners. Intervention group participants attributed this to increases in their confidence and knowledge of how to stay protected from STIs as well as greater confidence in being able to bring up the topic of condom use. Practical tips, including to prevent condoms to break or slip off, had been particularly helpful. One participant, however, said it would be helpful to have more advice on what to do if a partner refuses to use a condom. Those who used condoms did not necessarily use them on every occasion. Reportedly, the messages also led some to encourage their peers to use protection.

Effects on partner notification

Participants in the intervention group commonly reported that the text messages enabled them to speak more confidently (calmly and sooner) to their partners about their infection, impacting on how they told partners. Intervention content that chlamydia was common and easy to treat helped facilitate conversations with partners about infection. This content also reduced concerns about getting chlamydia. There were reports that the messages motivated some participants to tell partners. Some stated that the text message examples they received arrived after they had notified partners, and regretted that they had not received them earlier. Some reported only learning from the messages that the clinic could have informed their partner. Two comments referred to unknown partner contact details.

Increased STI testing

Participants from both groups reported they sought further STI testing as a result of being in the study. Messages made some participants feel it was ‘Ok to get tested and directly or indirectly reminded intervention and control group participants to test or test more frequently than they normally would have. Participants reported going for testing after having sex with a new partner (none mentioned testing before first sex).

A few intervention participants reported frequent STI testing rather than condom use as a way of managing STI risk and to ‘keep track of partners’.

For some participants, the STI home testing kit was perceived as a central positive aspect of the study, and knowing that another ‘screening’ test would be done made one control group participant ‘more inclined to use condoms’.

Reduction of isolation and stigma

Many intervention participants said that taking part in the study reassured them and reduced their feeling of being ‘the only one’, a common feeling after being diagnosed with an STI. Participants frequently commented on the reduction of ‘stigma’, ‘shame’ and feeling ‘less embarrassed’ about having had an STI which was perceived to be reassuring and to have benefits for emotional and mental well-being. In addition, learning that STIs could be easily treated reportedly reassured participants. Some control group participants also noted feeling ‘less alone’ as they ‘belonged to a group of people that have had chlamydia or gonorrhoea’, and one reported that being in the study reduced their embarrassment about having an STI. Another control group participant, however, emphasised that the study made her ‘feel less alone’, but not ‘feel less ashamed’ and she would have liked to be in the group that received texts with support and information.

STI diagnosis and trial participation effects

Some participants from both groups reported that changes in their behaviour were a consequence of having an STI rather than receiving intervention messages. Additionally, in open feedback many in the control group commented that participating in the study enabled them to make a commitment to changing their behaviour, and a few said that it prompted them to seek help, for example, about abusive relationships. As mentioned in the relevant sections above, the control group texts simply about trial participation had reminded many to adopt precautions such as using condoms, STI testing and asking partners about their last test for STIs.

A few participants mentioned that they joined safetxt when they had been at a ‘turning point’, and would have changed their behaviour anyway, but appreciated the safetxt support during this time of change. One control group participant, who had reportedly meanwhile changed due to the STI and becoming more mature, thought that safetxt support if targeted at younger people could help them avoid having to go through the same ‘quite big stressful event’ of having an STI.

Recommendations for future interventions

Recipients felt the intervention was especially helpful for younger people such as late secondary school/first year post school (online supplemental file 3). Many interview participants and free-text comments reported that not enough was taught in schools and the texts were much more useful than what they were taught at school. Participants mentioned additional topics that would be helpful to include, such as peer pressure to have sex, further content on dealing with people who do not want to use protection, and pleasurable aspects of condom use; a few women who have sex with men and women requested more information on safer sex between women and two men who have sex with men (MSM) wanted the intervention to cover ‘chem sex’ (stimulant enhanced and prolonged ‘no-strings’ sexual sessions between MSM connecting through apps28).

A few participants suggested further personalisation of safetxt messages and an option to choose from a wider range of topics from the outset (in addition to the ‘text 2 to hear more’ option). Some requested better mental health support to explore why people have unprotected sex. Suggestions from participants for changes in the timing and frequency of messages often focused on having some form of control of message frequency, with some wanting less messages (especially at the beginning) and others more (especially towards the end).

Although many participants said that certain intervention message content would ‘stick’ with them, some would have liked to continue receiving texts, as they served as reminders.


According to recipients, the safetxt intervention increased awareness of the importance of avoiding STIs and related knowledge about ways to prevent them. Participants reported improved confidence, agency, sexual well-being and communication about sexual health with partners, friends and family members. They attributed to these improvements, increases in condom use, STI testing, more confident partner notification and (for a few) disclosure of diagnoses. There was a reduced sense of isolation, stigma, shame and embarrassment about having an STI which reportedly reassured some participants and improved their emotional well-being.

Participants from both the intervention and control group reported that having an STI influenced their safer sex behaviours. Control group participants reported that taking part in the study had influenced their commitment to safer sex behaviours. The control group text message about trial participation reminded many about the importance of safer sex and acted as a trigger for STI testing and condom use.

Our qualitative analyses of interviews and open feedback are mainly consistent with the trial results. However, recipients’ reports suggest larger differences in behaviour than were demonstrated in the trials results. Possible reasons include social desirability bias, an incorrect attribution of changes in behaviour to the intervention rather than the experience of STI and a strong Hawthorne effect29, including the trial participation messages sent to the control group reportedly acting as a prompt for safer sex behaviours.

Our findings suggest that young people felt positive impacts of the safetxt intervention on their sexual and reproductive well-being. These benefits include increase in confidence, agency, communication and precautionary behaviours.1 The perceived value of safetxt from recipients’ accounts accords with the trial results showing higher condom use at 12 months. The ‘spill-over’ effect resulting from participants reportedly encouraging their peers to use condoms, was not quantitatively assessed during the trial. Recipients accounts that the main perceived benefit of the intervention was in ‘how’ to tell partners rather than ‘whether’ to tell them about their STI accords with the only slightly higher levels of partner notification in the intervention group. The results are not in line with the public health impact of safetxt as the trial results found STIs were not reduced, with slightly more infections in the intervention group. The trial results suggested (although not statistically significant) that there were slightly more participants with two or more partners and a new partner in the intervention group compared with the control group during the course of the trial (altering partnerships was not an intervention aim). The findings from this study involving interviews and feedback obtained after the 12-month intervention of the safetxt trial were in keeping with the findings from telephone interviews conducted in 2013 during the intervention development 2–3 weeks after receiving the first messages, but included longer-term impacts.17

A strength of the interviews and the open feedback analysis was that it was conducted by two researchers not previously involved in the intervention development or trial.

We analysed all of the open feedback comments left by over 3500 trial participants (56% of participants who enrolled into the trial and 72% of those who completed the 12-month questionnaire). The experience of those not leaving a free-text comment may be different from those who did. However, the characteristics of respondents were similar to the characteristics of trial participants including those from diverse sociodemographic and ethnic groups. It is not possible to blind participants receiving a behavioural intervention, which could introduce bias when obtaining feedback. All open feedback comments were brief, optional and completed at the end of their involvement in the trial, so it was not possible to explore participant views in depth or follow-up on feedback. During interviews, however, (and despite having to stop the interview study slightly earlier due to the COVID-19 pandemic), we were able to gain greater insight into themes that had been generated during analysis of open feedback comments.

Our qualitative analyses provide little direct evidence to explain the unanticipated quantitative trial findings, but raise some plausible explanations. Both qualitative analyses and quantitative analyses of intermediate and secondary trial outcomes showed increased correct condom use self-efficacy and increased condom use. This effect did not seem big enough to translate into reduced reinfection rates in the intervention group, given that those who reported increasingly using condoms did not necessarily use them on every occasion. In addition, a few intervention participants seemed to prefer a secondary prevention approach with frequent STI testing over a primary prevention approach with consistent condom use.

In both intervention and control groups, there were large reductions between baseline and follow-up in the number of partners in the preceding year, as would be expected if high-risk people were reverting to the norm. However, there was a marginally smaller reduction in the intervention group. Previous trials of group interventions targeting those at high risk for STI, have had unanticipated effects in normalising risk behaviours and increasing STI.30

The ’shock’ of having had an STI and receiving control group messages reminding them of their STI might have deterred control group participants for a longer period from engaging in new relationships than intervention group participants. Some intervention recipients reported feeling less ashamed about their STI, generally more confident in discussing sexual health and/or reassured that their infection could be easily treated. Lower stigma about having an STI carried benefits in emotional well-being and reportedly gave a few the confidence to start a new relationship following their STI. While this was a positive outcome from recipient’s perspectives, starting a new relationship confers some additional STI risk. Whether that risk is worth taking depends on what people are getting out of new relationships. Our analysis suggest intervention recipients were better equipped to get the sex they want (and to avoid the sex they do not want). The trial suggests that sex was no less a risk for STIs, but it may have had more value to them.

Our qualitative analysis also suggested that testing after sex with new partners was increased, but not before first sex. The safetxt trial indicator assessed STI testing ‘prior’ to first sex with new partners (showing no difference between groups), whereas the few previous mHealth trials we identified in a systematic review that showed an effect on STI/HIV-testing, only enquired about whether participants had an STI test within a specified time period.31 Secondary analysis of the safetxt trial data looking at overall testing data in clinics (rather than self-reported tests ‘prior’ to first sex) is consistent with this with slightly higher clinic testing for STI in the intervention groups (1549/3123, 50%) vs the control group (1477/3125, 47%).


This research has described the perceived impacts of receiving the intervention and control group messages on participants. A randomised controlled trial was needed to identify slightly higher STI diagnoses in the intervention group. The qualitative findings and trial results both show that the components of the safetxt intervention promoting condom use were effective. Since this is a unique finding not seen in any previous similar mHealth interventions,31 service providers could consider delivering this content. Further research could consider recipients recommendations for future interventions and explore how to achieve and measure positive impacts of reduced stigma about having an STI and increase sexual well-being as well as reduce subsequent STI.

Data availability statement

Data are available on reasonable request. Deidentified data collected as part of the randomised controlled trial will be made available via the data sharing portal FreeBIRD after publication of the primary and secondary analyses as outlined in the Data sharing statement of the trial publication Free et al (2022). Part of the study materials and anonymised extracts of the interview study conducted after trial completion, have been included in online supplemental files of this article. Sharing of further anonymised qualitative data extracts on reasonable request would have to be in line with data protection laws and subject to appropriate ethics committee approval.

Ethics statements

Patient consent for publication

Ethics approval

This study involves human participants and the research was approved by the London School of Hygiene & Tropical Medicine (reference 10464) and the NHS Health Research Authority—London—Riverside Research Ethics Committee (REC reference: 15/LO/1665). Participants gave informed consent to participate in the study before taking part.


We would like to thank safetx trial team members, Zahra Jamal, Lauren Jerome, Faran Dhaliwal and Megan Knight for helping with the pilot testing of the topic guide. We would also like to acknowledge the work by the specialist transcription service 'The Typing Works', who transcribed our interview recordings. Last, but not least, we would like to thank all of our study participants for their time and trust.


Supplementary materials


  • SB and AG are joint first authors.

  • Twitter @BerendesSima

  • Contributors SB and AG contributed equally to this paper. AG, SB, RF, CF and FCIH developed the topic guide. SB conducted 11 and AG 7 interviews; SB and AG coded their interview transcripts after RF had (double) coded SB and AG’s first interview transcripts. AG and SB analysed the open feedback. RF and CF reviewed and commented on the coding framework. AG, SB, CF, RF and FCIH all contributed to the interpretation of results; SB, AG and CF wrote the first draft of the paper with comments and input from RF and FCIH; all authors finalised the manuscript. CF is responsible for the overall content as guarantor.

  • Funding This study has been sponsored by the London School of Hygiene and Tropical Medicine and funded under the NIHR PHR Programme (Project ref 14/182/07).

  • Disclaimer Funders have not directly been involved in study conduct, data analysis, interpretation and dissemination of the results.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.