Within this study, it is interesting to note there was no assocation between mode of invitation and response rate. As such, there is a suggestion professional illustration may not increase study invitation response rate. This is in contrast to some research indicating professionally designed invitation packs can improve recruitment rates. However, other research examining the optimisation of patient information sheets via professional design and user testing has failed to find increased recruitment rates compared to the provision of standard study information. As such, the time and financial resources required to engage a professional design service may not be warranted. However, it is important to note the present study examined response rates to an initial study invitation, as opposed to full study information sheets, as such current findings may not be comparable to existing research. In addition, the main modification to design was the use of professional illustration and presentation via a postcard versus standard letter. Future research may be required to examine whether additional design modifications, (e.g., language, structure, length) may impact recruitment rates.Overall, the majority of parents reported receiving initial study invitations via the post and sent via a researcher as acceptable. Interestingly, lower acceptability was reported for receiving an invitation to participate from another parent of a child previously treated for cancer (32.1%). This appears to be in conflict to the increasing importance placed on patient and public involvement in research (PPIR), commonly defined as research conducted ‘with’ or ‘by’ the population rather than conducting research ‘to’, ‘about’ or ‘for’ them. Indeed, previous research found advertising PPIR within study invitation packs did not increase recruitment rates. Conversely, other research suggests PPIR is associated with increased recruitment rates, however it is difficult to identify specific elements of PPIR associated with enhanced recruitment. It is important to note that research indicates the importance of recruiters having a professional background  with participants more likely to participate if recruiters are considered competent and experienced . As such, whilst there may be low acceptability for other parents acting as recruiters, it is important to recognise alternative ways high quality PPIR may enhance recruitment (e.g., developing user-friendly participant information, improving handling of sensitive topics, advising on acceptable trial design).
It is noteworthy that parents reported an overall preference for receiving initial study invitations via the post. Whilst postal recruitment from disease registers is a common recruitment strategy , evidence suggests the provision of telephone reminders enhances recruitment rates. Only 16.1% of parents surveyed considered contact via the telephone acceptable. However, the present survey specifically examined the acceptability of telephone contact regarding the receipt of initial study invitation, rather than preferred ways of receiving study invitation reminders. Future research may wish to examine what methods of sending study reminders would be considered acceptable to further identify acceptable recruitment strategies. It is also interesting to note that the majority of parents reported receiving full study information online in text and video format as acceptable. Indeed, there is some evidence to suggest the provision of trial information via video, to supplement the provision of written information, improves participation rates.
It is important to note that similar percentages of parents reported they would agree, or maybe agree, to participate in trials using waiting-list control, alternative active treatment, and patient-prefence designs. Further, little differences were found concerning acceptable waiting times for a hypothetical waiting list RCT. As such, the majority reported a willingness to participate in hypothesised trial designs utilising randomisation procedures. This is in contrast to research reporting a fear of randomisation being a common reason for declining trial participation. One potential explanation for this finding, may be the presentation of an informational video to participants explaining randomisation and the different designs presented in the survey. Indeed, previous research has demonstrated clinical trial educational videos can reduce barriers to trial participation and increase preparedness to consider clinical trial enrollent. Further, almost half of parents reported previous participation in research, with almost all reporting high to moderately high levels of trust in research. Again, this finding is in contrast to previous research whereby fear and mistrust of clinical trial research has been reported. Given many parents had participated in past research, the surveyed population may already have increased levels of knowledge regarding trial design, resulting in positive attitudes towards participation more generally.
In line with previous research, a significant proportion of participants reported past and current emotional distress. This further supports findings that parents experience a need for psychological support from the end of cancer treatment, persisting into the long-term. However, in contrast to previous research, the majority who had sought support for their distress had received support from a healthcare professional. Despite this, it is important to note the survey did not examine the type, quality, or acceptability of psychological support received by parents. The results also indicate internet-administered psychological interventions, supported by a psychologist, potentially represent an acceptable type of support for parents of children previously treated for cancer. These findings are in line with wider research indicating generally high levels of acceptablity for the delivery of internet-administered psychological interventions. However, future research will be required to examine the acceptability of the internet-administered psychological intervention from the perspective of actual intervention users.
This study has several limitations. First, willingness to participate in a hypothetical trial of an internet-administered psychological intervention may not predict actual trial enrollment. As such, although the majority of respondents reported a willingness to participate in a hypothetical trial, findings may not represent the decision made if parents were offered participation in a “real-life” trial. Second, a related point pertains to the examination of response rates. The study was a brief online survey, however participation in a trial takes time and committment. As such, the response rates obtained in this online survey may not reflect likely trial response rates. Third, there was no formal measurement of emotional distress utilising a standardised and validated self-report or clinician administered measurement of distress. As such, it is difficult to determine whether parents were experiencing levels of emotional distress suitable for psychological support. Consequently, findings may not be generalisable to parents experiencing clinical levels of emotional distress appropriate for formal psychological support. However, it is important to note the percentages of those parents reporting either past of current emotional distress are in line with studies examining clinically relevant levels of general psychological distress. Forth, the survey is limited by the 32% response rate and it is possible non-responders have different attitudes and preferences towards the design and conduct of psychological internet-administered intervention trials. Indeed, research has suggested a category of non-responders to research, labelled ’prior decliners’ who have an established and unmodifable position of declining particpation in clinical research. Indeed, the majority of responders had previously participated in research, and as such it is possible the sample represents parents with higher levels of acceptability concerning research more generally than non-responders. Finally, the survey examined the acceptability of more traditional methods of clinical trial recruitment, for example mail-out and clinician referral. However, evidence suggests online methods of recruitment into internet-administered intervention trials are effective. As such, future research examining acceptable methods of receiving study invitations for internet-administered psychological intervention studies may wish to examine online recruitment strategies.
Notwithstanding these limitations, to the best of our knowledge, this is the first study to examine attitudes towards clinical trials, preferences regarding study design and willingness to receive internet-administered psychological support amongst parents of children previously treated for cancer. Further, little is known regarding preferences and attitudes towards clinical trial design amongst the public more generally. As such, findings will make an important contribution to the design of a planned feasibility study, including initial study invitations being sent via postal letter by the research team, full study information being presented online via both text and video, and the provision of support from a psychologist for the developed internet-administered intervention.
The conduct of clinical trials is time and resource intensive, however little is known about attitudes and preferences towards trial design and participation. Likewise, little is known concerning the acceptability of internet-administered pychological interventions for parents of children previously treated for cancer. This study builds upon prior research to develop an ICBT intervention for the population and preliminary investigation of the acceptability of planned trial recruitment approaches and study design. Survey findings have further enhanced our understanding of the acceptability of internet-administered approaches for the population, alongside an appreciation of acceptable study procedures and design. Results will inform the design of a feasibility study of an ICBT intervention for parents of children previously treated for cancer, to further examine questions regarding methodological, procedural and clinical uncertainties.