The implementation and mechanisms of advance notification for cancer screening: A scoping review

To describe and synthesise information on the content and delivery of advance notifications (information about cancer screening delivered prior to invitation) used to increase cancer screening participation and to understand the mechanisms that may underlie their effectiveness.

Cancer is a leading cause of death worldwide. 1In 2020 alone, there were an estimated 19.3 million new diagnoses, and almost 10 million deaths attributed to cancer. 2 Screening is a highly effective means of reducing cancer-related morbidity, mortality, and associated health care costs. 3As such, population-level screening initiatives, typically targeting breast, bowel, and cervical cancer, have been implemented in many countries including Australia, Ireland, Scotland, the Netherlands, and Italy. 4,5These programs aim to increase detection of early-stage cancers or precancerous abnormalities within the target population, increasing the likelihood of effective treatment. 6e effectiveness of cancer screening programs worldwide is hindered by suboptimal participation, with screening rates as low as 16% for bowel, 5 11% for breast, 7 and 4% for cervical cancer screening. 8Optimising screening programs to increase uptake of cancer screening tests is critical to reducing the burden of cancer.
One strategy used to increase screening rates is 'advance notification', wherein eligible invitees are informed of an upcoming opportunity to screen for cancer, prior to invitation.This strategy is used in bowel cancer screening programs in many countries around the world, including Denmark, England, and Australia.The Australian National Bowel Cancer Screening Program (NBCSP) distributes advance notification letters four to six weeks prior to the arrival of the at-home screening kit, briefly informing recipients about the risk of bowel cancer, the benefits of screening, and to expect their test kit in the mail in the coming weeks.Compared to no advance notification, the Australian NBCSP's advance notification letter is estimated to account for an additional 54 per 100,000 bowel cancer deaths avoided and incurs less than $4000 in costs per life year gained, well below the Australian standard for intervention cost effectiveness. 9,10though advance notification has been repeatedly shown to increase participation in screening, especially for bowel cancer, [11][12][13][14][15] these increases are small to moderate, between 4% and 9%, 16,17 suggesting room for further enhancement.One study has also demonstrated its effectiveness in increasing adherence to prostate screening, although the size of this increase is unclear. 18Currently, there is a lack of knowledge regarding how advance notification increases screening participation.A deeper understanding of the mechanisms of advance notification can lead to the development of improved interventions with the potential to further increase screening rates.
There are several theoretical models that describe the psychological processes that underly the motivation to engage in a health behaviour (e.g., screening) and the behaviour itself, such as the Transtheoretical Model, 19 the Health Action Process Approach, 20 and the Precaution Adoption Process Model. 21Research has consistently demonstrated that interventions based on psychological and behaviour change theory are more effective than atheoretical interventions. 22,23For example, a 2016 Australian study examined the effectiveness of an advance notification letter including messaging informed by the Transtheoretical Model, compared to the standard letter implemented as part of the Australian NBCSP. 19,24e results showed that the theory-driven advance notification letter elicited a 4% increase in bowel cancer screening participation compared to the standard letter. 24This theoretical approach is an exception to the norm, however.Most existing bowel cancer screening interventions do not make explicit reference to behavioural theory in their design. 25The integration of psychological and behaviour change theory into the design of advance notifications may increase its effectiveness and facilitate further increases in cancer

This scoping review was conducted according to the Preferred
Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). 26A PRISMA-ScR checklist is provided in Supporting Information S1.A protocol was developed a priori by the research team using the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis, 27 and pre-registered via Open Science Framework (https://doi.org/10.17605/OSF.IO/S65HK).

| Eligibility criteria
Inclusion and exclusion criteria for the articles were designed in alignment with the Population, Concept, Context (PCC) framework 28 and are provided in Supporting Information S2.Only published, peerreviewed research in English was eligible for inclusion.All study designs were eligible; however, secondary research such as systematic reviews were excluded.No eligibility criteria were specified based on participant demographics and no date limits were applied.Included articles needed to involve the implementation of an advance notification intervention.This was defined as an intervention wherein (i) participants are informed of an upcoming opportunity to screen for cancer (ii) before they can take steps to participate (e.g., booking an appointment, completing a screening kit).The latter criterion was included to prevent conceptual overlap with other invitational strategies such as reminders.Further, studies examining advance notification in the context of any type of cancer screening were included, wherein screening was defined as a test aiming to detect early signs of cancer and/or precancer amongst asymptomatic individuals from the general population.Studies wherein screening tests were utilised for diagnostic purposes amongst symptomatic patients, or for surveillance purposes of cancer survivors, were thus excluded.

| Information sources and search strategy
Six databases (APA PsycINFO, CINAHL, Cochrane Library, Embase, PubMed, and Web of Science) were selected and searched on 30 May 2023, using keywords and subject headings (e.g., MeSH) relevant to advance notification and cancer screening (see Supporting Information S3 for search syntax).The search strategy was developed in consultation with an experienced research librarian and refined by the research team.Searches were adapted manually for each database.Five articles already known to meet the eligibility criteria 13,14,24,29,30 were selected and used to test that the search strategy identified relevant records across each of the databases.
Hand searching (i.e., perusing key journals and reference list scanning) was also used to locate relevant studies.As this review aimed to examine the content of advance notifications, study authors of included articles were contacted to request full versions of the advance notifications distributed to study participants, if not already publicly available.

| Study selection
Following the search, identified citations were uploaded into EndNote X7 citation management software 31 and duplicates removed.Articles were then uploaded into Rayyan for screening. 32tle and abstract and full text screening were based on the PCC eligibility criteria and performed by two independent reviewers (KC, AT-S), with disagreements resolved through discussion.

| Data analysis
A data extraction template was developed based on the JBI template source of evidence details, characteristics, and results extraction instrument (https://jbi-global-wiki.refined.site/space/MANUAL/4687579; see Supporting Information S4).Data from a selection of 10 included articles were re-extracted by another researcher (AT-S) for accuracy.In this review, we report study characteristics (Table 1) and features of the advance notifications implemented within the included articles (Table 2).
Study characteristics and the features of the distributed advance notifications, including target cancer type, format (e.g., letter), delivery time (e.g., 2 weeks in advance of screening invitation), and key content (i.e., statements or messages within the notifications) were summarised and compared between effective and ineffective notifications (i.e., those that significantly increased screening vs. those that did not).It has been suggested that advance notification is particularly effective in people who have not been invited to participate or have not participated in a screening program before. 55erefore, we also examined the proportions of participants in each sample that had been invited to participate in screening before.
The full versions of the distributed advance notifications, where available, were analysed via relational qualitative content analysis 56 to identify latent meaning from text. 57First, text within each of the advance notifications were read and coded line-by-line to generate an initial set of subcodes reflecting semantic meaning of the message communicated to screening invitees.Then, these subcodes were organised based on shared meaning to produce a set of overarching codes, representing the broad messaging strategy utilised (e.g., 'screening prevents cancer' and 'screening saves lives' subcodes were organised under a single code, 'benefits of screening').In line with PRISMA-ScR guidelines, a formal quality assessment of the included articles was not conducted. 26

| RESULTS
The database searches retrieved a total of 8228 records, of which 25 articles were eligible for inclusion (see Figure 1).A further seven articles were identified and included via hand search methods.A total of 32 articles were included in this review, reporting on 33 unique advance notifications.Twenty-two full versions of these unique advance notifications were obtained for content analysis; the remaining 11 were unable to be obtained from study authors.
In most studies (72%), no information was reported regarding the proportion of participants in the sample who had previously been invited to participate in cancer screening.Two studies examined advance notifications among a sample of only participants who had  39,51 and three studies examined only first-time screening invitees. 30,44,50Two studies included samples of 44% and 46% previously invited participants, respectively. 13,55

| Features of advance notifications
Of the 32 included articles (detailed in Table 1), six described the same advance notification, 34,35,37,46,49,51 and six described more than one different advance notification. 24,40,47,51,54,55This resulted in 33 unique advance notifications included in this review.Key features of each unique notification are provided in Table 2.
Most advance notifications informed participants of an upcoming invitation to screen for bowel cancer (79%) via faecal occult blood test (FOBT).Colonoscopy and flexible sigmoidoscopy (FS) were the target of two studies. 41,55Other notifications related to cervical cancer screening (9%) via self-sampling and/or Pap test, breast cancer screening (6%) via mammogram, lung cancer screening (3%) via low dose computed tomography scan, and prostate cancer screening (3%) via prostate specific antigen testing.The most common format used for advance notifications was a printed mailout (79%), such as a letter, postcard, or leaflet.The remainder were digital communications (12%) including text messages and emails, and phone calls (12%).Advance notifications were delivered from one day to 3 months prior to the screening invitation, with a median of 2 weeks Note: Result refers to the direction of the effect of the advance notification on cancer screening adherence compared to control, where ↗ = significant increase; ─ = no significant effect; NA = not applicable, effect of advance notification (alone) not statistically tested; NR = not reported.a For definitions of the subcodes referenced in the "Content" column, see Table 3 in advance (interquartile range: 0.7 weeks).Six of the 33 notifications did not specify how far in advance they were sent.

| Inductive content analysis
Twenty-one subcodes were created to capture the specific information provided within the advance notifications.These subcodes were organised based on shared meaning into five major codes capturing overall messaging strategies.Throughout the coding process, we identified that the major codes could be mapped to evidence-based mechanisms of behaviour change.These proposed mechanisms and the associated theoretical models are presented in Table 3.
Messaging strategies commonly addressed barriers to screening such as perceived difficulty of the test by highlighting the ease and simplicity of home bowel screening kits.Others addressed feelings of embarrassment, for example, by reassuring invitees that they could request a female practitioner for cervical screening, 42 and disgust, where bowel cancer screening invitees were informed of the cleanliness of the self-sampling procedure. 24,51,54Other barriers addressed related to the cost of screening, fear of a possible cancer diagnosis, and privacy of personal information.Notably, in two notifications delivered via phone call 34,51 invitees engaged in a discussion with the caller about their past and present barriers to screening and received information and strategies to help overcome these barriers upon receipt of their next screening offer.
Advance notifications also highlighted the risk of cancer.This included addressing the severity of a cancer diagnosis (i.e., risk of mortality), highlighting personal susceptibility to cancer, and promoting urgency around screening completion.Complementing these risk messages, however, was information about the benefits of screening, including increased early detection and decreased risk of mortality, and the possibility of preventing cancer all together.
Reinforcement of positive social norms was also used.For example, one notification described screening as a normal part of patient care at the recipient's medical practice. 51Others included more explicit endorsements by healthcare providers, typically when notifications were provided via phone, where the caller framed the screening offer as on behalf of the recipient's primary care provider. 34,51vance notifications were also used to navigate the overall screening process.The invitation process was described, including when to expect the screening offer, what to do upon its arrival, and in the case of one mailed notification, how to distinguish the screening invitation from other mail, 18 presumably to prevent misplacement.
Details of what to expect during the screening procedure, for example, a description of how to complete the bowel cancer screening kit 24,51,54 or how a cervical screening test is performed, 42 as well as what to expect after the test, such as the outcomes of a  positive test result, 38,50,54 were also sometimes provided.Advance notifications commonly provided facts about where to access more information about screening, usually providing helplines, websites, and other printed materials for reference, or in the case of phone calls, the opportunity to seek answers directly from the caller. 34,50,51

| Comparing features of effective and ineffective advance notifications
The features of the advance notifications are listed alongside the effect of the notification on screening participation in Table 2.The effect of the advance notification on cancer screening participation was tested for 19 of the notifications.Most of these notifications (n = 13; 68%) significantly improved cancer screening uptake.54,55 The remaining notifications had no significant effect on screening. 36,42,43,45,54Overall, effective and ineffective notifications could not be differentiated by their characteristics or content, with some exceptions.Advance notifications delivered prior to bowel cancer screening generally increased screening uptake [11][12][13]15,24,29,40,50,54,55 ; whereas the two notifications sent prior to breast and cervical cancer screening were ineffective. 36,42 The one notifiation sent prior to prostate cancer screening also increased participation, although the size of this increase is unclear.18 Effectiveness did not tend to vary by format, delivery time, or content included within the notification.

| DISCUSSION
This scoping review described the content and delivery of advance notifications implemented to increase cancer screening participation.
Notifications reviewed were typically delivered via postal mail, 2 weeks before an invitation, and targeted bowel cancer screening.
Notifications included information about the benefits and barriers of screening, the risks of cancer, social endorsement of screening, and navigating the screening process.Their effect on screening uptake did not tend to vary based on the content and format of the notification; however, most notifications targeting bowel cancer screening were effective, whereas the few notifications trialed for other cancer types were ineffective. 36,42st research examining advance notification to date has focused on its application to bowel cancer screening, typically via FOBT, raising generalisability concerns.FOBT is a non-invasive, selfsampling test, often sent directly to the recipient's home. 60 Various messaging strategies were utilised in the notifications reviewed, many of which were aligned with the processes theorised to underly intention formation. 19,20,58,59Due to their design, advance notifications have limited capacity to directly induce behaviour, arriving before the individual is able to screen; however, it has been theorised that advance notifications may provide a "head start" to intention formation, providing invitees the opportunity to contemplate the screening offer ahead of time, thus facilitating a more effective transition into behaviour upon invitation.time screening invitees the receipt of advance notification may be their first exposure to a cancer screening test, and thus the notification may be particularly crucial in informing the decision to screen (or abstain), compared to subsequent, familarised invitees.Less than a third of studies (28%) in this review reported any information about receipt of previous screening invitation. 13,30,39,44,51,55More research is needed to understand the direct and interactive effects of personlevel factors on uptake of cancer screening following advance notification.This knowledge may inform the tailoring of intervention approaches in future, to effectively increase participation among invitees of varying screening statuses.

| Clinical implications
The reliable effectiveness of advance notification and the commonly employed messaging strategies used in these notifications can inform the practice of healthcare professionals working to promote preventative health and cancer screening.For example, general practitioners are well placed to facilitate advance notification of cancer screening opportunities to their patients.In fact, text message advance notifications delivered by general practitioners to encourage bowel cancer screening show promise for increasing participation in national programs. 62,63In general, digital advance notifications, such as text messages and emails are highly efficient, convenient, and have widespread reach for promoting screening.While the effect of the four digital notifications captured in this review was mixed, 12,34,41,43 text message reminders (i.e., sent post-screening invitation) have been consistently shown to increase uptake of breast, bowel, and cervical screening, [64][65][66][67] suggesting that the use of electronic notifications may be a viable alternative to the dominant postal mail format.The use of digital advance notifications appears to be a topic of growing interest in literature, with included studies published from 2020 to 2022, and more research is needed to confirm their effects on screening uptake.While the shift to digitalised advance notifications may increase the cost-effectiveness of screening communications (e.g., reducing printing and posting costs), further work is needed to understand the potential drawbacks of this approach, particularly for screening invitees who are less inclined to engage with technology, such as older populations and those with disabilities. 68rther to this, unique motivational strategies can be applied through phone call advance notifications.Methods identified in the current review included encouraging recipients to reflect on barriers to screening and assisting them in devising strategies to overcome them. 34,51This process is known as coping planning, and according to the Health Action Process Approach, is key to facilitating the transition from intending to screen to screening participation. 20Primary care providers such as general practitioners can apply these coping planning strategies to allay patient concerns about screening and increase their likelihood of participation upon screening invitation.
Although only three phone call notifications were captured in this review, they were associated with screening uptake increases of up to 16%, 40,50 compared to notifications of mailed and digital modalities, which increased screening by up to 9%. 11,40It should be cautioned however, that while phone call reminders have indeed been shown to be more effective in increasing screening participation than reminders sent via mail, they are also more cost-and resourceintensive 69 and thus may not be as feasible for integration into routine medical care nor population-level cancer screening programs.
At the population level, there may be scope for future research to explore the use of artificial intelligence-assisted approaches to advance notifications in national screening programs, such as the distribution of links to chatbots capable of simulating the collaborative problem-solving approach of phone calls in a more cost-effective, scalable manner.

| Study limitations
The findings of this scoping review should be interpreted in the context of its limitations.The content analysis was constrained by the availability of the full versions of the advance notifications.Although all reasonable attempts were made to obtain the materials from the study authors, several were not retrievable, including all notifications delivered prior to breast cancer screening. 36,39This review therefore may not have captured the full breadth and variability of the content included within these interventions, especially those targeting breast cancer screening.

| Conclusion
screening participation.Advancing the current knowledge about how advance notification improves cancer screening participation holds potential benefit to intervention design.This understanding could lead to the development of advance notification interventions directly targeting evidence-based mechanisms of behaviour change, driving further increases in screening participation.However, current knowledge regarding how advance notification is used and the components of this intervention, which may account for its effectiveness, has not been comprehensively reviewed.The present study utilises a scoping review methodology to examine the content and delivery of advance notifications used to increase cancer screening participation.This review aims to gather a preliminary understanding of the potential mechanisms of advance notification and highlight gaps in the literature to inform the design of future primary research investigating potential mechanisms of advance notification.

F
I G U R E 1 PRISMA flow diagram of systematic searches.
This review found that most research to date has examined advance notifications sent via mail, prior to bowel cancer screening.Future research would benefit from investigation of advance notification sent via alternative, cost-effective modalities, prior to more complex screening procedures (particularly for nonbowel cancers), and including strategies theorised to bridge the intention-behaviour gap (such as coping planning).This would provide insight into the modifications most likely to enhance the intervention's effectiveness.It is important to note that the success of advance notification may also depend on the characteristics of the recipients, such as receipt of a previous screening invitation.Person-level factors should also be explored in relation to its effect on screening uptake.These avenues of research can inform understanding of the mechanisms that underly advance notification and the design of future interventions targeting cancer screening participation.
Characteristics of the 32 studies included for review.Features and effect on cancer screening participation of the advance notification interventions (n = 33).
COLLINS ET AL.T A B L E 1 a Study was an economic analysis of the cost-effectiveness of the use of an advance notification letter in the Australian National Bowel Cancer Screening Program and was based on a simulated population.T A B L E 2 Types of information reported in advance notifications from inductive content analysis (n = 22).
T A B L E 3 "Bowel cancer is one of the most common cancers in Australia.The risk of developing the disease is increased in those aged 50 years and over."(mail, bowel) Urgency "Please complete and return the kit as soon as you can." (mail, bowel) (Continues) COLLINS ET AL.