Social capital interventions for HPV immunization and cervical cancer screening

Abstract

Background: Social capital can be used as a conceptual framework to include social context as a predictor of human papillomavirus (HPV) vaccination and cervical cancer screening behaviours. However, the effectiveness of interventions that use social capital as a mechanism to improve uptake of immunization and screening remains elusive.

Objective: To synthesize empirical evidence on the impact of social capital interventions on HPV immunization and cervical cancer screening and describe key characteristics of such interventions.

Methods: Using a rapid review methodology, a search of literature published between 2012 and 2022 was conducted in four databases. Two researchers assessed the studies according to inclusion criteria in a three-step screening process. Studies were assessed for quality and data concerning social capital and equity components and intervention impact were extracted and analyzed using narrative synthesis.

Results: Seven studies met the inclusion criteria. Studies found improved knowledge, beliefs and intentions regarding HPV immunization and cervical cancer screening. None of the studies improved uptake of immunization; however, three studies found post-intervention improvements in uptake of cervical cancer screening. All studies either tailored their interventions to meet the needs of specific groups or described results for specific disadvantaged groups.

Conclusion: Limited evidence suggests that interventions that consider and reflect local context through social capital may be more likely to increase the uptake of HPV immunization and cervical cancer screening. However, further research must be done to bridge the gap in translating improvements in knowledge and intention into HPV immunization and cervical cancer screening behaviours.

Introduction

Human papillomavirus (HPV) is the most common sexually transmitted infection in North America, affecting most sexually active people at least once in their lifetime, if not immunized^{Footnote 1}. Persistent HPV infection can cause cancers of the cervix, as well as the vulva, vagina, penis, anus, mouth and throat^{Footnote 2Footnote 3}. While cervical cancer incidence has slowly declined, it remains the third most common cancer among people with a cervix aged 35–44 years^{Footnote 4}. Due to social and structural determinants, inequities in HPV infection rates and incidence of cervical cancer are also experienced by Indigenous people, immigrants, sexual and gender minorities and residents in rural and remote communities^{Footnote 1Footnote 5}. Therefore, slowing the spread of HPV infection and eliminating the incidence of cervical cancer through evidence-based, equitable interventions to improve prevention remains a pressing public health concern.

Morbidity and mortality of cervical cancer can be reduced or eliminated through primary and secondary prevention against HPV. In Canada, publicly funded vaccination programs in school, community and healthcare settings^{Footnote 6} have proven to be a highly effective primary prevention strategy for HPV infection and high-risk precancerous cervical lesions^{Footnote 1}. Secondary prevention through publicly funded cervical cancer screening programs (e.g., Pap smears and self-sampling test kits) can also detect cell changes to be treated before they progress to cervical cancer^{Footnote 4}. The provincial and territorial final dose uptake rate for HPV vaccination in schools ranges from 57% to 91%^{Footnote 7}, while adherence to recommended cervical cancer screening guidelines across the country also ranges, from 63% to 71%^{Footnote 4}.

Human papillomavirus immunization and cervical cancer screening behaviours are complex and influenced by numerous factors, including lack of information, vaccine hesitancy and gaps in access and financial coverage^{Footnote 6Footnote 8}. Social capital has been used as a conceptual framework to broaden the lens beyond conventional predictors of immunization and screening behaviours to include social context. Within public health, social capital most often refers to the resources available to people through their social networks (e.g., families, workplaces)^{Footnote 9}. Indicators of social capital fall into two dimensions: cognitive social capital (subjective perception of level of trust, sharing and reciprocity) and structural social capital (observable extent of social participation)^{Footnote 9}. Social capital is further understood through three functions: bonding social capital (resources accessed within groups that have similar socioeconomic and demographic characteristics), bridging social capital (resources that may be accessed across groups with different characteristics) and linking social capital (networks of trust connecting groups with differences in power)^{Footnote 9}.

Social capital interventions represent activities aimed at improving health through changes in an individual's or group's capacity to mobilize social capital^{Footnote 9}, including social norms, social cohesion, community networks, connectedness, belonging and reciprocity. For instance, social capital may help provide underserved individuals with information, financial assistance or transportation to access immunization programs. Such interventions may enhance individual uptake of cancer prevention behaviours, thereby reducing cancer incidence and mitigating cancer-related inequities^{Footnote 8}. However, there is limited knowledge concerning social capital as a mechanism to improve uptake of HPV immunization and cervical cancer screening. This paper aimed to synthesize empirical evidence on the impact of social capital interventions on HPV immunization and cervical cancer screening and describe key characteristics of such interventions.

Methods

Evidence concerning social capital and HPV-related cancer prevention was required for the development of a provincial-based intervention to reduce HPV-related cancers in Alberta. Accordingly, a rapid review methodology^{Footnote 10Footnote 11} was chosen for evidence-based, rapid decision-making. The research question was: What is the empirical evidence of the impact of social capital interventions on uptake of HPV immunization and/or cervical cancer screening (secondary prevention) to prevent HPV-associated cancers?

The search strategy was developed by a librarian in collaboration with content experts, from May 6 to June 22, 2022. The search strategy included testing, language, development, peer review, translations and deduping. The search was conducted in Ovid Medline, Ovid PsycINFO, Ovid Embase and EBSCOhost CINAHL on June 22, 2022 (the search protocol, including full search strategies, is available upon request). Studies were included if they were peer-reviewed intervention studies, systematic reviews, or meta-analyses published in English between 2012 and 2022 (see Appendix, Table A1 for inclusion and exclusion criteria).

Following a three-step screening process, two researchers began by independently conducting title-abstract screening for the same set of 10% of the studies. A third researcher helped resolve discrepancies. When an inter-rater agreement of 100% was reached, the database was split into two. The same two researchers completed the primary screening separately using half of the database each. This process was repeated for full text screening. Finally, the references of included studies were screened for potential inclusion. No protocol outlining all methodological steps in our rapid review was developed a priori or registered in an open-source platform.

One researcher extracted data (e.g., participants' characteristics, study limitations) from the studies using Microsoft Excel and a second researcher verified the data (available upon request). Through group discussion, social capital was categorized by dimensions and functions. The PROGRESS-Plus^{Footnote 12} characteristics from Cochrane Equity were used to organize findings by social factors influencing health inequities. Quality appraisal was performed independently by two researchers for 10% of studies using the Quality Assessment Tool for Quantitative Studies^{Footnote 13}. After achieving an inter-rater agreement of 100%, the two researchers completed the remaining quality appraisals. They discussed their independent scoring with each other to determine the final rating (see Appendix, Table A2). The 2020 PRISMA checklist^{Footnote 14} was used as a reporting guideline for our rapid review findings.

Due to heterogeneity of the data from the included studies, a meta-analysis could not be conducted. Rather, the evidence was synthesized narratively and thematically according to the social dimensions and functions of the interventions and social factors considered. The analysis focused on the characteristics of social capital interventions and their impact on HPV immunization and cervical cancer screening (e.g., uptake, knowledge, intentions).

Results

Overview

The search produced 2,873 studies. Through primary screening, 103 studies met the inclusion criteria. In the secondary screening, 97 studies were excluded. In the reference list screening process, one study met the inclusion criteria. This review included seven studies^{Footnote 15Footnote 16Footnote 17Footnote 18Footnote 19Footnote 20Footnote 21} (Figure 1).

Figure 1 - Text description

Process	n
Primary Screening
Number of studies imported for screening	2,873
Number of duplicates removed	8
Number of studies screened	2,865
Number of irrelevant studies removed	2,762
Secondary Screening
Number of full text studies assessed for eligibility	103
Number of studies excluded	97 (33 wrong interventions; 33 wrong outcomes; 31 wrong study designs)
Number of included studies	6
Included
Number of studies included from reference screening	1
Total studies included	7 (3 one-group quasi-experimental design studies; 2 non-equivalent quasi-experimental controlled design studies; 1 two-group quasi-experimental design study; 1 randomized controlled trial)

Key characteristics

Table 1 summarizes the key characteristics of the included studies. Most studies were conducted in the United States^{Footnote 15Footnote 17Footnote 18Footnote 19Footnote 20}. Six were quasi-experimental studies^{Footnote 15Footnote 16Footnote 17Footnote 18Footnote 20Footnote 21} and one was a randomized control trial^{Footnote 19}. All seven studies had an educational component. Six studies incorporated culture into the educational component by utilizing co-ethnic health professionals or lay health educators who came from the same ethnic groups and/or spoke the same language as the participants^{Footnote 15Footnote 17Footnote 18Footnote 19Footnote 20Footnote 21}. All seven studies included a cognitive dimension of social capital and two studies had a structural dimension of social capital^{Footnote 19Footnote 21}. All studies had a bonding and bridging function of social capital and five had a linking component^{Footnote 16Footnote 17Footnote 19Footnote 20Footnote 21}. Six studies had a "weak" quality rating score^{Footnote 15Footnote 17Footnote 18Footnote 19Footnote 20Footnote 21} and one received a "moderate" rating^{Footnote 16} (Appendix, Table A2). Overall, the evidence was weak due to data collection methods, withdrawal reporting and limitations of blinding.

Impact on human papillomavirus immunization

Only two studies reported the impact of social capital on HPV immunization^{Footnote 15Footnote 19} (Table 2). Factors associated with uptake included: HPV immunization-related knowledge; perceptions about one's susceptibility to HPV; understanding the risks of HPV-related diseases and benefits of the immunization; intentions to be vaccinated for HPV; and immunization behaviours. One culturally appropriate, community-based education program delivered by co-ethnic health professionals resulted in significant improvement in mothers' knowledge, beliefs and intentions to immunize their own children^{Footnote 15}. However, there were no statistically significant differences in HPV immunization uptake among children within a six-month time frame. A narrative intervention also resulted in higher levels of intention to immunize among girls, but no differences in actual HPV immunization uptake^{Footnote 19}. Due to the combination of multiple components (e.g., social capital and education) in the intervention, the effects of each component on the outcomes were not described. Despite improving knowledge, beliefs and intentions around HPV immunization, both studies reported the ineffectiveness of educational and narrative interventions in improving HPV immunization uptake in girls and their mothers^{Footnote 15Footnote 19}.

Impact on cervical cancer screening

Five studies found mixed results regarding the impact of social capital on cervical cancer screening^{Footnote 16Footnote 17Footnote 18Footnote 20Footnote 21} (Table 3). One study on Pap smear testing found no significant differences in subjective norms and perceived behavioural control between the groups receiving and not receiving an educational intervention^{Footnote 16}. However, these factors increased significantly among the participants within the education intervention groups, according to pre-post analysis. Two other studies found that the group format of the educational sessions contributed to higher overall scores in emotional, instrumental, reciprocal and perceived social support^{Footnote 17Footnote 18}. One study in local community and faith-based settings examined the knowledge, attitudes and uptake of HPV self-sampling tests that were provided by bilingual health educators^{Footnote 18}. All participants completed the HPV self-sample test, with most participants reporting that they were "comfortable/very comfortable" with self-sampling.

Groups receiving educational interventions reported outcomes that included increased knowledge related to cervical cancer and screening procedures, improved understanding of perceived susceptibility to HPV (i.e., the belief that one is likely to get HPV or HPV-related disease), severity of cervical cancer (i.e., risk and seriousness of HPV, HPV-related disease and associated complications to one's life), benefits of cervical cancer screening (i.e., reduction of risk and severity of getting HPV and HPV-related disease), increased intentions for cervical cancer screening uptake and greater uptake of the Pap smear test (e.g., administered by a physician or HPV self-sampling test)^{Footnote 16Footnote 18Footnote 20Footnote 21}. Among the four studies that included uptake measures^{Footnote 12Footnote 13Footnote 14Footnote 17}, three reported increased cervical cancer screening uptake^{Footnote 16Footnote 18Footnote 21}. One study found no significant differences in cervical cancer screening uptake between the cohort receiving education sessions in groups to promote social capital and the cohort receiving the session individually with no social capital component^{Footnote 17}. However, it also found that cervical cancer screening increased in both group and individual education sessions.

Equity considerations

Table 4 presents equity-related findings on HPV immunization and cervical cancer. The studies either tailored their interventions to meet the needs of specific groups or described results for specific disadvantaged groups (e.g., immigrants) considering, for example, education level and gender and/or sex.

Discussion

To our knowledge, this is the first review of social capital interventions in public health regarding HPV immunization and cervical cancer screening. Despite interest in the use of social capital to improve cancer outcomes^{Footnote 8Footnote 22Footnote 23}, only seven papers met this review's inclusion criteria. Concerning primary prevention, education interventions containing social capital dimensions and/or functions were found to increase HPV immunization knowledge, attitudes and intentions. They successfully addressed concerns, fears and doubts for providing accurate information, building a trustworthy relationship between participants and researchers or providers and meeting participants' life circumstances and sociocultural needs. However, they seemed to have failed in bridging the intention-uptake gap in HPV immunization. This finding speaks to the recognition that knowledge is only one of the multiple determinants of vaccine decision-making, as some vaccine-hesitant people delay or refuse vaccination after educational interventions^{Footnote 24}. Pairing social capital interventions with a vaccine offer or immunization appointment scheduling at the end of the intervention may effectively increase uptake. For those with limited access to the healthcare system, school-based health outreach and partnerships with communities should be part of the strategy to build multisectoral delivery platforms for vaccination and to promote uptake following educational intervention^{Footnote 25}.

Regarding secondary prevention, this review found that interventions improved several outcomes including knowledge on cervical cancer and screening procedures; understanding of perceived susceptibility to and severity of HPV infection and cervical cancer; benefits and intentions of cervical cancer screening; and emotional, instrumental, reciprocal and perceived social support. Among the four studies analyzing the uptake of cervical cancer screening, three found increased uptake. These three studies used the health belief model in the design of their interventions, which seeks to change an individual's beliefs, knowledge and perceived benefits and risks to positively influence their health behaviours^{Footnote 26}. This finding may indicate the value of using a theoretical health behaviour change model alongside dimensions of social capital to guide cervical cancer screening interventions. While our findings do not allow us to infer how much contribution social capital made on cervical cancer screening uptake, they indicate that social capital plays a role and should be a component in screening interventions. Further research should consider the influences of other factors on participation in cervical cancer screening (e.g., limited access to sexual and reproductive healthcare programs).

Consistent with the current literature, this review's findings support the need for interventions to consider perceptions of social capital in different contexts and to reflect the multidimensional factors influencing people's decision-making on HPV immunization and cervical cancer screening^{Footnote 27}. To create an environment conducive to positive HPV-related knowledge, intentions and behaviours, social capital interventions should address perceived social and structural barriers like affordability and accessibility of immunization and screening programs. Anticipating contextual barriers that jeopardize the success of social capital interventions for increasing uptake requires moving away from half measures such as charging for HPV vaccines or limiting vaccination appointments to work hours. The World Health Organization has called for actions to ensure affordability and expansion of HPV vaccination and cervical cancer screening coverage^{Footnote 28}, including single dose for adolescents to reduce costs and burden to the healthcare system and incorporation of cervical cancer screening into state health insurance schemes to address social inequities in secondary prevention. The World Health Organization also recommends developing partnerships between the public health sector and public, private and non-profit organizations to roll out services and address constraints in HPV vaccine supply and devices for cervical cancer diagnostics^{Footnote 25Footnote 28}.

Most studies in this review specified their HPV immunization target populations as "girls" and "women" and only one included mention of "boys." None of the studies focused on members of the Lesbian, Gay, Bisexual, Transgender, Queer and Questioning and Two-Spirit (LGBTQ2S+) community. This reflects an overlook of gender identity and sexual diversity in interventions utilizing social capital. Trends examining HPV immunization rates indicate a greater gap in HPV immunization rates among males generally and that HPV-related cancer rates are predicted to rise among populations who do not have a cervix^{Footnote 29}. This may be due to the prior focus of HPV vaccine promotions to prevent cervical cancer, which continues to act as a barrier for uptake of the newer nonavalent HPV vaccine that protects against oropharyngeal, anogenital and cervical cancer-causing strains of HPV. The LGBTQ2S+ community is more likely to experience an HPV infection and less likely to receive an HPV vaccine than heterosexual groups^{Footnote 30Footnote 31Footnote 32}. Social support may support HPV vaccine uptake among LGBTQ2S+ people^{Footnote 33}. As HPV infects both biological males and females and can lead to cancer in any person irrespective of their gender identity or sexual orientation, future research should expand the evidence base concerning interventions utilizing social capital targeting LGBTQ2S+ populations and biological males.

Limitations

The strengths of this rapid review include the use of a systematic methodology for screening and data extraction and analysis, assessment of methodological quality and consideration of social factors. However, data synthesis was limited to a small sample of studies, which may reflect the heterogeneity of study designs and measures. As the included studies focused on interventions across the world, the generalizability, transferability and applicability of the review findings are context-dependent and the unique circumstances of each region and population should be considered. This creates opportunity for future research and implementation work focusing on the unique knowledge and awareness needs of each population, such that HPV immunization and cervical cancer screening is promoted as an autonomous, yet supported, culturally appropriate decision among disadvantaged populations.

Conclusion

This rapid review examined the evidence concerning the characteristics and impact of interventions utilizing social capital on HPV immunization and cervical cancer screening. It found limited and mixed results regarding the use of social capital as a mechanism to improve uptake of HPV immunization and cervical cancer screening. However, evidence suggests that interventions that consider and reflect the local context may increase the uptake of HPV immunization and cervical cancer screening. Given the strength of evidence from experiments and quasi-experiments, more research using those design studies are needed to understand the impacts of social capital interventions on HPV immunization and cervical cancer screening. Health researchers examining those programs should consider designing interventions that include social capital components that, for instance, enhance participants' trust of health practitioners and engage with religious leaders. Public health agencies should consider the promising results of culturally appropriate and tailored interventions containing components of social capital for creating positive change in HPV-related knowledge, attitudes, intentions and behaviours toward HPV immunization and cervical cancer screening. Further research must translate these psychological changes into HPV immunization and cervical cancer screening behaviours.

Authors' statement

• CG — Writing–original draft, writing–review & editing
• LKAS — Conceptualization, methodology, writing–review & editing
• CIJN — Conceptualization, methodology, writing–review & editing
• APB — Methodology, formal analysis, writing–review & editing, visualization
• MOK — Formal analysis, writing–review & editing, visualization
• BL — Formal analysis, writing–review & editing, visualization
• LN — Methodology, writing–review & editing, project administration
• KA — Conceptualization, methodology, writing–review & editing
• EMO — Writing–review & editing

The content and view expressed in this article are those of the authors and do not necessarily reflect those of the Government of Canada.

Competing interests

None.

Acknowledgements

We are grateful to the Centre for Healthy Communities librarian for developing the search strategies and running the literature searches.

Funding

Funding provided, in whole or in part, by Alberta Health. Strategic direction and applied research support provided by the Alberta Health Services (AHS) Cancer Prevention and Screening Innovation (CPSI) team. Provision of funding by Alberta Health does not signify that this represents the policies or views of Alberta Health. The content and conclusions in this manuscript are those of the authors and do not necessarily reflect the official position of Alberta Health Services.

Appendix