Abstract

Objectives

To evaluate the immediate impacts of an illustrated book on puberty and periods for girls in the United States (US).

Methods

We conducted a randomized educational intervention between February鈥揗ay 2023 among girls ages 9鈥�12听years in after-school programs in the New York metropolitan area (n鈥�=鈥�123). Girls were assigned to read a book on puberty and periods or an alternative book on healthy eating. We conducted multivariate linear and logistic models to examine changes in knowledge, beliefs/attitudes, and comfort in communicating about puberty and periods between treatment groups using pre- and post-test surveys. We also examined for effect measure modification to assess if changes in knowledge about puberty and periods significantly differed by menarchal status.

Results

The intervention produced an increase in knowledge score (p鈥�<鈥�0.05). Girls in the treatment group compared to the control group were more likely to report positive shifts in beliefs/attitudes towards physical activity during their period and asking questions about periods. Knowledge scores were significantly higher among girls of pre-menarche status compared to girls who had听already experienced their first period (p鈥�=鈥�0.05).

Conclusion

Findings from our educational intervention demonstrated that a simple distribution of an illustrated puberty and period book, without the support of formal instruction, had positive attitude shifts and educational impacts among girls ages 9鈥�12听years. The intervention was efficacious in improving knowledge, particularly among girls who had not yet experienced their first period. Follow-up is needed to assess long-term health and social impacts of simple delivery of pubertal content to adolescents. Our study contributes to filling the gap in understanding the utility of puberty education in the US and our findings underscore the importance of appropriately timed puberty education.

Introduction

Puberty, the transitional period into adolescence, includes significant physical, psychological, and cognitive growth [1]. This critical stage has implications for long-term physical and mental health outcomes; with exposure to puberty guidance essential [2, 3]. During puberty, girls experience particular challenges, largely shaped by their developmental timing, level of knowledge, and preparedness [4]. Black and Hispanic girls, and girls from socioeconomically disadvantaged backgrounds, often experience earlier pubertal onset [5]. Early menarche in particular is associated with poorer body image, lower self-esteem, psychological distress, and poor academic performance [6,7,8]. Inadequate knowledge, preparation and support for the onset of menstruation, and its management and social implications, may lead to earlier sexual debut and adverse health outcomes [9]. More appropriately timed and systematically delivered puberty education 鈥� learning before and soon after changes occur 鈥� may better enable girls to navigate puberty鈥檚 physical and psychosocial changes and mitigate negative health outcomes.

The United Nations Organizations for Education, Science, and Culture (UNESCO) and the Sexuality Information and Education Council of the United States (SIECUS) recommend that by age 12, children should obtain a basic understanding of their body's developmental changes and know where to access medically accurate information about puberty [10, 11]. Yet puberty education is falling short in the United States (US). A 2014 US School Health Policies and Practices Study showed that puberty topics were taught in less than half of elementary and middle schools; more recent data is unavailable [2, 12]. Data on US adolescents鈥� access to puberty education are scarce, along with a dearth of rigorous research on the quality of puberty education delivered in and out of schools. To address this knowledge gap, this study examined the impacts of delivering puberty education via an illustrated book written for early adolescents.

The delivery of US health education in schools varies widely, posing challenges to examining classroom-based instruction including puberty content; the latter of which is often embedded within sex education [2, 13]. Evidence often references sexual and reproductive health (SRH) education, not the narrower content for early adolescence that incorporates pubertal emotional and physical changes [2, 14]. Documentation also suggests that most adolescents receive puberty education in middle and high school [15]. This is past the age of pubertal onset for girls (8鈥�13听years) and boys (9鈥�14听years); thus, most students have experienced the early stages of puberty before their first lesson [16]. Children need to receive puberty education before it occurs, with some rationale, including increased parental/caregiver comfort, for delivering content separately from sex education [14]. More evidence is needed to assess how exposure to puberty education, both in and outside of schools, impacts adolescents鈥� beliefs/attitudes and overall preparedness in navigating the pubertal transition successfully.

In considering how best to deliver puberty content to adolescents, topics that can feel sensitive or complicated, research suggests that adolescents understand the importance of such foundational education, and want accurate information [17]. Supplemental resources such as illustrated puberty books, combining images and text, are potentially useful tools, particularly for those with lower reading levels [18]. While the use of illustrated books as a puberty education tool is not entirely new, formal evaluations of such resources are rare [2]. Findings from these few studies demonstrate improved knowledge and attitudes around puberty and menstruation, though most of these studies were conducted in low- and middle-income countries [19, 20]. To our knowledge, few US-based studies have examined the learning outcomes of puberty books 鈥� as a standalone educational resource 鈥� for girls.

The aim of the present study was to explore a simple approach for delivering puberty content to girls in after-school programs that would not require a significant influx of resources or capacity. Our objective was to test whether a distribution of an illustrated book on girls鈥� puberty and periods improved levels of knowledge, beliefs/attitudes, and comfort in communication on puberty and periods among girls ages 9鈥�12听years. Outcomes were evaluated through an educational intervention incorporating components of the theory of reasoned action, specifically behavioral and normative beliefs, which we hypothesized would increase knowledge and improve attitudes around puberty and periods [21]. We further hypothesized that these changes would be higher among girls ages 9鈥�10 with the assumption that most of the girls in this age group may have received little to no exposure to information around puberty and periods at the time of intervention. Our findings contribute to the limited research on US puberty education and inform implementation of educational interventions among early adolescents.

Methods

The illustrated book of focus integrated first period stories and experiences of low-income and underrepresented girls from across the US to create a book representative of the diversity of American girls. The graphic novel style-format book was developed using participatory methods with US adolescent girls, and presents health content, guidance, and stories, using body positive and inclusive illustrations, to prepare girls to navigate pubertal changes and menstruation. Insights from the development of this book were previously documented in a qualitative assessment of girls鈥� experiences with menstruation and puberty within their families, school environments, and communities [22].

Study design and procedures

We conducted the educational intervention using a randomized design. Prior to recruitment, a power analysis was conducted to determine the sample size needed for this proposed study. Based on findings from a previous study, the calculation was based on an assumed moderate-to-large effect size of 0.6 (Cohen鈥檚 d), with a level of significance of 5% and with a power of 80% [20]. Accounting for a 10% non-response, the minimum sample size required to detect such a significant difference was estimated as n鈥�=鈥�120, with 60 participants in each arm. Recruitment began in November 2023 and the study was conducted between February鈥揗ay 2023. Eligible participants were identified through youth-focused community-based organizations serving low-income and underrepresented girls in after-school programming in the New York metropolitan area (New York County and New Haven County). The research team contacted the organizations, and to reduce potential bias and differences in baseline knowledge, those which included any form of SRH education were excluded. Prior to recruitment, program staff assessed and approved the book鈥檚 reading level and appropriateness. Girls between the ages of 9鈥�12听years enrolled at selected organizations were eligible and invited to participate through providing parents/caregivers information about听the study. A waiver of written informed consent from parents/caregivers was approved by the study team鈥檚 institutional review board (IRB). A passive parental consent (opt-out consent) model was used to obtain permission from parents/caregivers for their child to participate in the study. Of the 198 girls who met the inclusion criteria, 148 participants were initially enrolled across all organizations (Fig.听1). The intervention was conducted during one after-school session at each organization鈥檚 affiliated programming site to reduce loss-to-follow-up. All procedures performed in this study were in accordance with the ethical standards of the institutional research听ethics committee. A waiver of written consent was approved by the IRB for study participants as the study was of minimal risk and involved no procedures for which written consent is normally required. At the beginning of each session, the research team described the study procedures and obtained verbal assent from all participants. The study was approved by the Columbia University IRB.

Fig.听1

Flow diagram of participants through each stage of the randomized intervention. *Participants who reported having seen the book prior to the study (N鈥�=鈥�8)

All girls took part in the randomization activity. Each girl drew a piece of paper, one of two colors, out of a bag. Based on which color was selected, girls were randomly assigned to one of two groups, to read the puberty and periods book (treatment, n鈥�=鈥�78) or a book on nutrition (control, n鈥�=鈥�75) (Fig.听1). The control book was carefully selected to match the treatment book by its reading level, proportion of illustrations, and page听count. The randomization was done in the same room, and the research team was not blinded to treatment allocation.

First, all participants completed the pre-test paper survey. Participants were then asked to read their assigned book, independently and quietly, for approximately one hour. Following the intervention, all participants completed the post-test paper survey. Translated copies of books and survey materials were available in Spanish if needed (n鈥�=鈥�6). Regardless of which intervention book girls were assigned to read, each girl received a copy of the puberty and periods book to keep after study completion.

Outcomes

Data were collected using pre- and post-test surveys distributed to all participants. Survey sections included 1) general information (e.g., demographics, baseline exposure to information related to puberty and periods, whether girls had experienced their first period), 2) puberty and period knowledge, 3) beliefs/attitudes towards puberty and periods, and 4) comfort in communicating about puberty and periods. The primary outcome was change in knowledge and secondary outcomes were changes in beliefs/attitudes and comfortability in talking about puberty and periods. We considered beliefs/attitudes and comfort in communication as secondary outcomes due to the lack of existing valid measures in assessing these constructs. Instead, we examined specific types of beliefs/attitudes and comfort in our analyses.

Knowledge on puberty and periods

There is no validated instrument to measure knowledge on puberty and periods, thus these items were generated from prior literature and adapted referencing terminology and content from the puberty book [23]. Knowledge was assessed through eight True/False/Don鈥檛 Know items (Supplementary Table听1). The calculated Cronbach鈥檚 alpha statistics for both the听Knowledge pre-test items and post-test items were 0.69 and 0.70, respectively, indicating adequate acceptability of the Knowledge test used in our study [24]. For our primary outcome, we examined change scores in knowledge based on a score across all items, with a possible range from 0 to 8. Overall change scores were calculated by subtracting participants鈥� overall pre-test score from their post-test score, which were then calculated and coded to reflect percent change in knowledge score. For our secondary outcomes, we examined change scores for each individual knowledge item to assess which Knowledge items observed significant improvement in correct responses. In these analytical models, change scores for each item were recoded dichotomously to indicate whether a participant improved their score on the post-test (1鈥�=鈥塝es, 0鈥�=鈥塏o).

Beliefs/attitudes towards puberty and periods

We developed questions which measured various aspects of beliefs/attitudes towards puberty presented throughout the book. We referenced items from the Menstrual Attitude Questionnaire and Beliefs about and Attitude Towards Menstruation, which were then adapted to suit both pre- and post-menarche girls to answer [25, 26]. Beliefs/attitudes were assessed on a 5-Likert scale ranging from 鈥淎gree a lot鈥� to 鈥淒isagree a lot鈥� for 10 items (Supplemental Table 2a). We examined changes for each statement by calculating change scores. Positive scores indicated desirable changes in beliefs/attitudes towards puberty and periods. Changes for each statement were then coded dichotomously to indicate a positive shift (=鈥�1) or no shift (=鈥�0) for each statement (Supplemental Table 2b).

Comfort in communication

In an effort to examine how the 鈥淔irst Period鈥� stories presented in the book influenced comfort in communication, we asked participants how comfortable they would be talking about puberty and periods to the following types of people in their lives:1) any female family member, 2) any male family member, 3) a friend, 4) a female teacher, 5) a male teacher, 6) a school nurse, 7) a female doctor, and 8) a male doctor. Comfort levels were assessed on a 5-Likert scale ranging from 鈥淰ery Comfortable鈥� to 鈥淣ot At all Comfortable鈥�. Change in comfortability for each type of individual was calculated and then dichotomously coded to identify any positive shifts in comfortability. In other words, whether participants felt more comfortable talking about puberty and periods for each type of person following the intervention (1鈥�=鈥塝es, 0鈥�=鈥塏o).

Statistical analyses

We conducted an intention-to-treat protocol to analyze participants鈥� outcomes relative to their assigned treatment group, regardless of how much of the book they actually read. We first conducted bivariate analyses to assess the independent associations between all outcomes and treatment group. We then conducted an unadjusted model followed by a multivariable regression model, controlling for grade, race/ethnicity, county, and menarche status, to compare changes in knowledge, beliefs/attitudes, and comfort in communication between groups. We also examined effect modification by menarche status, whether or not a participant had experienced their first period by time of study. By including an interaction term in a separate linear regression model, we assessed whether the association between groups and overall knowledge change differed by menarche status. To address missingness in the data, we implemented multiple imputation using the multivariate imputation by chained equations algorithm to replace missing values with plausible replacement values based on statistical characteristics of the data [27]. Statistical significance was defined at p鈥�&濒迟;鈥�0.05.

Results

Most participants (83%) randomized into the intervention were present for the entire study duration. Full attendance rates varied at each site due to unanticipated early parent/caregiver pick-up times, however incomplete attendance rates were relatively comparable by region and treatment group (Fig.听1). In addition, participants who reported having seen the book prior to the study were removed from analysis (n鈥�=鈥�8). Our final analytical sample included girls who fully attended the intervention and completed both the pre- and post-test surveys (n鈥�=鈥�123). Study sample characteristics stratified by treatment group and region are shown in Table听1. The majority of participants were 11听years old (26.8%) and in the sixth grade (27.6%). Nearly forty percent of girls self-identified as Hispanic or Latina (39.8%) and approximately thirty percent of girls self-identified as Non-Hispanic Black (30.9%). Over fifty percent of participants had not had their first period at the time of study (52%). At baseline, the majority of participants reported not having yet learned about puberty (60.5%) or periods (75.6%) in school. However, over half of them responded knowing where to get this information (59.2%) and more than half of the sample responded having 鈥渟ome basic information鈥� about puberty (56.7%) and periods (50.4%). Nearly half of participants expressed interest in learning more about these topics (48.3%). The mean pre- and post-test Knowledge scores were 5.96 (Standard Deviation [SD]: 1.83) and 6.29 (SD: 1.80), respectively. At baseline, approximately a third of participants felt 鈥淰ery comfortable鈥� talking to anyone about puberty and periods (34.7%). Demographics and baseline knowledge levels were similar between the treatment (n鈥�=鈥�65) and the control group (n鈥�=鈥�58), indicating that the randomization activity was successful.

Table 1 Characteristics of study participants stratified by treatment and control group (N鈥�=鈥�123)

Primary outcome

Following the intervention, the mean post-test knowledge score for the treatment group (6.65, SD: 1.70) was significantly higher than the mean post-test score (5.90, SD: 1.84) for the control group (p鈥�<鈥�0.05). Results from the analytical models demonstrated positive findings for overall knowledge change (Table听2). On average, girls who read the puberty book had an 8% increase (0.08, 95% Confidence Interval [CI]: 0.04鈥�0.13) in overall knowledge score compared to those who read the alternative book. We also observed significant interaction (p鈥�=鈥�0.05) by intervention and menarche status (Model 3, Table听2). The intervention had a stronger effect among pre-menarche girls compared to post-menarche girls. Those who had not yet had their period had an average 12% increase in knowledge score (0.12, 95% CI: 0.06 鈥� 0.18), a significant difference than those who already had their period (0.03, 95% CI: -0.04, 0.09).

Table 2 Multivariate linear regression model for measuring the impact of an illustrated puberty book on girls鈥� overall knowledge (N鈥�=鈥�123)

Secondary outcomes

We examined individual knowledge items in adjusted logistic regression models and observed significant associations for three of the eight items (Models 1, 2, and 3 in Table听3): 1) 鈥淧imples and body smells are normal signs of body changes during puberty鈥� (adjusted Odds Ratio [aOR]: 11.01, 95% CI: 1.2, 100.63), 2) 鈥淭here is only one type of period care product to use鈥� (aOR: 3.36, 95% CI: 0.95, 11.88), and 3) 鈥淚t is safe to exercise and play sports during your period鈥� (aOR: 8.09, 95% CI: 2.04, 32.15).

Table 3 Multivariate logistic regression models for measuring the impact of an illustrated puberty book on secondary outcomes related to pubertal-related knowledge questions, beliefs, and attitudes (N鈥�=鈥�123)

The pre-test and post-test mean scores and any positive shift changes of beliefs/attitudes towards puberty and period among study participants by intervention group are shown in Supplemental Tables 2a and 2b. Participants in the treatment group compared to the control group experienced positive shifts for several beliefs/attitudes (Table听3). Girls in the treatment group had more than two times the odds of experiencing a positive shift towards 鈥淚t鈥檚 embarrassing to ask questions about periods鈥� compared to those in the control group (aOR: 2.64, 95% CI: 1.04, 6.72). A stronger association was observed for beliefs towards 鈥淕irls should avoid exercise during their period鈥�, in that, girls in the treatment group had more than three times the odds of having a positive shift compared to those in the control group (aOR: 3.31, 95% CI: 1.43, 7.63). We did not observe any differences in levels of comfort in communication between the groups.

Discussion

Our study is among the first to evaluate learning outcomes associated with reading an illustrated educational book on puberty and periods written for girls in the US. Findings showed that girls who were randomly assigned to read the puberty book, independently and without instruction, experienced an overall increase in knowledge, specifically related to physical body changes, types of period products, and safety of exercise during one鈥檚 period. Compared to those randomly assigned to the control group, girls who read the puberty book reported positive shifts in attitudes towards asking questions about periods and beliefs about exercising during their period. Our study鈥檚 novel findings contribute to the limited research on supplemental puberty education and its impacts on girls鈥� knowledge and attitudes towards puberty. While a plethora of related books written for girls in the US have existed in the last few decades, there have been few, if any, rigorous evaluations conducted of their content or delivery. This study鈥檚 findings support our main hypothesis that an opportunity to read an educational book about puberty and periods, even in a brief amount of time, has positive impacts on girls鈥� knowledge and beliefs/attitudes. While only immediate impacts were examined, they may be better maintained than classroom-based instruction since girls were able to keep the books to re-read and share knowledge with others.

Research on puberty programs in high-income countries is lacking, although findings from a US-based intervention using educational videos on pubertal health demonstrated some critical insights [28]. The content, delivered in three 5-min videos, increased knowledge, but did not impact participants鈥� attitudes towards puberty. Adolescents may need longer and/or repeated exposure to content in order to shift beliefs/attitudes, perhaps in the form of illustrated books. While there are reports of interest and uptake of puberty books across the US, formal evaluations provide evidence for increasing resources, and social and political commitment to improving the accessibility of puberty books [3]. Our study centered around the delivery of a puberty book developed through participatory research with girls across the country. We utilized a simple approach to deliver and evaluate the educational intervention (simply reading, no activities), and observed positive outcomes for girls鈥� knowledge and attitudes related to physical activity during menstruation. The book鈥檚 impacts on specific menstrual heath attitudes are a novel contribution to this limited research area. The negative impacts of menstruation on girls鈥� participation in physical activities have been documented in previous qualitative studies [22, 29]. Many girls share sociocultural and familial beliefs around menstruation which lead them to refrain from physical activity during school. The benefits and common myths around physical activity/exercise during menstruation is highlighted in several sections of the puberty book and it is likely that girls responded well to this repeated messaging.

The age of pubertal onset among girls in the US is declining, with the average onset now 11.9听years old, and girls within the same age group or grade level may be experiencing different stages of puberty [30]. Also important, a recent prospective study conducted in Northern California found that Black and Hispanic girls experience earlier onset of puberty relative to White girls, consistent with previous trend studies on pubertal timing and menarche [5]. We found that increased knowledge was significantly higher among girls who had not yet experienced their first period at the time of study. Our findings on girls of pre-menarche status underscores the importance of targeting earlier learning, such as grades 4 and 5, for pubertal health education. Equitable access and exposure to puberty content helps young people to feel more prepared, and also may reduce the risk of adverse health outcomes during adolescence and later adulthood [4, 5, 31].

Decades of pedagogical learning suggests the value of words and images in instructional settings. The use of comic books, graphic novels, and other types of visual aids as educational formats for health promotion among adolescents is increasing [32, 33]. Delivering puberty education in the form of illustrated standalone books has been a valuable tool in other parts of the world where this information is not covered in school [3] Oftentimes, school-based puberty education focuses only on the biological aspects of puberty, while guidance on physical and emotional changes, and managing periods is not covered [34]. In contrast, puberty (and period) books aim to inform young people about their changing bodies and emotions, help them feel more capable to ask questions from trusted individuals, and provide practical guidance on how to navigate new and complex experiences. They may also serve as supplementary resources for school-based puberty instruction, such as in school libraries, through delivery at youth-focused organizations or by parents/caregivers. Existing research suggests that families are often not confident in delivering puberty education to their children, thus creating a further need for a supplementary, or non-curriculum approach [22, 35].

Limitations

The study had several limitations to note. One, conducting a same-day intervention reduced the scope of relevant outcomes that could be evaluated, such as changes in behavior or long-term knowledge retention. Future evaluations should include longer follow-up periods. Two, we conducted the intervention in programs which occurred after a full day of instructional learning. Participants were more likely to feel fatigued and less likely to engage with the book to their fullest potential. Third, the book is targeted at younger reading levels and survey instruments underwent several rounds of field-testing, however we did not formally assess participants鈥� literacy levels. However, program staff reviewed and approved the materials beforehand. Fourth, we acknowledge the loss in granularity in our analysis of belief/attitudes, though these were our secondary outcomes. We were primarily interested in whether there was any positive shift following the intervention. Lastly, our measure of comfort was found to be inadequate. Comfort in communicating about body changes is multifaceted and impacted by different socio-cultural beliefs. Any changes in comfortability are more likely to occur with repeated exposure to the book over time. Results from the evaluation of an illustrated book on puberty and periods have important implications for research and the provision of puberty education in the US. Although our intervention was geographically limited to the New York metropolitan area, we focused on an understudied, hard-to-reach, and historically minoritized population. Our research emphasizes the need for future studies to replicate and build on these findings.

Conclusions

Our study contributes to filling the significant gap on the utility of supplemental puberty education. We demonstrated that a simple distribution of a book, without the support of formal instruction, had positive attitude shifts and educational impacts for girls. Further evaluations of puberty education resources are needed, including populations in diverse geographical and sociocultural contexts across the US. Our findings underscore the importance of appropriately timed puberty education, and overall, this study demonstrates the value of puberty books as a supplemental resource that, with greater visibility and accessibility, can fulfill an unmet health and educational need for US girls.