Acceptability and Preference for Human Papillomavirus Self-Sampling among Thai Women attending National Cancer Institute

Background: Cervical cancer screening is an important public health strategy to reduce cervical cancer incidence and mortality. Human papillomavirus (HPV) self-sampling is the alternative method that can potentially increase participation in cervical cancer screening. This study aimed to evaluate the acceptability of HPV self-sampling as a primary cervical cancer screening among Thai women. Methods: A cross-sectional study was conducted at National Cancer Institute, Thailand, between March and September 2021. Eligible women were invited to collect their own samples with a vaginal cotton swab for cervical screening. The data on demographics, acceptability, and preference for HPV self-sampling were collected via a self-administered questionnaire. A Likert scale was used to assess the response of self-sampling acceptability. The multivariable logistic regression determined factors that influence preference for HPV self-sampling. Results: A total of 265 participants were recruited. Over 70% agreed that self-sampling was easy, less embarrassing, and not painful. They also felt confident in their ability to self-sample correctly and would recommend this method to a friend or relative. For their next screening round, 66.4% preferred self-sampling whereas 33.6% preferred clinician-collected samples as routine screening. The factors that influence preference for self-sampling were age, marital status, feeling less embarrassed, and confidence in performing the tests. Conclusions: Most of the study participants accepted HPV self-sampling. This suggests that the self-sampling method will be an additional option to increase cervical cancer screening coverage which leads to improving the effectiveness of the national program.


Introduction
The national cervical screening program was introduced in Thailand in 2005 to reduce the incidence of invasive cancer of the cervix. A Pap smear was used as the primary screening test for cervical cancer, which has now been replaced by human papillomavirus (HPV) testing since 2020. Although an organized screening program has been implemented for over 15 years, cervical cancer continues to be a major public health problem affecting Thai women and still ranks as the fifth most common cancer in Thailand with an age-standardized rate (ASR) of 11.1 per 100,000 (Rojanamatin et al., 2021).
Several studies have shown that the successful implementation of cervical cancer screening depends on being able to achieve high screening coverage for women in the at-risk age group (Aoki et al., 2020;Bruni et al., 2022). related to cervical cancer screening (Haile et al., 2020;Serrano et al., 2022). Various studies have shown high concordance between HPV screening results from self-and physician-sampling specimens (Petignat et al., 2007;Onuma et al., 2020). Moreover, self-sampling was reported to be highly acceptable among women, and that would increase participation uptake in cervical screening programs (Yeh et al., 2019).
The present study aimed to evaluate the acceptability of HPV self-sampling as a primary cervical cancer screening among Thai women. We also examined attitudes and demographic variables affecting the preferences for HPV self-sampling. These findings will provide basic information to overcome the multiple barriers and enhance the coverage of cervical cancer screening in Thailand.

Study population
This cross-sectional study was conducted at National Cancer Institute, Bangkok, Thailand from March to September 2021. Participant eligibility criteria were as follows: (1) women aged 30-60 years who enrolled in cervical cancer screening clinic and gynecology clinic; (2) undergoing both self-sampling and clinician-based sampling; and (3) understanding the research background and willing to provide informed consent. The exclusion criteria were not meet eligibility criteria, pregnancy, or previous hysterectomy. Ethical approval for this study was obtained from the Ethics Committee of the National Cancer Institute (reference EC COA 026/2020).
Before starting the study process, participants were provided all information about the study's purpose. They were assured that their information would be kept private and confidential. After signing a written informed consent, participants were included in the study.

Study design
Participants were invited to perform HPV self-sampling using a vaginal cotton swab. The research staff explained step-by-step how to self-collect through written instructions diagrams, and tutorial videos until they fully understood the study procedures. Then a self-sampling kit (Aptima Multitest Swab Specimen Collection Kit, Hologic Inc., Marlborough MA, USA) was provided to each participant. Participants collected their own specimens in a private room and returned these to staff, then they underwent gynecological examination. After that, they were asked to complete the self-administered paper questionnaire about their acceptability of the self-sampling procedure.

Data collection
A self-administered questionnaire was developed using a validated structured questionnaire from the literature review of similar published studies to cover critical areas. Data collection consisted of three main parts. The first part was used to collect demographic characteristics information including age, education level, monthly income, marital status, menstruation, and previous Pap test experience. The second part assessed the acceptability of HPV self-sampling which included five indices: easy and convenient to perform, less embarrassment, not painful, confidence in performing the procedure, and would recommend self-sampling to a friend or relative. A five-point Likert scale was used to collect data. The rating scales range from 1 to 5 as follows: 1= "Strongly disagree", 2= "Disagree", 3= "Neither agree nor disagree", 4= "Agree", 5= "Strongly agree". A score point was used to classify into two groups of participants. Those who scored 4 or 5 were considered as having a positive response (deemed as acceptable), whereas those who scored below were categorized as negative responses toward HPV self-sampling for cervical cancer screening. In the third part, participants were asked about their preference for self-sampling compared with clinician-collected samples for the purpose of routine cervical cancer screening. The questionnaire took approximately 10-15 minutes to complete all questions.

Statistical analysis
Data was collected using Microsoft Excel and then exported to the Statistical Package for Social Science program, version 26 (IBM SPSS statistics 26) for final analysis. Cronbach Alpha coefficient was used to assess the internal consistency of the questionnaire, a value of ≥0.7 indicated good reliability of a construct. Descriptive results for categorical variables were presented as frequencies and percentages while continuous variables were expressed as mean and standard deviation. The association between independent variables and preference for HPV self-sampling was evaluated using multivariate logistic regression. The adjusted odds ratios with 95% confidence intervals (CI) were calculated as a measure of association. The P-value of less than 0.05 was considered statistically significant.

Participant characteristics
Of 268 eligible participants, 265 of them completed the survey questionnaire. The demographic characteristics of participants were shown in Table 1. Approximately 45% of participants were 50 years or older. The mean age was 47.5 years with a standard deviation of 8.3 years. Most participants (56.2%) were holding a diploma and bachelor's degree, 63.8% had a monthly income of over 30,000 Bath and 65.7% were married. Concerning their health information, 56.6% had regular menstrual and 91.7% had ever been screened for cervical cancer.

Acceptability of HPV self-sampling
The acceptability of HPV self-sampling was evaluated in five attitude indices as shown in Table 2. Overall, most of the participants provided a positive response (scored 4 and 5 on the Likert scale) in all five indices. 93.6% (248) of participants declared that the self-sampling was easy and convenient to perform, 86.4% (229) felt less embarrassed with the self-sampling, 92.5% (245) considered it did not cause pain, 73.2% (194) expressed confidence in performing the procedure, and 89.4% (237) stated that they would recommend self-test to a friend or relative.

Discussion
The present study was conducted to evaluate women's acceptability of HPV self-sampling and explored the key factors that could influence the preference for self-sampling. Overall, the results demonstrate that the majority of participants had a positive attitude toward self-sampling, more than 70% expressed that the self-sampling method was easy to perform, less embarrassing, and not painful. Also, they feel confident in their ability to self-sample correctly and would recommend this method to a friend or relative. These responses indicated that self-sampling was a well-accepted method among our study participants and will be a powerful strategy to overcome barriers to cervical cancer screening. These results are in line with those of previous studies (Sultana et al., 2015;Mulki and Withers, 2021;Chaw et al., 2022). In addition, the assessment of preference for self-sampling revealed that most of the participants (66.4%) were willing to repeat the HPV self-sampling as a routine cervical screening test. Our finding was consistent with studies undertaken in the USA, Greece, and Korea indicating the women's preference for self-sampling ranged from 51 to 86% (Mao et al., 2017;Chatzistamatiou et al., 2017;Shin et al., 2019).
Multivariate analysis showed that various variables were associated with a preference for HPV self-sampling. Women in the younger age group were significantly more likely to prefer self-sampling compared to the older age group. There is the possibility that the older age group may have experienced conventional smears previously and feel more confident with clinician sampling. This agrees with the Netherlands' study which reported that younger women preferred self-sampling higher than older women and they felt this method was able to reduce embarrassment (Bosgraaf et al., 2014). Women's marital status also presented a correlation with their preference for self-sampling. Single women were two times more

Preference for HPV self-sampling and its associated factors
All participants were asked to indicate their preference of method for cervical cancer screening, 33.6% (89) preferred clinician sampling, and 66.4% (176) preferred self-sampling as routine screening. The multivariable logistic regression was conducted to access independent variables affecting the preference for self-sampling (Table 3). The results showed that participants aged 30-39 were significantly more likely to prefer self-sampling as compared to those older than 40 years. Single women were more willing to use a self-sampling device as a routine screening compared to married women (adjusted OR 2.30; 95% CI 1.325 to 9.761, p-value = 0.043). However, the results in this study showed that the preference for self-sampling had no correlation with the level of education, monthly income, menstruation, and previous Pap test experience.
Participants' attitudes and feelings regarding the HPV self-sample method were also included in the model. Feelings of less embarrassment and confidence in performing the procedure were the key factors that significantly influenced the preference for self-sampling in the multivariable analysis with p-values equal to 0.041 and 0.001 respectively.  likely to use self-sampling than married women. This may be because some single women feel embarrassed about exposing private body parts during a clinician's examination. On the other hand, studies in Malaysia (Ma'som et al., 2016) and England (Waller et al., 2006) revealed that there was no significant association between marital status and willingness to self-collect. These findings illustrate different cultural beliefs may influence women's acceptability of self-sampling. In terms of participants' feelings about the experience of using self-sampling, we found that feeling less embarrassed and confident in performing the tests were the independent factors that influenced preference for self-sampling. The feeling of embarrassment is commonly viewed as a static psychosocial barrier that may play a great role in the cervical screening program (Teng et al., 2014). Similar to previous studies from Thailand, Oranratanaphan (2014) indicated that 80% of participants feel less embarrassed while using brush-type self-sampling devices. Also, Phoolcharoen (2009) reported that Thai women preferred the self-sample method because it does not cause embarrassment. Self-confidence in the ability to collect samples was also influential. Several studies showed that women preferred clinician sampling over self-sampling because of a lack of confidence in performing the test (Williams et al., 2017;Nishimura et al., 2021). Furthermore, some women worried about they might fail to take the sample from their vagina, and it would lead to an incorrect result (Kohler et al., 2019).
The presented study has a few limitations. First, our findings might represent a biased population because these women were recruited from Check-up Clinic and Gynecological Oncology Clinic. Besides, almost all the participants (91.7%) had ever undergone cervical cancer screening by clinicians. This indicated that they had awareness of good health behavior practices. Second, the small sample sizes might not be generalizable to the larger population. Therefore, future work should aim to include a diverse population, especially those who are never or under-screened because they felt embarrassed when examined by clinicians.
In conclusion, most of our study population accepted HPV self-sampling for cervical cancer screening and preferred to use this method as a routine screening test in the future. Our findings demonstrated the acceptability and feasibility of HPV self-sampling to increase participation in cervical cancer screening. However, the implementation of HPV self-sampling as a primary screening needs to consider several issues including raising knowledge and awareness of cervical screening and providing information on how to collect the sample.

Author Contribution Statement
SS conceived the study and initiated the study design. P Ploysawang, SP, WK, CT, KS, and PP carried out the data collection. P Ploysawang designed the analytical approach, performed the statistical analysis, interpreted the data, and drafted the manuscript under the supervision of SS. All authors contributed to the article and approved the submitted version.