Revisiting knowledge, attitudes and practice (KAP) on human papillomavirus (HPV) vaccination among female university students in Hong Kong

ABSTRACT

Despite cervical cancer can be preventable by HPV vaccination, little is known on its associated factors among young females in Hong Kong. This study aimed to investigate the present situation regarding the self-reported knowledge, attitudes and practice (KAP) of Human Papillomavirus (HPV) vaccination and to examine their associated factors among female university students in Hong Kong. 195 respondents were recruited to complete a self-administered questionnaire from two local universities through convenience sampling. 8.2% respondents indicated that family doctors as sources of knowledge of HPV and HPV vaccination. 59.0% of the sample identified more than four knowledge items, 82.6% thought that HPV vaccines can effectively prevent cervical cancer and 47.2% received HPV vaccination. Regression analyses found those at older age, thought that they might be infected by HPV and received HPV would have a higher level of knowledge. Those who knew HPV is sexually transmitted, thought may be infected by HPV and received HPV vaccination would have positive attitude on HPV vaccination. Those at older ages, knew their university provided discounted vaccination for female students, and were not afraid of the side effects were associated with HPV vaccination. Family doctors should take a more prominent role in disseminating accurate and precise information. Advocacies should be emphasised on the risk of HPV as a sexually transmitted disease and the availability of discounted and safe HPV vaccines in tertiary educational institutions to increase the uptake rate of HPV vaccines for first-year and non-health major university students.

Introduction

Human papillomavirus (HPV) infection is the most common sexually transmitted infection worldwide.¹ It is highly contagious and unlikely to be totally cleared by clinical treatment.^2,3 Official statistics shows that HPV types 16 and 18 account for 70% of all cervical cancer.⁴ In Hong Kong, the HPV prevalence, including all genotypes, was around 7–11% in those attending cervical screening services and cervical cancer was the eighth commonest cancers among females in Hong Kong in 2014.^5-7 169 women died by cervical cancer in 2015, which ranked the eighth leading cause of female cancer deaths in Hong Kong.^7,8

To tackle such threat on population health, published studies have revealed that HPV vaccination is an effective and efficient way in preventing cervical cancer and prolonging the life expectancy of female population.⁹ The Hong Kong Department of Health recommends that women should receive HPV vaccination before their sexual activity, so as to receive the full benefits of the vaccines.⁵ However, unlike other established economies, there remains no government-funded HPV immunisation programmes for women in Hong Kong.^10-14 People who are interested in taking the vaccine have to pay out-of-pocket.¹⁰ This might lead to a low HPV vaccines uptake rate of 9.7% for Chinese female university students in 2008 when the vaccines were newly introduced in Hong Kong.¹⁵

In line with many western countries, there were more Hong Kong females having their sexual activity during the university period than before.¹⁶ Also, compared to the general population, university students are well-educated and are less influenced by parents or others.¹⁵ They have greater autonomy to decide whether receiving HPV vaccination or not.¹⁵

Although a recent work by Chiang et al.¹⁷ examined the attitude of university students towards HPV vaccination, little is known on factors associated with HPV vaccination uptake among young females in Hong Kong. Previous studies focused on university students from one tertiary institution when HPV vaccines were newly introduced in 2006.^15,16,18 It is generally recognised that the perceived effectiveness of HPV vaccines, the cost of vaccination, and the perceived susceptibility to cervical cancer, were identified as associated with HPV vaccination.¹⁵ However, in recent years women have been encouraged to receive HPV vaccines through different channels, such as family doctors' recommendations, outdoor advertisements and television advertisements.¹⁹ Also, some local universities recently promote and provide discounted HPV vaccination in university clinics for female students. Therefore, it is possible that more female university students have received HPV vaccination in Hong Kong, compared to the sample of previous work in 2008.¹⁵

Therefore, the present study aims to fill this gap by applying the knowledge, attitudes and practice (KAP) framework²⁰ to investigate factors associated with HPV vaccination among female university students in Hong Kong. The KAP framework is recommended by the World Health Organization to access factors associated with HPV vaccination.²⁰ This framework helps to assess respondents' knowledge about HPV and HPV vaccination, their attitudes towards HPV vaccination. It also helps to identify comprehensively what factors are associated with HPV vaccination.²¹

Results

Descriptive statistics: Background information of the sample

Among the 215 female students approached, 195 of them responded and completed the questionnaires. The response rate was 90.7% and thus the effect of response bias was minimal. The characteristics of the sample are summarised in Table 1. The mean age of the respondents was 19.7 years (standard deviation: 1.48; range: 17–24). Of the 195 respondents, 87.7% were studying in CUHK and 12.3% in HKU, 22.1% were studying in a medical faculty and the rest in other disciplines, and 10.3% had sex experience.

Table 1.

Results of descriptive statistics and univariate regression analyses.

	% (Unless specified)	Model 1			Model 2			Model 3
		OR	95% CI	P-value	OR	95% CI	P-value	OR	95% CI	P-value
Basic profile
Age (years)	19.7	1.69	1.34–2.12	<0.0005	1.14	0.88–1.47	0.320	1.6	1.28–2.00	<0.0005
University (Being a CUHK student rather than an HKU student)	87.7	1.51	0.64–3.57	0.342	2.20	0.83–5.80	0.112	3.04	1.15–8.02	0.025
Studying in medical faculty	22.1	3.94	1.71–9.04	0.001	2.40	0.80–7.23	0.120	2.26	1.13–4.53	0.022
Family monthly income	NA	0.92	0.77–1.10	0.349	1.13	0.90–1.43	0.303	1	0.84–1.19	0.989
Have sex experience	10.3	1.33	0.51–3.49	0.564	4.42	0.57–34.17	0.155	1.42	0.56–3.59	0.461
Knowledge
Knew that “cervical cancer is mainly caused by HPV infections”	65.1	—	—	—	2.16	1.02–4.57	0.045	2.33	1.26–4.29	0.007
Know that “certain types of HPV can cause genital warts”	57.9	—	—	—	1.28	0.61–2.69	0.516	1.93	1.08–3.45	0.026
Know that “HPV is sexually transmitted”	76.9	—	—	—	3.45	1.57–7.55	0.002	2.74	1.33–5.63	0.006
Know that “HPV infection is not likely to be completely cured by clinical treatment”	56.4	—	—	—	0.48	0.21–1.06	0.070	1.3	0.73–2.29	0.370
Know that “most sexually active women are infected by HPV at some points in their lives”	22.6	—	—	—	0.94	0.39–2.24	0.882	1.86	0.94–3.68	0.074
Know that “HPV vaccines cannot 100% prevent cervical cancer”	86.7	—	—	—	2.44	0.96–6.20	0.060	1.26	0.54–2.89	0.593
Know that “it is recommended that females should receive all 3 shots of HPV vaccination within a 6-month period”	57.9	—	—	—	1.97	0.93–4.16	0.075	2.76	1.53–4.99	0.001
Know that “your university provides a discount on HPV vaccination for female students”	58.5	—	—	—	2.72	1.27–5.83	0.010	5.23	2.78–9.84	<0.0005
Attitude
Agree that “I may be infected by HPV in the future”	52.8	2.42	1.35–4.34	0.003	2.38	1.10–5.14	0.027	0.68	0.39–1.20	0.187
Agree that “I may have cervical cancer in the future”	61	1.83	1.02–3.29	0.043	1.45	0.71–3.15	0.289	0.64	0.36–1.14	0.131
Agree that “cervical cancer is a severe disease”	89.7	0.95	0.37–2.45	0.922	2.25	0.80–6.35	0.126	0.88	0.35–2.22	0.790
Agree that “HPV vaccines can effectively prevent cervical cancer”	82.6	2.08	0.98–4.39	0.056	—	—	—	2.96	1.30–6.73	0.010
Agree that “HPV vaccination is expensive”	69.7	0.98	0.53–1.82	0.948	2.10	0.98–4.49	0.056	0.98	0.53–1.81	0.959
Agree that “it is not easy to find a place to receive HPV vaccination”	10.8	0.24	0.09–0.65	0.005	1.30	0.36–4.69	0.688	0.41	0.15–1.10	0.078
Agree that “I am afraid of the side effects of HPV vaccination”	45.6	0.53	0.30–0.94	0.029	0.45	0.21–0.97	0.041	0.23	0.12–0.42	<0.0005
Agree that ‘I am afraid of being perceived as “sexually active” if I receive HPV vaccination'	15.9	0.70	0.32–1.51	0.365	0.86	0.32–2.28	0.759	0.04	0.17–0.92	0.031
Agree that “parents affect my decision as to whether or not to receive HPV vaccination”	51.8	1.46	0.82–2.59	0.197	1.45	0.69–3.06	0.326	1.69	0.96–2.99	0.069
Agree that “doctor's recommendation affects my decision as to whether or not to receive HPV vaccination”	75.9	1.09	0.56–2.11	0.807	1.96	0.89–4.36	0.097	0.81	0.42–1.57	0.541
Practice
Received at least one shot of HPV vaccination	47.2	5.02	2.67–9.45	<0.0005	2.96	1.30–6.73	0.010	—	—	—

Descriptive statistics: Source of knowledge of HPV and HPV vaccination

Nearly all respondents had heard of HPV (95.9%) and HPV vaccination (92.8%). Table 2 summarises the sources of knowledge of HPV and HPV vaccination of the respondents. Over half of the respondents acquired their knowledge from television advertisements (64.6%), the internet (59.5%) and schools (55.9%). There were 41.5% of respondents who did not know that the universities provide discounted HPV vaccines for female students. The majority (85.6%) of respondents would like to receive more information about HPV vaccination. Almost all (93.3%) respondents opined that the Government should provide subsidised HPV vaccination for all eligible women in Hong Kong.

Table 2.

Sources of knowledge of HPV and HPV vaccination.

Sources of Knowledge	Number of Respondents (Total: 195)	% of Respondents
Television advertisements	126	64.6
Internet	116	59.5
Schools	109	55.9
Peers	78	40.0
Parents	58	29.7
Outdoor advertisements	39	20.0
Newspapers	30	15.4
Family doctors	16	8.2
Magazines	12	6.2
Siblings	11	5.6

KAP item responses and findings of univariate regression

The questionnaire included 19 items for measuring the knowledge, attitudes and practice (KAP) regarding HPV and HPV vaccination and the results are shown in Table 1. Of the eight knowledge items, 86.7% (n = 169) of respondents knew that “HPV vaccines cannot 100% prevent cervical cancer”, followed by “HPV is sexually transmitted” at 76.9% (n = 150), “HPV is one of the major causes of cervical cancer” at 65.1% (n = 127) and “HPV in the body is unlikely to be cleared / eliminated by clinical treatment” at 63.6% (n = 110). By contrast, only 22.6% (n = 44) knew that “most sexually active women are infected by HPV at some points in their lives”. The proportion of remaining items ranged from 57.6% to 58.5%. 115 respondents (59.0%) correctly identified more than 4 knowledge items in the survey. In analysing their characteristics through univariate regression analyses, it is found that they were more likely to be older ([unadjusted] OR = 1.69; 95% CI = 1.34–2.12), have studied at the medical faculty (OR = 3.94; 95% CI = 1.71–9.04), have agreed that “may be infected by HPV in the future” (OR = 2.42, 95% CI = 1.35–4.34), “may have cervical cancer in the future” (OR = 1.83; 95% CI = 1.02–3.29) and have received HPV vaccination (OR = 5.02; 95% CI = 2.67–9.45). By contrast, they were less likely to have agreed that “it is not easy to find a place to receive HPV vaccination” (OR = 0.24; 95% CI = 0.09–0.65) and “I am afraid of the side effects of HPV vaccination” (OR = 0.53; 95% CI = 0.30–0.94).

In regard to respondents' attitude towards HPV vaccination, more than 80% of respondents agreed “cervical cancer is a severe disease” (89.7%, n = 175), “doctor's recommendation affects my decision as to whether or not to receive HPV vaccination” (87.2%, n = 170) and “HPV vaccines can effectively prevent cervical cancer” (82.6%, n = 161). On the contrary, 10.8% (n = 21) agreed that “it is not easy to find a place to receive HPV vaccination” and 15.9% (n = 31) were afraid of being perceived as ‘sexually active’ if they receive HPV vaccination. The range of remaining attitude items ranged from 45.6% to 69.7%.

Findings of logistic regression analyses showed that respondents agreed that “HPV vaccines can effectively prevent cervical cancer” were more likely to have known that “cervical cancer is mainly caused by HPV infections” (OR = 2.16; 95% CI = 1.02–4.57), “HPV is sexually transmitted” (OR = 3.45; 95% CI = 1.57–7.55) and “your university provides a discount on HPV vaccination for female students” (OR = 2.72; 95% CI = 1.27–5.83), have agreed that “I may be infected by HPV in the future” (OR = 2.38; 95% CI = 1.10–5.14) and have received HPV vaccination (OR = 2.96; 95% CI = 1.30–6.73). On the contrary, they were less likely to have agreed that “I am afraid of the side effects of HPV vaccination” (OR = 0.45; 95% CI = 0.21–0.97).

Ninety-two respondents (47.2%) in the survey had received at least one shot of HPV vaccination. Results of univariate regression found that those at older age, being a CUHK student, and studying in a medical faculty are found to be positively associated with HPV vaccination. For predictors of knowledge on HPV vaccination, those knew that “cervical cancer is mainly caused by HPV infections”(OR = 2.33, 95% CI = 1.63–3.33), “certain types of HPV can cause genital warts” (OR = 1.93, 95% CI = 1.37–2.71), “HPV is sexually transmitted” (OR = 2.74, 95% CI = 1.80–4.18), “it is recommended that females should receive all 3 shots of HPV vaccination within a 6-month period” (OR = 2.76, 95% CI = 1.95–3.91), and “your university provides a discount on HPV vaccination for female students” (OR = 5.23, 95% CI = 3.61–7.58) are found to be positively associated with HPV vaccination. In regard to attitude predictors, those agreed that “HPV vaccines can effectively prevent cervical cancer” (OR = 2.96, 95% CI = 1.82–4.79) was found to be positively associated with HPV vaccination. On the contrary, those agreed that “I am afraid of the side effects of HPV vaccination” (OR = 0.23, 95% CI = 0.16–0.33), and ‘I am afraid of being perceived as “sexually active” if I receive HPV vaccination' (OR = 0.40, 95% CI = 0.25–0.65) are found to be negatively associated with HPV vaccination.

Results of multivariate logistic regression analysis are illustrated in Table 3. After backward elimination, those at older ages (OR = 1.45, 95% CI = 1.13–1.86), agreed that “I may be infected by HPV in the future” (OR = 3.2, 95% CI = 1.60–6.42) and received HPV vaccination (OR = 5.14, 95% CI = 2.50–10.55) were positively associated with higher knowledge with HPV vaccination in Model 1. In terms of positive attitude towards HPV vaccination, multivariate regression analyses identified that those who knew that “HPV is sexually transmitted”, agreed that “I may be infected by HPV in the future” and received HPV vaccination were positively associated in Model 2. Finally, for predicting HPV vaccination in Model 3, “age” (OR = 1.37, 95% CI = 1.06–1.79, p = 0.018) and those knew that “your university provides a discount on HPV vaccination for female students” (OR = 3.79, 95% CI = 1.76–8.17, p = 0.001) are found to be positively associated with HPV vaccination. By contrast, those agreed that “I am afraid of the side effects of HPV vaccination” (OR = 0.19, 95% CI = 0.10–0.38, p < 0.0005) is found to be negatively associated with the outcome.

Table 3.

Multivariate logistic regression analyses between independent predictors and different outcomes of interest.

	Model 1			Model 2			Model 3
	Log likelihood = −102.59, χ2 = 58.83, p < 0.0001			Log likelihood = −80.53, χ2 = 19.40, p = 0.0002			Log likelihood = −105.45, χ2 = 58.81, p < 0.0001
	OR	95% CI	P-value	OR	95% CI	P-value	OR	95% CI	P-value
Age	1.45	1.13–1.86	0.003				1.37	1.06–1.78	0.018
Know that “HPV is sexually transmitted”				2.68	1.18–6.08	0.018
Know that “your university provides a discount on HPV vaccination for female students”							3.79	1.76–8.17	0.001
Agree that “I may be infected by HPV in the future”	3.2	1.60–6.42	0.001	2.58	1.15–5.81	0.022
Agree that “I am afraid of the side effects of HPV vaccination”							0.19	0.09–0.38	<0.005
Received HPV vaccination	5.14	2.50–10.55	<0.0005	2.86	1.20–6.80	0.017

Discussion

Our findings indicate that the uptake rate of HPV vaccines in the study sample was 47.2%, which was markedly higher than the 2008 level at 9.7%.¹⁵ This figure is lower than that of Germany (67%), but higher than that of Poland (9.5%), where HPV vaccination is not part of their national immunisation programmes as well.^22,23 Our findings revealed that current female university students had high awareness of HPV (95.9%) and HPV vaccination (92.8%). These figures are higher than that of Turkey, where only 48.8% had heard about HPV infection and 44.5% had heard of HPV vaccination.²⁴ Despite higher awareness, a clear majority of respondents (85.6%) would like to receive more information about HPV vaccination.

When compared with the findings of the 2008 study,¹⁵ none of the three factors, i.e. perceived effectiveness of HPV vaccines, cost of vaccination, and perceived susceptibility to cervical cancer, are found to be significantly associated with HPV vaccination in this study. Possible reasons for the change can be due to increased awareness of HPV vaccination, increased popularity and public acceptance of HPV vaccination and increased market competition in Hong Kong. All these issues deserve attention in future research.

Our findings suggested that family doctors should take a more proactive role in disseminating health information about HPV vaccination in future. Recent studies in Italy^25-27 and Argentina²⁸ recognised that those received information from physicians and medical establishments tended to have better knowledge and higher perceived need of more information about the HPV vaccine. Through the KAP framework, it is well known that knowledge often plays an important role in health care for improving their attitudes and even potential uptake of HPV vaccination, which are shown in the findings of this analysis. As only 8.2% of the respondents indicated that family doctors as sources of knowledge of HPV and HPV vaccination, it may indicate that current channels of communication for physicians are inadequate and more effective communication strategies between physicians and general public are needed to allow dissemination of accurate and precise information.²⁸

Implications on promotion of HPV vaccination

For the past 10 years, women in Hong Kong have been recommended by the Government to receive HPV vaccination before having sex experience to protect themselves from HPV infections.⁴ In achieving this aim, a more targeted approach on HPV vaccination advocacy should be adopted and health promoters should consider the following attributes identified in the present analysis to guide future development and evaluation of HPV vaccination communication strategies:

Firstly, first-year university students should be targeted as a priority. Since “age” was found to be a factor positively associated with both knowledge and practice of HPV vaccination, it indicates that being younger has a lower likelihood of being vaccinated. Tertiary educational institutions should therefore provide more information about their HPV vaccination programmes in the new student orientation each year.

Secondly, advocates of HPV vaccination should emphasize that HPV is a sexually-transmitted disease and everyone has a chance of being infected. This may help to increase female students' knowledge, perceived vaccine effectiveness and willingness to receive HPV vaccination as indicated elsewhere.^27,29 Additionally, the availability of discounted HPV vaccination for female students should be widely promoted while a significant portion of the respondents (41.5%) did not know that the universities provide a discount for female students and those who knew that “your university provides a discount on HPV vaccination for female students”' were more likely to be vaccinated.

Thirdly, there is a need to emphasise on the vaccine safety in the promotion of HPV vaccination. In our survey, it is revealed that those agreed that “I am afraid of the side effects of HPV vaccination”' were less likely to be vaccinated. Nowadays, The HPV vaccine is proven to be safe and effective and no serious side effects have been reported for years.⁵ HPV vaccination can only cause mild side effects on few recipients, such as headaches and muscle aches.⁴ Emphasising on the safety of HPV vaccination might help reduce the barriers among female university students to receive the vaccines.

There are several limitations of this study. This is a cross-sectional study, where certain items (e,g. sources of information) may be influenced by recall bias and casual relationships could not be established. Also, social desirability bias remains possible, despite we attempted to minimise its impact through self-administration of the questionnaire.³⁰ Due to limited manpower and time, convenience sampling was used on data collection and selection bias might be present. The sample size of this study is relatively small with 215 respondents. The respondents were recruited only from the two comprehensive universities in Hong Kong, and not from the non-comprehensive universities. Therefore, the generalizability of the results may be lowered.

Conclusion

Family doctors should take a more prominent role in disseminating accurate and precise information about HPV vaccination. Advocacies should be emphasised on the risk of HPV as a sexually-transmitted disease and the availability of discounted and safe HPV vaccines in tertiary educational institutions. First-year university students and students of non-health majors should be prioritised.

Methods

Data collection

Respondents from the two only comprehensive universities in Hong Kong, namely The Chinese University of Hong Kong (CUHK) and The University of Hong Kong (HKU), were recruited from July 2016 to September 2016. During the study period, each of the two universities had the Faculty of Arts, Business Administration, Education, Engineering, Law, Medicine, Science and Social Science. There were two more faculties at HKU, namely Architecture and Dentistry. In academic year 2015/16, there were 44,060 female undergraduate students studying in the government-funded tertiary institutions.³¹ Both institutions ranked the first and the second in the number of female undergraduate students, and accounted for 8,991 (CUHK: 20.4%) and 8,374 (HKU: 19.0%) female undergraduate students respectively in Hong Kong.³¹

Convenience sampling was adopted. The respondents were recruited on weekdays at different locations within the main campuses of CUHK and HKU, such as the exits of the Mass Transit Railway stations, the canteens, and the entrances of libraries. Potential respondents passing by these locations were approached by the first author to participate in this study. All non-eligible subjects were screened out by the first author. Eligible respondents would receive a self-administered questionnaire. As the questionnaires were kept anonymous, the completion of the questionnaire implied the respondents' consent. No incentives were offered to the respondents. This study received research ethics approval from the Survey and Behavioural Research Ethics Committee, CUHK. The inclusion and exclusion criteria of participants are listed as follows:

Inclusion criteria

• 1.Female undergraduate students studying for their first bachelor's degree in CUHK or HKU;
• 2.Permanent residents of Hong Kong

Exclusion criteria

• 1.Having diagnosed with any health problems (e.g. allergy) which prevent them from receiving HPV vaccines;
• 2.Having diagnosed with any HPV-related diseases;
• 3.Non-local students; and
• 4.Exchange students from overseas

Rationale

As reported by World Health Organization,³² KAP survey data can identify how knowledge gaps, cultural beliefs, or behavioural patterns that may facilitate understanding and action, as well as pose problems or create barriers for HPV vaccination. Therefore, it is reasonable to expect that the likelihood of receiving HPV vaccination was related to respondents' knowledge of HPV and HPV vaccination and their attitude towards HPV vaccination together with respondents' background information in the present analysis.

Instruments

A self-administered questionnaire in English was developed by the first author with reference to the relevant previous studies in the literature.^15,18,33 Face validity of each item was checked by the second author before the pilot test was conducted. The instrument was validated in a pilot test with 30 respondents. There were no subsequent revision of the questionnaire and the implementation procedures after the pilot test. The questionnaire included 34 questions, consists of four sections with 34 items. The four sections include (1) five items on background information: age; sex; faculty of study; family income and whether had sex experience, (2) eight items on respondents' HPV and HPV vaccination knowledge: “HPV is one of the major causes of cervical cancer”; “certain types of HPV can cause genital warts”; “HPV is sexually transmitted”; “HPV in the body is unlikely to be cleared / eliminated by clinical treatment”; “Most sexually active women are infected by HPV at some points in their lives”; “HPV vaccines cannot 100% prevent cervical cancer”; “Whether females should receive all 3 shots of HPV vaccination within a 6-month period” and “whether knew respondents' university provides discounted HPV vaccination for female student”, (3) ten items on respondents' attitudes towards HPV vaccination: “I may be infected by HPV in the future”; “I may have cervical cancer in the future”; “cervical cancer is a severe disease”; “HPV vaccines can effectively prevent cervical cancer”; “HPV vaccination is expensive”; “it is not easy to find a place to receive HPV vaccination”; “I am afraid of the side effects of HPV vaccination”; “I am afraid of being perceived as “sexually active” if I receive HPV vaccination”; “parents affect my decision as to whether or not to receive HPV vaccination”; “doctor's recommendation affects my decision as to whether or not to receive HPV vaccination”, and (4) respondents' practice on HPV vaccination.

Statistical analysis

All statistical analyses were performed by using Stata/SE 15.0 for Windows. Descriptive statistics were used to describe the prevalence of HPV vaccination by each potential factor. Chi-square tests and univariate logistics regression were conducted for bivariate analysis to assess the association between the independent predictors of the following outcomes of interest: knowledge about HPV and HPV vaccination (having correctly identified at least 5 out of 8 items) (Model 1); positive attitude of respondent towards HPV vaccination for preventing cervical cancer (i.e. agreed that “HPV vaccines can effectively prevent cervical cancer”) (Model 2); and whether a respondent received HPV vaccination) (Model 3).

Variables with a p-value below 0.05 in the univariate analysis were included in the multivariate logistics regression analysis model through backward elimination to establish whether the independent variables were associated with the outcome of interest after controlling the effect of other variables. Odds ratios (ORs) and their 95% confidence intervals (CIs) from the multivariate model were illustrated to demonstrate their statistical association. In the present analysis, a two-sided p-value <0.05 was considered as statistically significant.

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Acknowledgment

The authors would like to thank Dr May Yeung for her valuable comments and suggestions to improve the quality of the paper. No funding was received for this study.