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Awareness and knowledge about human papillomavirus vaccination and its acceptance in China: a meta-analysis of 58 observational studies

Sunday, 6th of March 2016

Awareness and knowledge about human papillomavirus vaccination and its acceptance in China: a meta-analysis of 58 observational studies

Yanru Zhang,
Ying Wang,
Li Liu,
Yunzhou Fan,
Zhihua Liu,
Yueyun WangEmail author and
Shaofa NieEmail author

BMC Public HealthBMC series – open, inclusive and trusted201616:216

DOI: 10.1186/s12889-016-2873-8

Received: 14 August 2015

Accepted: 16 February 2016

Published: 3 March 201

Excerpt below; full text is at

http://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-016-2873-8

Abstract

Background

The human papillomavirus (HPV) vaccines have been widely introduced in immunization programs worldwide, however, it is not accepted in mainland China. We aimed to investigate the awareness and knowledge about HPV vaccines and explore the acceptability of vaccination among the Chinese population.

Methods

A meta-analysis was conducted across two English (PubMed, EMBASE) and three Chinese (China National Knowledge Infrastructure, Wan Fang Database and VIP Database for Chinese Technical Periodicals) electronic databases in order to identify HPV vaccination studies conducted in mainland China. We conducted and reported the analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results

Fifty-eight unique studies representing 19 provinces and municipalities in mainland China were assessed. The pooled awareness and knowledge rates about HPV vaccination were 15.95 % (95 % CI: 12.87–19.29, I ² = 98.9 %) and 17.55 % (95 % CI: 12.38–24.88, I ² = 99.8 %), respectively. The female population (17.39 %; 95 % CI: 13.06–22.20, I ² = 98.8 %) and mixed population (18.55 %; 95 % CI: 14.14–23.42, I ² = 98.8 %) exhibited higher HPV vaccine awareness than the male population (1.82 %; 95 % CI: 0.50–11.20, I ² = 98.5 %). Populations of mixed ethnicity had lower HPV vaccine awareness (9.61 %; 95 % CI: 5.95–14.03, I ² = 99.0 %) than the Han population (20.17 %; 95 % CI: 16.42–24.20, I ² = 98.3 %). Among different regions, the HPV vaccine awareness was higher in EDA (17.57 %; 95 % CI: 13.36–22.21, I ² = 98.0 %) and CLDA (17.78 %; 95 % CI: 12.18–24.19, I ² = 97.6 %) than in WUDA (1.80 %; 95 % CI: 0.02–6.33, I ² = 98.9 %). Furthermore, 67.25 % (95 % CI: 58.75–75.21, I ² = 99.8 %) of participants were willing to be vaccinated, while this number was lower for their daughters (60.32 %; 95 % CI: 51.25–69.04, I ² = 99.2 %). The general adult population (64.72 %; 95 % CI: 55.57–73.36, I ² = 99.2 %) was more willing to vaccinate their daughters than the parent population (33.78 %; 95 % CI: 26.26–41.74, I ² = 88.3 %). Safety (50.46 %; 95 % CI: 40.00–60.89, I ² = 96.6 %) was the main concern about vaccination among the adult population whereas the safety and efficacy (68.19 %; 95 % CI: 53.13–81.52, I ² = 98.6 %) were the main concerns for unwillingness to vaccinate their daughters.

Conclusions

Low HPV vaccine awareness and knowledge was observed among the Chinese population. HPV vaccine awareness differed across sexes, ethnicities, and regions. Given the limited quality and number of studies included, further research with improved study designis necessary.

Keywords

Awareness Acceptance Human papillomavirus vaccines Cervical cancer Meta-analysis

Background

Cervical cancer, one of the most common cancers observed in females [1], affects more than 529,000 annually around the world [2]. More than 85 % of the global cervical cancer burden occurs in developing countries [2], with 75,500 incidences reported annually in China. Human Papillomavirus (HPV) infection is the most important risk factor for cervical cancer [3]. Although a single HPV infection can easily be eliminated through the immune system, malignant transformation of cervical epithelial cells may be induced in a small proportion of women affected by persistent virus infection.

Vaccines have always been among the most effective interventions for infectious diseases [4]. Prophylactic vaccines of cervical cancer manufactured by Merck &Co. have been approved by FDA and have been commercially available since 2006 [5]. The approval of vaccines for the HPV increased the possibility of eradicating cervical cancer in the near future. However, it is noteworthy that awareness of HPV and the general attitude towards vaccination were crucial factors for acceptance of vaccination among the population. In addition, increasing number of studies addressing the hesitation to get vaccinated have been conducted in the recent years, portraying the challenging and dynamic period of indecisiveness concerning HPV vaccination [6].

The HPV vaccine has been widely introduced in the vaccination programs of Hong Kong, however, is not popularly accepted in Mainland China at present. In addition, despite the numerous published studies focusing on the topic of HPV and vaccination in recent years, there is no comprehensive information concerning the acceptance and obstacles associated with vaccination among the population of Mainland China. In order to develop a practical vaccination program in the future, it is imperative to assess the level of awareness and knowledge about HPV, and the general attitude towards HPV vaccination among the Chinese population, as they are important behavioral determinants that will ultimately affect the acceptance of vaccination among the Chinese population. Therefore, we conducted a meta-analysis in order to gain a better understanding of this issue that may help generate new ideas to make future generalization of HPV vaccination possible in China.

Methods

Search strategy

The meta-analysis was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [7]. The Chinese literature was searched using the China National Knowledge Infrastructure (CNKI), Wan Fang Database and VIP Database for Chinese Technical Periodicals (VIP) using the keywords “HPV vaccine OR cervical vaccine”. The literature in English was searched using PubMed and EMBASE, and relevant studies were identified with the search terms “HPV OR cervical cancer” AND “vaccine OR vaccination OR immunization” AND “awareness OR knowledge OR acceptability OR acceptance OR willingness OR perception OR attitude OR recognition” AND “China OR Chinese.” The publication time was limited to 2006–2015, as HPV vaccine was introduced in the world in 2006. Data retrieval was supplemented by manually searching for the reference list of key reviews and references from retrieved studies. No language restriction was imposed.

Selection criteria

The inclusion criteria for the epidemiological studies were the following: (1)study involved at least one of the key terms “HPV vaccine awareness”, “knowledge”, and “acceptability”for any region of Mainland China (excluding studies conducted in Taiwan, Hong Kong and Macao due to differencesin socio-economic levels and health policies between these regions and Mainland China), (2) original data was available regardless of whether it was obtained directly from the article or traced from secondary data in the article. Studies that examining the effects of health educational interventions were excluded.

Data extraction

A data abstraction form was constructed after scanning the selected articles. For each included study, we extracted the following information: author, publication year, region, study instrument, study subject (age, sex and ethnicity), sampling method, sample size (N), the number of participants for the assessment of HPV vaccine awareness, knowledge, and acceptance, or the rate percentage proportions for these studied factors. We also extracted the reasons for unwillingness to be vaccinated if this information was available. The number of studied cases(n) and sample size(N) were the two necessary parameters for the calculation of the pooled rates of HPV vaccine awareness, knowledge, and acceptance of vaccination in the meta-analysis. In particular, the number of studied cases (n) was obtained directly from the original studies or by multiplying the sample sizes (N) with the proportions (%) associated with the investigated factors reported in the original studies.

Quality assessment

We employed a flexible appraisal scale suggested by Iain Crombie [8] for the assessment of the quality of cross-sectional studies. The scale contains seven indexes: (1) design is scientific, (2) data collection strategy is reasonable, (3) sample response rate is reported, (4) samples can represent the general population well, (5) the research purpose and method is reasonable, (6) the test efficiency is reported, (7) the statistical method is reasonable. For each index, the study was scored “1,” “0,”or “0.5” for “yes,” “no,”or “unclear,” respectively. The maximum score in the scale is 7 points, with scores of 6.0–7.0 points as grade A, scores of 4.0–5.5 points as grade B, and scores of less than 4.0 points as grade C.

Data analysis

We used “rate” to evaluate the studied items. The rate for HPV vaccine awareness was calculated by dividing the number of cases who were aware of HPV vaccine (n1) by the sample size (N); the rate for HPV vaccine knowledge was calculated by dividing the number of cases who knew the relationship between HPV (vaccine) and cervical cancer (n2) by the sample size (N); the rate for acceptance to be vaccinated was calculated by dividing the number of cases who were willing to get vaccinated (n3) by the sample size (N); the rate for acceptance of parents to vaccinate their daughters was calculated by dividing the number of cases who were willing to vaccinate their daughters (n4) by the sample size(N); the rate for reasons of unwillingness to be vaccinated was calculated by dividing the number of cases who gave a reason (n5) by the number of cases who were unwilling to be vaccinated (N-n3).

Meta-analysis was conducted using a random effects model. Given the requirement for normalization of single rate in meta-analysis, an arcsine transformation for the original rate was performed to meet the requirement [9]. Statistical heterogeneity among the studies was estimated by Chi-square test at the significance level of P < 0.10, and using the I-square (I ²) statistic to quantify the heterogeneity of the results. Publication bias was detected by Eggers test (P < 0.05 was considered statistically significant) [10]. R statistical software (Version 2.11.1) was used for all the calculations.

Consent statement

As this study was a meta-analysis, we did not include any humans and animals. This study was approved by the Ethics Committee of Huazhong University of Science and Technology.