ABSTRACT
Globally, Japan has the lowest rate of vaccine confidence. The persistent parental vaccine hesitancy has been attributed to safety and efficacy concerns and is primarily driven by the negative experience with human papillomavirus (HPV) vaccines. This literature review aimed to identify factors associated with HPV vaccine uptake and potential strategies to reduce vaccine hesitancy among Japanese parents. Articles published in English or Japanese between January 1998 and October 2022 that examined Japanese parental factors for HPV vaccine uptake were identified from PubMed, Web of Science, and Ichushi-Web. In total, 17 articles met the inclusion criteria. Four key themes which affected HPV vaccine hesitancy and acceptance were identified: perceptions of risk and benefits, trust and recommendation, information and knowledge, and sociodemographic characteristics. While governmental and healthcare provider recommendations are important factors, efforts to improve parental confidence in the HPV vaccine are required. Future interventions to counteract HPV vaccine hesitancy should actively disseminate information on vaccine safety and effectiveness, along with information on the severity and susceptibility of HPV infection.
ABSTRACT
Background: In double-blind randomized controlled trials (RCTs) of antidepressants, blinding can be broken due to the apparent side effects, and unsuccessful blinding can lead to overestimation of effect sizes. New generation antidepressants with less severe side effects may be less susceptible to broken blinding. However, successfulness of blinding in new generation antidepressant trials and its influence on trial effect size estimates remain unclear. Methods: Extending a previous systematic review assessing blinding successfulness in psychiatric trials (2000-2010), we searched PubMed/Medline for double-blinded antidepressant RCTs (2010-2020) for trials assessing blinding success. Our primary outcome was the degree of blinding successfulness, measured as kappa statistics between guesses and true allocations. We used random-effects meta-analysis to synthesize studies. We used meta-regression and Pearson's r to examine the relationship between blinding success and effect sizes. This study is registered with PROSPERO (CRD42021249973). Findings: Among 154 eligible studies, 11 (7·1%) contained information on blinding assessment between 2010 and 2020. Five studies were added from the previous review, and altogether nine of the 16 studies provided usable data. Agreement in individual studies ranged from κ=-0·14 to 0·38. The summary agreement between guesses and the truth was 0·21 (95% CI: 0·14 to 0·28) among patients and 0·17 (95% CI: 0·05 to 0·30) among assessors. Blinding success was not associated with effect size (patients: r = 0·37, p = 0·32; assessors: r = 0·28; p = 0·72). Meta-regression also failed to find a significant relationship between blinding success and depression effect sizes (ß=0·06, p = 0·09). Interpretation: Less than 10% of the antidepressant RCTs reported blinding assessment. The results in new generation antidepressant trials indicated that patients and assessors were unlikely to be able to judge treatment allocation. There was little evidence that the extent of unblinding biased the effect size estimates of new generation antidepressants. Funding: None.
