Changing risk and efficacy appraisals for flu vaccination amongst pregnant women

Background/Rationale: Although influenza (flu) does not normally cause serious health consequences, pregnant women are at increased risk of flu, and consequences amongst this population can be more severe. Physiological and immunological changes that occur during pregnancy, make pregnant women five times more likely to be hospitalised as a result of flu. During 2009-2012, one in 11 maternal deaths were attributable to flu, making it a considerable public health concern. Despite the increased risk that flu poses to pregnant women, uptake of the flu vaccination is suboptimal. Since the recommendation in 2010 that all pregnant women receive free flu vaccination, uptake in the UK has not exceeded 45% despite a target uptake of 75%. Aims: This thesis has four main aims: 1.) To examine the influence that interventions that aim to change risk and efficacy appraisals have on the intentions and uptake of vaccination, 2.) To explore the beliefs that pregnant women hold about flu and the flu vaccination, 3.) To design and develop an appropriate intervention, aiming to increase the uptake of flu vaccination amongst pregnant women, and 4.) Explore the acceptability and potential impact of the intervention. Method: This thesis describes a systematic review involving a systematic search to identify randomised controlled trials of interventions presenting a risk message and measuring risk appraisal and intentions and uptake post-intervention. Random effects meta-analyses investigated the size of the effect that interventions had on vaccination risk appraisal, and on vaccination behaviour or intention to vaccinate, and the size of the relationship between vaccination risk appraisal and vaccination intentions. A qualitative study, involving semi-structured interviews was conducted to explore pregnant women’s beliefs about flu and the flu vaccination, and to explore how well the data fits the Illness Risk Representation framework. Data was analysed using thematic analysis. Findings of the qualitative study were used alongside relevant theory to inform the design of an animation, guided by Intervention Mapping, and shaped by collaboration with pregnant women, midwives, Public Health professionals and clinicians. A further qualitative study involved think aloud methods and semi-structured interviews with pregnant and recently pregnant women to explore the acceptability and potential impact of the animation, analysed using content analysis. Results: Searches for the systematic review resulted in 18 studies that met the inclusion criteria (16 of which were eligible for inclusion in the meta-analysis). Interventions overall had small significant effects on risk appraisal (d= 0.161, p= .047) and perceptions of susceptibility (d= 0.195, p= .025), but no effect on perceptions of severity (d= -0.036, p= .828). Interventions showed no effect on intention to vaccinate (d= 0.138, p= .195) and no effect on vaccination behaviour (d= 0.043, p= .826). The qualitative study highlighted a number of beliefs, based on incorrect knowledge, that may have been having an unhelpful effect on vaccination decisions. These included the belief that pregnancy did not increase the severity of flu, that flu would not have any severe consequences on either pregnant woman or their unborn baby, and that the vaccination involved the administering of a live vaccine. The Illness Risk Representation framework was an adequate fit to the data. Following the application of Intervention Mapping techniques, perceived severity, perceived susceptibility, self-efficacy and response-efficacy were selected as appropriate determinants for the animation to target. The Performance Objective (the aim of the animation) was defined as ‘decide to have the flu vaccination.’ The completed animation contained information about the risks and consequences of flu during pregnancy, how the vaccination works to protect both the pregnant woman and the unborn baby, and provided information about the ingredients of the flu vaccine. Results of the think aloud study showed that the majority of participants felt that the length and the level of information provided was appropriate, and felt happy to recommend the animation to other pregnant women, which was considered to be helpful in helping them make the decision whether to vaccinate or not. Discussion: The systematic review was not able to answer whether interventions that contain a risk message are successful in increasing risk appraisal and vaccination uptake. It did however, highlight a number of methodological shortcomings of experimental studies that currently exist on this topic. The qualitative study identified a number of areas of incorrect knowledge that pregnant women held about flu and the flu vaccination, that appeared to be influencing their beliefs. Providing accurate information may help to shape vaccination decisions favourably. The animation is the first known animation, based on theory that aims to increase pregnant women’s acceptable of the flu vaccination, by targeting a change in risk and efficacy appraisals. Initial testing suggests that it is an acceptable intervention that has the potential to be useful in providing information to pregnant women which may help them make an informed decision about vaccinating against flu. Local Public Health departments have agreed to include the animation in local seasonal flu campaigns in the 2018/19 flu season, potentially reaching a large number of pregnant women.