Clinical trial NCT03431012: Improving Communication During a Pandemic Flu Outbreak
Official title: Improving Communication During a Pandemic Flu Outbreak
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Keywords: Adherence, medication
Pandemic Influenza
Lead sponsor: King's College London
Sponsor class: OTHER
Collaborators: name: National Institute for Health Research, United Kingdom
name: Public Health England
First posted: 2018-02-13
Enrollment: 349
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Intervention model description: This study was a vignette-based randomised controlled trial, with a 2 (human vs virus agency assignment) x 2 (negative vs positive frame of antivirals side effects) between-participants factorial design. All participants were presented with a hypothetical pandemic flu scenario describing moderate health consequences (i.e. about 1 in 1000 infected people dying). The scenario: 1) in the initial scenario participants were told to imagine that their GP (although not confirming whether it was a pandemic case) had advised them to take antivirals as a precaution; 2) after measuring baseline intentions, participants were introduced to the second part of the scenario where they were asked to imagine being at their local pharmacy where a pharmacist provided them with some health messages and information about the antivirals. Participants were randomised to one of the four health messages described below. After reading the health messages their intentions to use antivirals were re-measured.
Primary purpose: PREVENTION

Brief summary: During the last pandemic influenza antivirals were prescribed both as prophylaxis and treatment. However, adherence rates were suboptimal. This study assessed the effect of theory-based and evidence-based health messages, which promoted the use of antivirals as prophylaxis for pandemic influenza, on intentions to use antivirals. Using hypothetical scenarios, the investigators tested whether written health communications about pandemic flu and recommended preventative medication (i.e. a prophylactic treatment with antivirals) had an effect on study participants' beliefs about the pandemic flu and the advice received, and their intention to adhere to the recommendation. In particular, the investigators assessed the behavioural impact of health messages presented in four different linguistic formats, defined by a 2×2 (agency assignment × attribute framing) factorial design. The originality of this study relies on the attempt to maximise the behavioural impact of written health messages by combining the agency assignment and attribute framings, which have never been tested together, and by systematically targeting specific predictors of adherence intentions through these messages. The findings of this study may be used to improve the behavioural impact of health communications to the general public in case of a pandemic flu outbreak in the UK.

Detailed description: Background: In 2009, a new strain of influenza virus, called pandemic influenza A(H1N1)pdm09, was detected in humans. During the pandemic in 2009/2010, antiviral medications were prescribed both as prophylaxis and treatment for influenza. However, many people, including those with chronic health conditions, did not used the antivirals as prescribed. This study focused on adherence to antivirals used as prophylaxis, as this is a key preventative stage before any vaccine can be available to the public. To ensure protection of public health during public health emergencies, such as pandemic flu, it is essential that the general public follow the health advice received. Therefore, future risk communications about the use of antivirals for pandemic influenza will need to address the barriers and facilitators of adherence.

This study investigated the effect of theory-based and evidence-based health messages, which promoted the use of antivirals as prophylaxis for pandemic influenza, on intentions to use antivirals. In particular, using hypothetical scenarios, the investigators tested whether written health communications about pandemic flu and recommended preventative medication (i.e. a prophylactic treatment with antivirals) had an effect on study participants' beliefs about the pandemic flu and the advice received, and their intention to adhere to the recommendation.

The linguistic manipulation used in the present study was based on an adaptation of a successful manipulation carried out by McGlone et al. (2013), who found that using the virus agency assignment in medical factsheets increased students' perception of susceptibility to and worry about the virus A/H1N1, perception of the severity of the consequences of catching the virus, perception of efficacy of the vaccine and reported intention to get the vaccine compared to the human agency assignment. The investigators wanted to test whether these results could be replicated in the context of taking antivirals for pandemic flu, using a more representative sample of the general population and controlling for baseline intentions.

For what concerns the framing of the side effects, research shows that the way information on medication side-effects is presented affects people's intentions to accept the recommended medications. The same side-effect likelihood can be expressed in a positively framed message (i.e. 90% of people will not develop side-effects) or in negatively framed message (i.e. 10% of people will develop side-effects). Although a previous meta-analysis (Moxey et al. 2003) found no significant framing effect on either actual immunization or behavioural intention, it found that positively framed information increased positive attitudes toward immunization and perception of the benefits of immunization, decreased expectation of side-effects and led to a more realistic understanding of the side-effects of influenza vaccines.

In addition, the health messages used in this study targeted specific variables, which have been in the past associated with higher adherence to antivirals for pandemic influenza. In particular, a recently published systematic review (Smith et al. 2016) investigated the factors affecting adherence to antivirals for influenza, including pandemic flu. They included 26 studies, of which 23 assessed pandemic influenza. Although many of the reviewed studies had serious methodological flaws, the review identified several psychosocial factors associated with adherence to antivirals prescribed as prophylaxis for pandemic flu. In particular, 11 studies investigated actual adherence to prophylactic antivirals. These studies showed that actual adherence was associated with previous adherence to other preventative measures for pandemic flu, beliefs that the recommended prophylactic measures were necessary and having discussed taking oseltamivir, a commonly used antiviral, with someone who had not experienced side effects. Although only one study found that the presence of side-effects was a significant predictor of non-adherence, the occurrence of side-effects was the most commonly self-reported reason for the discontinuation of oseltamivir. The review also included 8 studies investigating psychosocial predictors of intention to adhere: for instance, higher perceived susceptibility to the pandemic flu, higher perceived severity of pandemic flu, knowledge of pandemic flu, higher self-efficacy and response efficacy, and having previously accepted the flu vaccine were all associated with higher adherence intentions.

Methods: In May/June 2016 the investigated conducted an online experiment. After reading a hypothetical pandemic flu scenario, 349 adult UK residents were randomly allocated to one of four conditions, defined by a 2x2 (agency assignment × attribute framing of side effects) factorial design. Each condition presented messages describing the pandemic flu using linguistic expressions that assigned agency to either the humans (HA: human agency) or the virus itself (VA: virus agency), whilst describing the antivirals side effects in terms of the chances of either experiencing (NF: negative framing) or not experiencing side effects (PF: positive framing). Although presented with different framings the health messages provided equivalent information that targeted specific predictors of adherence. Participants were blinded to group assignment. Intentions to use the antivirals and potential mediating factors were measured. The aim was to understand the potential behavioural impact of the four health messages developed and to better understand the factors influencing adherence intentions.

Eligibility criteria: Inclusion Criteria:

* To be eligible to participate, respondents had to be members of the UK general public in the adult age range (18-65 years), and be fluent in English.

Exclusion Criteria:

* non-UK residents
* younger than 18 or older than 65
* not fluent in English

Primary outcomes:
measure: Change in Intentions to Take Antivirals for Pandemic Flu
timeFrame: Straight after exposure to the health messages
Secondary outcomes:
measure: Worry of the Pandemic Flu Threat
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
measure: Perceived Susceptibility to the Pandemic Flu
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
measure: Perceived Severity of the Pandemic
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
measure: Perceived Self-efficacy
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
measure: Perceived Efficacy of the Antivirals
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
measure: Perceived Response Costs
timeFrame: At 20 minutes (i.e. straight after exposure to the health messages)
Other outcomes:
Locations:
Study officials:
affiliation: King's College London
name: Donatella D'Antoni
role: PRINCIPAL_INVESTIGATOR
References:
citation: McGlone MS, Bell RA, Zaitchik ST, McGlynn J 3rd. Don't let the flu catch you: agency assignment in printed educational materials about the H1N1 influenza virus. J Health Commun. 2013;18(6):740-56. doi: 10.1080/10810730.2012.727950. Epub 2012 Dec 5.
citation: Moxey A, O'Connell D, McGettigan P, Henry D. Describing treatment effects to patients. J Gen Intern Med. 2003 Nov;18(11):948-59. doi: 10.1046/j.1525-1497.2003.20928.x.
citation: Smith LE, D'Antoni D, Jain V, Pearce JM, Weinman J, Rubin GJ. A systematic review of factors affecting intended and actual adherence with antiviral medication as treatment or prophylaxis in seasonal and pandemic flu. Influenza Other Respir Viruses. 2016 Nov;10(6):462-478. doi: 10.1111/irv.12406. Epub 2016 Aug 8.