What have we learned about communication inequalities during the H1N1 pandemic: a systematic review of the literature

During public health emergencies, public officials are busy in developing communication strategies to protect the population from existing or potential threats. In many situations, such as the early stages of a pandemic, their capability to effectively communicate risk and recommend preventive behaviors may be the only public health strategy to reduce morbidity and mortality [1]. However, a population’s social and individual determinants (i.e. education, income, race/ethnicity) may lead to inequalities in individual or group-specific exposure to public health communication messages, and in the capacity to access, process, and act upon the information received by specific population sub-groups- a concept defined as communication inequalities [2‐6]. Such inequalities may lead to disparities across segments of the population in the ability to comply with recommended preventive behaviors [3, 7‐11]. In 2009, a new strain of H1N1 influenza virus spread around the world causing a new pandemic. The initial outbreak began in the state of Veracruz, Mexico, the Mexican government closed most of Mexico City's public and private facilities in an attempt to contain the spread of the virus [12, 13]. However, it continued to spread globally, and in June of the same year the World Health Organization (WHO) declared the outbreak a pandemic [14]. Historically, there has been a paucity of empirical literature in the investigation of social determinants of communication inequalities in emergency preparedness [7]. The H1N1 pandemic offered a unique opportunity to researchers to assess the impact of communication efforts in response to an influenza outbreak of uncertain evolution leading to a robust research program in the field of communications in public health emergency preparedness and risk communication [7].

What scientists have learned about communication inequalities from this experience could help public health officials in identifying what communication strategies work better to prepare the public to respond to future emergencies. The aims of this literature review are to: 1) characterize the scientific literature that examined issues related to communication to the public during the H1N1 pandemic, and 2) summarize the knowledge gained in our understanding of social determinants and their association with communication inequalities in the preparedness and response to an influenza pandemic.

The H1N1 pandemic has challenged public health officials around the globe in developing effective communication strategies in absence of clear information on the severity and transmissibility of the virus. Media “hype” and uncertainty of information have caused panic at the beginning of the pandemic. However, a few months into the pandemic when vaccine became ready for distribution, the severity of the disease was deemed to be mild and a lack of compliance with recommended preventive behaviors prevailed. Given the complexity of the scenario, the H1N1 pandemic has prompted researchers around the globe to study populations’ reactions to such events. This literature review provides an analysis and synthesis of data derived from 118 empirical studies focused on the H1N1 pandemic, investigating differences across various segments of the population in communication and preparedness outcomes. This review is important for the public health practitioner because communication strategies can be designed to address the impact of social factors, as well as people’s attitudes and beliefs on communication outcomes and preparedness behaviors only when evidence on the role of specific factors exists. The literature being examined demonstrates the existence of differences across various segments of the population on information exposure during the H1N1 pandemic as well as their reactions and behaviors. The literature does not examine the effectiveness of specific communication strategies, but few recommendations may be derived and suggested for public health practitioners engaged in the development of communication strategies. This review suggests that to reduce communication inequalities during a large scale emergency, such as a pandemic, public health officials should focus their communication efforts on the young, the less educated and the indigent because there is evidence that these are the people at risk of not knowing about the threat, perceiving the threat to be of low risk and ultimately being less likely to follow recommended behaviors. Exposure to various communication channels varies by educational level with the less educated being exposed to television rather than newspapers or other means of communication [57]. This result suggests the need to build and sustain, over the course of an emergency, collaboration between public health agencies and media in order to disseminate information in a timely and accurate manner, thereby avoiding hypes and lows in the flow of information and developing a strategy that counterbalances the inevitable spread of rumors on the safety of recommended practices (i.e. immunization) and on the overall impact of the threat. An honest reporting of what the threat looks like, through a presentation of known and unknown factors, seems to have a better impact on people’s knowledge, attitudes and beliefs, including trust in the way the government is handling the emergency. Consequently, there is some evidence that better knowledge and trust are likely to be associated with the adoption of recommended behaviors (i.e. immunization practices). Social networks and ties to the community are also drivers of better knowledge and compliance with preventive measures; these results suggest that non-traditional channels of communication (i.e. partnership with community leaders or organizations) should be used to reach out to the most vulnerable and those in need of a better understanding of the risks and actions needed to be able to protect themselves. The fact that during the H1N1 pandemic, people with a higher educational level were better informed about the risks is not a surprise but suggests that public health communication messages are still delivered at a literacy level that does not meet the needs of the less educated [19, 76]. Some limitations are to be highlighted when interpreting these results. Most empirical studies included in the review had a cross-sectional study design and, therefore, conclusions cannot be drawn on the causal relationship between some determinants and specific communication and preparedness outcomes. Longitudinal studies or experiments are required to provide stronger evidence for such relationships. The selected studies were conducted at different points in time during the H1N1 pandemic and across various countries making the interpretation of aggregated results difficult. For example, differences in the H1N1 vaccination policies imposed across the globe in terms of decisions about the target populations and timing of influenza vaccination, prioritization of vaccine distribution, and policy of non-compliance might explain some of the variations in the findings among the studies. Also, racial disparities bear different interpretations among different countries such as the United States, Malaysia, and China. However, the recommendations provided above seem to be valid across the globe with a need for public health practitioners to develop messages targeted to specific groups to reduce disparities in the adoption of preventive behaviors.

Consistently across studies, a list of potential predictors of behavioral compliance to preventive recommendations during a pandemic were identified, including socio-demographic characteristics (e.g. age and race and ethnicity), attitudinal factors (e.g. perceived severity) and communication determinants (e.g. media exposure, information seeking behaviors and levels of knowledge about the threat). Understanding these factors can help us tailor public health communication messages to the target audience according to their social-demographic characteristics by calibrating the messaging format and optimizing channels of communication. When addressed in interventions, it can close the gap of communication inequality and increase the effectiveness of the preparedness and response to influenza pandemics. Most importantly, data showed it will be critical to work with community leaders, physicians, and communication specialists, as well as mass media, to improve the reach, accuracy, and timeliness of public health messages. This will ensure the highest rates of compliance with recommended protection measures and reduce communication inequalities during future emergencies.