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KSR Number: KSRA572

Perceptions and behavioral responses of the general public during the 2009 influenza A (H1N1) pandemic: a systematic review

Risk of Bias Assessment

Overall summary: High risk of bias in the review

Bottom Line

Evidence from survey studies conducted across the world indicates that public perceptions and behaviours evolved during and after the 2009 influenza A (H1N1) pandemic. In most countries, perceived vulnerability increased, but perceived severity, anxiety, self-efficacy, and vaccination intention decreased. Improved hygienic practices and social distancing were practised most commonly. The review authors concluded that health authorities should continuously monitor public perceptions and provide up-to-date information, to avoid misconceptions. Because public perceptions and behaviours varied between countries during the pandemic, the review authors also recommended that risk communication should be tailored to the specific circumstances of each country. This article provides a good general overview of the topic, but has been rated high risk of bias because of weaknesses in the review methods and the potential for missed information created by the restriction to English language studies.

Risk of Bias Assessment

Overall summary High risk of bias in the review

High

The restriction of the review to English language publications means that relevant studies may have been missed. Weaknesses in the review methods (the majority of the review process was conducted by one reviewer) raise the potential for error and bias.

A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4? No
B. Was the relevance of identified studies to the review's research question appropriately considered? Yes
C. Did the reviewers avoid emphasizing results on the basis of their statistical significance? Yes
Risk of bias in the review High

Details of Review

Number of studies 70
Number of participants Unclear
Last search date December 2012
Review type Public health
Objective To explore public perceptions and behavioural responses to the 2009 influenza A (H1N1) pandemic, with a focus on trends over time and regional differences.
Population The general population.

Studies targeting specific groups (e.g. healthcare workers, parents, pregnant women, students, or patients at risk) were excluded.
Interventions NA.
Comparator NA.
Outcome Perceptions or behaviours, measured during the 2009 influenza A (H1N1) pandemic, under the following categories: knowledge, perceived severity, perceived vulnerability, feelings of anxiety, perceived (self-)efficacy, intention, and behaviour.
Study design Surveys (telephone, face-to-face, or online) reporting quantitative results.
Reference standard NA.
Exposure NA.
PP factor NA.

Results

The included studies were conducted in Europe (n = 23), Asia (n = 18), the United States (n = 14), Australia (n = 8), the Eastern Mediterranean (n = 3), and North America (n = 1); three studies collected data in more than one country or region, with over half (n = 38) collecting data only during the post-pandemic phase.

The number of respondents per study ranged from 186 to 22,050, with response rates ranging from 3% to 98%.

Knowledge:

High knowledge levels about the main modes of transmission of the H1N1 virus (i.e. through droplets or close contact with infected people) were observed in the general public of different countries and during the various pandemic phases. However, several misconceptions about other modes of transmission (e.g. oral-foecal route, water sources, insect bites, eating improperly cooked food, sexual route) were identified. High awareness of personal hygiene measures was observed in studies in the United States, Italy and China, during the post-pandemic phase; however, interpretation of recommendations varied widely. Reported misconceptions about vaccination included: that a H1N1 vaccine was available during the early and peak pandemic phases; that a seasonal influenza vaccine was effective against H1N1; that the efficacy of the H1N1 vaccine had been confirmed in clinical trials.

Perceived severity:

Multiple studies, across different countries, reported a decline in perceived severity over the course of the pandemic. Although declining trends were observed in all regions, differences were found in the absolute levels of perceived H1N1 severity between countries.

Perceived vulnerability:

The perceived vulnerability among the general public increased over time during the early and pandemic peak phases (reported in studies from the United States, Netherlands, and Hong Kong), and declined in the post-pandemic phase (reported in studies from the United States, Germany and Italy). Despite increasing trends in the early and pandemic peak phases, absolute levels of perceived vulnerability remained relatively low in most countries, and four studies conducted during the pandemic peak phase showed that respondents perceived themselves as being less likely to get infected with H1N1 than other individuals.

Feelings of anxiety:

Perceived anxiety about the pandemic/H1N1 virus in general showed decreasing trends in studies conducted in the Netherlands and in Italy, where it was reported that perceived anxiety waned as perception that the virus was an immediate threat decreased. One UK study reported that the proportion of respondents who were worried about personally becoming infected increased from the early (10% to 17%) to peak (33%) pandemic phases. Rates of both general and personal anxiety varied between regions and countries.

Perceived efficacy of preventative measures:

Studies conducted in the United States, Netherlands, and Hong Kong reported that improving hygienic practice (i.e. more frequent hand washing, using tissues when coughing or sneezing, cleaning or disinfecting things) was perceived as the most effective preventive measure. Perceived efficacy of vaccination was relatively high; during the post-pandemic phase, vaccination against H1N1 was perceived as effective by 82% of respondents in a study conducted in Taiwan, 81% in a study conducted in the United States, 76% in a study conducted in Malaysia, and 53% in a study conducted in the Netherlands.

Perceived self-efficacy:

Four studies, conducted in Hong Kong (n = 2), Malaysia (n = 1) and the Netherlands (n = 1), reported that the percentage of respondents who were confident that they or their family members could prevent an H1N1 infection in the next year decreased during the early and peak pandemic phases. However, all four studies reported relatively high levels of perceived self-efficacy to perform preventative measures.

Intention to take measures:

During the post-pandemic phase, declining trends in the intention to take up vaccination were reported in three studies, conducted in the United States, Italy and the Netherlands. During the early phase, the intention to improve hygienic practice, seek medical consultation at the onset of flu symptoms, and take antiviral medication was generally high. During the peak and post-pandemic phases, intention to take preventative measures remained relatively high across most countries; however, intention to get vaccinated was highly dependent upon the availability of scientific evidence on efficacy and safety, the vaccination provider, and the cost.

Actual behaviour:

Improved hygienic practice and social distancing were the most frequently reported preventive behaviours (reported in studies conducted in Mexico, the United States, Argentina, Saudi Arabia, Europe, and Asia). Decreasing trends, over time, were observed regarding social distancing measures (e.g. avoiding public transport and crowded places) in studies conducted in Hong Kong and Italy. Differences in behaviours, between regions and countries, were observed during the post-pandemic phase.

Full Risk of Bias Assessment

The objective of the review was clearly stated and the inclusion criteria were appropriately broad. The time period of the review was restricted to identify studies published since the 2009 influenza A (H1N1 pandemic). Only studies published in English were eligible for inclusion.

1.1 Did the review adhere to pre-defined objectives and eligibility criteria? Probably yes
1.2 Were the eligibility criteria appropriate for the review question? Yes
1.3 Were eligibility criteria unambiguous? Yes
1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)? Probably yes
1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)? No
Concerns regarding specification of study eligibility criteria High

PubMed, EMBASE, and PsycINFO were searched to identify relevant studies. The search strategies were reported in full and appeared adequate. No additional searching of sources other than bibliographic databases was reported. One reviewer screened titles and abstracts for inclusion, only those articles retrieved as full-text were independently assessed for inclusion by two reviewers, with any disagreements resolved by consensus.

2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports? Probably yes
2.2 Were methods additional to database searching used to identify relevant reports? Probably no
2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible? Probably yes
2.4 Were restrictions based on date, publication format, or language appropriate? Probably yes
2.5 Were efforts made to minimise error in selection of studies? No
Concerns regarding methods used to identify and/or select studies High

A summary of the included study characteristics and details of which studies reported each outcome are provided in tables in the main text of the article. Full details of all included studies and their findings are provided in the online supplement. Data were extracted from the included studies by one reviewer. The methodological quality of included studies was assessed using a tool created for the project, which combined response rate (<10% or not described = 1, 10% to 30% = 2, >30% = 3) and sampling methods (convenience sample or not described = 1, representative sample for a defined geographic area = 2, representative sample for a whole country = 3) to give an overall score out of 6.

3.1 Were efforts made to minimise error in data collection? No
3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results? Probably yes
3.3 Were all relevant study results collected for use in the synthesis? Probably yes
3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria? Probably yes
3.5 Were efforts made to minimise error in risk of bias assessment? No information
Concerns regarding methods used to collect data and appraise studies High

The use of a narrative synthesis, to summarise the findings of included studies was appropriate. All studies were included in the tables, and the text focused on studies with a response rate score of 2 or more and a sampling methods score of 2 or more.

4.1 Did the synthesis include all studies that it should? Probably yes
4.2 Were all pre-defined analyses reported or departures explained? Probably yes
4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies? Yes
4.4 Was between-study variation minimal or addressed in the synthesis? Probably yes
4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses? Probably yes
4.6 Were biases in primary studies minimal or addressed in the synthesis? Probably yes
Concerns regarding synthesis and findings Low

Abstract

The public plays an important role in controlling the spread of a virus by adopting preventive measures. This systematic literature review aimed to gain insight into public perceptions and behavioral responses to the 2009 influenza A (H1N1) pandemic, with a focus on trends over time and regional differences. We screened 5498 articles and identified 70 eligible studies from PubMed, Embase, and PsychINFO. Public misconceptions were apparent regarding modes of transmission and preventive measures. Perceptions and behaviors evolved during the pandemic. In most countries, perceived vulnerability increased, but perceived severity, anxiety, self-efficacy, and vaccination intention decreased. Improved hygienic practices and social distancing were practiced most commonly. However, vaccination acceptance remained low. Marked regional differences were noted. To prevent misconceptions, it is important that health authorities provide up-to-date information about the virus and possible preventive measures during future outbreaks. Health authorities should continuously monitor public perceptions and misconceptions. Because public perceptions and behaviors varied between countries during the pandemic, risk communication should be tailored to the specific circumstances of each country. Finally, the use of health behavior theories in studies of public perceptions and behaviors during outbreaks would greatly facilitate the development of effective public health interventions that counter the effect of an outbreak.