Around 77% of the respondents showed some avoidance behaviors. The studies covered the entire early 'pre-community outbreak phase' of the H1N1 epidemic in Hong Kong during which all confirmed cases were imported. During the study period, the local government had not given any public health advice about avoiding going to different places, though a previous analysis of our May 7 to May 9 data showed that 31.6% of the public misconceived that such an advice was given [17]. Avoidance of visiting hospital may be due to the fear of getting infected in hospitals, which was prominent during the SARS period [9]. The government only started advising people to avoid crowded places at the 'community outbreak phase' of the epidemic. There seemed to be no serious immediate public health threat for going out or visiting different places. Such avoidance behaviors were associated with negative psychological responses; emotional elements may therefore be strongly involved in making the decisions. Experience from SARS showed that such avoidance behaviors among large numbers in the population potentially damages the economy and disrupts daily lives.
About half of the respondents believed that Hong Kong has a lower chance of having an H1N1 outbreak as compared to other countries, whilst only less than 10% held the opposite belief. There were signs of underestimating the risk of having a community outbreak in Hong Kong [17]. The shift into the pandemic phase as announced by the WHO and the explosion of non-imported community cases in Hong Kong (629 as of June 27, 2009) may change the picture completely. The direction of change is however uncertain. A few international studies also documented strong levels of anticipated anxiety and avoidance behaviors at the early phase of human avian flu outbreaks or pandemic influenza [15, 26–28]. The impact of pandemics and unknown emerging infections has not been widely studied. Avoidance behaviors and emotional distress may have been under-emphasized in the preparedness plans.
It is seen that females, older people and those who were not full-time employed were more likely than others to show avoidance behaviors or signs of emotional distress. The results are consistent with those reported during the SARS period [9]. A recent study exploring people's emotional and behavioral responses to an avian flu outbreak also showed that females and older people were, respectively, more likely to express negative emotional responses and exhibit avoidance behaviors (e.g., avoiding leaving their residence, avoiding crowds and avoiding visiting hospitals) in response to avian flu [26]. Attention should therefore be given to avoidance behaviors and psychological needs of these subpopulations at times of a pandemic.
Perceptions still count in this context. There were substantial unconfirmed beliefs about the mode of H1N1 transmission (61.8% had at least one unconfirmed belief). Around 1/4 of the respondents did not know that the virus could be spread by touching contaminated objects. The aforementioned unconfirmed beliefs about transmission mode were significantly associated with avoidance behaviors. Unconfirmed beliefs about modes of transmission were also documented in H5N1 studies [12], suggesting that similar unconfirmed beliefs exist in general for emerging respiratory infectious diseases. Rectification of misconceptions is important - and may decrease and reduce unwarranted anxiety.
Around 20% of the respondents believed that H1N1 would result in high fatality or severe irreversible bodily damages. Such beliefs may be affected by the SARS experience. Perceived high fatality was associated with emotional distress (e.g. panic) due to H1N1 and perceived severe irreversible bodily damage was associated with 3 of the 5 outcome variables on avoidance behaviors and negative psychological responses. Up-to-date information about the clinical properties of H1N1 should be disseminated to the public in layman terms.
The actual fatality associated with H1N1, both local and international, remains low. The cost of assurance by Hong Kong government is however, high - with early summer closure of all primary schools and kindergarten and a number of secondary schools, 10 billion Hong Kong dollars being spent (1.2 billion US$) to purchase H1N1 vaccines and reorganization of the health services to accommodate escalating infection figures are not insubstantial. Tourism may be adversely affected. A substantial proportion of the public may be overestimating its fatality and physical damages. Since public understanding of risk and of these mitigation measures will help to reduce unnecessary concern and changes in lifestyle amongst the population, public education is important.
As expected, perceived personal/family susceptibility for contracting H1N1 was associated with negative psychological responses due to H1N1. The association between perceived personal/family susceptibility and avoiding going out was non-significant. The results suggest that the public did not avoid going out because of feeling susceptible. Avoidance behaviors may involve an irrational element. It is speculated that the SARS experience of avoiding going to different places [29] might have a spill-over effect.
The general public evaluated the government highly in the performance and ability to control the pandemic. They however, showed reservations about the availability of medicine and vaccine and protective equipments, possibly because H1N1 was a new disease and it was not certain whether effective medicine, vaccine and equipments were then available. The positive evaluations of governmental performance and perceived ability for Hong Kong or the government to control the H1N1 outbreak were significantly associated with the outcome variables in most of the univariate analyses. Nonetheless, most of these associations were statistically non-significant in the multivariate analysis. The associations between such variables and the outcome variables (avoidance behaviors and negative psychological responses) were hence mediated by other variables, such as worry about contracting H1N1 or perceived susceptibility. These potential mediators were multivariately associated with either the avoidance variables or the negative psychological response variables.
The study has some limitations. First, this was a cross-sectional baseline study. Second, the response rate was comparable to those of other relevant published studies but some non-responder bias may still exist [9, 14, 30]. Some telephone numbers are unlisted and we randomized the last two digits to cover some of the unlisted numbers. Moreover, the gender and age distributions were comparable to those of the census population data. Third, results were self-reported and social desirability bias may exist. The study was however anonymous. Fourth, Hong Kong went through unique SARS experience, the results may not be comparable with those of other countries. Fifth, the measures on negative psychological responses were based on those used in previous studies, rather than derived from some validated scales. Finally, the study was not intended to track changes within the short study period of a month - interactions between time and various independent variables were not explored. Similar data obtained from other countries are becoming available and can be compared with ours.