Qiuyan Liao

Factors Affecting Intention to Receive and Self-Reported Receipt of 2009 Pandemic (H1N1) Vaccine in Hong Kong: A Longitudinal Study

Background Vaccination was a core component for mitigating the 2009 influenza pandemic (pH1N1). However, a vaccination programs efficacy largely depends on population compliance. We examined general population decision-making for pH1N1 vaccination using a modified Theory of Planned Behaviour (TBP). Methodology We conducted a longitudinal study, collecting data before and after the introduction of pH1N1 vaccine in Hong Kong. Structural equation modeling (SEM) tested if a modified TPB had explanatory utility for vaccine uptake among adults. Principal Findings Among 896 subjects who completed both the baseline and the follow-up surveys, 7% (67/896) reported being “likely/very likely/certain” to be vaccinated (intent) but two months later only 0.8% (7/896) reported having received pH1N1 vaccination. Perception of low risk from pH1N1 (60%) and concerns regarding adverse effects of the vaccine (37%) were primary justifications for avoiding pH1N1 vaccination. Greater perceived vaccine benefits (β = 0.15), less concerns regarding vaccine side-effects (β = −0.20), greater adherence to social norms of vaccination (β = 0.39), anticipated higher regret if not vaccinated (β = 0.47), perceived higher self-efficacy for vaccination (β = 0.12) and history of seasonal influenza vaccination (β = 0.12) were associated with higher intention to receive the pH1N1 vaccine, which in turn predicted self-reported vaccination uptake (β = 0.30). Social norm (β = 0.70), anticipated regret (β = 0.19) and vaccination intention (β = 0.31) were positively associated with, and accounted for 70% of variance in vaccination planning, which, in turn subsequently predicted self-reported vaccination uptake (β = 0.36) accounting for 36% of variance in reported vaccination behaviour. Conclusions/Significance Perceived low risk from pH1N1 and perceived high risk from pH1N1 vaccine inhibited pH1N1 vaccine uptake. Both the TPB and the additional components contributed to intended vaccination uptake but social norms and anticipated regret predominantly associated with vaccination intention and planning. Vaccination planning is a more significant proximal determinant of uptake of pH1N1 vaccine than is intention. Intention alone is an unreliable predictor of future vaccine uptake.

Situational awareness and health protective responses to pandemic influenza A (H1N1) in Hong Kong: a cross-sectional study.

Background Whether information sources influence health protective behaviours during influenza pandemics or other emerging infectious disease epidemics is uncertain. Methodology Data from cross-sectional telephone interviews of 1,001 Hong Kong adults in June, 2009 were tested against theory and data-derived hypothesized associations between trust in (formal/informal) information, understanding, self-efficacy, perceived susceptibility and worry, and hand hygiene and social distancing using Structural Equation Modelling with multigroup comparisons. Principal Findings Trust in formal (government/media) information about influenza was associated with greater reported understanding of A/H1N1 cause (β = 0.36) and A/H1N1 prevention self-efficacy (β = 0.25), which in turn were associated with more hand hygiene (β = 0.19 and β = 0.23, respectively). Trust in informal (interpersonal) information was negatively associated with perceived personal A/H1N1 susceptibility (β = −0.21), which was negatively associated with perceived self-efficacy (β = −0.42) but positively associated with influenza worry (β = 0.44). Trust in informal information was positively associated with influenza worry (β = 0.16) which was in turn associated with greater social distancing (β = 0.36). Multigroup comparisons showed gender differences regarding paths from trust in formal information to understanding of A/H1N1 cause, trust in informal information to understanding of A/H1N1 cause, and understanding of A/H1N1 cause to perceived self-efficacy. Conclusions/Significance Trust in government/media information was more strongly associated with greater self-efficacy and handwashing, whereas trust in informal information was strongly associated with perceived health threat and avoidance behaviour. Risk communication should consider the effect of gender differences.

The Influence of Social-Cognitive Factors on Personal Hygiene Practices to Protect Against Influenzas: Using Modelling to Compare Avian A/H5N1 and 2009 Pandemic A/H1N1 Influenzas in Hong Kong

BackgroundUnderstanding population responses to influenza helps optimize public health interventions. Relevant theoretical frameworks remain nascent.PurposeTo model associations between trust in information, perceived hygiene effectiveness, knowledge about the causes of influenza, perceived susceptibility and worry, and personal hygiene practices (PHPs) associated with influenza.MethodsCross-sectional household telephone surveys on avian influenza A/H5N1 (2006) and pandemic influenza A/H1N1 (2009) gathered comparable data on trust in formal and informal sources of influenza information, influenza-related knowledge, perceived hygiene effectiveness, worry, perceived susceptibility, and PHPs. Exploratory factor analysis confirmed domain content while confirmatory factor analysis was used to evaluate the extracted factors. The hypothesized model, compiled from different theoretical frameworks, was optimized with structural equation modelling using the A/H5N1 data. The optimized model was then tested against the A/H1N1 dataset.ResultsThe model was robust across datasets though corresponding path weights differed. Trust in formal information was positively associated with perceived hygiene effectiveness which was positively associated with PHPs in both datasets. Trust in formal information was positively associated with influenza worry in A/H5N1 data, and with knowledge of influenza cause in A/H1N1 data, both variables being positively associated with PHPs. Trust in informal information was positively associated with influenza worry in both datasets. Independent of information trust, perceived influenza susceptibility associated with influenza worry. Worry associated with PHPs in A/H5N1 data only.ConclusionsKnowledge of influenza cause and perceived PHP effectiveness were associated with PHPs. Improving trust in formal information should increase PHPs. Worry was significantly associated with PHPs in A/H5N1.

Live poultry exposure, Guangzhou, China, 2006.

BACKGROUND Live poultry in wet markets and backyard husbandry comprise potentially major exposure sources for human cases of H5N1 avian influenza. In China the magnitude of risk from this exposure is unknown. We estimated exposure based on self-reported behavior. METHODS In January-March 2006, 1550 face-to-face interviews derived from stratified cluster and randomized within-household sampling provided data on live poultry exposure in Guangzhou, China based on self-reported buying and touching patterns. Standardized exposures were calculated and after adjustment extrapolated to the urban population. RESULTS The results, adjusted for gender, showed that 1,248/1,550 (80%, 95% Confidence Limits 78-82%) respondents reported an average of 20.5 live chicken purchases/household annually. Of those buying poultry 33% touched poultry before buying while 20% of households raised live poultry. Total exposures from wet market and backyard husbandry in Guangzhou greatly exceed those of adjacent Hong Kong (15,280,000 e/year vs. 1,110,900 e/year). Backyard exposure frequency likely exceeds that from live poultry retail, but purchases were more prevalent and hence comprise a significant risk source. CONCLUSION The Guangzhou population faces risks from the high prevalence of exposures during purchase and poultry rearing. Better management for raising and selling poultry in Guangzhou is needed.

Chinese immigrant parents’ vaccination decision making for children: a qualitative analysis

BackgroundWhile immunization coverage rates for childhood routine vaccines in Hong Kong are almost 100%, the uptake rates of optional vaccines remain suboptimal. Understanding parental decision-making for children’s vaccination is important, particularly among minority groups who are most vulnerable and underserved. This study explored how a subsample of new immigrant mothers from mainland China, a rapidly-growing subpopulation in Hong Kong, made decisions on various childhood and adolescent vaccines for their offspring, and identified key influences affecting their decision making.MethodsSemi-structured in-depth interviews were conducted with 23 Chinese new immigrant mothers recruited by purposive sampling. All interviews were audio-taped, transcribed and analyzed using a Grounded Theory approach.ResultsParticipants’ conversation revealed five underlying themes which influenced parents’ vaccination decision-making: (1) Institutional factors, (2) Insufficient vaccination knowledge and advice, (3) Affective impacts on motivation, (4) Vaccination barriers, and (5) Social influences. The role of social norms appeared overwhelmingly salient influencing parents’ vaccination decision making. Institutional factors shaped parent’s perceptions of vaccination necessity. Fear of vaccine-targeted diseases was a key motivating factor for parents adopting vaccination. Insufficient knowledge about vaccines and targeted diseases, lack of advice from health professionals and, if provided, suspicions regarding the motivations for such advice were common issues. Vaccination cost was a major barrier for many new immigrant parents.ConclusionsSocial norms play a key role influencing parental vaccination decision-making. Insight gained from this study will help inform healthcare providers in vaccination communication and policymakers in future vaccination programme.

Anxiety, worry and cognitive risk estimate in relation to protective behaviors during the 2009 influenza A/H1N1 pandemic in Hong Kong: ten cross-sectional surveys

BackgroundFew studies have investigated associations between psychological and behavioral indices throughout a major epidemic. This study was aimed to compare the strength of associations between different cognitive and affective measures of risk and self-reported protective behaviors in a series of ten cross-sectional surveys conducted throughout the first wave of influenza A/H1N1 pandemic.MethodsAll surveys were conducted using questionnaire-based telephone interviews, with random digit dialing to recruit adults from the general population. Measures of anxiety and worry (affective) and perceived risk (cognitive) regarding A/H1N1 were made in 10 serial surveys. Multivariate logistic regression models were used to estimate the cognitive/affective-behavioral associations in each survey while multilevel logistic models were conducted to estimate the average effects of each cognitive/affective measure on adoption of protective behaviors throughout the ten surveys.ResultsExcepting state anxiety, other affective measures including “anticipated worry”, “experienced worry” and “current worry” specific to A/H1N1 risk were consistently and strongly associated with adoption of protective behaviors across different survey periods. However, the cognitive-behavioral associations were weaker and inconsistent across the ten surveys. Perceived A/H1N1 severity relative to SARS had stronger associations with adoption of protective behaviors in the late epidemic periods than in the early epidemic periods.ConclusionRisk-specific worries appear to be significantly associated with the adoption of protective behaviors at different epidemic stages, whereas cognitive measures may become more important in understanding people’s behavioral responses later in epidemics. Future epidemic-related psycho-behavioral research should include more affective-loaded measures of risk.

Comparison of Different Risk Perception Measures in Predicting Seasonal Influenza Vaccination among Healthy Chinese Adults in Hong Kong: A Prospective Longitudinal Study

Background Risk perception is a reported predictor of vaccination uptake, but which measures of risk perception best predict influenza vaccination uptake remain unclear. Methodology During the main influenza seasons (between January and March) of 2009 (Wave 1) and 2010 (Wave 2),505 Chinese students and employees from a Hong Kong university completed an online survey. Multivariate logistic regression models were conducted to assess how well different risk perceptions measures in Wave 1 predicted vaccination uptake against seasonal influenza in Wave 2. Principal Findings The results of the multivariate logistic regression models showed that feeling at risk (β = 0.25, p = 0.021) was the better predictor compared with probability judgment while probability judgment (β = 0.25, p = 0.029 ) was better than beliefs about risk in predicting subsequent influenza vaccination uptake. Beliefs about risk and feeling at risk seemed to predict the same aspect of subsequent vaccination uptake because their associations with vaccination uptake became insignificant when paired into the logistic regression model. Similarly, to compare the four scales for assessing probability judgment in predicting vaccination uptake, the 7-point verbal scale remained a significant and stronger predictor for vaccination uptake when paired with other three scales; the 6-point verbal scale was a significant and stronger predictor when paired with the percentage scale or the 2-point verbal scale; and the percentage scale was a significant and stronger predictor only when paired with the 2-point verbal scale. Conclusions/Significance Beliefs about risk and feeling at risk are not well differentiated by Hong Kong Chinese people. Feeling at risk, an affective-cognitive dimension of risk perception predicts subsequent vaccination uptake better than do probability judgments. Among the four scales for assessing risk probability judgment, the 7-point verbal scale offered the best predictive power for subsequent vaccination uptake.

How do anticipated worry and regret predict seasonal influenza vaccination uptake among Chinese adults

OBJECTIVES To test two hypothesized models of how anticipated affect, cognitive risk estimate and vaccination intention might influence vaccination uptake against seasonal influenza. METHODS The study collected baseline and follow-up data during the main influenza seasons (January-March) of 2009 and 2010, respectively, among 507 university students and staff of a university in Hong Kong. Following logistic regression to determine eligible variables, two mediation models of cognitive risk estimate, anticipated affect, vaccination intention and vaccination uptake against seasonal influenza were tested using structural equation modeling. RESULTS Mediation analyses found that anticipated worry if not vaccinated influenced seasonal influenza vaccination uptake through its effects on either perceived probability of influenza infection (β=0.45) or intention (β=0.45) while anticipated regret if not vaccinated influenced vaccination uptake through its effect on intention (β=0.45) only; anticipated regret if vaccinated impeded vaccination uptake indirectly through its effect on vaccination intention (β=-0.26) or directly (β=-0.20); perceived probability of influenza infection influenced vaccination uptake through its effect on intention (β=0.20) or directly (β=0.22); and finally, intention influenced vaccination uptake directly (β=0.58). CONCLUSION The results suggest that anticipated affect seems to drive risk estimates related to seasonal influenza vaccination rather than vice versa and intention remains an important mediator of the associations of anticipated affect and cognitive risk estimate with vaccination uptake against seasonal influenza.

Psychometric assessment of the Chinese version of the decisional conflict scale in Chinese women making decision for breast cancer surgery

The decisional conflict scale (DCS) measures the perception of uncertainty in choosing options, factors contributing to decision conflict and effective decision making. This study examined the validity and reliability of the Chinese version of the DCS in Hong Kong Chinese women deciding breast cancer (BC) surgery.

Responses to Threat of Influenza A(H7N9) and Support for Live Poultry Markets, Hong Kong, 2013

We conducted a population survey in Hong Kong to gauge psychological and behavioral responses to the threat of influenza A(H7N9) and support for closure of live poultry markets. We found low anxiety and low levels of exposure to live poultry but mixed support for permanent closure of the markets.