Symptom-specific health-seeking behaviour for common acute infections in Hong Kong

Abstract

Common acute infections such as respiratory and acute diarrhoeal diseases are circulating year round in the community in Hong Kong, a subtropical city with high population density. Understanding how these infections affect health-related behaviour and disease burden may inform policy makers on healthcare resource allocation, health promotion programs, and disease prevention and control. The main aim of this thesis is to understand health-seeking behaviours from an illness-role perspective, by examining how specific symptoms experienced by sick persons could affect their behaviours.

I conducted three studies on health-seeking behaviour for common acute infections in Hong Kong, by specific symptoms or syndromes. The studies were based on a longitudinal health-seeking behaviour telephone survey conducted during 2014 to 2015. The survey studied healthcare-seeking behaviour, preventive measures, risk perception, and symptom history in the general population.

The first study examined healthcare-seeking behaviour of participants by each specific symptom. Participants were most likely to seek medical consultation when they had respiratory-related symptoms such as fever and shortness of breath. 91% of the participants with influenza-like illness (ILI) sought medical consultation, among which 63% within 12 hours of symptom onset. Participants were least likely to seek medical consultation when they had symptoms perceived relating to chronic conditions, such as fatigue or myalgia.

The second study described preventive measures taken by participants due to specific symptoms, and examined the associating factors. Participants with diarrhoea and vomiting were most likely to increase handwashing. Fever, cough, and runny nose were strongest drivers for wearing face masks. Participants with ILI were mostly likely to increase handwashing and wear face masks, especially for participants aged 35–54y (97%). Participants were more likely to reduce contacts with others during influenza seasons, during which the local health department took great effort to alert the population.

In the third study, I further investigated the role of risk perception on preventive measures. Perceived risk of severity was associated with adoption of all preventive measures considered, and perceived risk of transmitting disease to others was only associated with reducing social contacts. I also investigated the mediating role of symptom-specific risk perception on the pathway between symptoms to preventive measures. Perceived risk of severity of fever, and perceived risk of disease transmission due to fever, runny nose, ILI and acute respiratory illness (ARI) were found to mediate the association between symptoms and uptake of all measures considered.

Lastly, I adopted a hierarchical analytic framework to synthesise healthcare-seeking pattern with routine surveillance, to estimate the attack rate of symptomatic influenza in three influenza seasons in Hong Kong. There is no existing local community-based influenza surveillance to provide such estimates. By identifying healthcare-seeking behaviour in line with the ILI syndromic surveillance, I estimated that children had the largest attack rates (8.2–27.2%), followed by the elderly (1.4–3.0%).

In conclusion, symptoms experienced by the sick persons would affect health-seeking behaviour. Understanding health-seeking behaviour pattern in an illness-role perspective would provide the link from sickness in the community to healthcare utilization and shed light on the full burden of disease.