A series of major earthquakes began in Canterbury, New Zealand, in September 2010 which continued for approximately the next three years. The Canterbury earthquakes have left healthcare providers, teachers and parents concerned for the mental wellbeing of children growing up in Canterbury.
Previous research has indicated that exposure to a large natural disaster during childhood can lead to emotional and behavioural disturbances in children which could potentially have long lasting effects on personal and population health. There are, however, serious methodological limitations in many of the available studies on this topic.
The B4 school check, which has been in use in NZ since 2008, is a nation-wide health screening tool for four-year-olds which includes the Strengths and Difficulties Questionnaire (SDQ), a measure of behavioural and emotional problems in children. The current study aimed to investigate the impact of earthquakes on the emotional and behavioural wellbeing of four-year-olds in Canterbury by analysing data from the B4 School Check.
Temporal and geographical trends in various measures of wellbeing were analysed using logistic regression to ascertain whether the trends in Canterbury may have been impacted by the earthquakes. Mean population SDQ scores and the proportion of abnormal SDQ scores in the population over time both decreased on all measures over the study period. Analyses indicated that, when compared to a control population, an overall population-level negative impact on SDQ scores due to the earthquakes was not present in the considered data.
This finding is surprising given the extent of community disruption and distress following the Canterbury earthquakes and is not consistent with other most similar research findings. Various explanations can be given for why the current results were found. Firstly, the study findings may be a true result. This could be because of positive factors such as resilience, the age of participants being a possible protective factor, or a general failure for exposure levels to meet a threshold level. Alternatively, a possible true result could be explained by the effect of the earthquakes being on non-studied measures only. Secondly, other explanations such as chance, bias, confounding or error could explain why the current results were found.
Any practical implications must be made with caution due to limitations of the study and the narrow generalizability of the findings. Further work is needed to explore the health needs specific to the children in Canterbury.