Tracking the health and wellbeing of older New Zealanders affected by the Canterbury earthquakes

Abstract

This report summarises the findings from a study exploring the effects of a series of earthquakes in New Zealand between 2010 and 2013. These include the 7.1 Moment Magnitude (MM) earthquake striking Canterbury on Saturday 4th September 2010, a major aftershock of 6.3 MM with its epicentre in Christchurch city on 22 February 2011, and a 6.6 MM earthquake centred 10km south of Seddon damaging parts of Marlborough and Wellington city on 21 July 2013. The report uses data from the longitudinal Health, Work and Retirement (HWR) study of older New Zealanders.

A significant finding was that the effects of the earthquake were reported by older people across all of New Zealand and these effects persisted for over three years following the events. These effects generally decreased with greater distance from the most directly affected regions of NZ and over time. A significant proportion of older New Zealanders were affected by the Canterbury earthquakes and reports of these effects reduced with both physical and temporal distance from the site and time of the Christchurch events.

Effects to older New Zealanders from loss of life or injury (to family, friends or others) and providing social support because they had experienced an earthquake were reported as significant, but decreased over time. Emotional and economic impacts were more likely to be reported in the longer term. After taking into account general changes in the health and wellbeing of older people over time, there was no effect of exposure to earthquake effects on health. However, there was a short term benefit on emotional loneliness for those affected by the earthquake. People who had experienced the earthquake were more likely to report reduced loneliness immediately after the event.

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Technical Abstract

This report summarises the findings from a study exploring the effects of a series of earthquakes in New Zealand between 2010 and 2013. These include the 7.1 Moment Magnitude (MM) earthquake striking Canterbury on Saturday 4th September 2010, a major aftershock of 6.3 MM with its epicentre in Christchurch city on 22 February 2011, and a 6.6 MM earthquake centred 10km south of Seddon damaging parts of Marlborough and Wellington city on 21 July 2013.

The analysis takes into account data from the longitudinal Health, Work and Retirement (HWR) study of older New Zealanders, which has surveyed a population sample every two years since 2006 including a survey just prior to the 2010 earthquake. Accordingly, post-earthquake survey findings from 2012 and 2014 may be compared to measures of health and wellbeing before the earthquakes. Of the 2986 participants in 2012, the average age was 66.3 years old (SD 7.8), just over half were female (55%), and 36% were of Māori descent.

The present study had four main aims: (1) explore the ‘ripple effects’ reported from the earthquakes; (2) identify any groups whose health and wellbeing changed over the four years from the beginning of these events; (3) identify what factors have been most protective to those directly affected by the earthquakes; (4) analyse subgroups affected in different ways, taking into account pre-existing circumstances.

The HWR study included measures of Demographics (age, gender, ethnicity, marital status, education, work status, home ownership), Health (Physical & Mental, diagnosed health conditions), Social Indices (Social Support, Loneliness), Economic Status (Economic Living Standards Indicator), and in 2012 and 2014 specific questions on earthquake experience (were in area on the day of each earthquake event) and effects (personal/family, financial, and health effects).

The first finding was that the effects of the earthquake were reported by older people across all of New Zealand and these effects persisted over three years following the events. These effects generally decreased with greater distance from the most directly affected regions of NZ and over time. A significant proportion of older New Zealanders were affected by the Canterbury earthquakes and reports of these effects reduced with both physical and temporal distance from the site and time of the Christchurch events (Table 1). No differences across the demographic variables predicted participants’ reports of suffering effects.
 
Secondly, a series of multivariate multi-level models used to test for differences between groups and changes over time in wellbeing showed that the effects of loss of life or injury (to family, friends or others) and providing social support due to experiencing an earthquake decreased over time. Emotional and economic impacts were more likely to be reported in the longer term. After taking into account general changes in the health and wellbeing of older people over time, there was no effect of exposure to earthquake effects on health. However, there was a short term benefit on emotional loneliness for those affected by the earthquake. People who had experienced the earthquake were more likely to report reduced loneliness immediately after the event.