Ardagh, M.

Campbel, l. M.

Hogg, D.

Kingham, S.

Reed, K.

Wilson, T.

UC Research Repository

Spatial variations in stress related health compared to earthquake exposure: preliminary results and future directions Prof Simon Kingham1, Daniel Hogg1, Kim Reed1, Dr Malcolm Campbell1, Dr Thomas Wilson 2, and Prof Mike Ardagh3   1 GeoHealth Laboratory and Dept of Geography, University of Canterbury, Christchurch, NZ 2 Dept of Geological Sciences, University of Canterbury, Christchurch, NZ 3 Canterbury District Health Board 2010/2011 Christchurch earthquakes • 4th Sept 2010: Darfield earthquake ~40km from Christchurch. Mag 7.1 •  22nd Feb 2011: Port Hills earthquake. Close to Christchurch. Mag 6.3 – Vertical ground acceleration was highest recorded ever – 185 people killed & over 8,000 people injured – > 100,000 buildings damaged/destroyed – 15,000-20,000 homes to be rebuilt. – Estimated NZ$40 billion rebuild costs (€24bn, US$32) Background  • Over 12,000 aftershocks • Ongoing Background Source: www.canterburyquakelive.co.nz Background Source: Geonet Physical Impacts • Damage/Collapse of Buildings • Damage to Infrastructure • Widespread Liquefaction • Rockfall and Hill Collapse  Background   Source: http://www.stuff.co.nz/national/christchurch-earthquake/photos Background Ongoing (years) community/health impact  Facilities permanently or temporarily closed e.g schools, shops, GPs  Temporary housing arrangements  Smaller housing, garages, even cars + multiple moves  Community break up & geographical challenges  Uncertainty over state of land and rebuild  Red, orange, green, white etc.  Dispersal/Relocation of whole communities   Red zone area not to be rebuilt  Ongoing infrastructure repairs • Is there a spatial relationship between the extent of physical damage from the 2010/2011 Christchurch Earthquakes and stress-related health outcomes? • Are adverse stress-related health outcomes greater among people who have experienced greater physical damage to their communities and homes than others who have experienced less damage, but who also live in the city? Research questions • Estimate exposure to earthquake-related anxiety and stress  • Relate exposure to stress-related health outcomes Challenges Preliminary research • Hospital admissions for chest pain and anxiety May 2010-April 2012 aggregated to spatial units – Chest pain - mean 408 cases per month (329-545) – Anxiety - mean 22 cases per month (9-42) • Compared to presence of, and proximity to,  – Liquefaction – red zone land areas • Range of spatio-temporal approaches used (SatScan, linear and negative binomial regression) Preliminary findings • Cluster of both anxiety & chest pain within Christchurch at the same time the earthquakes occurred • Liquefaction a stronger predictor of anxiety than red zone land • Chest pain positively associated with all measures of earthquake damage with the exception of being in red-zone • Significant increase in  – anxiety cases 1 month after a major earthquake – chest pain cases 2 weeks after an earthquake (but then decreased over the following 5 weeks) Mood/anxiety in Christchurch • Annual summaries from July 1, 2009 to June 30, 2012 • Data sources from the Ministry of Health: – Mental health data (PRIMHD) – Pharmaceutical data (PHARMS) – Laboratory test information (LABS) – Public and private hospital data (NMDS) – Intellectual disability data (SOCRATES) • Diagnoses based on ICD-9 and -10 codes • Geocoded on a meshblock level based on the Primary Health Organisation (PHO) register Spatial variation of mood/anxiety • Very scattered picture of hot and cold spots, but  greater hot spot of mood/anxiety rates northeast of the CBD  hot spots mainly found in the east and cold spots in the west of Christchurch  • No big spatial difference before and after the earthquake Hot Spot analysis results of mood/anxiety rates per 1,000 people in Christchurch in the years 2009/10, 2010/11 & 2011/12 Spatio-temporal variation Space-Time cluster analysis results with a high rates cluster of mood/anxiety in 2011/12 Known risk factors Independent variable Odds Ratio p-value CI (95 %) Male gender 0.843*** <0.001 0.825 – 0.862 Age 15-39 2.290*** <0.001 2.049 – 2.560 Age 40-64 2.749*** <0.001 2.459 – 3.072 Age 65+ 3.118*** <0.001 2.786 – 3.491 Mental health comorbidity 1.954*** <0.001 1.889 – 2.021 Pre-existing mental health disorder 1.085*** <0.001 1.058 – 1.113 Pre-existing mood/anxiety disorder 1297.069*** <0.001 1163.931 – 1445.435 Year 2010/11 1.159*** <0.001 1.129 – 1.190 Year 2011/12 1.301*** <0.001 1.267 – 1.335 Significance level:    *** <0.001    **  <0.01    * <0.05 CERA land zones CERA Red Zone, TC3, TC2 and TC1 land classification published on the 23rd March 2012 Distance to CERA land zones in km Model Independent variable Odds Ratio p-value CI (95%) II i Distance to Red Zone areas 1.000 0.948 0.994 – 1.006 III i Distance to TC3 areas 0.980* <0.05 0.965 – 0.996 IV i Distance to TC2 areas 0.978* <0.05 0.958 – 0.997 V i Distance to TC1 areas 1.002 0.443 0.997 – 1.007 VI ii Distance to Red Zone areas 0.859** <0.01 0.769 – 0.960 VII ii Distance to TC3 areas 0.791 0.159 0.570 – 1.096 VIII ii Distance to TC2 areas 0.766 0.234 0.494 – 1.188 IX ii Distance to TC1 areas 1.020*** <0.001 1.017 – 1.024  Significance level:    *** <0.001    **  <0.01    * <0.05  Note:      i. adjusted for gender, age, comorbidity with other mental health problems, pre-existing other mental health disorders and pre-existing mood/anxiety disorder ii. adjusted for gender, age, comorbidity with other mental health problems, pre-existing other mental health disorders  excluding people with pre-existing mood/anxiety disorders, so that the risk for new incidences is tested Peak Ground Acceleration (PGA) & Modified Mercalli Intensity (MMI)     • Intensity of PGA and MMI as risk factors for getting mood/anxiety after the 22nd Feb 11 earthquake • Increased risk with higher intensity   Independent variable Odds Ratio p-value CI (95%) PGA 4.210* <0.05 1.344 – 13.191 MMI 3.170** <0.01 1.536 – 6.542 Significance level:    *** <0.001    **  <0.01    * <0.05 Distance to lateral spreading & liquefaction in km • Reduced risk as farther away someone lives • Findings only stat. significant for new incidences   Independent variable Odds Ratio p-value CI (95%) Distance to severe lateral spreading 0.831** <0.01 0.734 – 0.940 Distance to moderate to major lateral spreading 0.784* <0.05 0.649 – 0.946 Distance to severe liquefaction 0.674** <0.01 0.515 – 0.882 Distance to minor to moderate liquefaction  0.745* <0.05 0.583 – 0.953 Significance level:    *** <0.001    **  <0.01    * <0.05 Results • Earthquake specific risk factors for getting a mood or anxiety disorder include – Distance to TC3 and TC2 areas – Distance to Red Zone areas for people* – Peak Ground Acceleration (PGA)* – Modified Mercalli Intensity (MMI)* – Distance to liquefaction and lateral spreading*  * only statistically significant for new incidences  Limitations • CERA land zones a crude measure of damage • Missing confounders, e.g. socio-economic status • Lot of different diagnoses included in mood and anxiety • Great number of people with pre-existing mood or anxiety disorder • Spatial autocorrelation not considered within the regression analyses • Mobility of the people not considered Time as a component Mobility of the people     Three dimensional space-time prism for four individuals exposed to two risk factors (Source: Sabel et al. 2000) Future Work • Compare other stress-related disorders like cardiovascular diseases  • Compare further earthquake impacts like community disruption  • Use spatial regression models to account for spatial autocorrelation  • Use more accurate data to include time as a component   Thanks Questions? 

Spatial variations in stress related health compared to earthquake exposure: preliminary results and future directions

http://ir.canterbury.ac.nz/bitstream/handle/10092/11319/12647052_Kingham%26Hogg_Rhise_Conference_Presentation.pdf?sequence=1&isAllowed=y

Spatial variations in stress related health compared to earthquake exposure: preliminary results and future directions

Abstract

Similar works

Full text

Available Versions

UC Research Repository