title: Space-Time Covariation of Mortality with Temperature: A Systematic Study of Deaths in France, 1968-2009.
abstract: BACKGROUND
  The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.
  
  
  OBJECTIVE
  Our aim was to partition space with a high-resolution grid to assess the temperature-mortality relationship in a territory with wide climate diversity, over a period with notable climate warming.
  
  
  METHODS
  The 16,487,668 death certificates of persons > 65 years of age who died of natural causes in continental France (1968-2009) were analyzed. A 30-km × 30-km grid was placed over the map of France. Generalized additive model regression was used to assess the temperature-mortality relationship for each grid square, and extract the MMT and the RM25 and RM25/18 (respectively, the ratios of mortality at 25°C/MMT and 25°C/18°C). Three periods were considered: 1968-1981 (P1), 1982-1995 (P2), and 1996-2009 (P3).
  
  
  RESULTS
  All temperature-mortality curves computed over the 42-year period were U/J-shaped. MMT and mean summer temperature were strongly correlated. Mean MMT increased from 17.5°C for P1 to 17.8°C for P2 and to 18.2°C for P3 and paralleled the summer temperature increase observed between P1 and P3. The temporal MMT rise was below that expected from the geographic analysis. The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.
  
  
  CONCLUSIONS
  Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.
authors: U1169, INSERM (Institut national de la santé et de la recherche médicale), Le Kremlin-Bicêtre, France.
authors: Nicolas
authors: N
authors: Todd
authors: Alain-Jacques
authors: AJ
authors: Valleron
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged; D000369:Aged, 80 and over; D057231:Climate Change; D005602:France / Q000453:epidemiology; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D009026:Mortality; D011156:Population Density; D062211:Spatio-Temporal Analysis