title: Innovative approaches helpful to enhance knowledge on weather-related stroke events over a wide geographical area and a large population.
abstract: OBJECTIVE
  Results on the effect of weather on stroke occurrences are still confusing and controversial. The aim of this study was to retrospectively investigate in Tuscany (central Italy) the weather-related stroke events through the use of an innovative source of weather data (Reanalysis) together with an original statistical approach to quantify the prompt/delayed health effects of both cold and heat exposures.
  
  
  METHODS
  Daily stroke hospitalizations and meteorologic data from the Reanalysis 2 Achieve were obtained for the period 1997 to 2007. Generalized linear and additive models and an innovative modeling approach, the constrained segmented distributed lag model, were applied.
  
  
  RESULTS
  Both daily averages and day-to-day changes of air temperature and geopotential height (a measure that approximates the mean surface pressure) were selected as independent predictors of all stroke occurrences. In particular, a 5°C temperature decrease was associated with 16.5% increase of primary intracerebral hemorrhage of people ≥65 years of age. A general short-term cold effect on hospitalizations limited to 1 week after exposure was observed and, for the first time, a clear harvesting effect (deficit of hospitalization) for cold-related primary intracerebral hemorrhage was described. Day-to-day changes of meteorologic parameters disclosed characteristic U- and J-shaped relationships with stroke occurrences.
  
  
  CONCLUSIONS
  Thanks to the intrinsic characteristic of Reanalysis, these results might simply be implemented in an operative forecast system regarding weather-related stroke events with the aim to develop preventive health plans.
authors.affiliation: Interdepartmental Centre of Bioclimatology, University of Florence, Piazzale delle Cascine 18, 50144 Firenze, Italy. marco.morabito@unifi.it
authors.forename: Marco
authors.initials: M
authors.lastname: Morabito
authors.forename: Alfonso
authors.initials: A
authors.lastname: Crisci
authors.forename: Roberto
authors.initials: R
authors.lastname: Vallorani
authors.forename: Pietro Amedeo
authors.initials: PA
authors.lastname: Modesti
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Gensini
authors.forename: Simone
authors.initials: S
authors.lastname: Orlandini
mesh_terms: D000368:Aged; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006760:Hospitalization / Q000639:trends; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009936:Organizational Innovation; D011159:Population Surveillance / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology*; D013696:Temperature; D014887:Weather