title: Comparing methods of measuring geographic patterns in temporal trends: an application to county-level heart disease mortality in the United States, 1973 to 2010.
abstract: OBJECTIVE
  To demonstrate the implications of choosing analytical methods for quantifying spatiotemporal trends, we compare the assumptions, implementation, and outcomes of popular methods using county-level heart disease mortality in the United States between 1973 and 2010.
  
  
  METHODS
  We applied four regression-based approaches (joinpoint regression, both aspatial and spatial generalized linear mixed models, and Bayesian space-time model) and compared resulting inferences for geographic patterns of local estimates of annual percent change and associated uncertainty.
  
  
  RESULTS
  The average local percent change in heart disease mortality from each method was -4.5%, with the Bayesian model having the smallest range of values. The associated uncertainty in percent change differed markedly across the methods, with the Bayesian space-time model producing the narrowest range of variance (0.0-0.8). The geographic pattern of percent change was consistent across methods with smaller declines in the South Central United States and larger declines in the Northeast and Midwest. However, the geographic patterns of uncertainty differed markedly between methods.
  
  
  CONCLUSIONS
  The similarity of results, including geographic patterns, for magnitude of percent change across these methods validates the underlying spatial pattern of declines in heart disease mortality. However, marked differences in degree of uncertainty indicate that Bayesian modeling offers substantially more precise estimates.
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA; Division for Heart Disease and Stroke Prevention, Centers for Disease Control and Prevention, Atlanta, GA. Electronic address: asvaugh@emory.edu.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Vaughan
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA; Division for Heart Disease and Stroke Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Kramer
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA.
authors.forename: Lance A
authors.initials: LA
authors.lastname: Waller
authors.affiliation: Division for Heart Disease and Stroke Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Schieb
authors.affiliation: Division for Heart Disease and Stroke Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Sophia
authors.initials: S
authors.lastname: Greer
authors.affiliation: Division for Heart Disease and Stroke Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Michele
authors.initials: M
authors.lastname: Casper
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001499:Bayes Theorem; D002423:Cause of Death; D004777:Environment; D004812:Epidemiologic Methods; D005260:Female; D005843:Geography; D006331:Heart Diseases / Q000175:diagnosis / Q000401:mortality*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D062206:Spatial Analysis; D062211:Spatio-Temporal Analysis; D016019:Survival Analysis; D014481:United States
keywords: Bayesian methods; Generalized linear mixed models; Geographic patterns; Heart disease mortality; Joinpoint regression; Spatial analysis; Spatiotemporal trends