Spatial epidemiology of birth defects in the United States and the state of Utah using geographic information systems and spatial statistics

57 Introduction 58 Materials and Methods 63 Data and Data Sources 63 Maximum Likelihood Method 65 Hierarchical Bayesian models 66 Results 72 Discussion 75 Summary and Conclusions 79 References 81 4. A MULTI-SCALAR APPROACH TO THE SPATIAL CLUSTER ANALYSIS OF ORAL CLEFTS IN THE STATE OF UTAH FROM 1995 TO 2004: WITH CLUES FOR ETIOLOGY 105 Abstract 105 Introduction 106 Methods 110 Datasets and Data Sources 110 Statistical Framework 111 Test for Global Clustering 112 Tests for Detection of Local Clusters 116 Maternal Characteristics of Local Clusters 120 Results 120 Discussion 124 Conclusions 132 References 132 5. SUMMARY, CONCLUSIONS, AND FUTURE DIRECTIONS 151 Summary 151 Limitations and Future Directions 158 Conclusions 161 References 163 APPENDICES 165