1. Epidemic Asthma Ruth A. Etzel Problem-Based Exercises for Environmental Epidemiology World Health, WHO/EHG/98.2, 1998, 45-53. 16 November 2015

2. Barcelona Asthma Epidemic

4. Question 1: What is asthma?

5. 130 hospital visits for difficulty breathing on 21 Jan 1986 Question 3: Review of the hospital records reveals that the four hospitals treated 288 persons with asthma during the month of January 1986. Now can you determine if this is an epidemic? Question 2: Is this an epidemic of asthma? What further information do you need? 288 persons with asthma treated in Jan 1986

6. Question 4: Develop a preliminary case definition 1985 Average 159 acute asthma ER visits per month Max 199 Question 5: Do you now have sufficient information to determine if there is an epidemic of asthma?

7. January 1986 Total 288 acute asthma ER visits Average 9.3 per day Max 96 on Jan 21st

8. Question 6: Draw a bar chart of the number of acute asthma emergency room visits by day in January 1986 Question 7: What other information would be useful to characterize the epidemic?

10. 28 44 9 3 3 3 2 4 Question 8: On the attached city map, show the geographic distribution of the place of onset of illness (Table 3) for the 96 persons who came to the emergency rooms with acute asthma on January 21 st. What does this distribution suggest?

11. 28 44 9 3 3 3 2 4

12. Question 8: Draw a bar-chart of the cases by hour of occurrence (Table 3), What hypotheses are suggested?

13. Question 10: What conclusion can you draw from this information?

14. Question 11: How would you use this information to further explore this problem?

15. Counts of days on which each product was loaded or unloaded from barges or boats Days Product is Handled Days Product is NOT Handled (Loaded or Unloaded) Asthma Epidemic Days PRODUCTNOYES NOYES Coal19645219 Fuel Oil150356710 Gasoline180253722 Cotton39973186 Coffee30054178 Corn135158212 Soybeans249134680 Butane140157712

16. Question 12. Using the information in Table 4, complete the tables on the following pages and calculate the risk ratios. Optional: calculate the confidence interval (C.I.) for each table. OR (95% CI)=1.18 (0.26, 4.29)

17. Question 13: How do you interpret the risk ratios and confidence intervals you have calculated?

18. Question 14: Now substitute a 1.0 for the 0 in cell B (soybeans) and recalculate.