Study questions

1. Prepare a table to summarise the results of the weighted analysis of variance of schistosomiasis in humans reported in this case study. The student may wish to refer to Case Study 3 which shows how to summarise results from a regression analysis.

2. Carry out a randomised block analysis with age and gender as factors and site as block on the variable P_infected in CS14Data2. Remember to omit Site 1. Compare your results with those from the weighted analysis of variance. Which method would you recommend as being more suitable for these data and why?

3. Summarise in 50 words or less the results of the statistical analysis of river variables and their effects on numbers of Biomphalaria snails.

4. Prepare a talk with illustrations to be given to the communities who participated in the study to explain the results in a way that they would understand.

5. Assuming that the Government's mass chemotherapy programme that took place during the year prior to this study resulted in much lower incidences of schistosomiasis than would normally have been the case, decide how you would repeat the study and suggest any modifications to the design.

6. This study indicates a possible link between Biomphalaria snail numbers and infection incidence in humans. Based on the information contained in this study and the results obtained, design a new study which focuses just on this objective.