Epidemiology module of practical skills for mbbs student

Incidence and Prevalence

Solution for Exercise D

1. 
   Risk refers to incidence data. Since there is no information about new cases for 1995, this question cannot be answered.
   

2. 
   120/1450 = 8.3%
   

3. 
   130/1370 = 9.5%
   

4. 
   No, these two prevalence estimates do not provide any information about the risk of developing asthma among children in Community A.
   

5. 
   Knowing the incidence rate helps somewhat but does not tell the entire story as children seeking care for their asthma in the ER are not representative of the entire population of children with asthma in Community A. Incidence rate: 42/1282 =3.3%
   
6. 
   It would be helpful to have baseline information on the incidence rate of childhood asthma diagnoses in the ER at Hospital X in Community A. Short of obtaining information from population based child health surveys over time, it would also be important to obtain data from primary care physicians in the community, other community hospitals, from the schools, and possibly from the pharmacists in the community. In addition, it might be helpful to compare Community A's data to data from similar communities
   

Example: If incidence is 10 cases / 1000 people per year and mean duration of disease is 5 years, then

Prevalence = 10 X 5 = 50 / 1000 population.