Question

       There were 53 diagnoses of new cases of Multiple Sclerosis (MS) in Tasmania in 2018, increasing the total number of Tasmanians living with MS to 2550. The population of Tasmania is 500,000 people. Calculate the incidence and prevalence of MS in Tasmania per 100,000 people per year.

1. incidence of MS
2. prevalence of MS

iii. Improvements treatment mean people are now living longer with MS. Explain how this will change the incidence and prevalence of MS in Australia.   

Answer 1

1. Incidence is a ratio of the number of new cases and the total population in a given area.

Here, the number of new cases is 53 and the total population is 500,000 people. Hence, the incidence ratio becomes 53/500000. Therefore, the incidence per 100,000 will be (53/500000)*100000 = 53/5 = 10.6

2. Prevalence is the ratio of the total number of cases and the total population in a given ara.

Here, the total number of cases is 2550 and the total population is 500,000 people. Hence, the prevalence ratio becomes 2550/500000. Therefore, the incidence per 100,000 will be (2550/500000)*100000 = 2550/5 = 510

3. The improvements in treatment have led to people with MS living longer. Hence, the total number of cases will increase. However, this will not impact the rate of increase. Hence, this will impact the prevalence by increasing it but this will not change the incidence.