Question

Hypertension is one of the risk factors for stroke. You have been collecting information on the patients of a hospital who have been exhibiting symptoms of hypertension over the last five years. You had 1,000 male patients aged 40–45.

Complete the following calculations and provide an explanation of your findings:

The study began with 1,000 men (ages 40–45). Of the 1,000 men, 50 are already hypertensive. The remaining 950 are tracked over five years, during which time 64 more men develop hypertension. (Assume there is no loss to follow-up or death due to competing risks).

1. Determine the prevalence of hypertension at the beginning of the study.
2. Calculate the five-year incidence proportion (risk) of hypertension.
3. Calculate the incidence rate of hypertension in the cohort with and without an actuarial adjustment. Did the actuarial adjustment make a difference? Explain your answer.
   • With the adjustment: _________________________________
   • Without the adjustment: _______________________________

Answer 1

Prevalence of the hypertension at the beginning of study is as below:-

Prevalence is the proportion of individuals in a defined population that have a disease at a specified point in time

Prevalence formula= No.of persons with a specific disease/ Total no.of persons

At the beginning 50 are with hypertension

Total population =1000

Prevelence = 50×100/1000

=5%

Incidence proportion=(Number of new cases of disease/Size of population at start of period) ×100

No. Of new cases in five years =64

Total population =1000

IP = (64/1000)×100

=6.4%

Incidence rate with actual adjustment (prevalence)= (114/1000)×100

=11.4%

Incidence rate without actuarial adjustment =(64/950)×100

=6.74%

Actuarial adjustment also known as point prevalence or just prevalence..

Actuarial adjustment makes difference because it includes the existing hypertension cases to both the diseased and total population.