Question

Problem 4: Distinguishing between Point and Period Prevalence, Cumulative Incidence and Incidence Density at Happy Kids Day Care Center (11 points)

There were 11 children enrolled in the Happy Kids Day Care Center from the beginning of Month One until the end of Month Four. The 11 children were watched for a total of 4 months. The staff tries to keep good records about when children fall ill from disease X.

Child	Month 1		Month 2		Month 3		Month 4
1
2
3
4
5
6
7
8
9
10
11

               

You are asked to inspect these records and report the following information. The information has been assembled in the figure above. The grey bar indicates the disease is present. For ease of calculations consider one month is equal to 30 days and disease begins on either the 1^st or 15^th of the month, except for Child #1 who was already ill when record-keeping began. Show all steps, including numerator and denominators. Express all final answers as percentages (multiplier of 100).         

1. Calculate the point prevalence of disease X at the beginning of Month 1. (2 points)

Answer 1

Point prevalence is the proportion of a population that has the condition at a specific point in time.

The point prevalence of disease X at the beginning of Month 1

=(the number of children who were ill from disease X at the beginning of Month 1) / ( total number of children enrolled in the Happy Kids Day Care Center )

Here,the number of children who were ill from disease X at the beginning of Month 1= 1

Total number of children enrolled in the Happy Kids Day Care Center=11

Therefore, the point prevalence of disease X at the beginning of Month 1= 1/11=0.09090

the point prevalence of disease X at the beginning of Month 1 in terms of percentage= (1/11)*100=9.090