Watching television in childhood and adolescence has been li

Watching television in childhood and adolescence has been linked to adverse health indicators including obesity, poor fitness, smoking, and raised cholesterol. However, there have been no longitudinal studies of childhood viewing and adult health. A group of New Zealand researchers explored these associations in a birth cohort of 1000 individuals born in 1972-1973 and followed up at regular intervals up to age 26. Television viewing was measured at regular intervals throughout the individuals’ lives as less than 2 hours per day or more than 2 hours per day; at age 26, BMI, cardiorespiratory fitness, serum cholesterol, smoking status, and blood pressure were recorded. A total of 250 cases of obesity were identified out of all 1000 individuals. Specifically, in those 600 individuals who watched more than 2 hours per day of TV during childhood, 180 individuals were obese. Whereas, in the 400 individuals who watched less than 2 hours per day of TV during childhood, 70 were obese. (10 points)

What kind of study design is used in this example and why?  (1)

Identify the exposure and outcome within this study. Be sure to identify their levels as well.  (1)   

Exposure:

Two Levels of the Exposure:

Outcome:

Two Levels of the Outcome:

Solution

This is a longitudinal study, since the same individuals are observed over a long period of time.

expoure is the number of hours of watching tv. the two levels here are > 2 hours of watching tv and <2 hours of watching tv.

outcome is the obesity. two levels are obese ant not obese.