Which of the following preventative screenings are matched correctly with the age at which they should be initially completed?

The correct pairing of preventative screenings with the appropriate age for initial completion in this instance is indeed significant due to recent guidelines and recommendations from health organizations.

Colonoscopy screening is recommended to begin at 45 years old for average-risk individuals, a guideline change made in response to a rising incidence of colorectal cancer in younger populations. This screening is crucial as it allows for the detection of precancerous polyps and can significantly reduce the risk of developing colorectal cancer through early intervention.

Mammography is typically recommended to start at age 40 for most women, although some guidelines suggest starting at 50 based on various factors such as risk level; hence the pairing of mammography with the age of 50 does not align with most recommendations.

Blood pressure screening can begin in young adulthood, typically around 18 years of age, making the suggestion to start at 30 years outdated. Cholesterol screening often begins at age 40 for men and 45 for women, depending on cardiovascular risk factors, while younger adults should also be screened if they have specific risk factors present.

Therefore, the pairing of colonoscopy with the age of 45 is the most accurate representation of current preventative health guidelines.