91Ó°ÊÓ

The given investigation is:

According to a study published in the Journal of the American Public Health Association, left-handed people do not die at an earlier age than right-handed people, contrary to the conclusion of a highly publicized report done 2 years earlier. The investigation involved a 6-year study of 3800 people in East Boston older than age 65. Researchers at Harvard University and the National Institute of Aging found that the "lefties" and "righties" died at exactly the same rate. "There was no difference, period," said Dr. J. Guralnik, an epidemiologist at the institute and one of the coauthors of the report.

The observational study makes use of existing observational data. As in a sample survey, the investigators in this study observe the characteristics of the provided requirements and gather the data.

According to the research.

The researchers compared the fatalities of left-handed people with right-handed people in a two-year study of 3800 people in East Boston over the age of 65. The investigators look at previous data (which already exists) to identify earlier deaf people and right-handed people.

Therefore, the given study is an observational study.