Long term trend of CT scans in eastern areas of special wards of Tokyo, Japan : analysis of the patient's age

Abstract

The purpose of this research was to clarify the characteristics of CT-scanned patients at Tokyo Metropolitan Bokutoh Hospital and to investigate effects of the aging of the population on CT scan study. We retrospectively surveyed patient's age who had undergone CT scan study at Tokyo Metropolitan Bokutoh Hospital from 2002 through 2011. The patients were divided into four age groups: age under 15, age 15-64, age 65-74, and age over 75. Median age and mean age for patients increased from 52.6 and 58.8 years in 2002 to 56.8 and 63.0 years in 2011. The proportion of the patients 75 years or older increased from 14% in 2002 to 23% in 2011. The proportion of the patients 15 to 64 years decreased from 55 % in 2002 to 46% in 2011. The proportion of the patients 75 years or older and 15 to 64 years were highly-correlated to the percentage of regional population (Sumida-ku, Koto-ku, Edogawa-ku) of 75 years or older and 15 to 64 years. The result of this research indicates that the proportion of CT-scanned patients at least 75 years old will increase to about 40% by the year 2025.