Koreans have relatively low life satisfaction, which is an essential determinant of health and well-being and even affects mortality, particularly among older people, data showed on Thursday.

According to a study report titled “Difference of Associating Factors of Happiness Index among Korean Adults by Life Cycle Age Brackets” published in the journal of the Korea Disease Control and Prevention Agency (KDCA), the average happiness index of adults in Korea stood at 6.68 points out of 10.

Communication was an important factor in increasing happiness, while unmet health needs were an important factor in decreasing happiness. The impact of these factors varied, depending on the participants' "life cycle," referring to their age group.

The data sources used were the results of the 2015 Community Health Survey, with a total of 226,545 people. The participants were divided into four life cycle categories by age: between 19 and 44; 45 and 64; 65 and 74; and 75 or older. The average Happiness Index of the entire target group was 6.68 points out of 10, and the subjective happiness awareness rate was 34.7 percent.

The Happiness Index and Subjective Happiness is a significant determinant of health and is closely linked to diseases and mortality, according to the report. Many studies have shown that individuals who perceive themselves as happy tend to have longer lifespans.

By gender, 35.4 percent of men and 34.2 percent of women perceived themselves as happy. By age, the older the age, the lower this figure was. About 39.5 percent of those aged 19-44 said they were happy, compared to 35.3 percent of those aged 45-64, 29.7 percent of those aged 65-74, and 25.7 percent of older people.

"It can be interpreted that the older Koreans become, the less happy they are. This reflects the current situation in Korean society, where the elderly poverty rate and the elderly suicide rate are high," the researchers explained.

By household, the higher the income, the higher the satisfaction of life across all age groups. Among households earning below 990,000 won ($762) per month, 23.1 percent subjectively perceived themselves as happy. Meanwhile, the figure was 31.6 percent for people earning between 1 million to 2.99 million won per month, 39.8 percent for those earning between 3 million won to 4.99 million won per month, and 49.1 for those earning above 5 million won per month.

The researchers found that those who live with their spouses are happier than those who do not have a spouse. They also found that people were more likely to say they were happy if they actively participated in religion, friendship, leisure and volunteering activities.

In addition, people who have breakfast regularly and those who sleep eight hours or more were more likely to report that they were happy. Conversely, those unable to receive necessary medical care, diagnosed with three or more chronic diseases, and smokers were associated with decreased perceived happiness.

"In relation to the rapid aging and low birth rate in Korea, subjective happiness should be treated as important in terms of maintaining and preserving the quality of the population, and efforts to create and improve a supportive environment are needed," the report said.

This research was submitted to the Public Health Weekly Report, published by the KDCA.