Diabetes mellitus (DM) is a chronic disorder caused by an increase in glucose concentration in the blood, which in turn may damage other systems of the body. The condition is increasing continually, especially in developing countries and is caused by factors like rapid population growth, aging, unhealthy diet, obesity, and sedentary lifestyles [1]. Indonesia reports the second highest percentage of deaths caused by diabetes, after Sri Lanka, with a prevalence that tends to increase from 5.7% in 2007 to 6.9% in 2013, out of which two-thirds of patients were unaware of having the condition [2].
According to the Centers for Disease Control and Prevention (CDC) (2014), type 2 is the most common type of DM, accounting for 90-95% of all the diagnosed cases of diabetes and in disease control and environmental health field data of the South Sulawesi Provincial Health Office recorded 27,470 new cases of DM and 66,780 old cases with 747 cases of death resulting from DM. The highest number of cases were found in the individuals aged 55-74 years (13.4%) [4]. Increased cases of DM were reported, especially in the city of Makassar from January to December, amounting to 7,000 cases [5]. The incidence continued to increase from 17,746 cases in 2014 to 18,755 cases in 2015 [6].
In order to overcome the continual increase of the disease, the need of the hour is the healthy living behaviors. This behavior is formed by several factors that can be classified as self-factors (often referred to as responses) and environmental factors (usually called stimuli) [7]. According to Green & Ottoson (2006), a person’s behavior from the health point of view is influenced by behavioral factors (behavior causes) and external factors (non-behavior causes), which require management of the program through the stages of assessment, planning, intervention up to assessment and evaluation. The control is one of the factors that can determine individual behavior and health conditions. Each individual has a different power of perception for the control factor within them; one of the personality variables that distinguish one person from another is the locus of control or control center [9]. DM control is then possible, provided that the patient has the ability to sort out the sources of information required to enter the control center (locus of control) within them.
The control center acts as a place where self-control is both is internal and external, and would then result in an act or controlled behavior. According to Rotter (1966), an individual’s acceptance of various events as a part of behavior is the influence of the locus of control they own. Research that supports the relationship between the locus of control and health behavior shows that individuals actively seeking health-related information are the ones who possess an internal locus of control [11].
Individuals who can control their health tend to practice good healthy living habits [12]. A person may lead to a good quality of life, based on his behavior and actions in controlling health. Quality of life itself is an analysis of the ability of an individual to acquire a normal life related to that person’s perceptions of goals, expectations, standards and specific attention to life experienced, which are in turn influenced by the values and culture of the environment the individual resides in [13].
Quality of life is intended as an effort to bring judgment in obtaining health. It is defined as the individual’s perception of their position in life, in the context of culture and value systems in which they reside, and the link to their goals, standard expectations, and concerns. In general, diabetes has a detrimental effect on the health of patients, especially on their quality of life. A significant decrease in the quality of life of patients is caused by complications resulting from DM [14]. Therefore, the authors intend to assess the influence of locus of control of patients with type 2 DM on their quality of life.