1406 Indian Journal of Forensic Medicine & Toxicology, January-March 2021, Vol. 15, No. 1 Level of Knowledge and Family Support toward Medication Adherence among Patient with Diabetes Mellitus in Malang, Indonesia Nur Lailatul Masruroh 1* , Alifa Fatehana Pangastuti 2 , Nur Melizza 1 , Anggraini Dwi Kurnia 1 1 Lecturer, 2 Nursing student, Departement of Community Health Nursing, Faculty of Health Science, University of Muhammadiyah Malang, Jl. Bendungan Sutami 188A Malang, Indonesia Abstract Patient compliance with long-term therapy for chronic diseases in developing countries is still low. Efforts to control blood sugar levels remain normal with medication adherence depending on family support and patient knowledge of the disease. This study aimed to determine the relationship between the level of knowledge and family support with medication adherence in patients with diabetes mellitus in Malang, Indonesia. The study design was cross-sectional. The sample of this study was 48 people with diabetes mellitus recorded in Ciptomulyo Health Center. This study uses a simple random sampling technique. The questionnaire used consisted of demographic data, knowledge, family support, and medication adherence. The results of the study were that there is no relationship between the variable level of knowledge and medication adherence in patients with diabetes mellitus with a signifcance value of p = 0.561. There was a relationship between family support and medication adherence in patients with diabetes mellitus with a signifcance value of p = 0,000 and a Correlation Coeffcient value of 0.616 which indicates a signifcant relationship with a strong degree of relationship strength. There is a relationship between family support and medication adherence in patients with diabetes mellitus at the Ciptmulyo Health Center. The better the family support, the more obedient the patient is undergoing treatment. Keywords: Knowledge, Family Support, Medication adherence, Diabetes Mellitus Corresponding author: Nur Lailatul Masruroh Departement of Community Health Nursing, Faculty of Health Science, University of Muhammadiyah Malang, Indonesia, Email: masruroh@umm.ac.id Introduction The global diabetes prevalence in 2019 is estimated to be 9.3% (463 million people), rising to 10.2% (578 million) by 2030 and 10.9% (700 million) by 2045. The prevalence is higher in urban (10.8%) than rural (7.2%) areas, and in high-income (10.4%) than low-income countries (4.0%). Indonesia became Top 10 countries or territories for number of people with diabetes (20– 79 years) in 2019, 2030 and 2045 1 . In addition to the world and Indonesia level, the increase in the incidence of Diabetes Mellitus in the data based on the diagnosis of doctors, the prevalence of Diabetes Mellitus in the population of all ages by the province in 2018 especially in the province of East Java was recorded as much (2%), the average age of 55-64 years sufferers ( 6.3%), male (1.2%) while the female (1.8%). In urban areas more (1.9%) and rural areas only (1.0%). The prevalence of Diabetes Mellitus according to the 2015 Consensus consensus in the population aged ≥ 15 years was recorded at 10.9% 2 . According to WHO, it is predicted that there will be an increase in Diabetes sufferers in Indonesia from 8.4 million in 2000 to 21.3 million in 2030 3 . WHO reports that the average patient adherence to long-term therapy for chronic diseases in developing countries is still low, whereas in developed countries it reaches 50%. Several reasons can affect diabetics who do not routinely take OAD / insulin injections, among others: feeling healthy, not routinely going to a health care facility, taking traditional medicine, often forgetting, not being able to take side effects, not being able to buy