The World Health Organization (WHO) groups barriers to drug compliance into five categories; Health care team and systemic factors, social and economic factors, conditional factors, therapy factors and patient-related factors. Common obstacles include:[62] This is a tripartite agreement that is suitable for three people who propose the creation of a new company in which each of them will be a shareholder and director. It is a 4-page document. Prieto et al. highlighted the influence of ethnic and cultural factors on adherence. They stressed that groups are different in their attitudes, values and beliefs about health and disease. This view could affect addidaty, especially for preventive treatments and drugs for asymptomatic diseases.