Personal health also depends partially on the social structure of a person's life. The maintenance of strong social relationships, volunteering, and other social activities have been linked to positive mental health and also increased longevity. One American study among seniors over age 70, found that frequent volunteering was associated with reduced risk of dying compared with older persons who did not volunteer, regardless of physical health status. Another study from Singapore reported that volunteering retirees had significantly better cognitive performance scores, fewer depressive symptoms, and better mental well-being and life satisfaction than non-volunteering retirees.
Since 1974, New Zealand has had a system of universal no-fault health insurance for personal injuries through the Accident Compensation Corporation (ACC). The ACC scheme covers most of the costs of related to treatment of injuries acquired in New Zealand (including overseas visitors) regardless of how the injury occurred, and also covers lost income (at 80 percent of the employee's pre-injury income) and costs related to long-term rehabilitation, such as home and vehicle modifications for those seriously injured. Funding from the scheme comes from a combination of levies on employers' payroll (for work injuries), levies on an employee's taxable income (for non-work injuries to salary earners), levies on vehicle licensing fees and petrol (for motor vehicle accidents), and funds from the general taxation pool (for non-work injuries to children, senior citizens, unemployed people, overseas visitors, etc.)
The universal compulsory coverage provides for treatment in case of illness or accident and pregnancy. Health insurance covers the costs of medical treatment, medication and hospitalization of the insured. However, the insured person pays part of the costs up to a maximum, which can vary based on the individually chosen plan, premiums are then adjusted accordingly. The whole healthcare system is geared towards to the general goals of enhancing general public health and reducing costs while encouraging individual responsibility.
Health, as defined by the World Health Organization (WHO), is "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." This definition has been subject to controversy, as it may have limited value for implementation. Health may be defined as the ability to adapt and manage physical, mental and social challenges throughout life.