It includes inter-sectoral action by health staff, for example, encouraging the ministry of education to promote female education, a well-known determinant of better health. Healthcare providers are institutions or individuals providing healthcare services. Individuals including health professionals and allied health professions can be self-employed or working as an employee in a hospital, clinic, or other health care institution, whether government operated, private for-profit, or private not-for-profit (e.g. non-governmental organization). They may also work outside of direct patient care such as in a government health department or other agency, medical laboratory, or health training institution. Examples of health workers are doctors, nurses, midwives, dietitians, paramedics, dentists, medical laboratory technologists, therapists, psychologists, pharmacists, chiropractors, optometrists, community health workers, traditional medicine practitioners, and others. There are generally five primary methods of funding health systems:  Most countries' systems feature a mix of all five models. One study based on data from the OECD concluded that all types of health care finance "are compatible with" an efficient health system. The study also found no relationship between financing and cost control. The term health insurance is generally used to describe a form of insurance that pays for medical expenses. It is sometimes used more broadly to include insurance covering disability or long-term nursing or custodial care needs. It may be provided through a social insurance program, or from private insurance companies. It may be obtained on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. In each case premiums or taxes protect the insured from high or unexpected health care expenses. By estimating the overall cost of health care expenses, a routine finance structure (such as a monthly premium or annual tax) can be developed, ensuring that money is available to pay for the health care benefits specified in the insurance agreement. The benefit is typically administered by a government agency, a non-profit health fund or a commercial corporation. Many commercial health insurers control their costs by restricting the benefits provided, by such means as deductibles, co-payments, coinsurance, policy exclusions, and total coverage limits. They will also severely restrict or refuse coverage of pre-existing conditions. Many government schemes also have co-payment schemes but express exclusions are rare or limited because of political pressure. The larger insurance schemes may also negotiate fees with providers. Many forms of social insurance schemes control their costs by using the bargaining power of the community they are intended to serve to control costs in the health care delivery system.