Health is a universal right and providing health services is a government’s responsibility . Health systems are created to provide affordable and accessible health care for all people and to make this dream come true. One of the designs that brought us closer to this goal was the primary healthcare system (PHC). [2, 3]. The PHC was introduced as an acceptable, accessible and possible strategy for national health systems regarding health promotion and as a route to realizing sustainable social and economic development .
Primary healthcare & Family Physician Program (FPP) in Iran
Concurrent with the Iranian Revolution in 1979, some major changes were made to promote social justice. In this regard, significant changes were made as a provider of health services using establishing and expanding health networks in 1984 . In the Iranian health network system, health services are provided at three levels. The first level relates to PHC. The so-called health houses are considered to be the starting point for serving rural communities. Those which are run by community health workers are known as Behvarz. These centers have proven to be very effective in improving health indicators [5, 6]. In larger settlements, in addition to health houses, there are Rural Health Centers (RHCs). The RHCs staff includes a general physician and a team of up to 10 health workers. In urban areas, health services are provided by health posts and Urban Health Centers (UHCs). All rural and urban centers are managed by district health centers, under the supervision of the Medical Sciences University. In urban areas, with a population of more than 50000, there is at least one general hospital and a polyclinic that provides secondary care level. There is one Medical Sciences University per province. There are teaching hospitals in each province capital providing specialized and sub-specialized services as the third level of healthcare services under the supervision of Medical Universities .
Family physician plan (FPP) was launched in the Iranian health system in rural and urban areas with a population below 20,000in 2005. . Since it was emphasized in the fourth national strategic program on Iran’s economy, social and cultural development to expand the coverage of health insurance with a significant focus on family physician and referral system, it was planned to extend the implementation of the plan to large urban areas. According to the law of the fifth development plan, approved in 2010, the Iranian Health Insurance Organization (IHIO) was obliged to comply with the referral system and was designated as the main implementer of the FPP . The IHIO is one of Iran’s main insurance organizations covering 41% of the total population, including residents of rural areas .
Accordingly, since the 8th of July 2012, the FPP has been running as a pilot project in urban areas of two provinces, Fars and Mazandaran . According to the Iranian FPP and in line with the referral system instructions for rural and urban areas, participating family physicians are responsible for people's primary care and follow-up of patients who have been referred to the specialized and sub-specialized levels . The referral system consists of all physicians included in FPP, regardless of whether they work in the private or public sector, at the second and third levels. The second and third levels of the provision of services in Iran are obligated to providing specialized services for patients who had been referred by the first level . Adherence to the referral system is not mandatory in Iran. Some people are directly referred to the specialized levels and bypass the referral system, the process known as self-referral. In this case, the fees are slightly higher than those whose referrals were processed through the referral system .
Family Physician extent and consequences
To deliver basic health care in the form of the gatekeeping concepts , primary care physicians in various countries are employed by health systems. Gatekeeping is common in Europe, both in tax-funded and in social health insurance systems. Gatekeeping in the United States is prevalent, especially in the context of managed care [16, 17]. Quality, accessible and cost-effective health services as well as the satisfaction of end-users, are the core principles in any health care system, following through family physicians and referral systems . Six pathways have been introduced by Starfield et al. (2005), to illustrate the positive effects of having a primary care physician on health outcomes including greater access to needed services, better quality of care, greater focus on prevention, early management of health problems, cumulative effect of the main primary care delivery characteristics, and the role of primary care in reducing unnecessary specialist care .
The FPP emerged and was developed with its primary goal of managing and rationalizing health services utilization . Health systems whose main focus is to provide primary care through family physicians, reduce unnecessary specialized services through enhancing the continuity and coordination of care . The results of a systematic review revealed the positive consequences of family physician gatekeeping in terms of reduction in health services utilization and economic burden by 78 and 80 percent, respectively . Ma et al. (2016) examined the utilization of services and their costs in patients diagnosed with arthritis, which had enrolled in gatekeeper and non-gatekeeper plans. The results revealed that gatekeeper health plans are associated with lower health services (office-based medical visits, hospital inpatient visits, outpatient visits, and prescription medications) use and expenditures . The results of other studies have shown that having a primary care physician was associated with lower utilization of specialists, emergency rooms  as well as receipt of a variety of preventive health care checks including blood pressure, cholesterol, blood sugar, blood stool test, and reduced number of those receiving flu shot services .
In Iran, despite the long history of implementing the FPP, there are very few studies on the effectiveness of FPP in services` utilization management. Based on the view of Heshmati and Joulaei (2016), FPP in Iran has not been well implemented and the option of self-referring to specialists still exists . A survey among 500 households living in urban and rural areas of Fars province showed, that direct referral to a specialist physician while disregarding the health problem, was common among approximately 60 percent of participants . Furthermore, Barati et al. (2016) showed that, after the implementation of FPP in urban areas in Shiraz (The biggest city of Fars province), utilization of Para-clinic services has decreased by 4 and 19 percent in public and private centers, respectively . Also, high inequalities of specialist visits’ utilization were revealed in Iran .
The Iranian FPP and referral system have longstanding challenges that may affect its function in terms of service utilization management. Lack of interaction and constructive communication between the three levels of service delivery, disagreement among service providers regarding the effectiveness of this program, diversity of basic insurance plans, absence of complete public awareness, lack of compulsion on the way of receiving service and a small difference in payment on different routes, as well as limited IT infrastructure to create electronic health record are just some of the challenges they face [13, 27, 28].
A lack of comprehensive evidence in this area is another challenge policy-makers are facing. Pilot field studies have generally been conducted without comparison to other environments as a measure of control [14, 25]. Accordingly, this study will design to extract evidence on the effects of FPP on the burden of referral for outpatients visit through family physician program (FPP) in Iran.