Awareness of community health priorities is a necessity to achieve the appropriate educational content for medical students. It is worth noting that the consequences of allocating health resources as well as diseases that can face social and economic challenges play a role in determining the priorities of each community. These priorities are very helpful in the discussion of accountability of medical education which can well reflect the problems and needs of society. Accordingly, the high prevalence of a disease and its high impact on the patient's life have been accepted as criteria for determining the need to learn diseases in the content of general medical education . In the literature, there are diverse methods in different educational environments to achieve these priorities. At the University of Manchester, O'Neill et al.  earlier identified the necessary educational content in two stages using the opinions of GPs, clinical professors, health officials, and medical professionals. In the first stage, a list of clinical situations that GPs should be able to overcome alone, or with guidance, or with the help of a team was recognized. In the second stage, the educational content and the necessary skills and knowledge that GPs should have in dealing with these situations were determined with the help of all doctors and medical staff, as well as colleagues of health. At the University of Sheffield, Newble et al.  first prepared a list of clinical signs and symptoms of diseases using textbooks and medical school curricula in order to identify the necessary educational content. The common cases were then selected and prioritized with the opinions of university professors. Tandeter et al.  applied the Delphi method with the participation of 40 family physicians and medical instructors to determine the minimum content necessary for general medicine internship. After three Delphi stages, fifteen topics were identified as the most important items to be included in the curriculum. However, our studies were mainly based on the information obtained from Iran's IHS and not according to physicians' opinions. Finley et al.  showed that there was not only a difference between the statements of physicians and patients but also a discrepancy in the rate of PHC referrals between developed and developing countries. Nonetheless, this difference might be useful for the development of PHC guidelines, the allocation of resources, and the design of programs and curricula. On the other hand, it should be noted that this difference may be due to a lack of information in developing countries and therefore does not reflect reality. This fact may also be due to more or less accurate estimates of physicians, as well as their mistake in diagnosing diseases like mental disorders .
In the present research, items such as follow-up and request for medical consultation, lab test, digestive complaints such as abdominal pain, and respiratory complaints like cough were identified as priorities to be considered in the educational planning. In a study on referrals to family physicians for four years at the FLSD, the most important diagnoses among patients were hypertension (11.1%), upper respiratory tract infections (URTIs, 11.0%), physical examination (8.6%), diabetes (5.3%), sinusitis (4.8%), bronchitis (4.7%), degenerative joint disease (4.0%), asthma (3.7%), otitis (3.2%), and depression (2.9%), respectively . Another study investigated the time required by physicians to provide preventive services to common chronic diseases at the FLSD. The results showed that the ten most common chronic diseases included hyperlipidemia, hypertension, depression, asthma, diabetes, arthritis, anxiety, osteoporosis, chronic obstructive pulmonary disease, and coronary artery disease, respectively. Besides, each physician should daily allocate 3.5 working hours to provide preventive services . A practice-based morbidity survey in Birmingham was conducted to examine changes in disease patterns at the FLHC using two disease record systems based on ICD-9 codes. The results showed an increase in gastrointestinal disorders, malignant and benign skin tumors, hypothyroidism, and diabetes. A general decrease in the prevalence of infectious diseases (e.g., conjunctivitis, ear infections, respiratory infections, etc.), acute myocardial infarction, heart failure, and injuries was also observed. This study emphasized the prominent role of GPs in the management of non-communicable diseases . The difference between this study and ours was in the coding system. To design PHC-specific guidelines in India, 17 primary care centers were asked to report the most common diseases and administered drugs in prescriptions by physicians only with clinical diagnosis. Diseases recorded in order of prevalence included URTIs (45.3%, mainly colds, and acute sore throats), lower respiratory infections (15.9%, mostly bronchitis), parasitic infections (12.6%), anemia (11.4%), dyspepsia as well as ulcer (8.8%), and urinary tract infections (6.1%) . The prevalence rate of URTIs with a high frequency in colds and sore throats was consistent with the present study.
A study in Malaysia compared the incidence and referral patterns of patients according to the top ten priorities of the main complaint and diagnosis in the private and public sectors of primary care using the ICPC-2 coding system over a working week . There was a significant difference in terms of age and sex between the two groups so that the patients in the public sector were older and more women. In the public sector, the three main complaints of the patients were respiratory, general, and cardiovascular complaints, respectively. Most patients had chronic and complex diseases such as hypertension and diabetes, as well as pregnancy complaints. In the private sector, the three main complaints of primary care clients were respiratory, general, and digestive complaints, respectively. It seems that most of the acute patients with respiratory and fever as well as patients with better general conditions had referred to the private sector . In a consistent survey with the present study, Salvi et al.  assessed the health profile of all Indian patients throughout the country in all age groups at PHC level. The most common complaints in the general classification were fever (35.5%), headache-body pain (19.5%), loss of appetite (10.2%), and injuries (3.1%), respectively. In our study, fever, pain, and fatigue also were the first three priorities. In the different classification in different organs, the most common reasons for referrals were respiratory symptoms (50.6%), gastrointestinal (25.0%), blood (12.5%), cutaneous (9.0%), and endocrine (6.6%), respectively . In our study, gastrointestinal and respiratory symptoms were in second and third ranks of clinical complaints after PCs.
In the present study, women more than men referred to CHSCs. In Iran, CHSCs often provide health services in the morning. Since men are mostly present at work during this time, the lower referral number of men than women is explainable. The second and third priorities between them were different so that respiratory complaints in men than women were more common. Since these sex groups are different in biology, social roles, and responsibilities are different, they due to different risk factors and needs will experience various morbidity and mortality. It will be important for policymakers to address these differences for population planning. Studies from different countries showed that health services and health costs were higher in women than men. Here, the burden of diseases should be considered as a significant component for using PHC services between the sexes. A retrospective descriptive study on 79,809 adults referred to PHC using health details in the EHR showed that the use of health services as a result of the higher disease incidence was more in women than men in all age groups. However, there was no significant difference between the two sexes in the use of services and the number of visits after being assigned to the age and burden of infection . A retrospective study in the UK reviewed the non-emergency counseling of GPs and nurses working in the NHS system over a period of 7 years using data recorded in the EHR. Results showed that the number of patients, counseling, and its duration during this period was increased. The highest counseling rate in the age group of 0–4 and ≥ 85 years was observed. Similar to our results, women in all age groups referred more than men . Salvi et al.  reported that men in all age groups and geographies referred more compared to women. They explained that this difference may be a result of the sex preference of men in Indian societies. As women and the elderly have the maximum need for health services, fewer reports in this study clearly showed the social inequality in India.
In our study, the first five complaints of Iranian patients were requests, gastrointestinal, respiratory, general, and musculoskeletal, respectively. However, these priorities in clinical complaints are different in other world’s countries due to the discrepancy in health systems, cultural differences, and the burden of disease. For example, pregnancy and family planning, blood/immunity complaints (e.g., HIV), as well as unknown general and neurological causes in South Africa were more prevalent among referrals. However, a largely the same pattern was detected when the 52 most common symptoms/complaints in the Netherlands, Poland, Japan and the United States were compared to the 56 most common causes in South Africa. But, psychological complaints such as depression, anxiety, and sleep disorders beside common complaints in older people (e.g., vision and hearing complaints) were more in these countries compared to the South African. Complaints appear on the South African list, possibly reflecting the burden of HIV/AIDS and tuberculosis (e.g., weight loss, sweating, appetite loss, abnormal sputum, respiratory pain, and dysphagia), and sexually transmitted infections (e.g., genital/pelvic and vaginal pains). In addition, eye-ear infections (e.g., eye pain and discharge, redness of the eyes, and ear discharge), and trauma/injuries were very rare. This fact may indicate different disease loads in these areas .
Study strengths and limitations
The most important strengths of this study were the assessment of health needs of the whole country among different age ranges in both sex and also its applicability for the development of educational curricula to train appropriate human resources in providing health services. Moreover, the accessibility to information of the most deprived sections of society was provided. In general, there is often a possibility of defects or errors in the actual diagnosis steps because most physicians working in the PHC evaluate the type of patients' disorder/disease based on their medical history and examination without any access to diagnostic methods (required tests or imaging). Therefore, the results of complaints related to the non-use of valid diagnostic methods can lead to adopting a new approach to satisfy patients from the diagnostic and therapeutic process in these healthcare centers. As the information in all seasons over several years was recorded, the collected findings in this study were not affected by seasonal changes in referring patients. Another advantage was the use of the ICPC-2 coding system, which is internationally accepted for the PHC system. Although the conducted literature review was according to the qualitative and interview-based studies, the experimental data used in this research were extracted from electronic PHC records. Thus, the research output obtained from our study will have more reliability, complementing previous studies. On the other hand, the main limitation in this study is the underestimation of the real complaints due to no identification of patients' complaints, possible coding errors of the research team, and failure to report diagnoses according to the ICPC-2 coding system. However, although some of the registered complaints were diagnoses in the coding system, they were not removed from the list due to the valuable information of the patients. Besides, all information related to CHSCs with the presence of family physicians was collected from the public sector, while private sector information was not included.