Primary care physician
A primary care physician, or PCP, is a physician who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions, not limited by cause, organ system, or diagnosis. A PCP generally does not specialize in the treatment of specific organ systems, such as neurology, cardiology, or pulmonology, nor perform surgery. The term "PCP" is most commonly used in the United States. A primary care physician can be described by training, skill and scope of practice, role in the health care system, and the usual setting in which care is delivered. Primary care physicians are declining in numbers in many developed countries.
Defining primary care physicians
Certain clinicians, most commonly those trained in family practice, general practice, pediatrics and internal medicine are referred to as primary care physicians. Some HMOs consider gynecologists as PCPs for the care of women, and have allowed certain subspecialists to assume PCP responsibilities for selected patient types, such as allergists caring for people with asthma and nephrologists acting as PCPs for patients on kidney dialysis. Some experts and groups have included nurse practitioners and physician assistants by broadening the term to primary care practitioners.
Scope of practice
A set of skills and scope of practice may define a primary care physician, generally including basic diagnosis and non-surgical treatment of common illnesses and medical conditions.  Diagnostic techniques include interviewing the patient to collect information on the present symptoms, prior medical history and other health details, followed by a physical examination. Many PCPs are trained in basic medical testing, such as interpreting results of blood or other patient samples, electrocardiograms, or x-rays. More complex and time-intensive diagnostic procedures are usually obtained by referral to specialists, due to either special training with a technology, or increased experience and patient volume that renders a risky procedure safer for the patient.  After collecting data, the PCP arrives at a differential diagnosis and, with the participation of the patient, formulates a plan including (if appropriate) components of further testing, specialist referral, medication, therapy, diet or life-style changes, patient education, and follow up results of treatment. Primary care physicians also counsel and educate patients on safe health behaviors, self-care skills and treatment options, and provide screening tests and immunizations.
Role in the health care system
A primary care physician is usually the first medical practitioner contacted by a patient, due to factors such as ease of communication, accessible location, familiarity, and increasingly issues of cost and managed care requirements. Many health maintenance organizations position PCPs as "gatekeepers", who regulate access to more costly procedures or specialists. Ideally, the primary care physician acts on behalf of the patient to collaborate with referral specialists, coordinate the care given by varied organizations such as hospitals or rehabilitation clinics, act as a comprehensive repository for the patients records, and provide long-term management of chronic conditions. Continuous care is particularly important for patients with medical conditions that encompass multiple organ systems and require prolonged treatment and monitoring, such as diabetes and hypertension.
Health care setting
PCPs provide the majority of services at the primary level of care, an entry point to a system that includes secondary care (by community hospitals) and tertiary care (by medical centers and teaching hospitals), also referred to an ambulatory care setting versus inpatient care. Many primary care physicians follow their patients in a variety of health care settings, such as offices, hospitals, critical care units, long-term facilities, and at home. A PCP may supervise a non-physician health professional, such as a nurse practitioner or physician assistant.
Studies of the quality of care provided by primary care physicians
Studies that compare the knowledge base and quality of care provided by generalists versus specialists usually find that the specialists are more knowledgeable and provide better care . However, these studies examine the quality of care in the domain of the specialists. In addition, these studies need to account for clustering of patients and physicians .
Studies of the quality of preventive health care find the opposite results - primary care physicians perform best. An analysis of elderly patients found that patients seeing generalists, as compared to patients seeing specialists, were more likely to receive influenza vaccination. In health promotion counseling, a studies of self-reported behavior found that generalists were more likely than internal medicine specialists to counsel patients  and to screen for breast cancer .
Exceptions may be diseases that are so common that primary care physicians develop their own expertise. A study of patients with acute low back pain found the primary care physicians provided equivalent quality of care, but at lower costs that orthopedic specialists .
Low value care may be more common in settings with low numbers of primary care physicians.
Factors associated with quality of care by primary care physicians include:
- The more experience the primary care physician has with a specific disease..
- Physician group affiliation with networks of multiple groups.
Dissemination of information to generalists compared to specialists
The dissemination of information to generalists compared to specialists is complicated . Two studies found specialists were more likely to adopt COX-2 drugs before the drugs were recalled by the FDA . One of the studies went on to state "using COX-2s as a model for physician adoption of new therapeutic agents, specialists were more likely to use these new medications for patients likely to benefit but were also significantly more likely to use them for patients without a clear indication". Similarly, a separate study found that specialists were less discriminating in their choice of journal reading. 
FInancial incentives to primary care physicians are not clearly effective.
In summary, each type of physician has strengths, especially when practicing in areas of their expertise and experience. Accordingly, one study found the best care after myocardial infarctions was when both a specialist and a generalist cared for a patient .
Challenges for primary care
Primary care physicians are less satisfied when employeded and salaried in a large medical group with more physicians.  Other the other hand, primary care physicians in micropractices have higher satisfaction.
Shortages of primary care physicians are an increasing problem in many developed countries. In the United States, the number of medical students entering family practice training dropped by 50% between 1997 and 2005.  In 1998, half of internal medicine residents chose primary care, but by 2006, over 80% became specialists or hospitalists.  Causes parallel the evolutionary changes occurring in the US medical system: payment based on quantity of services delivered, not quality; aging of the population increases the prevalence and complexity of chronic health conditions, most of which are handled in primary care settings; and increasing emphasis on life-style changes and preventative measures, often poorly covered by health insurance or not at all.  In 2004, the median income of specialists in the US was twice that of PCPs, and the gap is widening.  Primary care practices in the United States increasingly depend on foreign medical graduates to fill depleted ranks. 
Insufficient time for tasks
Primary care physicians have insufficient time to manage chronic disease.
Replacement by non-physicians
Non-physicians may replace much of the work of primary care physicians. This disruption has been predicted by Clayton Christensen in his book, The Innovator’s Prescription: A Disruptive Solution for Healthcare
Developing countries face an even more critical disparity in primary care practitioners. The Pan American Health Organization reported in 2005 that "...the Americas region has made important progress in health, but significant challenges and disparities remain. Among the most important is the need to extend quality health care to all sectors of the population...Experience over the last 27 years shows that health systems that adhere to the principles of primary health care produce greater efficiency and better health outcomes in terms of both individual and public health..."  The World Health Organization (WHO) has identified worsening trends in access to PCPs and other primary care workers, both in the developed and the developing nations: 
- "Worker numbers and quality are positively associated with immunization coverage, outreach of primary care, and infant, child and maternal survival"
- "The quality of doctors and the density of their distribution have been shown to correlate with positive outcomes in cardiovascular diseases"
- "In health systems, (primary care) workers function as gatekeepers and navigators for the effective, or wasteful, application of all other resources such as drugs, vaccines and supplies"
- "there are currently 57 countries with critical shortages equivalent to a global deficit of 2.4 million doctors, nurses and midwives"
- "In many countries, the skills of limited yet expensive professionals are not well matched to the local profile of health needs"
- "...all countries suffer from maldistribution characterized by urban concentration and rural deficits"
- "Richer countries face a future of low fertility and large populations of elderly people, which will cause a shift towards chronic and degenerative diseases with high care demands"
- "Growing gaps will exert even greater pressure on the outflow of health workers from poorer regions"
Lagging quality of care measures
A survey of 6,000 primary care physicians in seven countries revealed disparities in several areas that affect quality of care. Differences did not follow trends of the cost of care; primary care physicians in the United States lagged behind their counterparts in other countries, despite the fact that the US spends two to three times as much per capita. Arrangements for after-hours care were almost twice as common in the Netherlands, Germany and New Zealand as in Canada and the United States, where patients must rely on emergency facilities. Other major disparities include automated systems to remind patients about follow-up care, give patients test results or warn of harmful drug interactions. There were differences as well among primary care doctors, regarding financial incentives to improve the quality of care.
- ↑ Institute of Medicine (1996). Primary Care: America's Health in a New Era. page 27: National Academies Press. Retrieved 2006-08-30.
- ↑ Institute of Medicine (2000). Interpreting the Volume-Outcome Relationship in the Context of Health Care Quality. National Academies Press. Retrieved 2006-08-30.
- ↑ Majumdar S, Inui T, Gurwitz J, Gillman M, McLaughlin T, Soumerai S (2001). "Influence of physician specialty on adoption and relinquishment of calcium channel blockers and other treatments for myocardial infarction". J Gen Intern Med. 16 (6): 351–9. PMID 11422631.
- ↑ Fendrick A, Hirth R, Chernew M (1996). "Differences between generalist and specialist physicians regarding Helicobacter pylori and peptic ulcer disease". Am J Gastroenterol. 91 (8): 1544–8. PMID 8759658.
- ↑ "Summaries for patients. Comparing the quality of diabetes care by generalists and specialists". Ann Intern Med. 136 (2): I42. 2002. PMID 11928735.
- ↑ Rosenblatt R, Hart L, Baldwin L, Chan L, Schneeweiss R (1998). "The generalist role of specialty physicians: is there a hidden system of primary care?". JAMA. 279 (17): 1364–70. PMID 9582044.
- ↑ Lewis C, Clancy C, Leake B, Schwartz J (1991). "The counseling practices of internists". Ann Intern Med. 114 (1): 54–8. PMID 1983933.
- ↑ Turner B, Amsel Z, Lustbader E, Schwartz J, Balshem A, Grisso J. "Breast cancer screening: effect of physician specialty, practice setting, year of medical school graduation, and sex". Am J Prev Med. 8 (2): 78–85. PMID 1599724.
- ↑ Carey T, Garrett J, Jackman A, McLaughlin C, Fryer J, Smucker D (1995). "The outcomes and costs of care for acute low back pain among patients seen by primary care practitioners, chiropractors, and orthopedic surgeons. The North Carolina Back Pain Project". N Engl J Med. 333 (14): 913–7. PMID 7666878.
- ↑ Ganguli I, Morden NE, Yang CW, Crawford M, Colla CH. Low-Value Care at the Actionable Level of Individual Health Systems. JAMA Intern Med. Published online September 27, 2021. doi:10.1001/jamainternmed.2021.5531
- ↑ Kitahata M, Koepsell T, Deyo R, Maxwell C, Dodge W, Wagner E (1996). "Physicians' experience with the acquired immunodeficiency syndrome as a factor in patients' survival". N Engl J Med. 334 (11): 701–6. PMID 8594430.
- ↑ Friedberg et al., “Does Affiliation of Physician Groups with One Another Produce Higher Quality Primary Care?,” Journal of General Internal Medicine 22, no. 10 (October 21, 2007): 1385-1392, http://dx.doi.org/10.1007/s11606-007-0234-0 (accessed September 28, 2007).
- ↑ Turner BJ, Laine C (2001). "Differences between generalists and specialists: knowledge, realism, or primum non nocere?". Journal of general internal medicine : official journal of the Society for Research and Education in Primary Care Internal Medicine. 16 (6): 422–4. doi:10.1046/j.1525-1497.2001.016006422.x. PMID 11422641. PubMed Central
- ↑ Rawson N, Nourjah P, Grosser S, Graham D (2005). "Factors associated with celecoxib and rofecoxib utilization". Ann Pharmacother. 39 (4): 597–602. PMID 15755796.
- ↑ 15.0 15.1 De Smet BD, Fendrick AM, Stevenson JG, Bernstein SJ (2006). "Over and under-utilization of cyclooxygenase-2 selective inhibitors by primary care physicians and specialists: the tortoise and the hare revisited". Journal of general internal medicine : official journal of the Society for Research and Education in Primary Care Internal Medicine. 21 (7): 694–7. doi:10.1111/j.1525-1497.2006.00463.x. PMID 16808768.
- ↑ McKibbon KA, Haynes RB, McKinlay RJ, Lokker C (2007). "Which journals do primary care physicians and specialists access from an online service?". Journal of the Medical Library Association : JMLA. 95 (3): 246–54. doi:10.3163/1536-5050.95.3.246. PMID 17641754.
- ↑ Burstein DS, Liss DT, Linder JA (2022). "Association of Primary Care Physician Compensation Incentives and Quality of Care in the United States, 2012-2016". J Gen Intern Med. 37 (2): 359–366. doi:10.1007/s11606-021-06617-8. PMID 33852143 Check
- ↑ Ayanian J, Landrum M, Guadagnoli E, Gaccione P (2002). "Specialty of ambulatory care physicians and mortality among elderly patients after myocardial infarction". N Engl J Med. 347 (21): 1678–86. PMID 12444183.
- ↑ Grembowski D, Ulrich CM, Paschane D, Diehr P, Katon W, Martin D; et al. (2003). "Managed care and primary physician satisfaction". J Am Board Fam Pract. 16 (5): 383–93. PMID 14645328.
- ↑ Paddock E, Prince RJ, Combs M, Stiles M (2013). "Does micropractice lead to macrosatisfaction?". J Am Board Fam Med. 26 (5): 525–8. doi:10.3122/jabfm.2013.05.120278. PMID 24004704.
- ↑ American Academy of Family Physicians, National Resident Matching Program data: Family Medicine Residency Positions and Number Filled by U.S. Medical School Graduates, 1994-2006 Retrieved 30 August 2006
- ↑ "The Impending Collapse of Primary Care Medicine and Its Implications for the State of the Nation's Health Care" (PDF) (Press release). The American College of Physicians. January 30, 2006. Retrieved 2006-08-30.
- ↑ 23.0 23.1 Bodenheimer, Thomas (2006-08-31). "Primary care - Will It Survive?". The New England Journal of Medicine. 355 (9): 861–864. Retrieved 2006-08-31. Check date values in:
- ↑ Medical Group Management Association Physician Compensation Survey, 1998 - 2005: Median Compensation for Selected Medical Specialties Retrieved 30 August 2006
- ↑ Østbye T, Yarnall KS, Krause KM, Pollak KI, Gradison M, Michener JL (2005). "Is there time for management of patients with chronic diseases in primary care?". Ann Fam Med. 3 (3): 209–14. doi:10.1370/afm.310. PMC 1466884. PMID 15928223.
- ↑ Shaw RJ, McDuffie JR, Hendrix CC, Edie A, Lindsey-Davis L, Nagi A; et al. (2014). "Effects of nurse-managed protocols in the outpatient management of adults with chronic conditions: a systematic review and meta-analysis". Ann Intern Med. 161 (2): 113–21. doi:10.7326/M13-2567. PMID 25023250.
- ↑ Altschuler J, Margolius D, Bodenheimer T, Grumbach K (2012). "Estimating a reasonable patient panel size for primary care physicians with team-based task delegation". Ann Fam Med. 10 (5): 396–400. doi:10.1370/afm.1400. PMC 3438206. PMID 22966102.
- ↑ Christensen, Clayton (2009) The Innovator’s Prescription: How disruptive innovation can transform health care (slide set). See slide 8.
- ↑ Pan American Health Organization (September 2005): Regional Declaration on the New Orientations of Primary Health Care Retrieved 30 August 2006
- ↑ World Health Organization: World Health Report-2006 Retrieved 30 August 2006
- ↑ Cathy Schoen, Robin Osborn, Phuong Trang Huynh, Michelle Doty, Jordon Peugh, and Kinga Zapert (1999-11-02). "On The Front Lines Of Care: Primary Care Doctors' Office Systems, Experiences, And Views In Seven Countries". Health Affairs. Retrieved 2006-11-06. Check date values in: