Epidemiology: Open Access
Open Access

Primary care epidemiology is needed to describe the incidence, prevalence, severity, and natural history (duration, remission, and recurrence) of symptoms and signs, as well as defined illnesses, that occur in the community; how these problems differ among different groups within the community (e.g., by age, gender, socioeconomic status, ethnicity, and place of residence); and how these problems cluster or relate to one another. The need for, and opportunities available, to consider the complex genetic, physical, psychological, social, and cultural influences on the onset and natural history of common symptoms and illnesses is highlighted by the long-term continuous nature of primary care, which often extends to entire families. The development of successful evidence-based interventions, such as cough pamphlets that minimise re-consultation rates [1], can be aided by understanding the natural course of symptoms. Deeper knowledge of the psychosocial aspects linked to attitudes about back pain and its primary care management has resulted in public health education campaigns that reduce work-related absenteeism and improve beliefs, [2] with effects that last three years [3].

Description

Most symptoms experienced in the community are managed without seeking medical help (the so-called symptom iceberg phenomenon), according to studies [4]. For different conditions, the proportion of visible (presented to health care services) and a submerged (nonpresented) symptom varies. Although this phenomena is commonly thought to be limited to minor, self-limiting health issues, mounting evidence suggests that substantial submerged proportions also occur for major illness symptoms like as angina [5, 6] chronic back pain [7], and asthma [8]. Long-term repercussions could be significant [6], but further research is needed utilising a number of outcome indicators such as comorbidity, mortality, quality of life, economic expenditures, and use of health care services for other illnesses. This research will identify instances in which earlier involvement may be beneficial, as well as situations in which the medical profession should stay out of [9, 10]. For example, the introduction of genetic tests in primary care without appropriate epidemiological evaluation may lead to inappropriate ‘medicalization,' either because 'illness' is diagnosed decades before symptoms appear (e.g. Huntingdon's chorea) or because genes are incompletely penetrant (e.g. only 1% of homozygotes develop frank hemochromatosis) [11].

The predictive usefulness of different symptoms or clusters of symptoms seen in the population, particularly for serious disease, is currently unknown. Positive predictive values of individual symptoms are expected to be quite low, given the great frequency of various symptoms and the low incidence of serious disease in the general population, especially among younger people. Rectal bleeding, for example, is seldom linked to bowel cancer [12] or headaches to a brain tumour [13]. If low predictive values like these may be improved by looking at clusters of symptoms in conjunction with individual and family variables including age, gender, family history, and comorbidity, more research is needed. Referral recommendations, such as those for probable cancer [14], are likely to remain ineffective without this information.

Providing information that will allow primary care services to be used more efficiently

Governments all throughout the world are working to create health-care systems that are safe, patient-centered, prompt, efficient, and equitable. Primary care plays a central referral (gatekeeping) function in various nations, such as the Netherlands, Spain, Denmark, Norway, and the United Kingdom (UK). Other countries, including as France, Germany, India, and the United States, give unfettered (parallel) access to primary and secondary care. The amount to which primary care serves as an entry point into the health-care system, as well as its comprehensiveness, community/population emphasis, and degree of centralization and computerization, all influence the scope and purpose of primary care epidemiology. Some of the issues that primary care epidemiology can address are system-specific, such as who is utilising health care services, when, and why. Others will be broader, such as what is the predictive value of (typically undifferentiated) symptoms presented to health care providers (whether they are a nurse, community pharmacist, general practitioner, or hospital specialist) for the first time? Primary care systems with patient registration lists are far more able to look at issues at the community level than those without, because the registration lists supply the essential denominators (at-risk groups) for research.

Primary care services are in high demand regardless of the healthcare system. In the United Kingdom, for example, more than 250 million consultations with a general practitioner are anticipated to take place each year41, with hundreds of millions more with other members of the primary health care team. Small variations in demand (a few percentage points) can considerably relieve or strain the system with such enormous numbers. Primary care epidemiology not only describes what proportion of people with specific symptoms or clusters of symptoms seek health care, but it also shows how that usage varies depending on the characteristics of individuals and their symptoms, as well as the availability of various health care services.

Acknowledgement

None

Conflict of Interest

None

1. Macfarlane JT, Holmes WF, Macfarlane R.M (1997) Reducing reconsultations for acute lower respiratory tract illness with an information leaflet: a randomized controlled study of patients in primary care. Br J Gen Pract 47(424): 719-722.

Google scholar,Crossref

2. Buchbinder R, Jolley D, Wyatt M (2001) Population based intervention to change back pain beliefs and disability: three part evaluation. Bmj 322(7301): 1516-1520.

Indexed at,Google scholar,Crossref

3. Buchbinder R, Jolley D (2004) Population based intervention to change back pain beliefs: three year follow up population survey. Bmj 328(7435): 321.

Indexed at, Google scholar,Crossref

4. Last JM (2013) The iceberg:‘completing the clinical picture’in general practice. Int J Epidemiol 42(6): 1608-1613.

Indexed at,Google scholar,Crossref

5. Richards H, McConnachie A, Morrison C, Murray K, Watt G (2000) Social and gender variation in the prevalence, presentation and general practitioner provisional diagnosis of chest pain. J Epidemiol Community Health 54(9): 714-718.

Indexed at,Google scholar, rossref

6. Owen-Smith V, Hannaford PC, Elliott AM (2003) Increased mortality among women with Rose angina who have not presented with ischaemic heart disease. Br J Gen Pract 53(495): 784-789.

Indexed at, Google scholar

7. Croft PR, Macfarlane GJ, Papageorgiou AC, Thomas E, Silman AJ (1998) Outcome of low back pain in general practice: a prospective study. Bmj 316(7141): 1356.

Indexed at, Google scholar, , Crossref

8. Frank P, Ferry S, Moorhead T, Hannaford P (1996) Use of a postal questionnaire to estimate the likely under-diagnosis of asthma-like illness in adults. Br J Gen Pract 46(406): 295-297.

Google scholar

9. Coyne JC, Klinkman MS, Gallo SM, Schwenk TL (1997) Short-term outcomes of detected and undetected depressed primary care patients and depressed psychiatric patients. General hospital psychiatry, 19(5), pp.333-343. 

Indexed at, Google scholar, Crossref

10. Mayor S (2004) Pfizer will not apply for a licence for sildenafil for women. Bmj 328(7439): 542.

Google scholar, , Crossref

11. Melzer D, Zimmern R (2002) Genetics and medicalisation. BMJ 324: 863-864.

 

12. Fijten GH, Blijham GH, Knottnerus JA (1994) Occurrence and clinical significance of overt blood loss per rectum in the general population and in medical practice. Br J Gen Pract 44(384): 320-325.

Indexed at, Google scholar

13. Boiardi A, Salmaggi A, Eoli M, Lamperti E, Silvani A (2004) Headache in brain tumours: a symptom to reappraise critically. Neurol Sci 25(3): s143-s147.

Indexed at, Google scholar, , Crossref

14. Green LA, Phillips RL, Fryer GE (2003) The nature of primary medical care. Oxford Textbook of Primary Medical Care 1:3-10.

Google scholar