Preventive medicine

Preventive medicine or preventive care refers to measures taken to prevent diseases,^[1] (or injuries) rather than curing them or treating their symptoms. The term contrasts in method with curative and palliative medicine, and in scope with public health methods (which work at the level of population health rather than individual health).

Levels

Preventive medicine strategies are typically described as taking place at the primary, secondary, tertiary and quaternary prevention levels. In addition, the term primal prevention has been used to describe all measures taken to ensure fetal well-being and prevent any long-term health consequences from gestational history and/or disease.^[2] The rationale for such efforts is the evidence demonstrating the link between fetal well-being, or "primal health", and adult health.^[3][4] Primal prevention strategies typically focus on providing future parents with: education regarding the consequences of epigenetic influences on their child,^[5] sufficient leave time for both parents, and financial support if required. This includes parenting in infancy as well.

Simple examples of preventive medicine include hand washing, breastfeeding, and immunizations. Preventive care may include examinations and screening tests tailored to an individual's age, health, and family history. For example, a person with a family history of certain cancers or other diseases would begin screening at an earlier age and/or more frequently than those with no family history. On the other side of preventive medicine, some non-profit organizations, such as the Northern California Cancer Center, apply epidemiological research towards finding ways to prevent diseases.

Prevention levels[6]			Doctor’s side
			Disease
			absent	present
Patient’s side	Illness	absent	Primary prevention illness absent disease absent	Secondary prevention illness absent disease present
		present	Quaternary prevention illness present disease absent	Tertiary prevention illness present disease present

Level	Definition
Primary prevention	Methods to avoid occurrence of disease.[7] Most population-based health promotion efforts are of this type.
Secondary prevention	Methods to diagnose and treat extant disease in early stages before it causes significant morbidity.[8]
Quaternary prevention	Methods to mitigate or avoid results of unnecessary or excessive interventions in the health system.[9]
Tertiary prevention	Methods to reduce negative impact of extant disease by restoring function and reducing disease-related complications.[10]

Universal, selective, and indicated

Gordon (1987) in the area of disease prevention,^[11] and later Kumpfer and Baxley in the area of substance use^[12] proposed a three-tiered preventive intervention classification system: universal, selective, and indicated prevention. Amongst others, this typology has gained favour and is used by the U.S. Institute of Medicine, the NIDA and the European Monitoring Centre for Drugs and Drug Addiction.

Tier	Definition
Universal prevention	Involves whole population (nation, local community, school, district) and aims to prevent or delay the abuse of alcohol, tobacco, and other drugs. All individuals, without screening, are provided with information and skills needed to prevent the problem.
Selective prevention	Involves groups whose risk of developing problems of alcohol abuse or dependence is above average. Subgroups may be distinguished by traits such as age, gender, family history, or economic status. For example, drug campaigns in recreational settings.
Indicated prevention	Involves a screening process, and aims to identify individuals who exhibit early signs of substance abuse and other problem behaviours. Identifiers may include falling grades among students, known problem consumption or conduct disorders, alienation from parents, school, and positive peer groups etc.

Outside the scope of this three-tier model is environmental prevention. Environmental prevention approaches are typically managed at the regulatory or community level, and focus on interventions to deter drug consumption. Prohibition and bans (e.g. on smoking, alcohol advertising) may be viewed as the ultimate environmental restriction. However, in practice environmental preventions programmes embrace various initiatives at the macro and micro level, from government monopolies for alcohol sales, through roadside sobriety or drug tests, worker/pupil/student drug testing, increased policing in sensitive settings (near schools, at rock festivals), and legislative guidelines aimed at precipitating punishments (warnings, penalties, fines).

Professionals

Professionals involved in the public health aspect of this practice may be involved in entomology, pest control, and public health inspections. Public health inspections can include recreational waters, swimming pools, beaches, food preparation and serving, and industrial hygiene inspections and surveys.

In the United States, preventive medicine is a medical specialty, one of the 24 recognized by the American Board of Medical Specialties (ABMS). It encompasses three areas of specialization:

• General preventive medicine and public health
• Aerospace medicine
• Occupational medicine

To become board-certified in one of the preventive medicine areas of specialization, a licensed U.S. physician (M.D. or D.O.) must successfully complete a preventive medicine medical residency program following a one-year internship. Following that, the physician must complete a year of practice in that special area and pass the preventive medicine board examination. The residency program is at least two years in length and includes completion of a master's degree in public health (MPH) or equivalent. The board exam takes a full day: the morning session concentrates on general preventive medicine questions, while the afternoon session concentrates on the one of the three areas of specialization that the applicant has studied.

In addition, there are two subspecialty areas of certification:

• Medical toxicology (MT)
• Undersea and hyperbaric medicine (UHB), formerly "undersea medicine"

These certifications require sitting for an examination following successful completion of an MT or UHB fellowship and prior board certification in one of the 24 ABMS-recognized specialties.

Prophylaxis

Prophylaxis (Greek "προφυλάσσω" to guard or prevent beforehand) is any medical or public health procedure whose purpose is to prevent, rather than treat or cure a disease. In general terms, prophylactic measures are divided between primary prophylaxis (to prevent the development of a disease) and secondary prophylaxis (whereby the disease has already developed and the patient is protected against worsening of this process).

Examples

Some specific examples of prophylaxis include:

• Many vaccines are prophylactic, vaccines such as polio vaccine, smallpox vaccine, measles vaccine, mumps vaccine and others have greatly reduced many childhood diseases; HPV vaccines prevent certain cancers; influenza vaccine.^[13]
• Birth control methods are used to prevent unwanted pregnancy. Condoms, for instance, are sometimes referred to as "prophylactics" because of their use to prevent pregnancy as well as the transmission of sexually transmitted infections.
• Daily and moderate physical exercise in various forms can be called prophylactic because it can maintain or improve one's health. Cycling for transport appears to very significantly improve health by reducing risk of heart diseases, various cancers, muscular- and skeletal diseases, and overall mortality.^[14]
• Fluoride therapy and tooth cleaning, either at home or by a professional, are parts of dental prophylaxis or oral prophylaxis.

• Antibiotics are sometimes used prophylactically: For example, during the 2001 anthrax attacks scare in the United States, patients believed to be exposed were given ciprofloxacin. In similar manner, the use of antibiotic ointments on burns and other wounds is prophylactic. Antibiotics are also given prophylactically just before some medical procedures such as pacemaker insertion.^[15]
• Tricyclic antidepressants (TCAs) may, with caution, be an example of a chronic migraine preventive (see amitriptyline and migraines' prevention by medicine).
• Antimalarials such as chloroquine and mefloquine are used both in treatment and as prophylaxis by visitors to countries where malaria is endemic to prevent the development of the parasitic Plasmodium, which cause malaria.
• Low-molecular-weight heparin is used as a prophylaxis in hospital patients, as they are at risk for several forms of thrombosis due to their immobilisation.
• Risk reducing or prophylactic mastectomies may be carried out for carriers of the BRCA mutation gene to minimise the risk of developing breast cancer.
• Early and exclusive breastfeeding provides immunological protection against infectious diseases and well as reduced risk of chronic diseases for both mother and child.^[16]
• Polypill for prevention of e.g. cardiovascular disease.
• Potassium iodide is used prophylactically to protect the thyroid gland from absorbing inhaled or ingested radioactive iodine, which may lead to the development of thyroid cancer; radioactive iodine may be released into the environment in the event of an accident at a nuclear power plant, or the detonation of a nuclear explosive (see thyroid protection due to nuclear accidents and emergencies).
• Prophylaxis may be administered as oral medication. Oral prophylaxis includes: PEP, nPEP, or PrEP. PEP stands for post-exposure prophylaxis used in an occupational setting e.g., to prevent the spread of HIV or Hepatitis C from patient to staff following an accidental needlestick. nPEP is non-occupational post-exposure prophylaxis. nPEP may be used in a sexual or injection exposure to HIV, hepatitis, or other infectious agents; for example, during intercourse, if the condom breaks and one partner is HIV-positive, nPEP will help to decrease the probability that the HIV-negative partner becomes infected with HIV. (An nPEP is sometimes known as a PEPse - i.e. post-exposure prophylaxis sexual encounter.) PrEP is a measure taken daily (before, during, and after) possible exposure; for example, by a person who inconsistently uses condoms during sex with a partner who may have an HIV infection.

Limitations

Since preventive medicine deals with healthy individuals or populations the costs and potential harms from interventions need even more careful examination than in treatment. For an intervention to be applied widely it generally needs to be affordable and highly cost effective.

For instance, intrauterine devices (IUD) are highly effective and highly cost effective contraceptives, however where universal health care is not available the initial cost may be a barrier.^[17] IUDs work for several years (3 to 7 or more) and cost less over a year or two's time than most other reversible contraceptive methods.^[18] They are also highly cost effective, saving health insurers and the public significant costs in unwanted pregnancies.^[18] Making contraceptives available with no up front cost is one way to increase usage, improving health and saving money.^[19]

Preventive solutions may be less profitable and therefore less attractive to makers and marketers of pharmaceuticals and medical devices. Birth control pills which are taken every day and may take in a thousand dollars over ten years may generate more profits than an IUD, which despite a huge initial markup only generates a few hundred dollars over the same period.^[17]

Leading cause of preventable death

Main article: List of preventable causes of death

Leading causes of preventable death worldwide as of the year 2001.^[20]

Cause	Deaths caused (millions per year)
Hypertension	7.8
Smoking	5.0
High cholesterol	3.9
Malnutrition	3.8
Sexually transmitted infections	3.0
Poor diet	2.8
Overweight and obesity	2.5
Physical inactivity	2.0
Alcohol	1.9
Indoor air pollution from solid fuels	1.8
Unsafe water and poor sanitation	1.6

Main article: List of preventable causes of death in children

Leading preventive interventions that reduce deaths in children 0–5 years old worldwide, by percent indicated.^[21]

Intervention	Percent of all child deaths preventable
Breastfeeding	13
Insecticide-treated materials	7
Complementary feeding	6
Zinc	4
Clean delivery	4
Hib vaccine	4
Water, sanitation, hygiene	3
Antenatal steroids	3
Newborn temperature management	2
Vitamin A	2
Tetanus toxoid	2
Nevirapine and replacement feeding	2
Antibiotics for premature rupture of membranes	1
Measles vaccine	1
Antimalarial intermittent preventive treatment in pregnancy	<1%

Leading causes of preventable deaths in the United States in the year 2000.^[22]

Cause	Deaths caused	% of all deaths
Tobacco smoking	435,000	18.1
Poor diet and physical inactivity	365,000	15.2
Alcohol consumption	85,000	3.5
Infectious diseases	75,000	3.1
Toxicants	55,000	2.3
Traffic collisions	43,000	1.8
Firearm incidents	29,000	1.2
Sexually transmitted infections	20,000	0.8
Drug abuse	17,000	0.7

See also

• Post-exposure prophylaxis
• Pre-exposure prophylaxis
• Prophylactic rule
• Quaternary prevention
• Monitoring (medicine)
• American Journal of Preventive Medicine
• Preventive Medicine (journal)

References

Footnotes

1. ^ MeSH Preventive+Medicine
2. ^ Primal Research Centre, London
3. ^ Primal Health Research Databank
4. ^ Effect of In Utero and Early-Life Conditions on Adult Health and Disease, by P.D.Gluckman et al., N ENGL J MED 359;1
5. ^ Origins: How the Nine Months Before Birth Shape the Rest of Our Lives, by Annie Murphy Paul, Free Press, september 2010
6. ^ Kuehlein T, Sghedoni D, Visentin G, Gérvas J, Jamoule M. Quaternary prevention: a task of the general practitioner. PrimaryCare. 2010; 10(18):350-4.
7. ^ MeSH Primary+Prevention
8. ^ MeSH Secondary+Prevention
9. ^ Gofrit ON, Shemer J, Leibovici D, Modan B, Shapira SC. Quaternary prevention: a new look at an old challenge. Isr Med Assoc J. 2000;2(7):498-500.
10. ^ MeSH Tertiary+Prevention
11. ^ Gordon, R. (1987), ‘An operational classification of disease prevention’, in Steinberg, J. A. and Silverman, M. M. (eds.), Preventing Mental Disorders, Rockville, MD: U.S. Department of Health and Human Services, 1987.
12. ^ Kumpfer, K. L., and Baxley, G. B. (1997), 'Drug abuse prevention: What works?', National Institute on Drug Abuse, Rockville.
13. ^ How should influenza prophylaxis be implemented?
14. ^ Lars Bo Andersen et al. (June 2000). "All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work". Archives of Internal Medicine 160 (11): 1621–8. doi:10.1001/archinte.160.11.1621. PMID 10847255. 
15. ^ de Oliveira JC, Martinelli M, D'Orio Nishioka SA, et al. (2009). "Efficacy of antibiotic prophylaxis prior to the implantation of pacemakers and cardioverter-defibrillators: Results of a large, prospective, randomized, double-blinded, placebo-controlled trial". Circulation: Arrhythmia and Electrophysiology 2 (1): 29–34. doi:10.1161/CIRCEP.108.795906. PMID 19808441. 
16. ^ Ip S, Chung M, Raman G, ChewP, Magula N, DeVine D, Litt M, Trikalinos T, Lau J. Breastfeeding and maternal and infant health outcomes in developed countries. Evidence Report/Technology Assessment Number 153. 2007 April; AHRQ Publication No. 07-E007.
17. ^ ^{a b} J. Joseph Speidel, Cynthia C. Harper, and Wayne C. Shields (September 2008). "The Potential of Long-acting Reversible Contraception to Decrease Unintended Pregnancy". Contraception. http://www.arhp.org/publications-and-resources/contraception-journal/september-2008. 
18. ^ ^{a b} James Trussell, Anjana Lalla, Quan Doan, Eileen Reyes, Lionel Pinto, Joseph Gricar (2009). "Cost effectiveness of contraceptives in the United States". Contraception 79 (1): 5–14. doi:10.1016/j.contraception.2008.08.003. PMID 19041435. 
19. ^ Monea J, Thomas A (June 2011). "Unintended pregnancy and taxpayer spending". Perspectives on Sexual and Reproductive Health 43 (2): 88–93. doi:10.1363/4308811. PMID 21651707. 
20. ^ Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJ (May 2006). "Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data". Lancet 367 (9524): 1747–57. doi:10.1016/S0140-6736(06)68770-9. PMID 16731270. 
21. ^ Jones G, Steketee R, Black R, Bhutta Z, Morris S, and the Bellagio Child Survival Study Group* (July 5, 2003 2003). "How many child deaths can we prevent this year?". Lancet 362 (9524): 1747–57. 
22. ^ Mokdad AH, Marks JS, Stroup DF, Gerberding JL (March 2004). "Actual causes of death in the United States, 2000". JAMA 291 (10): 1238–45. doi:10.1001/jama.291.10.1238. PMID 15010446. http://www.csdp.org/research/1238.pdf. 

Notations

• Sackett DL. The arrogance of preventive medicine. CMAJ. 2004;167:363-4.
• Gérvas J, Pérez Fernández M. Los límites de la prevención clínica. AMF. 2007; 3(6):352-60.
• Gérvas J, Pérez Fernández M, González de Dios J. Problemas prácticos y éticos de la prevención secundaria. A propósito de dos ejemplos de pediatría. Rev Esp Salud Pública. 2007;81:345-52.
• Starfield B, Hyde J, Gérvas J, Heath I. The concept of prevention: a good idea gone astray? J Epidemiol Community Health. 2008;62(7):580-3.
• Gérvas J, Starfield B, Heath I. Is clinical prevention better than cure? Lancet. 2008;372:1997-9.
• Gérvas J, Pérez Fernández M. Los daños provocados por la prevención y por las actividades preventivas. RISAI. 2009; 1(4).
• Gérvas J. Abuso de la prevención clínica. El cribaje del cáncer de mama como ejemplo. Rev Espaço Saùde. 2009; 11(1):49-53.
• Gérvas J, Heath I, Durán A, Gené J; Members of the Seminar of Primary Health Innovation 2008. Clinical prevention: patients' fear and the doctor's guilt. Eur J Gen Pract. 2009; 15(3):122-4.
• Heneghan C. Considerable uncertainty remains in the evidence for primary prevention of cardiovascular disease (editorial). The Cochrane Library 2011 (19 Jan).

External links

• US Preventive Medicine Task Force
• US Preventive Medicine
• The Prevention Plan
• Health-EU Portal Prevention and Promotion