With the expanding knowledge concerning diseases and the further development of technology in diagnostics, screening has become a method in improving the state of public health through its potential for disease prevention. However, people may have misconceptions about this process because they were inadequately informed. This paper attempts to provide an understanding about the many aspects of screening. It is concerned with how screening is defined, its limitations and advantages, the issues involved and conditions where it is acceptable and not acceptable.
Information on current government policies regulating its practice and the proposed amendments are also provided. What is screening? Screening is a set of procedures intended to help determine the risk of individuals to certain diseases (National Health Service, 2008). Individuals may not be aware that they are at risk for a disease or that they are already experiencing its signs, symptoms or complications. As such, they are recommended to undergo an interview or test to find out if they have such likelihood.
With significant risk of disease, individuals are then asked to undergo further tests to rule out the presence of the disease. As a public health service, screening is offered nationwide by the U. K. National Health Services at a certain cost per person per screening. By being informed of risks to their health or that they already have the disease being screened for, persons will have the opportunity to institute measures that can either prevent or mitigate the condition (University of Kentucky Health Care, 2007).
Early prevention and treatment reduces the debilitating or life-threatening effects of disease and its complications. Specific screening services target a defined population deemed to have the highest risk for the disease and may be based on age, gender, race, occupation, pregnancy, family history or other factors (University of Kentucky Health Care, 2007). For example, screening for breast cancer is offered to women 50 years old and above, screening for bowel cancer is suggested for both women and men between 60-69 years old and screening for spina bifida is done for newborns.
Tests for occult blood in the faeces, Papanicolau Smear (Pap Smear), colonoscopy, mammography, blood tests, computed tomography and ultrasound scans are examples of screening tests (Patient UK, 2004). There are tests that may also have negative consequences on health. For this reason, screening is offered only to people who have a greater likelihood of benefiting from it over being harmed, rather than recommending the test for everyone in a population. However, screening programmes have their limitations.
As is the case with most diagnostic procedures, there exists a probability – albeit small, that on one hand, persons will be erroneously determined to possess risks to or already have the disease (false positive) when they do not (Elliman, 2002). On the other, it is also possible that persons will be ruled out of the risks and the disease when they in fact have it (false negative). Therefore, screening should be appreciated in its capacity to save lives and ensure a higher quality of life through risk reduction and prevention of disease rather than a fail-safe process.
In order to be more comprehensive, screening is part of a programme that involves not only risk detection or diagnosis but also treatment in the event that disease conditions are correctly determined to be present. Advantages, Disadvantages and Ethical Issues Ethical issues arise because screening is generally offered to people who are generally in good health. The code of ethics of health care workers states “do no harm” to clients. With the possible side-effects of tests or the probability of errors in the results, screening may unnecessarily interfere with and impact negatively on health.
Health care providers may also engage in opportunism. They target individuals for screening when the opportunity arises even if these individuals do not belong to the population to which the procedure is recommended. A case is in inviting women under 50 years old to undergo annual breast cancer screening when evidence suggests that screening procedures are mostly sensitive for menopausal women only (National Health Service, 2008). The average age of menopause onset in women is 50 years old.
The disadvantages of screening arise from the nature of the tests involved. Some tests are invasive. For instance, colonoscopy employed in bowel cancer screening involves the insertion of a scope from the anus up to the colon to view for inflammation, ulcers or abnormal growth along its lining (National Digestive Diseases Information Clearinghouse, 2008). Complications may arise when the scope punctures the intestinal lining and results in bleeding and pain. The effects mentioned may not only be physiological but also psychological.
People usually experience a degree of anxiety prior to screening procedures because of the discomfort or pain involved, having to expose private body parts, the fear of positive results and also the knowledge that samples of their body tissues such as blood or cervical cells are to be taken for analysis (Health Protection Agency, 2009). A false positive result is a disadvantage because the knowledge that one is at risk for or has a disease, even if incorrect, results in undue emotional stress.
It requires the exercise of coping mechanisms because this information has both social and economic implications. A false positive also predisposes healthy persons to medical treatment that they do not actually need (Cancer Research UK, 2002). On the other hand, a false negative will result in persons succumbing to the disease because early prevention or treatment measures were not undertaken. For these reasons, screening programmes should undergo extensive research and government regulation. In resolving these issues, screening must also be regarded in terms of its advantages.
The benefits of screening programmes include the reduction of morbidity and mortality rates from common diseases afflicting the population. For instance, as early as 2000, statistics showed that breast cancer screening in the U. K. has lowered mortality rates in the 55-69 age group (U. K. National Screening Committee, 2002). Through adequate health education, persons determined to be at risk for disease gain knowledge as to lifestyle changes, drug regimens, vaccinations or prophylactic treatments that are necessary in preventing the onset of disease.
This is especially advantageous when the disease in question is chronic in nature. It saves persons from the long-term financial and social costs of chronic disease. For example, heart disease and breast and colon cancers belong to the top 10 causes of mortality in women in 2005 (BBC News, 2006). The NHS currently offers screening programmes for these diseases. Early detection will increase the chances of recovering from these diseases through the ability to make informed decisions for treatment before the disease is full blown and becomes harder and more expensive to treat.
Women whose breast cancer was detected early through screening only have to undergo surgery to excise the abnormal tissue growth in the breast while women who did not undergo screening had to undergo mastectomy or removal of the entire breast because of the spread of cancerous cells (National Health Services Breast Screening Program, 2006). Further stages of the cancer also require continuous chemotherapy as treatment. To which diseases is screening appropriate? Screening is appropriate for diseases in which evidence-based research suggests that screening will provide more benefits compared to harm.
Without adequate research, screening should not be recommended because of the possibility of yet to be determined health risks or high costs of the procedure in the long term. Medical errors in screening occur because there is a disparity in practice and precede the acceptance of a standard which serves as a basis for quality practice (Eddy, 2005). Evidence-based research in the context of medicine requires a systematic and critical examination of existing medical research literature (Fox, 2005).
Aside from systematic reviews, it also requires the actual conduct of research to produce sufficient evidence that will back-up the effectiveness of a screening procedure. This includes randomized control trials and statistical analysis of experimental results (Havighurst, Hutt, McNeil & Miller, 2000). The outcome of a these activities is the formulation of a standard or protocol that will guide screening practice such as the conduct of procedures, the choice of screening test, interpretation of results, the target population and treatment methods (Waugh, et. al. , 2007).
In addition, all other available information is weighed and used to determine cost-effectiveness of the programme, its appropriateness over other alternatives and its advantages over disadvantages (Claxton, Cohen & Neumann, 2005). From these, decisions are made as to whether the screening programme should be permitted and made routine. To date, screening is done for breast, cervical and bowel only. No screening programs are available for cancers of the prostate, anal, urinary bladder, lungs, oral cavity, ovary and stomach because of the lack of evidence-based research (NHS, 2006).
However, for prostrate cancer, a programme to manage risks through assessment and risk reduction is offered. What is the policy of the U. K. with regard to screening? Prior to implementation, screening programs have to comply with criteria prescribed by the U. K. National Screening Committee. These criteria conform to current international standards and involve the consideration of three aspects – the condition, the test, the treatment and the screening programme (U. K. National Screening Committee, 2003).
A set of criteria is necessary in order to minimize the disadvantages involved in screening. With respect to the condition, screening should be warranted only for diseases affecting a significant portion of the population or is a major risk to public health. In addition, there should be a dearth of information and understanding already available with respect to the factors that lead to the development and progression of the disease (U. K. National Screening Committee, 2003).
This enables the identification of the segment of the population who are most likely to develop the disease. In order for the screening programme to be effective, risk factors to the disease and disease markers should also be readily identifiable and a latent stage or early symptomatic stage should also exist as well (U. K. National Screening Committee, 2003). Without early symptoms or markers such as in influenza, an acute viral infection, there is no point in early detection.
Markers, risks and early symptoms also aid in the objective interpretation of results in order to minimize false positives. The test should itself be very sensitive for it to have the least probability for errors. It should also cause the least discomfort or complications to the client with the least cost. Treatment for the disease screened should likewise be widely acceptable in order to make the screening worthwhile (Henschke, 2006). What diseases does the NHS screen for?
The National Health Service screens for diseases classified into the following: cancers, vascular diseases, antenatal (prior to birth) and newborn diseases, sexually transmitted infections and childhood diseases (National Health Service, 2008). As was mentioned earlier, only three types of cancers are being screened at present. Vascular diseases include heart diseases, stroke and arterial diseases which are regarded to be of epidemic proportions today along with diabetes and kidney disorders (Gray, 2006).
This epidemic is due to factors such as diet, genetics, smoking, excessive alcohol intake and sedentary lifestyle. Screening is also coupled with risk management and treatment programs. Antenatal and newborn screening is focused on the detection of anaemia, bacteriuria, blood grouping, placenta previa, pre-eclampsia and psychiatric illness in pregnant mothers while screening for congenital defects such as Tay Sach’s disease, spina bifida, Down’s Syndrome and other fetal anomalies is done for the newborns via physical assessment, blood examination or amniocentesis (NHS, 2008).
Tests for viral infections – HIV, rubella (measles), Hepatitis B and syphilis are also available. In the area of sexually transmitted infections, existing programs screen for Chlamydia in adults and pregnant women, genital herpes, Hepatitis B and C, HIV and syphilis. These infections have become a public health concern because of their increasing prevalence. For instance, approximately 7,000 new HIV infections have been recorded in 2007 and prior years and at present there is an estimated 7(Health Protection Agency, 2009).
Diseases in children open for routine screening are the following: congenital cataract, congenital heart disease, cryptorchidism (undescended testes), developmental dislocation of the hip, abnormal growth, and hearing and vision defects (NHS, 2008). No screening is currently offered for autism, development and behaviour disorders, hypertension, dental diseases, obesity and scoliosis among others (NHS, 2008). What changes are proposed?
There are several changes being proposed in the 2008 U. K. National Screening Committee Policy Position. First, screening for fetal anomalies in pregnant women is to be offered as a national programme in accordance to guidelines that will be released and second, improved laboratory screening for sickle cell and thalassaemia are also available and should be recommended to women in a population where the diseases are common (U. K. National Screening Committee, 2008).
Third, screenings for amino acid metabolism disorder, fatty acid oxidation disorder, kernicterus, anal cancer, coronary heart disease, stroke and domestic violence have been proposed but are not to be offered yet as evidence-based research are still insufficient or implementation guidelines have not yet been established (U. K. National Screening Committee, 2008). Fourth, the age for eligibility for bowel cancer screening through occult blood testing of faecal material has been lowered to 50 years old and above.
Other screening programmes are also currently undergoing pilot study for future national implementation such as those targeting kidney diseases, Type II diabetes and abdominal aortic aneurism (Thomas & Proudlock, 2008). Here controlled trials are conducted with a limited population (pilot testing) as a sample before the screening programme will begin to be offered to all members of the target population. Why are some diseases not screened even if reliable tests are available? The existence of reliable tests is not the only basis for the adoption of a policy implementing routine screening for a disease.
Other factors are also considered mainly cost-effectiveness, the ratio of benefit over harm, the extent of danger that the condition poses to public health and the effectiveness of the screening test in reducing cases of the disease. Pilot studies have to be conducted in order to gather further information and provide evidence for the formulation of policies and programmes. Conclusion Screening for diseases is an effective method for the prevention of disease and its early treatment. Despite existing ethical issues, this process has been shown to have decreased the mortality and morbidity rates of certain predominant diseases.
In order to ensure that advantages far outweigh disadvantages and cost, policies for routine screening should be based on evidence-based research. Also, screening service providers should adhere to nationally accepted criteria and other regulatory measures in order for services to be quality, safe and affordable. Likewise, the public needs to be educated regarding the benefits and harm of disease screening in order for them to make informed decisions as to undergo screening or not. Reference List BBC News 2006, Heart Disease is Biggest Killer, viewed 2 April 2009 <http://news. bbc. co. uk/2/hi/health/5016720. stm> Claxton, K.
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