Chapter 004. Screening and Prevention of Disease (Kỳ 4) ppsx

Screening and Prevention of Disease Kỳ 4 a Screening is performed earlier and more frequently when there is a strong family history.. Randomized, controlled trials have documented that

Chapter 004 Screening and Prevention of Disease

(Kỳ 4)

a

Screening is performed earlier and more frequently when there is a strong family history Randomized, controlled trials have documented that fecal occult blood testing (FOBT) confers a 15 to 30% reduction in colon cancer mortality Although randomized trials have not been performed for sigmoidoscopy or colonoscopy, well-designed case-control studies suggest similar or greater efficacy relative to FOBT

b

In the future, Pap smear frequency may be influenced by HPV testing and the HPV vaccine

Note: Prostate-specific antigen (PSA) testing is capable of enhancing the

detection of early-stage prostate cancer, but evidence is inconclusive that it

improves health outcomes PSA testing is recommended by several professional organizations and is widely used in clinical practice, but it is not currently recommended by the U.S Preventive Services Task Force (Chap 81)

Source: Adapted from the U.S Preventive Services Task Force, 2005

http://www.ahrq.gov/clinic/uspstfix.htm

Cost-Effectiveness

Screening techniques must be cost-effective if they are to be applied to large populations Costs include not only the expense of testing but also time away from work and potential risks When the risk-to-benefit ratio is less favorable, it is useful to provide information to patients and factor their perspectives into the decision-making process For example, many expert groups, including the USPSTF, recommend an individualized discussion about prostate cancer screening, as the decision-making process is complex and relies heavily on personal issues Although the early detection of prostate cancer may intuitively seem desirable, risks include false-positive results that can lead to anxiety and unnecessary surgery Potential complications from surgery and radiation treatment include erectile dysfunction, urinary incontinence, and bowel dysfunction Some men may decline screening, while others may be more willing to accept the risks

of an early-detection strategy Another example of shared decision-making is the

choice of colon cancer screening techniques (Chap 78) In controlled studies, the use of annual FOBT reduces colon cancer deaths by 15–30% Flexible sigmoidoscopy reduces colon cancer deaths by ~60% Colonoscopy offers the same, or greater, benefit than flexible sigmoidoscopy, but its use incurs additional costs and risks These screening procedures have not been directly compared in the same population, but the estimated cost to society is similar: $10,000–25,000 per year of life saved Thus, while one patient may prefer the ease of preparation, less time disruption, and the lower risk of flexible sigmoidoscopy, others may prefer the sedation and thoroughness of colonoscopy

When considering the impact of screening tests, it is important to recognize that tobacco and alcohol use, diet, and exercise comprise the vast majority of factors that influence preventable deaths in developed countries Perhaps the single greatest preventive health care measure is to help patients quit smoking (Chap 390)

Commonly Encountered Issues

Despite compelling evidence that prevention strategies can have major health care benefits, implementation of these services is challenging because of competing demands on physician and patient time and because of gaps in health care reimbursement Moreover, efforts to reduce disease risk frequently involve behavior changes (e.g., weight loss, exercise, seatbelts) or managing addictive

conditions (e.g., tobacco and alcohol use) that are often recalcitrant to intervention Public education and economic incentives are often useful, in addition to counseling by health care providers (Table 4-4)

Table 4-4 Counseling to Prevent Disease

Reference

Tobacco cessation 390

Drug and alcohol use 387, 388

Nutrition to maintain caloric balance and vitamin

intake

54

Calcium intake in women >18 years 318

Folic acid: Women of childbearing age 71

Aspirin use to prevent cardiovascular disease in

selected men >40 years and women >50 years

235

Chemoprevention of breast cancer in women at high

risk

65

STDs and HIV prevention 124, 182 Physical activity

Injury prevention (loaded handgun, seat belts, bicycle

helmet)

Issues in the elderly 9

Polypharmacy

Fall prevention

Hot water heater <120° Vision, hearing, dental evaluations Immunizations (pneumococcal, influenza)

Note: STDs, sexually transmitted diseases