This statement summarizes the recommendation of the third U.S. Preventive Services Task Force (USPSTF) for aspirin for the primary prevention of cardiovascular events, as well as the supporting scientific evidence. The complete information on which this statement is based, including evidence tables and references, can be found in a companion article in this issue. Copies of this document, the summary of the evidence, and the systematic evidence review can be obtained through the USPSTF Web site (http://www.ahrq.gov/clinic/uspstfix.htm) and in print through the Agency for Healthcare Research and Quality Publications Clearinghouse (800-358-9295).

The dual aims of treating patients with chronic stable angina are 1) to reduce morbidity and mortality and 2) to eliminate angina with minimal adverse effects and allow the patient to return to normal activities. In the absence of contraindications, beta-blockers are recommended as initial therapy. All beta-blockers seem to be equally effective. If the patient has serious contraindications to beta-blockers, unacceptable side effects, or persistent angina, calcium antagonists should be administered. Long-acting dihydropyridine and nondihydropyridine agents are generally as effective as beta-blockers in relieving angina. Long-acting nitrates are considered third-line therapy because a nitrate-free interval is required to avoid developing tolerance. All long-acting nitrates seem to be equally effective. Patients with angina should take 75 to 325 mg of aspirin daily unless they have contraindications. Such risk factors as smoking, elevated low-density lipoprotein cholesterol level, diabetes, and hypertension should be treated appropriately. Coronary revascularization has not been shown to improve survival for most patients with chronic angina but may be required to control symptoms. However, coronary artery bypass grafting (CABG) is often indicated for symptomatic patients with left-main disease, three-vessel disease, or two-vessel disease including proximal stenosis of the left anterior descending coronary artery; it improves their survival. Percutaneous transluminal coronary angioplasty is an alternative to CABG for patients with normal left ventricular function and favorable angiographic features. Coronary artery bypass grafting is initially more effective in relieving angina than medical therapy, but the two procedures yield similar results after 5 to 10 years. Eighty percent of patients who undergo CABG remain angina-free 5 years after surgery. In low-risk patients, percutaneous transluminal coronary angioplasty seems to control angina better than medical therapy, but recurrent angina and repeated procedures are more likely than with CABG. Patient education is an important component of management. Long-term follow-up should be individualized to ascertain clinical stability at regular intervals and to reassess prognosis when warranted.

Patients with suspected chronic stable angina can be evaluated in three stages. In stage one, the clinician uses information from the history, physical examination, laboratory tests for diabetes and hyperlipidemia, and resting electrocardiography to estimate the patient's probability of coronary artery disease (CAD). In stage two, additional testing for patients with a low probability of CAD focuses on diagnosing noncoronary causes of chest pain. Patients with a high probability of CAD have stress tests to assess their risk from CAD, and patients with an intermediate probability of CAD have stress tests to estimate the probability of CAD and assess their risk from CAD. Most patients with new-onset angina can start stress testing with exercise electrocardiography. The initial stress test should be a stress imaging procedure for patients with rest ST-segment depression greater than 1 mm, complete left bundle-branch block, ventricular paced rhythm, preexcitation syndrome, or previous revascularization with percutaneous coronary angioplasty or coronary artery bypass grafting. Patients who cannot exercise can have an imaging procedure with stress induced by pharmacologic agents. In stage three, patients with a predicted average annual cardiac mortality rate between 1% and 3% should have a stress imaging study or coronary angiography with left ventriculography. Those with a known left ventricular dysfunction should have cardiac catheterization. Patients with CAD who have an estimated annual mortality rate greater than 3% should have cardiac catheterization to determine whether their anatomy is suitable for revascularization. Patients with an estimated annual mortality rate less than 1% can begin to receive medical therapy.

To review critically the available data on diagnostic evaluation, risk stratification, and therapeutic management of patients with acute exacerbations of chronic obstructive pulmonary disease (COPD).

The following principles of appropriate antibiotic use for adults with acute bronchitis apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease.1. The evaluation of adults with an acute cough illness or a presumptive diagnosis of uncomplicated acute bronchitis should focus on ruling out serious illness, particularly pneumonia. In healthy, nonelderly adults, pneumonia is uncommon in the absence of vital sign abnormalities or asymmetrical lung sounds, and chest radiography is usually not indicated. In patients with cough lasting 3 weeks or longer, chest radiography may be warranted in the absence of other known causes.2. Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended, regardless of duration of cough. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated.3. Patient satisfaction with care for acute bronchitis depends most on physician-patient communication rather than on antibiotic treatment.

The following principles of appropriate antibiotic use for adults with acute pharyngitis apply to immunocompetent adults without complicated comorbid conditions, such as chronic lung or heart disease, and history of rheumatic fever. They do not apply during known outbreaks of group A streptococcus.1. Group A beta-hemolytic streptococcus (GABHS) is the causal agent in approximately 10% of adult cases of pharyngitis. The large majority of adults with acute pharyngitis have a self-limited illness, for which supportive care only is needed.2. Antibiotic treatment of adult pharyngitis benefits only those patients with GABHS infection. All patients with pharyngitis should be offered appropriate doses of analgesics and antipyretics, as well as other supportive care.3. Limit antibiotic prescriptions to patients who are most likely to have GABHS infection. Clinically screen all adult patients with pharyngitis for the presence of the four Centor criteria: history of fever, tonsillar exudates, no cough, and tender anterior cervical lymphadenopathy (lymphadenitis). Do not test or treat patients with none or only one of these criteria, since these patients are unlikely to have GABHS infection. For patients with two or more criteria the following strategies are appropriate: a) Test patients with two, three, or four criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results; b) test patients with two or three criteria by using a rapid antigen test, and limit antibiotic therapy to patients with positive test results or patients with four criteria; or c) do not use any diagnostic tests, and limit antibiotic therapy to patients with three or four criteria. 4. Throat cultures are not recommended for the routine primary evaluation of adults with pharyngitis or for confirmation of negative results on rapid antigen tests when the test sensitivity exceeds 80%. Throat cultures may be indicated as part of investigations of outbreaks of GABHS disease, for monitoring the development and spread of antibiotic resistance, or when such pathogens as gonococcus are being considered.5. The preferred antibiotic for treatment of acute GABHS pharyngitis is penicillin, or erythromycin in a penicillin-allergic patient.

The following principles of appropriate antibiotic use for adults with acute rhinosinusitis apply to the diagnosis and treatment of acute maxillary and ethmoid rhinosinusitis in adults who are not immunocompromised.1. Most cases of acute rhinosinusitis diagnosed in ambulatory care are caused by uncomplicated viral upper respiratory tract infections. 2. Bacterial and viral rhinosinusitis are difficult to differentiate on clinical grounds. The clinical diagnosis of acute bacterial rhinosinusitis should be reserved for patients with rhinosinusitis symptoms lasting 7 days or more who have maxillary pain or tenderness in the face or teeth (especially when unilateral) and purulent nasal secretions. Patients with rhinosinusitis symptoms that last less than 7 days are unlikely to have bacterial infection, although rarely some patients with acute bacterial rhinosinusitis present with dramatic symptoms of severe unilateral maxillary pain, swelling, and fever.3. Sinus radiography is not recommended for diagnosis in routine cases. 4. Acute rhinosinusitis resolves without antibiotic treatment in most cases. Symptomatic treatment and reassurance is the preferred initial management strategy for patients with mild symptoms. Antibiotic therapy should be reserved for patients with moderately severe symptoms who meet the criteria for the clinical diagnosis of acute bacterial rhinosinusitis and for those with severe rhinosinusitis symptoms-especially those with unilateral facial pain-regardless of duration of illness. For initial treatment, the most narrow-spectrum agent active against the likely pathogens, Streptococcus pneumoniae and Haemophilus influenzae, should be used.

The following principles of appropriate antibiotic use for adults with nonspecific upper respiratory tract infections apply to immunocompetent adults without complicating comorbid conditions, such as chronic lung or heart disease.1. The diagnosis of nonspecific upper respiratory tract infection or acute rhinopharyngitis should be used to denote an acute infection that is typically viral in origin and in which sinus, pharyngeal, and lower airway symptoms, although frequently present, are not prominent. 2. Antibiotic treatment of adults with nonspecific upper respiratory tract infection does not enhance illness resolution and is not recommended. Studies specifically testing the impact of antibiotic treatment on complications of nonspecific upper respiratory tract infections have not been performed in adults. Life-threatening complications of upper respiratory tract infection are rare.3. Purulent secretions from the nares or throat (commonly observed in patients with uncomplicated upper respiratory tract infection) predict neither bacterial infection nor benefit from antibiotic treatment.

When provided by a skilled, multidisciplinary team, palliative care is highly effective at addressing the physical, psychological, social, and spiritual needs of dying patients and their families. However, some patients who have witnessed harsh death want reassurance that they can escape if their suffering becomes intolerable. In addition, a small percentage of terminally ill patients receiving comprehensive care reach a point at which their suffering becomes severe and unacceptable despite unrestrained palliative efforts; some of these patients request that death be hastened. This paper presents terminal sedation and voluntary refusal of hydration and nutrition as potential last resorts that can be used to address the needs of such patients. These two practices allow clinicians to address a much wider range of intractable end-of-life suffering than physician-assisted suicide (even if it were legal) and can also provide alternatives for patients, families, and clinicians who are morally opposed to physician-assisted suicide. This paper will define the two practices, distinguish them from more standard palliative care interventions and from physician-assisted suicide, illustrate them with a real clinical scenario, provide potential guidelines and practicalities, and explore their moral and legal status. Although medicine cannot sanitize dying or provide perfect answers for all challenging end-of-life clinical problems, terminal sedation and voluntary refusal of hydration and nutrition substantially increase patients' choices at this inherently challenging time.

The American College of Rheumatology (ACR) established criteria to discriminate among patients with seven types of vasculitis. Although designated as "classification criteria" for research, these criteria are often used for diagnosis.

To review information on the benefits of screening with a sensitive thyroid-stimulating hormone (TSH) test for thyroid dysfunction in asymptomatic patients seeking primary care for other reasons. This paper focuses on whether screening should be aimed at detection of subclinical thyroid dysfunction and whether persons with mildly abnormal TSH levels can benefit.