Coronary artery calcium scoring: an evidence-based guide for primary care physicians.

Primary care physicians often must decide whether statin therapy would be appropriate (in addition to lifestyle modification) for managing asymptomatic individuals with borderline or intermediate risk for developing atherosclerotic cardiovascular disease (ASCVD), as assessed on the basis of traditional risk factors. In appropriate subjects, a simple, noninvasive measurement of coronary artery calcium can help clarify risk. Coronary atherosclerosis is a chronic inflammatory disease, with atherosclerotic plaque formation involving intimal inflammation and repeated cycles of erosion and fibrosis, healing and calcification. Atherosclerotic plaque formation represents the prognostic link between risk factors and future clinical events. The presence of coronary artery calcification is almost exclusively an indication of coronary artery disease, except in certain metabolic conditions. Coronary artery calcification can be detected and quantified in a matter of seconds by noncontrast electrocardiogram-gated low-dose X-ray computed tomography (coronary artery calcium scoring [CACS]). Since the publication of the seminal work by Dr. Arthur Agatston in 1990, a wealth of CACS-based prognostic data has been reported. In addition, recent guidelines from various professional societies conclude that CACS may be considered as a tool for reclassifying risk for atherosclerotic cardiovascular disease in patients otherwise assessed to have intermediate risk, so as to more accurately inform decisions about possible statin therapy in addition to lifestyle modification as primary preventive therapy. In this review, we provide an overview of CACS, from acquisition to interpretation, and summarize the scientific evidence for and the appropriate use of CACS as put forth in current clinical guidelines.

A cost-effectiveness analysis of epoetin usage for patients with AIDS.

Epoetin (recombinant human erythropoietin) therapy for patients with AIDS may reduce the need for blood transfusion; however, it is expensive. We conducted a cost-effectiveness analysis of the use of epoetin for AIDS patients from a healthcare system perspective. We constructed a decision analysis model using probability, outcome and cost data from the literature and hospital sources. The incremental cost-effectiveness ratio was measured in dollars per unit of blood saved. In AIDS patients undergoing transfusion with serum epoetin concentrations less than or equal to 500 U/L treatment with epoetin cost $US1007 per unit of blood saved compared with treatment without epoetin. One-way sensitivity analysis revealed that the incremental cost-effectiveness ratio was sensitive to the efficacy and unit price of epoetin, but less sensitive to the current price cap determined by the distributor.

Physicians' risk attitudes, laboratory usage, and referral decisions: the case of an academic family practice center.

Individual differences in physicians' laboratory use and referral rates are important aspects of practice variation that have real financial and health consequences. A way to explain these differences is needed. In this empirical study, physicians' risk attitudes (measured on a multidimensional scale) are shown to be good predictors of use rates for certain specific laboratory procedures, but not good predictors of physicians' referral rates. A 15-item survey form that measured risk-taking attitudes in the financial, health, social, and ethical domains was administered to all clinical faculty at an academic family practice center (n = 14). Each physician's utilization rates for the 17 most frequently ordered laboratory procedures were calculated for all patient visits for one calendar year. Overall referral rates were calculated for the same period. Physicians' risk attitudes (12 completed the survey) accounted for over 50% of the variance for several of the laboratory procedures. For example, the rank-order correlation between the complete blood count utilization rate and a Likert-scale item measuring physicians' propensity to take physical risks was 0.91 (p less than 0.001). The details of these findings help to explain an important component of practice variation.

Population-based time preferences for future health outcomes.

CONTEXT: Time preference (how preference for an outcome changes depending on when the outcome occurs) affects clinical decisions, but little is known about determinants of time preferences in clinical settings. OBJECTIVES: To determine whether information about mean population time preferences for specific health states can be easily assessed, whether mean time preferences are constant across different diseases, and whether under certain circumstances substantial fractions of the patient population make choices that are consistent with a negative time preference. DESIGN: Self-administered survey. SETTING: Family physician waiting rooms in four states. PATIENTS: A convenience sample of 169 adults. INTERVENTION: Subjects were presented five clinical vignettes. For each vignette the subject chose between interventions maximizing a present and a future health outcome. The options for individual vignettes varied among the patients so that a distribution of responses was obtained across the population of patients. MAIN OUTCOME MEASURE: Logistic regression was used to estimate the mean preference for each vignette, which was translated into an implicit discount rate for this group of patients. RESULTS: There were marked differences in time preferences for future health outcomes based on the five vignettes, ranging from a negative to a high positive (116%) discount rate. CONCLUSIONS: The study provides empirical evidence that time preferences for future health outcomes may vary substantially among disease conditions. This is likely because the vignettes evoked different rationales for time preferences. Time preference is a critical element in patient decision making and cost-effectiveness research, and more work is necessary to improve our understanding of patient preferences for future health outcomes.

Family practice in the tropics.

A one-week practice experience in a remote tropical rain forest area of Colombia is described. Frequency of diagnoses by ICD-9 category are compared between this practice setting and the author's university family medicine residency-based practice in Oklahoma. Implications of the similarities between the practices, as well as the differences, are discussed.

Faculty development for foreign teachers of family medicine.

BACKGROUND: The development of family medicine in Latin America is inhibited by limited resources. Successful strategies to promote the specialty include academic exchanges between countries. Short-term faculty development opportunities are needed for foreign academic family physicians. METHODS: After 2 years of unstructured visits by Latin American physicians planning to teach family medicine, we designed a faculty development course, in Spanish, that continues to evolve through constructive feedback. This includes workshops in project planning, computer training, clinical decision making, family systems, clinical teaching, problem-based learning, and clinical epidemiology. Each fellow designs a project to be implemented subsequently in the country of origin. RESULTS: Since 1991, we have trained 37 physicians from nine Latin American countries, 27 since 1993 in the structured course. A full schedule encourages fellow to complete course objectives within 8 weeks. All participating physicians have rated highly the course content and quality. Twenty-five of the 27 course participants are or will soon begin teaching in family practice residency programs in their home countries. CONCLUSIONS: This faculty development course for Latin American physicians is perceived as an effective way to enhance academic skills. Ongoing evaluation will show how the fellowship impacts the physicians' teaching effectiveness and the development of family medicine in their countries.

Impact of spirometry on the management of chronic obstructive airway disease.

A simple spirometer was tested in an outpatient family practice to determine whether its use increased detection of chronic obstructive airway disease (COAD) in patients at risk, more accurately identified patients with reversible bronchospasm, and helped to make the most of their bronchodilator therapy. Three (17 percent) of 18 patients at risk, previously unlabeled, were found to have COAD. Of 28 patients with a previous COAD diagnosis, 5 (18 percent) had the diagnosis deleted, and 5 who had previously been classified as "reversible" were reclassified as having "irreversible" bronchospasm (P less than .025). Of 46 patients studied, bronchodilator therapy was changed in 18 (39 percent); 12 of these improved symptomatically according to a subjective score (P less than .02). A few patients demonstrated a significant improvement in 1-second forced expiratory volume.

A statewide university hospital-based family medicine referral service.

A statewide university hospital-based family medicine referral service was established at the University of Oklahoma in July 1983. During the first six months of operation, 14 percent of all patients admitted to the family medicine inpatient service were referred by outside physicians. Referral patients had more diagnoses coded per admission (2.25) than continuity patients (1.56) (P less than .05). In referral patients, 23.3 percent of diagnoses fell into the 52 most common diagnostic cluster described by Rosenblatt et al compared with 50.9 percent in continuity patients (P less than .0005). Specialty consultations, invasive diagnostic procedures, surgical procedures, and average length of hospital stay were compared in the subgroup of patients with medical, pediatric, surgical, and gynecological principal diagnoses. Referred patients averaged 0.974 consultations per admission compared with 0.578 in continuity patients (P less than .01). An average of 1.237 invasive diagnostic procedures per admission were performed in referral patients compared with 0.626 in continuity patients (P less than .0005). Referral patients averaged 0.145 surgical procedures per admission compared with 0.123 in continuity patients (not significant). The average length of stay for both continuity and referral patients was 9.68 days per admission. A survey of the referring physicians indicated that both the physicians and the patients whom they referred were generally satisfied with the care provided by the service.

Care of adults with type 2 diabetes mellitus. A review of the evidence.

BACKGROUND: The purpose of this study was to provide primary care physicians with a concise review of the evidence that guides selected aspects of type 2 diabetes care, including glycemic control, macrovascular risk reduction, and screening for microvascular complications of diabetes. METHODS: We identified randomized clinical trials that addressed selected aspects of the care of adults with type 2 diabetes using systematic literature review, review of existing clinical guidelines, and other sources. The results of these trials were interpreted as absolute risk reduction, and the number of patients that need to be treated to obtain a specific clinical outcome was calculated. RESULTS: Good glycemic control with metformin may reduce overall mortality in obese patients with type 2 diabetes (number need to treat [NNT] = 14 for 10 years), and improved blood pressure control reduced diabetes-related mortality (NNT = 15 for 10 years); improved glycemic control with agents other than metformin, or with combinations including metformin, does not reduce diabetes-related or overall mortality. Major cardiovascular events (CVE) in type 2 diabetes can be prevented by control of blood pressure with low-dose diuretics, atenolol, or angiotensin-converting enzyme inhibitors (NNT = 10 to 20 for 5 to 10 years for primary prevention of one CVE); by use of aspirin (NNT = 45 for 5 years for primary prevention of one CVE); and by use of simvastatin to lower low-density lipoprotein (LDL) cholesterol (NNT = 6 for 5 years for secondary prevention of one CVE). Glycemic control (NNT = 19 for 10 years) and hypertension control (NNT = 6 for 10 years) slow the progression of complications in patients with type 2 diabetes. Retinopathy and nephropathy are more preventable than neuropathy. The benefits of glycemic control are less for patients with shorter life expectancy and are greater for those with the highest levels of Hb A1c because larger Hb A1c improvements can be achieved in such patients. Periodic screening of patients for eye, kidney, and foot complications is supported because effective early treatment of these complications is available. CONCLUSIONS: In patients with type 2 diabetes, control of hypertension reduces microvascular and macrovascular complications more than glycemic control does. Control of LDL cholesterol with statins, aspirin, and smoking cessation reduce major cardiovascular events. Metformin reduces overall mortality in obese patients with creatinine levels < 1.5 mg/dL. Glycemic control reduces microvascular complications. The evidence supports angiotensin-converting enzyme inhibitors, atenolol, or low-dose diuretics for blood pressure control. Effective treatment of eye, kidney, and foot complications is available, and regular screening for these complications is justified.

Prostate cancer screening: a decision analysis.

BACKGROUND: The issue of whether to screen men for prostate cancer is controversial. No randomized clinical trials have been completed to confirm the efficacy of screening for prostate cancer. We created a mathematical model of the clinical risks and benefits of screening for prostate cancer. METHODS: A Markov decision-analytic model evaluated the outcomes of annually screening asymptomatic men for prostate cancer beginning at age 50 years. The screening and testing algorithm included the digital rectal examination, transrectal ultrasound, and prostate-specific antigen test. A sample of 10 male patients with no history of prostate disease were interviewed to assess their utilities (preferences) regarding the various adverse outcomes of prostate cancer treatment. RESULTS: The model indicated that no screening was preferred to screening when patients' utilities were considered (24.14 vs 23.47 quality-adjusted life years expected). The optimal decision was sensitive to the utilities of impotence and urethral stricture, the most common adverse outcomes for patients under the age of 65 years. When adverse outcomes of treatment were ignored, screening was favored (24.86 vs 24.22 years of life expectancy. CONCLUSIONS: When quality-of-life preferences of men are considered, the annual screening of asymptomatic patients for prostate cancer is not recommended.

Cost-effectiveness analysis of screening health care workers for HIV.

BACKGROUND: Because of the public's concern regarding the possibility of human immunodeficiency virus (HIV) transmission from health care worker to patient, this study evaluated the cost-effectiveness of screening health care workers for HIV. METHODS: The study examined a screening protocol that would include a sequence of antibody tests (enzyme-linked immunosorbent assay and the Western blot) and culture for HIV. The incremental cost-effectiveness of applying this protocol as opposed to the status quo for the prevention of transmission of HIV from health care worker to patient was evaluated. Sensitivity analysis was performed on appropriate variables. The incremental cost-effectiveness ratio was then compared with that of other interventions. RESULTS: The expected annual cost of screening to a large hospital was found to be $244,382 to prevent 0.02663 transmissions. The incremental cost-effectiveness ratio was $9,177,615 per transmission prevented. Sensitivity analysis revealed that the incremental cost-effectiveness ratio is relatively insensitive to the variability in the performance characteristics of the individual tests but highly sensitive to variance in HIV prevalence, estimated risk of transmission, and the number of exposure-prone procedures performed annually. Cost-effectiveness ratios ranged from $917,762 to $91,776,156 per transmission prevented. CONCLUSIONS: Screening health care workers for prevention of potential HIV transmission to patients is an expensive use of health care resources.

Screening for prostate cancer with the prostate-specific antigen test: are patients making informed decisions?

BACKGROUND: The benefits of early detection of prostate cancer are uncertain, and the American College of Physicians and the American Academy of Family Physicians recommend individual decision making in prostate cancer screening. This study reports the knowledge of male primary care patients about prostate cancer and prostate-specific antigen (PSA) testing and examines how that knowledge is related to PSA testing, preferences for testing in the future, and desire for involvement in physician-patient decision making. METHODS: The sample included 160 men aged 45 to 70 years with no history of prostate cancer who presented for care at a university-based family medicine clinic. Before scheduled office visits, patients completed a questionnaire developed for this study that included a 10-question measure of prostate cancer knowledge, the Deber-Kraestchmer Problem-Solving Decision-Making Scale, sociodemographic indicators, and questions on PSA testing. RESULTS: In general, patients who were college graduates were more knowledgeable about prostate cancer and early detection than those with a high school education or less. Aside from college graduates, most patients could not identify the principle advantages and disadvantages of PSA testing. Patients indicating previous or future plans for PSA testing demonstrated greater knowledge than other patients. Desire for involvement in decision making varied by patient education but was not related to past PSA testing. CONCLUSIONS: Patients lack knowledge about prostate cancer and early detection. This knowledge deficit may impede the early detection of prostate cancer and is a barrier to making an informed decision about undergoing PSA testing.

The evaluation and treatment of men with asymptomatic prostate nodules in primary care: a decision analysis.

BACKGROUND: Whether to perform periodic rectal examinations in asymptomatic men as a screening test for prostatic cancer remains controversial. A randomized clinical trial that tests the efficacy of further evaluation and treatment of men who have been found to have asymptomatic prostate nodules may never be carried out. Decision analysis was therefore used to further investigate this clinical issue. METHODS: A decision tree was developed to model the decision of whether to biopsy an asymptomatic prostate nodule found by digital rectal examination in a 65-year-old man by his primary care physician. Test operating characteristics, probabilities of disease at different stages, probabilities of side effects from various treatments, and average life expectancies were obtained from the medical literature. Utilities for the various possible health outcome states were obtained from ratings by two experienced primary care physicians using the Kaplan-Anderson Quality of Well-Being Scale. These were used to adjust the quality-of-life expectancies for each outcome state. Multiple sensitivity analyses were performed to assess the robustness of the conclusions. RESULTS: Disregarding patient utilities, the average survival benefit of evaluation and treatment is 1.1 months. When quality-of-life adjustments are included in the analysis, evaluation and treatment results in an average loss of 3.5 quality-adjusted months of life. Factors that shift the decision toward evaluation and treatment include a positive predictive value of a prostate nodule for cancer of 49% or greater, specificity of prostate biopsy of 98.3% or greater, and the availability of much more effective treatment for stage D cancers. Factors that do not substantially affect the decision are cancer-free life expectancy, the percentage of cancers that are stage B at time of discovery, the sensitivity of prostate biopsy, and more effective treatment for stage C cancer, assuming the same rate of adverse consequences from treatment. CONCLUSIONS: The evaluation and treatment of prostatic nodules found by digital rectal examination in asymptomatic men in the primary care setting does not lead to significant improvement in life expectancy and adversely affects quality of life. Digital rectal examination should not be performed by primary care physicians as a screening test for prostate cancer.

Controlling blood glucose levels in patients with type 2 diabetes mellitus. An evidence-based policy statement by the American Academy of Family Physicians and American Diabetes Association.

OBJECTIVE: To review evidence about the benefit of intensive glycemic control for patients with type 2 diabetes and to develop practice recommendations. PARTICIPANTS: A 9-member panel composed of family physicians, general internists, endocrinologists, and a practice guidelines methodologist was assembled by the American Academy of Family Physicians, the American Diabetes Association, and the American College of Physicians. EVIDENCE: Admissible evidence included published randomized controlled trials and observational studies regarding the effects of glycemic control on microvascular and macrovascular complications and on adverse effects. We followed systematic search and data abstraction procedures. Greater weight was given to clinical trials and to evidence about health outcomes. CONSENSUS PROCESS: Interpretations of evidence and approval of documents were finalized by unanimous vote, with recommendations linked to evidence and not expert opinion. The full report was prepared by the chair and 2 panel members, representing each of the 3 organizations. The initial draft underwent external review by 14 diabetologists and family physicians and changes consistent with the evidence were incorporated. CONCLUSIONS: The evidence demonstrates that the risk of microvascular and neuropathic complications is reduced by lowering glucose concentrations. Whether glycemic control affects macrovascular outcomes is less clear. The potential benefits of glycemic control must be balanced against factors that either preempt benefits (eg, limited life expectancy, comorbid disease) or increase risk (eg, severe hypoglycemia). The magnitude of benefit is a function of individual clinical variables (eg, baseline glycated hemoglobin level, presence of preexisting microvascular disease). Appropriate targets for treatment should be determined by considering these factors, patients' risk profiles, and personal preferences.

The medical school without walls: who will be the faculty?

To involve community physicians as medical school faculty, a survey was completed to establish the needs of 64 community physicians participating in a third-year family medicine clerkship. We received 48 responses that indicated issues of practice regulation, training office staff, and local continuing medical education were highest priority needs. The 27 respondents in rural areas placed more emphasis on issues of referral/consultation, recruiting of physician associates, and faculty development. As a result of the survey, The University of Texas Medical Branch at Galveston has implemented a comprehensive strategy to address the stated needs, with special emphasis on a rural health initiative. This strategy includes a special program for faculty to provide rural practice coverage technical assistance for practice management, a rural communications network, faculty development, and provider recruitment. The goal of this strategy is to continue developing the "medical school without walls."