Academic Staff - Hourly - CSL, Medicine - Primary Care and Population Health
According to probability theory, the interpretation of new information should depend on the prior probability of disease. We asked if this principle applies to interpreting the history in patients with chest pain. We compared the prevalence of coronary artery disease (CAD) in patients who had similar histories but who came from populations with different disease prevalence.We studied two high-disease-prevalence populations (patients referred for coronary arteriography) and two low-disease-prevalence populations (patients from primary care practices). We used clinical characteristics of one arteriography population to develop a logistic rule for estimating the probability of coronary artery narrowing. The number of clinical findings determined the logistic score, which was proportional to the prevalence of CAD.The prevalence of CAD was much lower in the primary care population than in the arteriography population, even when patients with similar logistic scores, and thus similar clinical histories, were compared.A clinician must take account of the overall prevalence of disease in the clinical setting when using the patient's history to estimate the probability of disease. Failure to observe this caution may lead to errors in test selection and interpretation.
View details for Web of Science ID A1990DN17900002
View details for PubMedID 2242131
An algorithm for screening psychiatric patients for physical disease was empirically derived from a comprehensive assessment of 509 patients in California's mental health system. The first 343 patients were used to develop the algorithm, and the remaining 166 were used as a test group. Calculations were made for several versions of the algorithm, and the data were compared with the diagnoses listed in the patients' admission mental health record. The algorithmic procedure was more accurate and more cost-effective than the medical evaluation procedures used by the state mental health system. When applied to the test group, the algorithm detected up to 90 percent of patients who had an active, important physical disease at a cost of $156 per patient. The mental health system had detected 58 percent of test-group patients with a disease at a cost of $230 per patient.
View details for Web of Science ID A1989CC17600008
View details for PubMedID 2512242
Thorough medical evaluation of 529 patients drawn from eight program categories in California's public mental health system revealed active, important physical disease in 200 patients who had 291 diseases. Fourteen percent of the patients had diseases known to themselves but not to the mental health system, and 12% of the patients had diseases newly detected by the study team. We estimate that of the more than 300,000 patients treated in the California public mental health system in fiscal year 1983 to 1984, 45% had an active, important physical disease. The mental health system had recognized only 47% of study patients' physical diseases, including 32 of 38 diseases causing a mental disorder and 23 of 51 diseases exacerbating a mental disorder. Patients treated in public sector mental health facilities should receive careful medical evaluations.
View details for PubMedID 2787623
View details for Web of Science ID A1989AJ47500007
In order to study how physicians choose to use electronic fetal monitoring and interpret tracings, we administered a questionnaire to which 107 practicing obstetricians and 11 experts in electronic fetal monitoring responded. Sixty-one (57%) of the respondents monitored more than half of their deliveries (high users). In comparison to the less frequent users of electronic fetal monitoring (low users), they showed more positive attitudes toward electronic fetal monitoring and were nearly always more likely to perform cesarean sections on hypothetical patients described in the questionnaire. These differences appeared to be due to the high users' higher estimate of danger to the fetus. We also found that most physicians were generally more likely to perform a cesarean section on a high-risk mother than a low-risk mother with the same tracing. The majority of high and low users and nearly all of the experts, however, felt that antepartum risk factors are not of value in deciding what to do about an abnormal tracing. We conclude that there is wide variation in the way in which obstetricians use, interpret, and act on electronic fetal monitoring tracings. Some of these differences may be due to differing attitudes toward electronic fetal monitoring, differences in interpretation of electronic fetal monitoring tracings, and differences in the way obstetricians incorporate maternal risk factors into their decision-making.
View details for Web of Science ID A1985AEB7300008
View details for PubMedID 3976782
Education is an effective tool for modifying physician use of the laboratory. We compared two interventions by assigning 56 medical house officers into four groups: control group; feedback group, which received feedback concerning its use of tests; manual group, which received a manual concerning cost-effective laboratory use; and manual plus feedback group, which received both interventions. All intervention groups experienced significant decreases in test use. When we controlled for diagnosis, the manual plus feedback group had the most profound decrease (42%) in laboratory use, followed by the manual group. The feedback and control groups had no change. Attitudes and knowledge did not change. We conclude that one can, via simple techniques, modify house staff use of the outpatient laboratory. The less-expensive intervention was a cost-oriented manual, which may have a "sensitizing" rather than educational effect.
View details for Web of Science ID A1985AGN4100004
View details for PubMedID 3888133
Tutored videotape-instruction (TVI) is a method for providing high quality instruction in topics for which the supply of expert teachers is limited. A small group of students and a tutor can watch a videotaped lecture that can be interrupted for discussion or questions. The tutor facilitates discussion and directs the students to outside reading. The authors in this report describe the use of tutored videotape-instruction in teaching clinical decision-making. Students were randomly assigned to a tutored videotape-instruction group or to a group that heard identical live lectures. The two groups had the same mean score on a final examination on the course material. The group that heard the live lectures rated the quality of instruction higher than the videotape group; however, the ratings were high for both groups. Tutored videotape-instruction provides expertise in a specialized topic and the advantages of instruction in small groups.
View details for Web of Science ID A1984SG95300005
View details for PubMedID 6699892
We prospectively evaluated 91 patients with involuntary weight loss. Thirty-two (35%) had no identifiable physical cause of weight loss, whereas the remainder had various physical illnesses. During the year after the index visit, 23 (25%) of the patients died and another 14 (15%) deteriorated clinically. Physical causes of weight loss were clinically evident on the initial evaluation in 55 of 59 patients. The four patients in whom the diagnosis was initially missed had cancer, and in only one of these patients was the illness truly occult. Because diagnoses were usually made rapidly in patients with a physical cause of weight loss, we conclude that involuntary weight loss is rarely due to "occult" disease. We developed a decision rule that used six attributes to correctly identify 57 of 59 patients (97%) with a physical cause of weight loss and 23 of 32 patients without. Thus, our rule may help in the early triage of patients with involuntary weight loss.
View details for Web of Science ID A1981MP09500006
View details for PubMedID 7294545
View details for Web of Science ID A1980JF97400008
The usefulness of a clinical examination was compared with several other procedures (ultrasonography, pancreatic function tests, endoscopic retrograde cholangiopancreatography and angiography) for diagnosing pancreatic cancer. We used a simplified form of decision analysis to show the effects of different strategies on direct diagnostic costs, missed diagnoses and false-positive diagnoses. Our analysis indicates that existing laboratory tests are either too non-specific or too invasive to be used successfully as screening tests for pancreatic cancer. To decrease the number of unnecessary laparotomies due to false-positive test findings, patients should have a high probability of pancreatic cancer, based on clinical criteria, before further testing is carried out. In fact, existing clinical criteria are both sensitive and specific for pancreatic cancer.
View details for Web of Science ID A1980KC23000004
View details for PubMedID 7222644
Problems with patient screening, disease labeling, diagnosis confirmation, patient compliance and physician adherence continue to undermine efforts to control hypertension and prevent its complications.Simple screening involves patient selection bias, limited new diagnosis, arterial pressure lability, ambiguous disease definition, complex measurement imprecision and deficient patient follow-through. Case finding may improve some of these deficiencies. Recent data suggest that labeling a person as hypertensive may produce impaired self-concept, marital dissatisfaction and absence from work. Newer series confirm the low prevalence of curable, secondary hypertension among unselected patients and strongly argue for restricting extensive hypertensive evaluations to selected subpopulations. Patient noncompliance is highly prevalent, poorly predicted and imprecisely measured. Based on successful trials, specific suggestions can be made to achieve maximum patient compliance and physician adherence to diagnostic and therapeutic guidelines.
View details for Web of Science ID A1979JE66100001
View details for PubMedID 18748465
The medical services of two teaching hospitals were assessed for the frequency of and complications from invasive procedures. There were 231 procedures performed on 303 patients. The frequency of procedures was significantly higher at one hospital (62% vs 39%, P less than .01). Twenty-nine complications occurred in 20 cases: 14% of patients who underwent procedures had at least one complication. Left-sided cardiac catheterization was the most common procedure. Procedures with more than one complication included the following: left-sided cardiac catherization (18% probability of complication); arteriovenous shunt (60% probability); thoracentesis (19%); bronchoscopy (25%); and percutaneous liver biopsy (8%). While no permanent damage or deaths were observed, over three fourths of the complications either required specific therapy or prolonged hospitalization or both. This study suggests invasive procedures are common and carry appreciable risks of serious complications. Appropriate clinical decision making and medical-legal protection require accurate estimates of those risks.
View details for Web of Science ID A1978GA32700013
View details for PubMedID 718346
Rarely is endocarditis attributed to the species of Hemophilus. Most frequently implicated are H aphrophilus and H parainfluenzae, but H influenzae also is seen. We report six cases of endocarditis due to H aphrophilus or H parainfluenzae and review the literature. Emboli to skin, lungs, kidneys, spleen, brain, and other organs are common complications, and acute glomerulonephritis and meningitis often occur. Ampicillin is the mainstay of antimicrobial therapy for patients whose isolates are sensitive to it, but the duration of antimicrobial therapy necessary for eradication of the infection is not clear. Studies of antimicrobial synergism are warranted in instances of endocarditis caused by ampicilin- or penicillin-resistant strains of Hemophilus, or when patients are allergic to penicillin; in these instances, combination antimicrobial therapy must be given when bactericidal synergism can be demonstrated. Intensive management of complications caused by embolization is crucial to patient survival.
View details for Web of Science ID A1977DU93100025
View details for PubMedID 302487