A Geospatial Analysis of Factors Affecting Access to CT Facilities: Implications for Lung Cancer Screening

ObjectiveThe association between access to CT facilities for lung cancer screening and population characteristics is understudied. We aimed to determine the relationship between census tract–level socioeconomic characteristics (SEC) and driving distance to an ACR-accredited CT facility.MethodsCensus tract–level SEC were determined from the US Census Bureau. Distance to nearest ACR-accredited CT facility was derived at the census tract level. Census tract–level multivariable regression modeling was used to determine the relationship between driving distance to a CT facility and census tract SEC, including population density (a marker of rural versus urban), gender, race, insurance status or type, and education level.ResultsIn an adjusted multivariable model, census tract–level population density was the greatest relative determinant of distance to a CT facility. Namely, rural census tracts had relatively longer distances to CT facilities than urban census tracts (P < .001). Census tracts with higher uninsured, Medicaid, undereducated (less <high school degree) populations had relatively greater distances to CT facilities (p<0.001), whereas those with higher non-White, female, and Medicare populations had shorter distances (p<0.001).DiscussionRural populations have relatively less geographic access to CT facilities. Furthermore, other vulnerable populations, such as the uninsured, those on Medicaid, and the undereducated, may also have relatively less access to CT imaging facilities. These variations in access to CT may affect the uptake and utilization of lung cancer screening.     

Pharmacotherapy Approaches in Nontuberculous Mycobacteria Infections

Nontuberculous mycobacteria (NTM) comprise a heterogeneous group of organisms, with only a small subset known to cause disease in humans. Although NTM infection is not a reportable disease, both the increasing clinical recognition and recent advancements in laboratory diagnostic capabilities of NTM infections in immunocompromised and immunocompetent patients are rapidly evolving. We reviewed antimicrobial agents used to treat the most frequently encountered NTM infections and examined optimized drug dosing strategies, toxicity profiles, drug-drug interactions, and the role of therapeutic drug monitoring. Antimicrobial susceptibility testing and patient monitoring on therapy were also examined. We used PubMed to review the published literature on the management of select NTM pathogens, the common syndromes encountered since 2000, and select pharmacokinetic principles of select antimicrobial agents used since 1990. We included select clinical trials, systematic reviews, published guidelines, and observational studies when applicable. The prolonged duration and the necessity for combination therapy for most forms of NTM disease can be problematic for many patients. A multidisciplinary care team that includes pharmacy engagement may help increase rates of optimal patient tolerability and successful treatment completion.     

Two-dimensional echocardiographic appearance of left ventricular thrombi with systemic emboli after myocardial infarction

To test the hypothesis that left ventricular (LV) thrombi that project into the lumen and are mobile are more likely to embolize than those that do not have these characteristics, the 2-dimensional echocardiograms of 16 patients with LV thrombi after myocardial infarction were retrospectively reviewed. Ten had evidence of peripheral embolization and 6 did not. The studies were reviewed in random order by an observer blinded to the clinical data. Each echocardiogram was graded as showing a protruding or nonprotruding thrombus and the presence or absence of increased mobility. The thrombus projected into the lumen on the echocardiograms of 8 of 10 patients who had had emboli and in 0 of 6 who had not. The thrombus had increased mobility in 4 of 10 patients with emboli and 0 of 6 without. Thus, LV thrombi that project into the lumen and have increased mobility are more likely to embolize than those without these characteristics.     

Observations of the aetiology of primary intestinal lymphoma

The aetiology of primary intestinal lymphoma (PIL) is not known. In this paper virus capsid antibodies (VCA) in sera from 43 lymphoma patients (40 PIL, three Burkitt type lymphoma) were compared to thirty-nine control sera taken from patients who were age and sex matched to the lymphoma patients.The results indicate that VCA antibody levels are not significantly raised in patients with PIL; this contrasts with the marked rise in antibodies found in Burkitt's lymphoma.     

Isolated cleft mitral valve: a variety of congenital mitral regurgitation identified by 2-dimensional echocardiography

Nine children with isolated cleft mitral valve, aged 1 day to 12 years, were studied. The electrocardiogram showed a normal QRS axis in 5 subjects. Cardiac catheterization was performed in 4 patients and demonstrated severe mitral insufficiency in 3 but failed to clearly demonstrate a cleft mitral valve or gooseneck deformity. The mitral cleft was confirmed at operation in 2 patients. Two-dimensional echocardiography demonstrated a cleft dividing the anterior mitral leaflet into 2 portions in each patient. The mitral anulus was normally positioned and the atrioventricular septum present. Atrial and ventricular septa were intact. Features similar to anatomic studies such as accessory chordae and thickening of the edges of the cleft with increasing age were also seen. Two-dimensional echocardiography is the only method available to reliably diagnose isolated cleft of the mitral valve.     

Effect of a twelve-hour hiatus in propranolol therapy on exercise tolerance in patients with angina pectoris

To determine whether propranolol can be administered twice daily without any loss of antianginal effect, we studied nine men receiving long-term propranolol therapy for stable angina pectoris. Each patient performed bicycle exercise to the point of angina on two consecutive mornings. By means of double-blind placebo-propranolol administration before the test, the study created a situation whereby on one day the exercise took place 12 hours after the last dose of propranolol, and on the other day, $\text{1}\text{1}\text{2}\text{hours}$ after a dose. Despite markedly lower blood levels of propranolol on the day that exercise was performed 12 hours after the last dose, exercise time to angina was nearly identical on the 2 days. We conclude that long-term therapy with propranolol for angina pectoris can be administered on a twice daily basis with no loss of effectiveness.