Faculty Bibliography

SETTING: Five IS6110 chromosomal insertion sites were characterized in the multidrug resistant Mycobacterium tuberculosis 'W' strain. OBJECTIVE: To use insertion site probes to study the phylogenetic distribution of IS6110 in the M. tuberculosis genome. DESIGN: A total of 722 M. tuberculosis isolates, previously genotyped using the standard IS6110 Southern blot hybridization methodology, were re-hybridized with the Region A insertion site probe and representative strains were further hybridized with the Region B and C probes. Strains were grouped on the basis of having IS6110 insertions in these different regions and their relatedness was further compared by sequencing the IS6110 insertion sites. RESULTS: The insertion site probes revealed that the collection of Chinese isolates previously grouped as the Beijing strain family shared IS6110 insertions in common with the W and other genotypic group 1 strains. Unexpectedly, we found that IS6110 integrated at least 10 independent times between the dnaA and dnaN genes encoding deoxyribonucleic acid replication proteins. CONCLUSIONS: IS6110 insertion site mapping is able to identify genetic relatedness among a collection of M. tuberculosis clinical strains representing the breadth of species diversity. The mapping data indicate that IS6110 insertion sites are not always random

The value and necessity of performing right heart catheterizations for coronary artery disease have been increasingly questioned. Preliminary analyses of the procedure among Medicare and Medicaid patients in New York State revealed significant inter-hospital variations in the frequencies with which such catheterizations were performed. These data suggested that right heart catheterizations (RHC) were being performed routinely. Medicare and Medicaid claims data for bilateral catheterizations were analyzed before and after an educational intervention program involving the state's 53 catheterization laboratories. The educational intervention was multifaceted and consisted of disseminating suggested guidelines established with the assistance of the New York State Chapter of the American College of Cardiology, the Committee on Cardiovascular Disease of the Medical Society of the State of New York, and the Cardiac Advisory Council of the New York State Department of Health. Posteducational intervention assessments were made over a 4-year period. The baseline data for 1992 demonstrated that 10 (18.4%) laboratories had performed RHC routinely (70-100%) on Medicare and Medicaid patients undergoing catheterization. In contrast, 34 (64.2%) laboratories performed RHC in less than 20% of their Medicare cases, whereas 39 (73.5%) did so among Medicaid cases. Eighteen (34%) laboratories performed RHC in less than 10% of Medicare cases. These data indicated that there was significant inter-hospital variation in the frequency with which RHC was performed. Beginning in 1993, ongoing educational meetings and conferences were held with all laboratories, but especially with the 10 that were at the high end of the RHC performance level. As a result of this ongoing intervention, the rate of RHC among Medicare patients fell from 89/100,000 in 1992 to 65/100,000 beneficiaries in 1996. From another perspective, the percentage of catheterized Medicare patients undergoing RHC fell from 30.5% in 1992 to 17.4% in 1996. The decline among the 10 laboratories was even more dramatic; the percentage of catheterized Medicare patients undergoing RHC fell from 89.1% in 1992 to 31.6% in 1996. The parallel drop for Medicaid patients over the same time period was from 92.8 to 32.7%. The results of the study indicate that many previously performed RHC in patients with coronary artery disease were routine and not medically indicated. The dramatic decreases in RHC documented in this study over a 4-year period demonstrate the success of quality improvement efforts jointly undertaken by providers and a peer review organization