Q & A |
June 2003 Richard A. Savage, MD Q. Can DNA analysis be done on cremated remains? A.
The question of DNA identification of cremains or partially incinerated
remains comes up surprisingly often for those who perform DNA typing
on skeletal remains. DNA within bone is very stable and can withstand temperatures of several hundred degrees or more for short time periods. DNA cannot be recovered, however, when a bone becomes calcined. Calcined bone, often described as porcelain-like, has been reduced to its white or blue mineral constituents, indicating all organic material has been destroyed. Scorched and blackened bones may or may not yield DNA and generally should be tested. Many DNA analysts have been surprised to find a typable result when it appeared that the bone was not worth testing. DNA is destroyed by progressive fragmentation. This may result in some DNA identification markers being successful when others are not, so one may be left with a partial set of DNA identity markers. In such cases, the discriminatory power may be reduced, yet a likelihood of identity established. Most DNA identity
testing involves short tandem repeat analysis that is performed
on the nuclear (chromosomal) DNA, but in these cases mitochondrial
DNA testing may be required. Mitochondrial DNA tests are more likely
to be successful because a cell may have only one copy of nuclear
DNA but hundreds or thousands of copies of mitochondrial DNA in
the cytoplasm of the cell. Mitochondrial DNA testing, however, is
less discriminating, more expensive than short tandem repeat nuclear
DNA analysis, and performed by only a few laboratories. Q. Many articles state that the half-life of low-molecular-weight heparin is longer than that of unfractionated heparin, but they do not give a specific figure for the half-life. What is the half-life of LMWH? LMWH is monitored by the anti-Xa inhibition test. What is the principle behind the chromogenic anti-Xa test? A. The answer to your first question is clear-cut. The half-life
of low-molecular-weight heparin is three to four hours.1,2
In the United
States, the APTT remains the most commonly used test for monitoring
unfractionated heparin. On the 2002-CG-2B proficiency testing challenge,
fewer than 200 laboratories reported results for a heparin assay.
The heparin assay is most frequently used only in uncommon settings
when the APTT will not suffice. LMWH does not usually need to be
monitored, but when monitoring is necessary, only the factor Xa
inhibition method can currently be used.
John D. Olson, MD, PhD A. First, let’s note that even under the fee-for-service payment system that predated inception of the Medicare prospective payment system, or PPS, in 1983, Medicare and other third-party payers typically paid only about 80 percent of costs, with the remainder covered by the patient. CMS uses the same methodology to reimburse hospitals for blood products and services under the PPS as it does to reimburse hospitals for other products and services. Medicare does not reimburse hospitals for the cost of acquiring blood products per se. Instead, Medicare pays flat amounts for specific types of hospital discharges, defined by diagnosis related groups. Each DRG payment is intended to represent the bundle of costs involved in caring for a patient whose stay is categorized under that DRG. The payment level for each of the more than 500 DRGs is a function of a base payment rate for each hospital and the relative weight of each DRG, both of which are updated annually. (Hospital costs are just one component used to update a national standardized payment amount, which is subject to area- and hospital-specific adjustments to yield a hospital’s base payment rate.) The DRG weights are recalibrated each year to reflect relative changes in the resources required to provide care among the respective DRGs. This recalibration does not increase overall Medicare payments; it simply provides a way to reallocate Medicare payments in the inpatient PPS. Here’s the kicker for blood payments: These DRG weights are based on the charges, not costs, that hospitals report to Medicare each year. The Medicare inpatient PPS is based on the assumption that reported charges are good proxies for the relative resource use among DRGs. CMS only knows what hospitals report to the agency. If charges are not reported or if the charge amounts for a product or service are low, then the charges on which DRG payments are based will be underrepresented. (The DRG updates generally lag behind the charge data by two years.) CMS recently reported that only 48 percent of hospitals billed for one or both of the blood-related cost centers in their Medicare reports to CMS. Our analysis found great disparities in how often hospitals bill for blood products and services and in the charges they use when blood is billed. On average, the hospital markup of charges over costs for blood products and services is less than half the markup for other hospital products and services. Together, these factors significantly underrepresent the costs to hospitals of blood products and services in Medicare’s determinations of DRG weights and the reimbursement for blood-intensive DRGs, accordingly. CMS has acknowledged the importance of paying appropriately for blood products and services. The Department of Health and Human Services Advisory Committee on Blood Safety also has endorsed appropriate payment rates, specifically in reference to the outpatient payment system. Medicare is keenly aware that many of its billing rules are complex and that this may have contributed to inadequate hospital coding and billing. Medicare appears
to be interested in simplifying these rules and informing hospitals
how to implement them. The health care sector welcomes such efforts
by CMS. At the same time, however, it is unlikely that Medicare
will establish a special mechanism to pay for blood products and
services under the PPS. The accounting for blood-related costs in
the Medicare PPS will not improve until CMS obtains more complete
and accurate charge data from hospitals. CMS should, therefore,
work with hospitals, blood collection and banking organizations,
and other stakeholders to provide clear, comprehensive guidance
for coding and billing of blood products and services. |
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