Hospitals need better ADR reporting systems
Hospitals need better ADR reporting systems
The first study to evaluate adverse drug reactions (ADRs) in a large population of hospitalized Medicare patients has found that only 53% of hospitals representing 67% of the patients studied appeared to have functional systems for reporting ADRs. Lead researcher C.A. Bond, PharmD, of the Texas Tech University Health Sciences Center department of pharmacy practice, says that finding suggests that Medicare and perhaps the Joint Commission on Accreditation of Healthcare Organizations may need to consider strengthening requirements for reimbursement and accreditation to mandate such reporting systems. The study was published in the May issue of Pharmacotherapy.
"Expanding the E-code system to include specific drugs recently approved by FDA would not be difficult," Bond wrote. "Strengthening reporting systems and expanding the E-code system this way could create a robust post-marketing surveillance system for newly approved drugs. This also would help satisfy the demands of professional organizations and the public to improve the safety of the drug therapy system in the United States. In addition, expanding (or enforcing) Medicare ADR reporting with an expanded E-code system could correct problems that have been identified with FDA's MedWatch programs and adverse event reporting system. Data not only could be collected faster, but also could be compared with other drug classes or individual drugs much faster. This database also would be larger than FDA's current ADR database."
Bond tells Drug Formulary Review no one really knows how much of a problem there is in reporting ADRs because of the lack of an accurate reporting system. "We rely largely on voluntary reporting rather than a systematic effort," he says. "Address-ing this problem would require a major initiative. The Joint Commission would have to require reporting and the federal government would have to create a repository for the information."
Bond said that while improved hospital systems have resulted in fewer medication errors over the last 10 years, little attention has been directed to the safety of individual drugs and devices. But with the recall of Celebrex and Vioxx due to the increased risk of associated cardiovascular events, health care professionals and the general public have begun to focus on drug adverse effects.
ADRs are a leading cause of death
This study reviewed literature from 1964 to 1996 and found that overall incidence of ADRs in hospitalized patients was 6.7% (range, 1.2-24.1%) and of fatal ADRs 0.32% (range, 0.1-0.85%). "These aggregate figures translate to 2,216,000 hospitalized patients per year who experience a serious ADR and 106,000 a year who die from an ADR," he said. "Fatal ADRs rank fourth to sixth in leading causes of death. As sobering as these figures appear, ADRs also are one of the more frequent causes of hospitalization (3.7-6.5% of patients). Cost estimates for these ADRs are $1.56-$4 billion a year, and as many as half of them may be preventable."
The most common drug classes associated with ADRs in this study were cardiotonic glycosides, adrenal corticosteroids, antineoplastic agents, anticoagulants, and analgesics. And the most common associated diagnoses were hypertension, congestive heart failure, atrial fibrillation, volume depletion disorders, and atherosclerotic heart disease.
Relative to frequency of reported ADRs, risk of death was higher when an ADR was associated with cardiotonic glycosides, antineoplastic and immunosuppressive drugs, and anticogulants. The ADRs were most frequently associated with essential hypertension (27.6%), congestive heart failure (19.54%), volume depletion disorders (14.7%), and atherosclerotic heart disease (12.21%).
Relative to frequency of diagnosis, ADRs were more commonly reported in patients with cardiac dysrhythmias, volume depletion disorders, hypo-potassemia, hyposmolarity and/or hyponatremia, and atrial fibrillation. Relative to the mean death rate in patients who experienced an ADR, those more likely to die if they experienced an ADR were those diagnosed with atrial fibrillation, volume depletion disorders, or congestive heart failure.
Bond tells DFR he was surprised at the number of cases involving volume depletion disorders, saying he did not expect those diagnoses to contribute as many cases as they did. Three of the four top diagnoses associated with risk of ADRs were volume depletion or electrolyte disorders. Bond said these disorders may be overlooked as potential risk factors for ADRs. On the other side, Bond said he was surprised that antidiabetic agents were not higher on the list of those associated with ADR risk.
While the rate of ADRs found in this study (1.73%) was lower than the average of 6.7% found in previous studies, Bond said extrapolation of the data still resulted in 212,128 Medicare patients experiencing an ADR, and projected that nearly 600,000 of all 34.3 million U.S. hospital patients experience an ADR.
Data likely underreport frequency
"These data reflect real-world reporting systems, which most likely report only serious ADRs that can clearly be identified and linked to specific drugs," he said. "Previous studies of ADRs and adverse drug events (ADEs) specifically looked for ADRs or ADEs as part of the study protocols and thus were more likely to reveal ADRs and ADEs. The 1.73% rate of ADRs found in our study was similar to the 1.5% observed in a recent study involving 4.3 million patients with ADEs who visited doctors' offices, hospital outpatient clinics, and emergency facilities."
The study found that experiencing an ADR while hospitalized substantially increased the risk of death. Bond said the finding reflected some 20% increase in mortality associated with an ADR in hospitalized patients. Extrapolating that finding to all patients suggested that 2,976 Medicare patients a year and 8,336 total patients a year die in U.S. hospitals as a result of ADRs, or about 1.5 patients per hospital per year.
"Logically," Bond said, "it would appear that elderly Medicare patients are less likely than younger patients to survive an ADR. Considering that up to 50% of ADRs may be preventable, this finding is significant."
In addition to the increased risk of death associated with an ADR, the increase in costs is significant. Average hospital length of stay increased by 8.25% (0.55 day) or an additional 77,769 days for all study patients with an ADR. Extrapolating that finding to the entire population of Medicare patients resulted in 118,200 additional hospital days associated with ADRs.
Increased costs are significant
Bond said in his study, the total cost for patients with an ADR increased an average of $2,401 per patient (19.86% increase), or an additional $339,496,598 for all study patients. Extrapolating that finding to the entire Medicare population resulted in $516,034,829 in costs associated with ADRs.
Drug costs for patients with an ADR increased an average of $175 per patient (9.15% increase) or an additional $24,744,650 for all study patients. For the entire Medicare population, additional drug costs associated with ADRs would be $37,611,868. Laboratory costs increased an average of $44 per patient (2.82% increase) and extrapolate to $9,456,698 in additional laboratory costs for all Medicare patients associated with ADRs.
Fatal adverse drug events that resulted in legal judgments or settlements cost an additional $1.1 million per death. And adverse drug events that caused permanent disability and resulted in legal judgments or settlements cost an additional $4.3 million per patient. Also, 13% of patients who experienced an adverse drug event that led to litigation received average settlements and judgments of $3.1 million per patient.
"Given the nature of hospital reporting systems," Bond said, "these data probably reflect fairly serious ADRs that are easily identified and traced to a specific drug. As such, the data probably underreport the true incidence of ADRs in U.S. hospitals."
Bond tells Drug Formulary Review he hopes the research gives hospital pharmacists and clinicians a road map to look at high-risk patients and adjust risk profiles regarding ADR management.
[Contact Dr. Bond at (806) 356-4000, ext. 244 or e-mail: [email protected].]
The first study to evaluate adverse drug reactions (ADRs) in a large population of hospitalized Medicare patients has found that only 53% of hospitals representing 67% of the patients studied appeared to have functional systems for reporting ADRs.Subscribe Now for Access
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