您现在的位置是:首页 > 英语听力 > VOA英语听力下载|VOA news > voa标准英语|美国之音常速英语下载|在线收听
正文
VOA常速英语:Study Questions Results of Clinical Trials That End Early
2010-03-29来源:和谐英语
Update Required
To play the media you will need to either update your browser to a recent version or update your Flash plugin.
When researchers end a clinical trial early because the results are better than expected, it allows a drug to get on the market and patients to receive it sooner than if the trial were carried out as planned.
It sounds like a good thing, but it may not be.
A new international analysis of 100 clinical trials that ended early found that the results were often wrong and sometimes life-threatening.
Dr. Victor Montori of the Mayo Clinic is one of the authors of the report. "What is happening is they are catching the data at a random high. The data is accumulating and it looks like a big effect, but if you let it go a little bit, that effect may become smaller over time," he explained.
Or, the benefit of the treatment may not even exist.
"Not only were the studies misleading, in terms of how big the treatment effect was really, but also whether a treatment effect existed at all," Dr. Montori said.
The clinical trials that Dr. Montori and his colleagues reviewed ended early because the results of an experimental treatment were much better than those of an existing therapy.
An example is a study on beta-blockers, drugs often prescribed for high blood pressure. Beta blockers slow the heart rate and can prevent heart attack during surgery. An initial trial was stopped early because these drugs looked to be highly effective if given prior to surgery. The drugs seemed to improve survival rates. But a larger trial showed that some patients given the drugs had significantly higher death rates.
Dr. Montori and other researchers compared the 100 trials that were called off early with more than 400 comparable trials that went through to completion. They found that the results were especially misleading in the smaller trials that ended early.
"What the investigators are caught on is when they look at the data at a given time before the study was supposed to finish, and they find a large treatment effect, then they get mislead by that treatment effect, and then in fact, if they decide to stop at that point, they end up misleading everyone else when they publish the results," he said.
Dr. Montori says the false findings discourage other researchers from repeating the study to see if they get the same positive results.
The authors of the study say researchers need to resist pressures to end clinical trials early. They say this will prevent patients and physicians from making treatment choices based on inaccurate information, or even worse, choosing one treatment when another would be far better.
相关文章
- VOA常速英语:日增20万确诊病例,印度疫情失控
- VOA常速英语:美国驱逐10名俄罗斯外交官
- VOA常速英语:US Marks One Year of Pandemic Shutdown with Hope, Concern
- VOA常速英语:US Senate Nears Vote on $1.9 Trillion Biden COVID Aid Package
- VOA常速英语:What Is Clubhouse and Why Did It Get So Popular?
- VOA常速英语:Thermal Water Helps Recovering COVID Patients
- VOA常速英语:Deadly Drug Overdoses Epidemic Rages On
- VOA常速英语:International Women’s Day Marks Year of Increased Hardships for Women Worldwide
- VOA常速英语:US States Relax Restrictions, Health Officials Warn Against It
- VOA常速英语:Virginia Starts Reopening Schools for In-Person Learning