Institute:Office of National Coordinator (ONC) Workforce Training Curriculum
Component:The Culture of Health Care
Lecture:Phrasing the clinical question
Harm and prognosis
Slide content:Evidence and Its Limits Continued 3 Case series/report No comparison group Famous example was Bendectin for nausea in pregnancy, where adverse publicity led to removal from market of safe and effective treatment Was combination of two agents, both of which were effective and neither of which were harmful (Magee, Mazzotta , & Koren , 2002; Hale, 2012) Re-introduced use of ingredients in a delayed-release combination pill after US FDA approval in 2013 ( Nuangchamnong , 2014) 10
Slide notes:10 The lowest form of evidence is the case series, or even worse, the single case report. The reason a case series provides the lowest form of evidence is that theres no comparison group. A case series can be used to generate a hypothesis that could then be tested with more rigorous study designs, but a case series or case report, in and of itself, isnt considered to provide high-quality evidence. A classic example of poor evidence resulting from a case series is the drug Bendectin [ben- dek -tin] that came out in the 1980s as treatment for nausea in pregnancy. We should always be careful about giving any medication to pregnant women, but it turns out that Bendectin was unfairly singled out. The adverse publicity was so strong that it was taken off the market. Some women actually benefitted from the drug, because one of the ingredients in Bendectin was a vitamin. Bendectin was a combination of two agents, both of which were known to be effective and neither of which had any harmful effects, but because there was a case series of birth defects, Bendectin was taken off the market, withdrawing an effective treatment for women with nausea from pregnancy. In 2013, the US Food and Drug Administration (FDA) approved the two ingredients doxylamine and pyridoxine and they are now offered in a delayed-release pill as a first-line treatment for the management of nausea and vomiting in pregnancy.