The Article in Brief

Sufficiently Important Difference for Common Cold: Severity Reduction

Bruce Barrett, MD, PhD , and colleagues

Background In this study, people with colds were interviewed about 4 cold treatments. They were asked about the amount of benefit they would want in exchange for the costs and possible side effects of the treatments. The study set out to determine the sufficiently important difference (SID) in these treatments, that is, the smallest benefit that a treatment would require in order to justify its costs and risks.

What This Study Found Of the 4 treatments, a $0.05 vitamin C pill with few or no side effects required the least benefit to justify treatment, followed by a $0.50 dose of an herbal extract with no side effects (other than bad taste), a $0.20 lozenge, which could taste bad and cause nausea, and finally a $2 prescription-only pill with unknown side effects. The study finds that, on average, people want the severity of a cold to be reduced by 25% to 57% to justify the costs and risks of cold treatments.

Implications

• This study sheds light on patients’ health values, which play a role in medical decision making and the design of research studies.
• The authors suggest that the concept of sufficiently important difference be tested for other medical conditions.