Common Cold: Controlled Trials

Blindness in Randomized Controlled Trials

In combination with randomization, blinding or masking is an important factor in randomized controlled trials (RCTs), particularly in trials that assess therapeutic effects. Here an attempt is made to explain blindness and why it is important. In clinical trials, blinding is defined as the condition imposed on a study in which study participants, health care providers and assessors collecting o...

James Angus Doull and the well-controlled common cold.

Zinc gluconate and the common cold: a controlled clinical study.

A report in 1984 on the success of zinc gluconate against common cold symptoms could not be confirmed in three subsequent studies, which are now known to have used formulations that inactivated zinc. A non-chelating formulation including glycine, which releases 93% of contained zinc into saliva, was tested in a randomized, placebo-controlled, double-blind trial in 73 young adults. Efficacy was ...

Placebo effects and the common cold: a randomized controlled trial.

PURPOSE We wanted to determine whether the severity and duration of illness caused by the common cold are influenced by randomized assignment to open-label pills, compared with conventional double-blind allocation to active and placebo pills, compared with no pills at all. METHODS We undertook a randomized controlled trial among a population with new-onset common cold. Study participants were...

Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND Results of randomized controlled trials evaluating zinc for the treatment of the common cold are conflicting. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of zinc for such use. METHODS We searched electronic databases and other sources for studies published through to Sept. 30, 2011. We included all randomized controlled trials comparing or...