Merck/Centers for Disease Control and Prevention Varicella Vaccine Pregnancy Registry: 19-Year Summary of Data From Inception Through Closure, 1995-2013.

Background: The VARIVAX® Pregnancy Registry was established in 1995 to monitor pregnancy outcomes of women who received varicella vaccine (ie, VARIVAX) inadvertently while pregnant.

Methods: Health care providers and consumers sent voluntary reports about women who received VARIVAX 3 months before or during pregnancy. Follow-up occurred to evaluate pregnancy outcomes for birth defects.

The effects of an open design on trial participant recruitment, compliance and retention--a randomized controlled trial comparison with a blinded, placebo-controlled design.

Background: In randomized trials there may be no overriding reason whether or not to have a placebo control.

Purpose: We assessed the effects of an open trial design (no placebo and people know what tablets they are given) compared with a blinded, placebo-controlled design on recruitment, compliance and retention within a randomized trial of secondary osteoporotic fracture prevention.

Methods: We undertook a randomized controlled comparison nested within a placebo-controlled trial of nutritional supplementation amongst people aged 70 years or over who had previously sustained a fracture, recruited in a UK teaching hospital.