Background: The Internet is increasingly used as a medium for the delivery of interventions
designed to promote health behavior change. However, reviews of these interventions to …

Background Loss to follow‐up from randomised trials can introduce bias and reduce study
power, affecting the generalisability, validity and reliability of results. Many strategies are …

Missing data affect nearly every discipline by complicating the statistical analysis of collected
data. But since the 1990s, there have been important developments in the statistical …

Background Poor retention of participants in randomised trials can lead to missing outcome
data which can introduce bias and reduce study power, affecting the generalisability, validity …

Background: Increasingly, governments, health care agencies, companies, and private
groups have chosen Second Life as part of their Web 2.0 communication strategies. Second …

Health care and health care services are increasingly being delivered over the Internet.
There is a strong argument that interventions delivered online should also be evaluated …

Enhanced schedules of counseling can improve response to routine opioid-agonist
treatment, although it is associated with increased time demands that enhance patient …

Abstract Background The abbreviated Alcohol Use Disorder Identification Test for
Consumption (AUDIT-C) is rapidly becoming the alcohol screening tool of choice for busy …

Background Attrition from follow-up is a major methodological challenge in randomized
trials. Incentives are known to improve response rates in cross-sectional postal and online …

Background: Asthma is the most common pediatric illness in the United States, burdening
low-income and minority families disproportionately and contributing to high health care …