Bias

Occurs when a factor influences a research study’s outcomes or interpretation of outcomes. There are many types of bias. Some are by accident, some are on purpose, some are caused by the research and some are caused by other factors. Sampling bias occurs when the people or entities chosen to represent the entire population are not representative. For example, a study that enrols patients on a first‐come, first‐served basis may be biased towards those who are already receiving better health care. Publication bias occurs because journals are more likely to publish only the results of studies that show a benefit. Studies that show no effect are often not published, even though their findings are just as important. ^HTAI