What Does Participant Attrition Mean?

What Does Participant Attrition Mean?
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Attrition is a term used to describe a rate of decline over time. For example, employee attrition in the workplace refers to the rate at which employees quit or leave to take other jobs, and student attrition in a school setting can refer to the rate at which students drop out or transfer. Participant attrition typically refers to the behavior of people who participate in a multi-step research study, and how their lack of full participation impacts findings.

Measuring Participant Attrition

If a research project is conducted over a period of time -- for example, one day a week over a month-long period -- participants who drop out between the first session and subsequent sessions can skew the findings of the project. For example, if 10 participants are taking part in a three-day sleep study, and all 10 participants are present on the first day, but only eight take part on the second day, and only six remain by the final day of the study, research findings will not be as accurate as if all participants were actively involved over the full three-day session. Researchers will have to note the rate of participant attrition in their findings and describe the impact it has had on their conclusions.

Reasons for Participant Attrition

There are a variety of reasons for participant attrition. For example, in a medical research study, participants may die during the course of the study, or experience a significant change in health status that excludes them from participation. In other cases, participants may decide they don't like the course of the research, don't have the time to devote to the project, or are otherwise not interested in continuing their involvement. In studies in which participants are subjected to physical or mental tests, results may be undesirable or overwhelming to the point that individuals wish to discontinue their involvement.

Ways to Reduce Attrition

While it's not possible to plan for every contingency for keeping participants involved in a project, some degree of pre-planning and education can help reduce the participant attrition rate. For example, make sure participants are fully educated about the need for full participation and understand and agree to the commitment and the parameters of the project with which they'll be involved. Ensuring participants understand in advance what is expected of them can make them less likely to leave the project abruptly. Asking for signed commitments and offering a stipend or payment of some sort may also help keep participant attrition rates down.

Working With Attrition Figures

Surveys, research projects and other data collection methodologies often have a margin of error built in to address factors beyond a researcher’s control. For example, a researcher may claim a study has a potential error rate of plus or minus a certain percentage that is factored based on participant attrition. This helps reviewers and users of the data understand the variables on which the researcher is basing any suppositions.