Investigation and adjustment for attrition needs to consider any risk factors that may be associated with the outcome of interest in each particular study and how these risk factors might be associated with different types of attrition [ 2, 3].
Moreover, telomerase inhibitors dependent on mechanisms of telomere attrition would need to be continuously administered on a long-term basis for weeks to months in order to produce anti-tumor effects [ 3].
Migration through host tissues has major costs for parasitic helminths in terms of energy expenditure, risks of attrition and the need to adapt to varying physicochemical environments.
Hence, a good understanding of the pattern and causes of attrition is needed to improve program performance, contribute to patient survival, and reduce the risk of further HIV transmission in the community (9).
83 Potential threats to external validity from self selection or attrition bias underline the need to take care when generalising the results beyond the context of the trial.
The attrition assessment highlighted the need to ensure clear roles and responsibilities, job security, and an appropriate career trajectory for this new cadre.
Furthermore, to control the effects of selective attrition, there is a need to perform sensitivity analyses in order to monitor the make-up of the sample and perhaps some purposive sampling to protect against biasing the sample towards a healthier baseline and therefore reduced effect at follow-up, particularly in longitudinal studies.
This allows for a round of screening to be accomplished in one or two visits, reducing costs and the inevitable attrition that occurs when women need to be recalled to obtain their results.
Mr. Kelly's proposals, which come two weeks into his second tour as New York's police commissioner, underscore how seriously he considers the need to slow attrition within the department, an issue that has been vexing city officials for much of the past two years.
