Convenience Studies:
Ethical Considerations
Amina White, MD, MA, FACOG
Department of Obstetrics and Gynecology
University of North Carolina at Chapel Hill
Task Force on Research Specific to Pregnant Women and
Lactating Women
November 7, 2017
Disclaimer
• I have no conflicts of interest to
declare.
• The views presented are my own.
2
Objectives – Convenience Studies
• Description
• Potential benefits in research involving
pr
egnant/lactating women
• Ethical considerations
• Summary
3
Convenience Studies -
Description
4
Hedt and Pagano 2011
• Convenience sampling involves
• Collecting data from individuals who are
easily accessible to the investigator
• Type of non-probability (non-random)
sampling
• Ex) Women who present to labor &
delivery or outpatient clinic during a
certain time period
Convenience Sampling – Benefits
• Potential benefits
• Convenience of sampling
• Helpful f
or pilot studies and for hypothesis
generation
• Qualitative or quantitative data collection
• Often faster, less expensive t
o implement
than random sampling
5
Convenience Sampling –
Disadvantages
• Disadvantages
• Selection bias: participants usually not
representative of the population
• Ex)“the recruited study population was less
ethnically diverse, more affluent and more
educated than the background population of
pregnant women in Vancouver”
6
Webster et al. 2012
Convenience Sampling – Ethical
Considerations
• Several requirements for clinical research to be
ethical
• Fair subject selection is one requirement:
Scientific objectives, not privilege or
v
uln
erability, should determine the selection of
participants
Fair balance of burdens and benefits from
resea
rch participation
• Ex) May be more convenient to recruit pregnant women who
speak English, have transportation, etc.
7
Emanuel et al. 2000
Convenience Sampling – Ethical
Considerations
• Could be ethically appropriate for
• Recruitment when resources are limited
• Little is known about a behavior or exposure,
and p
ilot data would be useful
• Attempts made to reduce biased selection
• Best when merged with additional methodologies
for r
andom representative sample
8
Webster et al. 2012
In summary
• Convenience studies, while limited by
selection bias, can be a feasible and
ethically appropriate way to begin filling
research gaps with preliminary or pilot
data
9
Thank you
10
References
• Emanuel, Ezekiel J., David Wendler, and Christine Grady. “What Makes
Clinical Research Ethical?” JAMA 283, no. 20 (May 24, 2000): 2701–11.
• Hedt,
Bethany L., and Marcello Pagano. “Health Indicators: Eliminating Bias
from Convenience Sampling Estimators.” Statistics in Medicine 30, no. 5
(February 28, 2011): 560–68.
• Webster, Glenys M., Kay T
eschke, and Patricia A. Janssen. “Recruitment of
Healthy First-Trimester Pregnant Women: Lessons from the Chemicals,
Health & Pregnancy Study (CHirP).” Maternal and Child Health Journal 16,
no. 2 (February 2012): 430–38.
11
