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Practical application of opt-out recruitment methods in two health services research studies

View Article: PubMed Central - PubMed

ABSTRACT

Background: Participant recruitment is an ongoing challenge in health research. Recruitment may be especially difficult for studies of access to health care because, even among those who are in care, people using services least often also may be hardest to contact and recruit. Opt-out recruitment methods (in which potential participants are given the opportunity to decline further contact about the study (opt out) following an initial mailing, and are then contacted directly if they have not opted out within a specified period) can be used for such studies. However, there is a dearth of literature on the effort needed for effective opt-out recruitment.

Methods: In this paper we describe opt-out recruitment procedures for two studies on access to health care within the U.S. Department of Veterans Affairs. We report resource requirements for recruitment efforts (number of opt-out packets mailed and number of phone calls made). We also compare the characteristics of study participants to potential participants via t-tests, Fisher’s exact tests, and chi-squared tests.

Results: Recruitment rates for our two studies were 12 and 21%, respectively. Across multiple study sites, we had to send between 4.3 and 9.2 opt-out packets to recruit one participant. The number of phone calls required to arrive at a final status for each potentially eligible Veteran (i.e. study participation or the termination of recruitment efforts) were 2.9 and 6.1 in the two studies, respectively. Study participants differed as expected from the population of potentially eligible Veterans based on planned oversampling of certain subpopulations. The final samples of participants did not differ statistically from those who were mailed opt-out packets, with one exception: in one of our two studies, participants had higher rates of mental health service use in the past year than did those mailed opt-out packets (64 vs. 47%).

Conclusions: Our results emphasize the practicality of using opt-out methods for studies of access to health care. Despite the benefits of these methods, opt-out alone may be insufficient to eliminate non-response bias on key variables. Researchers will need to balance considerations of sample representativeness and feasibility when designing studies investigating access to care.

Electronic supplementary material: The online version of this article (doi:10.1186/s12874-017-0333-5) contains supplementary material, which is available to authorized users.

No MeSH data available.


Tailoring study flow diagram
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Fig2: Tailoring study flow diagram

Mentions: Figures 1 and 2 are recruitment flow diagrams for the Access and Tailoring studies. Relatively few potential participants who received opt-out packets chose to opt out of the study prior to phone contact from staff: 15.2% (Access) and 10.6% (Tailoring). An additional 27.7% (Access) and 29.2% (Tailoring) of potential participants could not be reached due either to incorrect address information (in which case attempting phone contact would have involved “cold calling” because study packets had not been delivered) or unsuccessful phone contact despite multiple attempts. Among those potential participants who could be reached by phone, 27.9% (Access) and 37.8% (Tailoring) agreed to participate.Fig. 1


Practical application of opt-out recruitment methods in two health services research studies
Tailoring study flow diagram
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5391553&req=5

Fig2: Tailoring study flow diagram
Mentions: Figures 1 and 2 are recruitment flow diagrams for the Access and Tailoring studies. Relatively few potential participants who received opt-out packets chose to opt out of the study prior to phone contact from staff: 15.2% (Access) and 10.6% (Tailoring). An additional 27.7% (Access) and 29.2% (Tailoring) of potential participants could not be reached due either to incorrect address information (in which case attempting phone contact would have involved “cold calling” because study packets had not been delivered) or unsuccessful phone contact despite multiple attempts. Among those potential participants who could be reached by phone, 27.9% (Access) and 37.8% (Tailoring) agreed to participate.Fig. 1

View Article: PubMed Central - PubMed

ABSTRACT

Background: Participant recruitment is an ongoing challenge in health research. Recruitment may be especially difficult for studies of access to health care because, even among those who are in care, people using services least often also may be hardest to contact and recruit. Opt-out recruitment methods (in which potential participants are given the opportunity to decline further contact about the study (opt out) following an initial mailing, and are then contacted directly if they have not opted out within a specified period) can be used for such studies. However, there is a dearth of literature on the effort needed for effective opt-out recruitment.

Methods: In this paper we describe opt-out recruitment procedures for two studies on access to health care within the U.S. Department of Veterans Affairs. We report resource requirements for recruitment efforts (number of opt-out packets mailed and number of phone calls made). We also compare the characteristics of study participants to potential participants via t-tests, Fisher’s exact tests, and chi-squared tests.

Results: Recruitment rates for our two studies were 12 and 21%, respectively. Across multiple study sites, we had to send between 4.3 and 9.2 opt-out packets to recruit one participant. The number of phone calls required to arrive at a final status for each potentially eligible Veteran (i.e. study participation or the termination of recruitment efforts) were 2.9 and 6.1 in the two studies, respectively. Study participants differed as expected from the population of potentially eligible Veterans based on planned oversampling of certain subpopulations. The final samples of participants did not differ statistically from those who were mailed opt-out packets, with one exception: in one of our two studies, participants had higher rates of mental health service use in the past year than did those mailed opt-out packets (64 vs. 47%).

Conclusions: Our results emphasize the practicality of using opt-out methods for studies of access to health care. Despite the benefits of these methods, opt-out alone may be insufficient to eliminate non-response bias on key variables. Researchers will need to balance considerations of sample representativeness and feasibility when designing studies investigating access to care.

Electronic supplementary material: The online version of this article (doi:10.1186/s12874-017-0333-5) contains supplementary material, which is available to authorized users.

No MeSH data available.