Send to

Choose Destination
Gac Sanit. 2011 Sep-Oct;25(5):353-6. doi: 10.1016/j.gaceta.2010.05.011. Epub 2011 Jun 23.

Participation rates in the selection of population controls in a case-control study of colorectal cancer using two recruitment methods.

Author information

Center for Research in Environmental Epidemiology, Barcelona, Spain.



Low participation rates in the selection of population controls are an increasing concern for the validity of case-control studies worldwide.


We conducted a pilot study to assess two approaches to recruiting population controls in a study of colorectal cancer, including a face-to-face interview and blood sample collection. In the first approach, persons identified through a population roster were invited to participate through a telephone call by an interviewer telephoning on behalf of our research center. In the second approach, individuals were identified from the lists of selected family practitioners and were telephoned on behalf of the family practitioner.


When the second method was used, participation rates increased from 42% to 57% and the percentage of refusals decreased from 47% to 13%. The reasons for refusing to participate did not differ significantly between the two methods.


Contact through the family practitioner yielded higher response rates in population controls in the study area.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Ediciones Doyma, S.L.
Loading ...
Support Center