title: Retention strategies for health disparities preventive trials: findings from the Early Childhood Caries Collaborating Centers.
abstract: OBJECTIVE
  To identify successful strategies for retention of participants in multiyear, community-based randomized controlled trials (RCTs) aiming to reduce early childhood caries in health disparities populations from diverse racial/ethnic backgrounds and across diverse geographic settings.
  
  
  METHODS
  Four RCTs conducted by the Early Childhood Caries Collaborating Centers (EC4), an initiative of the National Institute of Dental and Craniofacial Research, systematically collected information on the success of various strategies implemented to promote participant retention in each RCT. The observational findings from this case series of four RCTs were tabulated and the strategies rated by study staff.
  
  
  RESULTS
  Participant retention at 12 months of follow-up ranged from 52.8 percent to 91.7 percent, and at 24 months ranged from 53.6 percent to 85.9, across the four RCTs. For the three RCTs that had a 36-month follow-up, retention ranged from 53.6 percent to 85.1 percent. Effectiveness of different participant retention strategies varied widely across the RCTs.
  
  
  CONCLUSIONS
  Findings from this case series study may help to guide the design of future RCTs to maximize retention of study participants and yield needed data on effective interventions to reduce oral health disparities.
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Raul I
authors.initials: RI
authors.lastname: Garcia
authors.affiliation: Department of Applied Dentistry, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Tamanna
authors.initials: T
authors.lastname: Tiwari
authors.affiliation: Division of Growth and Development, School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA.|Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Francisco
authors.initials: F
authors.lastname: Ramos-Gomez
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Brenda
authors.initials: B
authors.lastname: Heaton
authors.affiliation: Division of Growth and Development, School of Dentistry, University of California Los Angeles, Los Angeles, CA, USA.|Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Mario
authors.initials: M
authors.lastname: Orozco
authors.affiliation: Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Margaret
authors.initials: M
authors.lastname: Rasmussen
authors.affiliation: Center for Native Oral Health Research (CNOHR), Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Patricia
authors.initials: P
authors.lastname: Braun
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Henshaw
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Belinda
authors.initials: B
authors.lastname: Borrelli
authors.affiliation: Center for Native Oral Health Research (CNOHR), Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Albino
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Courtney
authors.initials: C
authors.lastname: Diamond
authors.affiliation: Center for Research to Evaluate and Eliminate Dental Disparities (CREEDD), Department of Health Policy and Health Services Research, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Gebel
authors.affiliation: Center for Native Oral Health Research (CNOHR), Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
authors.forename: Terrence S
authors.initials: TS
authors.lastname: Batliner
authors.affiliation: Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Judith C
authors.initials: JC
authors.lastname: Barker
authors.affiliation: Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.|Department of Medicine, School of Medicine, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Gregorich
authors.affiliation: Center to Address Disparities in Children's Oral Health (CAN DO), Department of Preventive & Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Gansky
mesh_terms: D002648:Child; D002675:Child, Preschool; D055812:Community-Based Participatory Research; D003731:Dental Caries / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control*; D005006:Ethnicity; D005260:Female; D054624:Health Status Disparities; D006801:Humans; D007223:Infant; D008297:Male; D054584:National Institute of Dental and Craniofacial Research (U.S.); D010349:Patient Compliance / Q000706:statistics & numerical data*; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic; D014481:United States / Q000453:epidemiology
keywords: attrition; child; dental caries; health status disparities; minority groups; participant retention; randomized controlled trials; refusal to participate