title: Impact of participant and interventionist race concordance on weight loss outcomes.
abstract: OBJECTIVE
  We have previously shown that racial composition of behavioral intervention groups does not affect achieved weight loss. However, it is unclear if the race of the interventionist affects intervention outcomes. The objective of this analysis is to estimate the impact of race concordance between participant and interventionist on weight change in the initial weight loss phase (phase I) of the Weight Loss Maintenance trial (WLM).
  
  
  METHODS
  A total of 1,685 overweight or obese adults (BMI 25-45 kg/m(2) ) who were taking medication for hypertension and/or dyslipidemia participated in phase I of the WLM trial. All participants received a 6-month intensive behavioral intervention in groups of 15-20 facilitated by a trained interventionist. The main outcome is change in weight at 6 months.
  
  
  RESULTS
  Participants were on average 55 years of age, 67% female and 44% African American (AA). Three of seventeen interventionists were AA, 14 were non-AA. Seventy-three percent of participants shared race concordance with the interventionist. There was a small but statistically significant difference in weight change of participants who were the same race as the interventionist (-5.84 kg, s.e. 0.17) as compared with those who were not race concordant (-5.04 kg, s.e. 0.33), a difference of 0.8 kg, (P = 0.04). The impact of concordance on weight change differed by race (i.e., interaction of race and concordance was significant, P = 0.02).
  
  
  CONCLUSIONS
  In a post hoc analysis of a group-based behavioral intervention, race concordance for non-AA participants was associated with slightly greater weight loss. Race concordance was not associated with weight loss for AA participants.
authors.affiliation: Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, North Carolina, USA. bryan.batch@duke.edu
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Batch
authors.forename: Jamy D
authors.initials: JD
authors.lastname: Ard
authors.forename: William M
authors.initials: WM
authors.lastname: Vollmer
authors.forename: Kristine
authors.initials: K
authors.lastname: Funk
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Appel
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Stevens
authors.forename: Carmen
authors.initials: C
authors.lastname: Samuel-Hodge
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Loria
authors.forename: Jack F
authors.initials: JF
authors.lastname: Hollis
authors.forename: Laura P
authors.initials: LP
authors.lastname: Svetkey
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D015331:Cohort Studies; D002149:Energy Intake; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000628:therapy; D050177:Overweight / Q000628:therapy; D010349:Patient Compliance; D044469:Racial Groups; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D015431:Weight Loss