Predictors of contact difficulty and refusal in a longitudinal study.
BACKGROUND
Attrition presents a serious problem to researchers collecting longitudinal data. Participant loss threatens both the internal and external validity of research findings. This study sought to examine predictors related to contact difficulty and refusals in a longitudinal study.


METHODS
Data for this paper came from the Developmental Trends Study, a longitudinal study investigating the development of disruptive behaviour disorders in a sample of 177 clinic-referred boys. Annual follow-up assessments were conducted, ages for the periods examined ranged from 11 to 19 years. The predictor domains during project years 1-4 included demographics, child functioning, parental functioning, parenting skills and participant dispersion.


RESULTS
These indicated that participant's older age, low socioeconomic status, the presence of callous and un-emotional behaviours, and having a father with antisocial personality disorder predicted contact difficulty, while participant's older age, living in a rural environment and attention deficit hyperactivity disorder were predictive of refusals. Participant dispersion was not significantly related to either contact difficulty or refusal status.


CONCLUSIONS
Investigating a broader range of variables may better allow researchers to identify participants who may be at risk of attrition. Early identification of 'difficult' participants enables development of retention strategies to minimize attrition.
Western Psychiatric Institute and Clinic, University of Pittsburgh, Medical Center, Pittsburgh, PA 15213, USA. cotterrb@upmc.edu
Robert B
RB
Cotter
Jeffrey D
JD
Burke
Rolf
R
Loeber
John
J
Mutchka
D000293:Adolescent; D001741:Black or African American / Q000523:psychology*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000523:psychology*; D002648:Child; D005845:Georgia; D006801:Humans; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D010290:Parents / Q000523:psychology; D010414:Pennsylvania; D045808:Refusal to Participate / Q000208:ethnology*; D015203:Reproducibility of Results; D035844:Researcher-Subject Relations; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D044465:White People / Q000523:psychology*