Predictors of attrition in a longitudinal cognitive aging study: the Maastricht Aging Study (MAAS)

J Clin Epidemiol. 2002 Mar;55(3):216-23. doi: 10.1016/s0895-4356(01)00473-5.


A large sample of older participants of the Maastricht Aging Study (MAAS) were compared to drop-outs at the 3-year follow-up with respect to socio-demographic, health, and cognitive characteristics. In addition, the impact of selective drop-out on measures of cognitive change was examined. To this end, hypothetical scores were estimated for drop-outs by using single and multiple imputation methods. Of the initial sample of 539 subjects, aged 49 years and older at baseline, 116 (22 %) did not return for the follow-up (n = 32 had died, n = 84 refused participation). Drop-outs who refused to participate in the follow-up were more often women, had lower educational levels, and had lower baseline scores on neurocognitive tests. Follow-up drop-outs who had died were more often men, older, and had a poorer performance on cognitive tests than the follow-up participants. Although follow-up participants and drop-outs differed in terms of socio-demographic and cognitive characteristics, attrition appeared to have little effect on the estimates of cognitive change.

MeSH terms

  • Aged / psychology*
  • Aged, 80 and over
  • Analysis of Variance
  • Chi-Square Distribution
  • Cognition*
  • Female
  • Geriatric Assessment
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Patient Dropouts*
  • Population Surveillance
  • Regression Analysis
  • Selection Bias