Five methods for computing significant individual client change and improvement rates: support for an individual growth curve approach

J Consult Clin Psychol. 1995 Dec;63(6):1044-8. doi: 10.1037//0022-006x.63.6.1044.


Interest has been renewed in methods for determining individual client change. Currently, there are at least 4 pretreatment-posttreatment (pre-post) difference score methods. A 5th method, based on a random effects model and multiwave data, represents a growth curve approach and was hypothesized to be more sensitive to detecting significant (p < .05) change than the pre-post methods. The change rates produced by the 5 methods were compared in a sample of 73 older outpatients with 3 to 5 assessments per client on a measure of well-being (H. J. Dupuy, 1977). Results indicated that the growth curve approach improvement rate was the highest (68.5%). The growth curve and the Edwards-Nunnally (63.0%) methods produced significantly (p < .05) higher improvement rates than the other 3 methods, with 1 exception.

Publication types

  • Comparative Study

MeSH terms

  • Adaptation, Psychological
  • Adult
  • Aged
  • Female
  • Humans
  • Individuality*
  • Male
  • Middle Aged
  • Models, Statistical
  • Personality Assessment / statistics & numerical data*
  • Personality Development*
  • Psychometrics
  • Psychotherapy*
  • Quality of Life
  • Treatment Outcome