Distinguishing between-person and within-person relationships in longitudinal health research: Arthritis and quality of life

Ehri Ryu, Stephen West, Karen H. Sousa

Research output: Contribution to journalArticle

8 Scopus citations


Background Many health measures (e.g., blood pressure, quality of life) have meaningful fluctuation over time around a relatively stable mean level for each person. Purpose This didactic paper describes two closely related statistical models for examining between-person and withinperson relationships between two or more sets of measures collected over time: the latent intercept model with correlated residuals (LI) in structural equation modeling framework and the multivariate multilevel model (MVML) in multilevel modeling framework. Results We illustrated that the basic LI model and the MVML model are equivalent. We presented an illustrative example using a national arthritis data resource to examine between-person and within-person relationships of symptom status, functional health, and quality of life in arthritis patients. Discussion Additional design and modeling issues for the treatment of missing data are considered.We discuss contexts in which one of the two models may be preferred. Mplus and SAS syntax are available.

Original languageEnglish (US)
Pages (from-to)330-342
Number of pages13
JournalAnnals of Behavioral Medicine
Issue number3
Publication statusPublished - Jun 2012



  • Arthritis
  • Between-person and within-person relationship
  • Latent intercept model
  • Multivariate multilevel model

ASJC Scopus subject areas

  • Psychology(all)
  • Psychiatry and Mental health
  • Medicine(all)

Cite this