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Activities of the International Network on the
Methodology of Longitudinal Studies on Aging
Dorly J.H. Deeg, PhD
Department of Psychiatry and Institute for
Research in Extramural Medicine Vrije
Universiteit Amsterdam, The Netherlands
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International Network on the Methodology of
Longitudinal Studies of Aging (MLSA)

• Initiator
• George C. Myers, PhD ?
• Center for Demographic Studies on Aging
• Duke University, U.S.A.
• Initial funding
• National Institute on Aging, USA

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Aims of the network

• Address and help resolve methodological issues in
  conducting and analysing longitudinal studies of
  older persons
• Promote comparative, cross-national
  investigations of transitions in health, social
  and economic conditions of older persons
• Create a network of researchers to further
  co-ordinate and harmonise international
  longitudinal research

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Participants (1)

• Asset and Health Dynamics Among the Oldest Old,
  USA (AHEAD)
• Australian Longitudinal Study of Ageing (ALSA)
• Cross-sectional And Longitudinal Aging Study,
  Israel (CALAS)
• Italian Longitudinal Study on Aging (ILSA)
• Longitudinal Aging Study Amsterdam, the
  Netherlands (LASA)

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Participants (2)

• Longitudinal Study of Aging, USA (LSOA)
• National Health And Nutrition Examination Survey,
  USA (NHANES)
• National Long-Term Care Study (NLTCS)
• Manitoba Longitudinal Study of Aging, Canada
  (MLSA)

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Activities (1)

• Symposia at the World Congress of Gerontology
• 1997 Measuring health transitions, chair
  G.C. Myers
• 2001 Design and analytical issues in the study
  of trajectories of functioning, chairs S.
  Maggi, J.E. Dowd

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Activities (2)

• Three-day workshop, Italian National Research
  Council, Rome, October 1998
• Transitions in health status of older persons
  International comparisons
• Main objective
• Determination of critical issues for achieving
  comparability

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Issues discussed in workshop (1)

• Issues of comparability in international
  longitudinal studies
• 1. Conceptual issues
• a. Prevalence to incidence
• b. Causation
• 2. Design issues
• a. Sampling
• b. Periodicity
• c. Questionnaire content
• 3. Non-response issues, Selection bias

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Issues discussed in workshop (2)

• Measuring transitions in health status
• 1. Scope
• a. Personal interviewing
• b. Clinical assessment
• 2. Evaluation of measures
• a. Analytic procedures
• b. Follow-up
• c. Record linkages
• 3. Achieving comparability

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Issues discussed in workshop (3)

• Analysing health transitional data
• 1. Descriptive analysis
• 2. Multivariate modelling
• 3. Multi-level modelling
• Additional methodological approaches
• 1. Sample weighting
• 2. Use of proxy respondents
• 3. Imputation for item non-response (incomplete
  data)
• 4. Procedures for case non-response

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Example of common analysis

• Self-rated health Transitions
• Males initial ages 80-84 Longitudinal Aging
  Study Amsterdam 1992/3-1995/6 (T1-T2)
• Excellent Good Fair Poor Instit. Dea
  d Total
• Excellent 37.5 12.5 9.4
  0.0 9.4 31.3 14.4 ( 32)
• Good 6.9 36.2 13.8
  0.9 6.9 35.3 52.3 (116)
• Fair
  2.4 17.0 35.4 11.0 21.3 33.3 31.1 ( 69)
• Poor 0.0
  0.0 20.0 40.0 0.0 40.0 2.3 ( 5)
• Total 9.5 25.2 18.0
  3.6 9.0 34.7 100.0 (222)

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Product

• E. Agree, P. Sadaphal. Health transitions among
  the elderly An annotated bibliography.
  Baltimore Department of Population and Family
  Health Sciences / Department of Epidemiology,
  Johns Hopkins University, October 1998

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Spin-off

• CLESA Comparison of Longitudinal European
  Studies on Aging funded by EU-FP5
• Objective
• Multidisciplinary study of cross-national
  determinants of quality of life and health
  services for the elderly in six countries

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CLESA method

• 1. Creation of harmonized database from six
  ongoing longitudinal studies on aging
• CALAS (Israel), ILSA (Italy), LASA (The
  Netherlands), LEGANES (Spain), SATSA (Sweden),
  TAMELSA (Finland)
• 2. Data collection on health services (case
  studies)

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Future of the MLSA network (1)

• Extension to other studies (Europe, Japan)
• Update on bibliography
• Description of MLSA studies according to template
• Further discussion of methodology and analytic
  strategy

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Future of the MLSA network (2)

• Development of substantial questions for
  cross-national comparison
• Selection of experimental modules for
  implementation in MLSA studies
• Development of guidelines for new
  cross-nationally comparative studies

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Current organizers

• E.M. Agree, Johns Hopkins University, USA
• L.S. Corder, Duke University, USA
• D.J.H. Deeg, Vrije Universiteit Amsterdam, The
  Netherlands
• J.E. Dowd, Duke University, USA / WHO Geneva
• D. Inzitari, NRC Targeted Project on Aging, Rome,
  Italy
• S. Maggi, NRC Centre on Aging, Padua, Italy
• K.G. Manton, Duke University, USA
• B.J. Soldo, University of Pittsburgh, USA