Introduction to LASA

Introduction to the Longitudinal Aging Study Amsterdam (LASA)

Aging research and collecting data on aging in the Netherlands
The Longitudinal Aging Study Amsterdam (LASA) is a longitudinal study to determine predictors and consequences of aging. LASA started in 1991. LASA focuses on physical, emotional, cognitive, and social functioning in late life, the connections between these aspects, and the changes that occur in the course of time. Over the years LASA has built up by far the largest data source on aging in the Netherlands.


Population-based study of aging in the Netherlands
The Longitudinal Aging Study Amsterdam (LASA) is initiated by the Ministry of Health, Welfare and Sports in 1991 to investigate predictors and consequences of aging. LASA has been conducted since then by the VU University and VU University Medical Center. LASA focuses on physical, emotional, cognitive and social functioning in late life, the connections between these components, the changes in these components that occur in the course of time within and between respondents, and the consequences of these changes (e.g. in terms of care and social participation).

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Key characteristics of the study

  • Cross-sequential longitudinal study
  • Multidisciplinary approach
  • Nationally representative sample obtained from registries of 11 municipalities across 3 culturally distinct regions in the Netherlands (see map)
  • Initial ages 55-84
  • N (cohort 1) = 3,107 (1992)
  • N (cohort 2) = 1,002 (2002)
  • N (cohort 3) = 1,023 (2012)


Measurement and observation cycles
Data collection started in 1992-1993 among a cohort of respondents aged 55-84 years old (N=3,107, wave B, baseline). Since then, measurement cycles have been conducted about every three years. Measurements are performed by trained interviewers, who visit respondents at home. Usually two separate interviews are conducted: a main interview and a medical interview, with clinical measurements. Also, respondents are asked to fill out a questionnaire.

So far, observation cycles for this first cohort (cohort 1) took place from 1992-1993 (wave B, baseline) until the latest in 2011-2012 (wave H, see Table 1). An additional cohort of respondents aged 55-64 years was included from the same sampling frame and was measured for the first time exactly ten years after the original baseline measurement, in 2002-2003 (cohort 2, N=1,002, wave 2B). Since then, respondents from this second cohort of respondents have been included in regular LASA measurement waves. In 2012-2013, exactly twenty years after the baseline measurement, a third cohort study (cohort 3, wave 3B) was initiated with new respondents aged 55-64 years from the same sampling frame.  This sample will also be included in regular LASA measurement waves. So, in 2015-2016 a new wave (I) has been started containing respondents from cohorts 1, 2, and 3. Note that the Migrant cohort MB which was examined in 2013-2014 has its own sampling frame.

For more details about the phasing at LASA, see the Table 1 below.

Table 1. Measurement cycles 1992-2016

        Wave
  N

Cohort       

B
3107

B

C
2545

B

D
2076

B

E
1691

B

2B
1002

2B

F
2165


B+2B

G*
1818


B+2B

H*
1522


B+2B

3B*
1023


3B

MB**
478


MB

I***
2014

B+2B+3B

 Cohort 1

1992-1993

1995-1996

1998-1999

2001-2002

 

 

2005-2006

 

2008-2009

 

2011-2012

    2015-
2016
 Cohort 2

2002-2003

 

 
 Cohort 3

 

 

 

 

 

 

 

 

2012-
2013

 

 Migrant   Cohort

                  2013-2014  

*) Data can be obtained from LASA upon request.
**) MB: Migrant 1st cohort, Baseline 2013-2014 (data processing started, more information about this sample of people with a Moroccan or Turkish background will be provided in the near future).
***) This new cycle is still in the early phases of deployment.

The longitudinal nature of the study, together with its cross-sequential design and follow-up of more than a decade provide several unique opportunities for data analysis. In addition to data on changes in functioning over time within respondents, provided by the long-term follow-up of the same participants, the addition of respondents from younger generations after ten and twenty years of follow-up allow for cohort and period comparisons.

Objectives
LASA is designed to be an interdisciplinary, longitudinal study on aging. Besides a strong academic basis, the study should provide opportunities for developing and evaluating (central and local government) policy in the field of aging. These principles guide the selection of measurements and data that is available from the LASA study.

LASA's main topics of interest are autonomy and quality of life of older persons. Autonomy is operationally defined as functioning, i.e. observable behavior; quality of life is defined as the evaluation by older persons of their functioning. Four components of functioning are distinguished: physical, cognitive, emotional and social functioning. Examples of measures of functioning that are included in the LASA database are: disability and physical performance, general cognitive functioning, depression and mastery, loneliness and social participation. Because LASA includes data about these multiple components of functioning, the data is especially useful for investigating cross-component associations.

Data availability
A set of core data is made available in a Public User File (PUF) in EASY DANS (after registration).

References
Access to additional data from the LASA study can be requested by contacting Martijn Huisman. Further information about LASA can be found in the following articles:

Huisman, M., Poppelaars, J.L., Van der Horst, M.H.L., Beekman, A.T.F., Brug, J., Van Tilburg, T.G., Deeg, D.J.H. (2011). Cohort Profile: The Longitudinal Aging Study Amsterdam. International Journal of Epidemiology, 40, 868-876.

Hoogendijk, E., Deeg, D.J.H., Poppelaars, J.L., Van der Horst, M.H.L., Broese van Groenou, M.I., Comijs, H.C., Pasman, H.R.W., Van Schoor , N.M., Suanet, B.A., Thomése, G.C.F., Van Tilburg, T.G., Visser, M., Huisman, M. (2016). The Longitudinal Aging Study Amsterdam: cohort update 2016 and major findings. European Journal of Epidemiology, 31, 927-945.

Watch the LASA video.

The terms 'cycle' and 'wave' are used interchangeably