DOI: 10.3886/icpsr38899.v1
title: Chinese Longitudinal Healthy Longevity Survey (CLHLS), [China], 1998-2018
title: Version 1

description: The Chinese Longitudinal Healthy Longevity Survey (CLHLS) provides information on health status and quality of life of the elderly aged 65 and older in 23 provinces of China from 1998 to 2018. The study was conducted to shed light on the determinants of healthy human longevity and oldest-old mortality. To this end, data were collected on a large percent of the oldest population, including centenarians and nonagenarians; the CLHLS provides information on the health, socioeconomic characteristics, family, lifestyle, and demographic profile of this aged population. 
The questionnaire data collected provides information on family structure, living arrangements and proximity to children, activities of daily living (ADL), the capacity of physical performance (picking up a book from the floor; standing up from a chair; turning 360 degrees without help), self-rated health, self-evaluation of life satisfaction, cognitive functioning, chronic disease prevalence, care needs and costs, social activities, diet, smoking and drinking behaviors, psychological characteristics, economic resources, and care giving and family support among elderly respondents and their relatives. Information about the health status of the CLHLS participants who were interviewed in the previous wave but died before the current survey was collected by interviewing a close family member, and includes information such as cause of death, chronic diseases, ADL before dying, frequency of hospitalization or instances of being bedridden from the last interview until death, whether bedridden before death, length of disability and suffering before death. 
For the participants from the in-depth study sites of the 8 longevity areas, in
addition to the questionnaire interview data, the CLHLS conducted lab tests of
the biomarkers using blood/urine samples collected from the voluntary
participants as well.
description: General goals of the Chinese Longitudinal Healthy Longevity Study (CLHLS) are to discover the social, behavioral, environmental, and genetic factors and their interactions that may influence healthy longevity, as well as to provide data for academic research, and information for health and healthy aging policy analysis.
description: The CLHLS baseline survey was conducted in 1998, and the follow-up surveys with replacements for deceased elders were conducted in 2000, 2002, 2005, 2008-2009, 2011-2012, 2014, and 2017-2018 in a randomly selected half of the total number of counties and cities in 23 provinces in China. The survey areas covered 985 million persons in the baseline year 1998 and 1.156 billion persons in the census year
2010, about 84-85 percent of the total population of China. An enumerator and a nurse or a medical school student conducted the interview and performed a basic health examination at each interviewee's home.
The CLHLS attempted to interview all centenarians who voluntarily agreed to participate in the study in the randomly selected half of the counties and cities of the 23 provinces. For each centenarian, one near-by octogenarian (aged 80-89), one near-by nonagenarian (aged 90-99) and 1.5 younger-old aged 65-79, of pre-designated age and sex was interviewed. "Near-by" is loosely defined - it could be in the same village or
street if available, or in the same town or in the same sampled county or city. The predefined age and sex, used to identify the approximately equal numbers of male and female nonagenarians, octogenarians and younger-old aged 65-79, are randomly determined, based on the code numbers of the centenarians. The goal was to have comparable numbers of male and female octogenarians, nonagenarians and younger-old
aged 65-79 at each age from 65 to 99.
description: This collection contains the following weights which should be used in any analysis: W_1998 (Dataset 1), W_2000 (Dataset 2), W_2002 (Dataset 3), W_2005 (Dataset 4), W_2008 (Dataset 5), W_2011 (Dataset 6), W_2014 (Dataset 7), and W_2018 (Dataset 8). For more information on weighting, please see the documentation.
description: Response Rates: 98 percent
description: Presence of Common Scales: The following scales were used in this collection: Mini-Mental State Examination (MMSE), Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL)
description: All centenarians from the randomly selected counties and cities of 23 provinces in China who agreed to participate in the study. For each centenarian, one octogenarian aged 80-89 living nearby, one nearby nonagenarian aged 90-99, and one nearby younger elder aged 65-79 of predesignated age and sex were interviewed.
description: Datasets: 
DS0: Study-Level Files
DS1: 1998-2018 Longitudinal Data
DS2: 2000-2018 Longitudinal Data
DS3: 2002-2018 Longitudinal Data
DS4: 2005-2018 Longitudinal Data
DS5: 2008-2018 Longitudinal Data
DS6: 2011-2018 Longitudinal Data
DS7: 2014-2018 Longitudinal Data
DS8: 2018 Cross-Sectional Data
description: The most elderly population aged 80 and older in the counties and cities of 23 provinces in mainland China. From 2002 on, the CLHLS also includes those young elders aged 65-79 as comparisons. Smallest Geographic Unit: province
description: coded on-site observation; cognitive assessment test; face-to-face interview; self-enumerated questionnaireAdditional information about the Chinese Longitudinal
Healthy Longevity Survey as well as study design can be found at the
Duke Aging Center Web site.