The Chinese Longitudinal Healthy Longevity Survey (CLHLS) is the world's largest survey on centenarians, nonagenarians and octogenarians with a comparative group of younger elderly, and also one of the world's largest surveys concerning health and aging. CLHLS has conducted eight waves of in-depth surveys between 1998-2018 in 23 provinces in China, using internationally compatible questionnaires. In total, 113,000 face-to-face interviews have been conducted, with 19,500 centenarians, 26,700 nonagenarians, 29,700 octogenarians, 25,500 younger elders aged 65-79 and 11,300 adults aged 35-64. Data on mortality and degree/length of disability before death for 28,900 participants, who died between waves, were collected in interviews with a close family member of the deceased. The CLHLS has a long history of data sharing and contributing important information to international research on aging. CLHLS has also collected DNA samples from in total 25,000 CLHLS participants: 5,000 centenarians, 5,200 nonagenarians, 5,300 octogenarians, 4,800 aged 65-79 and 4,700 aged 40-64.
The survey conducted its 8th wave of data collection in 2018 that: (1) includes the Community Screening Instrument for Dementia (CSI-D) scale by incorporating 4 relevant questions previously included in the CLHLS with newly added questions from the CSI-D scales of HRS/CHARLS-HCAP, in addition to the Mini-mental State Examination (MMSE) scale collected in all previous waves of CLHLS; (2) substantially extends the depression symptoms questions in CLHLS by adopting Center for Epidemiologic Studies Depression (CESD) Scale of HRS/CHARLS-HCAP; and (3) significantly extends the questions about elderly emotional characteristics, by adopting relevant components of the positive and negative affect scale (PANAS). To further extend and develop the CLHLS database, which has the world’s largest samples of centenarians/nonagenarians plus comparable younger groups aged 65-89, efforts to harmonize with HRS databases have been funded; the expanded and harmonized CLHLS phenotype database is available through NIA.
The survey entered its 9th wave of data collection in 2021 and extended as “The Chinese Longitudinal Healthy Longevity and Happy Family Study" (CLHLS-HF), through adding several family-relevant questions in addition to CLHLS’ initial questionnaire which contained about one-third of the total number of questions. This wave is substantially extended to cover 27 provinces, municipalities and autonomous regions in China, including four additional provinces of Guizhou, Yunnan, Ganshu and Ninxia.
CLHLS Data and Documents Availability
The baseline, the cross-sectional and follow-up survey datasets and documents (questionnaires, users’ guides, etc.) of the eight waves of CLHLS conducted in 2000, 2002, 2005, 2008-2009, 2011-2012, 2014 and 2017-2018 are available to the research community. Researchers who are interested in using the CLHLS data need to first sign a Data Use Agreement and then download the datasets free of charge from the following Websites (1) or (2):
(1) http://opendata.pku.edu.cn/; Peking University Open Access Research Database.
(2) https://www.icpsr.umich.edu/icpsrweb/NACDA/series/487; National Archive of Computerized Data on Aging (NACDA) sponsored by U.S. National Institute of Aging (NIA/NIH), Inter-university Consortium for Political and Social Research (ICPSR) at University of Michigan.