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 seven waves of in-depth surveys between 1998-2014 in 22 provinces in China, using internationally compatible questionnaires. In total, 96,805 face-to-face interviews were conducted, with 16,557 centenarians, 23,081 nonagenarians, 25,842 octogenarians, 19,650 younger elders aged 65-79 and 11,675 adults aged 35-64. Data on mortality and degree/length of disability before death for 26,701 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 24,692 CLHLS participants: 4,849 centenarians, 5,190 nonagenarians, 5,274 octogenarians, 4,770 aged 65-79 and 4,609 aged 40-64.
Currently the survey is conducting its 8th wave of data collection 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 are underway to harmonize with HRS databases. The expanded and harmonized CLHLS phenotype database will distributed by the NIA.