The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; early rearing environment and the adult working, family and social environments. For the TRA subjects, circumstances of separation were also explored.

Twin pairs who were over 50 years of age and had both responded to the initial questionnaire participated in the in-person testing (IPT) component, which included a health examination, blood sampling, interviews, and tests on functional capacity, cognitive abilities, and memory.

Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, lung function, grip strength, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily living (e.g. turn key in lock, pour glass of water). In addition, one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam; Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

Beginning at IPT2, a questionnaire was given to the participant during IPT in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes. Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

Additionally during IPT3, an assessment of risk related to occupation and leisure and a risk evaluation comparison within twin pairs were done. A questionnaire was given to the IPT participant in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes. Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and had both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

A questionnaire was given to the IPT participant in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes.Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

Twin pairs who were over 50 years of age and had both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection. Additionally during IPT5, the following was done: a risk evaluation comparison within twin pairs, assessment of risk related to occupation and leisure, assessment of the twin’s family history, and relatives of the twin were asked to give an assessment of dementia. Twins who refused to participate in IPT5 were asked participate in a telephone interview using the TELE protocol. A questionnaire was given to the IPT participant in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes. Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

Twin pairs who were over 50 years of age and had both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection. Twins who refused to participate in IPT6 were asked participate in a telephone interview using the TELE protocol. A questionnaire was given to the IPT participant in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes. Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and where both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection. Twins who refused to participate in IPT7 were asked participate in a telephone interview using the TELE protocol. A questionnaire was given to the participant during IPT in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes.Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and where both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

A questionnaire was given to the participant during IPT in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes.Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and where both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

A questionnaire was given to the participant during IPT in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes.Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.

Twin pairs who were over 50 years of age and where both responded to the initial questionnaire participated in the IPT component, which included interviews; a health examination; tests on functional capacity, cognitive abilities, and memory; and biosamples collection.

A questionnaire was given to the participant during IPT in lieu of mailing the questionnaire. The questionnaire was the same as the postal questionnaire that included items concerning health status, how they were raised, work environment, alcohol consumption, and dietary and smoking habits, as well as questions about personality and attitudes.Participants completed a nutritional survey to allow computation of quantity and frequency measures of several nutrients.

Physical measures included: blood pressure, pulse, anthropometric measures, dental status, lung function, grip strength, gait and balance, physical performances measures for upper and lower body functional activity, validity for measuring activities of daily (e.g. turn key in lock, pour glass of water). In addition one series of tests was included to determine possible impairment of the cranial nerves.

The cognitive battery was designed to represent the domains of crystallized and fluid intelligence and memory. The battery included the Mini-Mental Status Exam, Information test, Synonyms test, Analogies test, Figure logic test, Block design test, Card rotation test, Digit span (Forward and Backward) test, Picture memory test, Names and faces test, Digit symbol test, and Figure identification test.

A fasting blood and a morning urine samples were also collected.

The mail-out questionnaires assessed physical and mental health status; selected personality dimensions; activities of daily living; health-related behaviors of smoking, alcohol consumption and legal drug use; and the adult working, family and social environments.