The population consisted of twin pairs born in 1958 or earlier regardless of gender composition or vital status of the pair, selected from the Swedish Twin Registry and asked to participate to the study.
Data Collection Event
SALT - HARMONY
SALT participants aged 65 or older were included in HARMONY and administered a screening instrument for dementia as part of the SALT interview. All twins who screened positive, together with their co-twins and a sample of cognitively intact controls, were referred to a clinical phase.
Information about participants' complete medical history, including use of prescription and non-prescription medications, as well as onset and sequence of memory and cognitive symptoms, was collected through medical records review and informant interview. Dementia diagnosis, including differential diagnosis, was then set at a multidisciplinary conference.
Cognitive screening was based on the twin’s performance on the TELE cognitive screening instrument, which incorporates the 10-item mental status questionnaire (MSQ), two other cognitive domains, and questions about health and daily functioning. For individuals who performed poorly on the TELE, an informant was interviewed with the Blessed Dementia Rating Scale (BDRS) about how much the twin’s cognitive status interfered with daily functioning.
Participants underwent a visit by an assessment team composed of a nurse and a physician, which included physical and neurological examination, a neuropsychological assessment; and referral for neuroimaging.
Blood was collected for laboratory tests.