Geriatric Sleep Research Program

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Elderly Co-Morbidity Index for Sleep Disorders


The incidence of insomnia in the elderly ranges from 10-45% in a variety of studies. Insomnia can be primary, or secondary to another medical condition. This later group is expected to represent about 80% of all insomniacs, with one of the most common causes being chronic pain. In addition to the psychosocial stresses that insomnia creates there is also the significant sedative consumption of this population. In many surveys, although the elderly represent 10-13% of the surveyed population they consume 30-35% of the prescriptions for sedatives.

Yet while secondary insomnia is the most common form of insomnia, relatively few research studies have examined the relationship between chronic medical conditions and insomnia. Part of this is due to the lack of a standardized instrument to measure the burden of co-morbid medical illness. Commonly used instruments, such as the Charlson co-morbidity index, suffer from having been designed in the early 1990s, thus they inappropriately weight certain conditions, such as HIV. Other instruments, such as the Cumulative Illness Rating Scale, provide a more detailed approach, but require that a skilled healthcare worker conduct the interview. There are no self-report instruments that can be used in large-scale epidemiology studies of sleep and co-morbid medical illness at present.

We are interested in developing such a self-report measure, the Elderly Comorbidity Index for Sleep Research (ECI-S), that would allow for accurate determination of co-morbid medical conditions and an assessment of their impact on sleep in older adults.

Participating Staff

Nalaka Gooneratne
Allan Pack
Sonia Ancoli-Israel
Frances Pack, research coordinator
Jacqueline Cater, biostatistician