Individuals with dementia survive an average of four and a half years after diagnosis, a report in the British Medical Journal says. Age, gender, and existing disability all play a part.

Researchers studied more than 13,000 people over age 65 for 14 years, during which 438 developed dementia, 356 of whom died. Those between 60 and 65 lived 10.7 years, and those over 90 survived for 3.8 years. In men the average survival time from the onset of dementia to death was 4.1 years, in women, 4.6 years. Frailer individuals died three years earlier on average than the most able, according to the study.