Researchers have developed a score-based score that can help doctors predict a person’s risk of developing dementia over the age of 13, allowing for steps to delay or prevent early cognitive problems. However, some experts are skeptical.
The risk score does not require neuroimaging and “can achieve nearly 100% predictive accuracy,” said study researcher Xi-jian Dai, PhD, of the Second Affiliated Hospital of Nanchang University in China. Medscape Medical News.
The study was published online on November 17 JAMA Network Open.
The researchers developed the dementia risk model using the British Biobank of nearly 445,000 men and women (mean age, 56 years) who were cognitively normal at baseline. During the 13-year follow-up, 0.7% of men and 0.5% of women developed dementia.
Not surprisingly, increasing age was strongly associated with a higher risk of dementia. Other risk factors for dementia include socioeconomic disadvantage, sleep disturbances, and several comorbidities, including respiratory disease, cerebrovascular disease, diabetes, hypertension, and cardiovascular disease.
Men and women shared certain modifiable dementia risk and protective factors, but they also had some independent risk factors that accounted for about 32% of men and 53% of women developing dementia, the researchers say.
The overall risk model score ranged from -18 to 30 for men and -17 to 30 for women.
For example, a 70-year-old (10 points) man with underweight (3 points), low education level (1 point) and a history of diabetes (1 point) and cerebrovascular disease (5 points) would have a total risk of 20 points and the corresponding risk of dementia is 9% after 5 years, 31% after 9 years and 54% after 13 years.
The multivariate Cox proportional hazards regression model for predicting 5-, 9-, and 13-year risk of dementia had a C statistic of 0.86 for males and 0.85 for females in the training set and 0.85 for males and 0.87 for women in the test set.
The risk score had a predictive accuracy for 9-year dementia risk of 97.59% in men and 99.59% in women, and close to 100% predictive accuracy for 13-year dementia risk in both men and women, the researchers say.
They caution that the results have not been externally validated with other independent cohorts.
Individuals in the UK biospecimen also have a limited age range, and some measurements were based on a subjective assessment of a single item, which could lead to misclassification.
Other limitations include that all participants were hospitalized, which could lead to selection bias, and some potentially important predictors, such as diet, were not taken into account.
Despite these limitations, they say this “proposed” risk prediction tool “can help individuals identify their potential risk profile and provide guidance for accurate and timely interventions to prevent or delay dementia.”
Dementia experts skeptical
In a statement, the British agency and the independent Center for Science Media urged caution in drawing firm conclusions about the tool’s predictive value.
“The claim ‘the risk score model gave 100% predictive accuracy of 13-year risk of dementia’ is extremely misleading,” said David Curtis, MBBS, MD, PhD, of University College London’s Genetics Institute.
“The score doesn’t accurately predict whether or not someone will develop dementia in 13 years, but it gives the likelihood that someone will develop dementia,” Curtis said.
“That would be like saying I can predict the risk of getting a head when I flip a coin with 100% accuracy—the risk of getting a head is 0.5. The score is a poor predictor of whether or not someone will develop dementia, it only predicts their chance of developing dementia,” Curtis added.
Curtis noted that the results of this study “reconcile already well-known risk factors such as age, low education, and vascular disease, along with a number of symptoms that may indicate that the subject already has early dementia but that it is yet to emerge.” formally intelligent.”
Echoing Curtis, Tom Russ, PhD, director of the Alzheimer Scotland Dementia Research Center in Edinburgh, noted that these risk factors had previously been highlighted in “great detail” in 2020 Lancet article of the commission, as previously reported by Medscape Medical News.
“Important,” Russ said Lancet The commission’s report “warned of different points in the life cycle when certain risk factors may be most important.”
Ivan Koychev, PhD, a senior clinical scientist at the University of Oxford in Oxford, England, had a slightly different take on this study.
He noted that the dementia risk model with a 5- to 13-year time horizon has “sound methodology and has the benefit of working with one of the largest datasets currently available.”
“The implications are that models such as the one described are in a good position to be implemented in clinical practice to complement dementia screening methods such as blood tests. The costs and benefits of such dementia screening programs remain to be established,” Koychev told the Science Media Center.
This research was supported by grants from the Guangdong Basic and Applied Basic Research Foundation, the Natural Science Foundation of Hunan Province, and the University of Macau. The authors, Curtis and Russ, have disclosed no relevant financial relationships. Koychev is a medical advisor to Five Lives, a digital technology company developing a solution to provide dementia risk prediction and lifestyle changes for older adults.
JAMA Network Open. 2022;5(11):e2242596. Full text
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