Researchers analyzed 13 studies of 30,257 participants to determine average time to diagnosis in dementia. Across 10 studies, the pooled mean time to diagnosis was 3.52 years, and similar delays were observed across memory clinics, university medical centers, and other health care services in the US, Europe, Australia, and China.
The researchers found that diagnostic delay varied by dementia subtype. In 7 studies that included 20,564 participants, the mean time to diagnosis (TTD) for Alzheimer's disease (AD) was 3.61 years. TTD was longer (4.21 years) in 5 studies that covered 1,016 patients with frontotemporal dementia (FTD). Young-onset dementia, defined as symptom onset before age 65, showed a similar delay as FTD: Among 972 participants from 6 studies, the average TTD was 4.13 years. Young-onset AD had a TTD of 3.97 years, and TTD for young-onset FTD reached 4.69 years. From 2 studies with 240 participants, the meta-analysis investigators found that late-onset dementia had a shorter mean TTD of 2.90 years. Only one study examined racial disparities: Researchers from this study reported that Black patients in the United States had longer TTD compared with White patients. This difference was partially explained by lower levels of education and income.
Several factors were consistently associated with longer diagnostic delays. In addition to the links between extended TTD and younger age at symptom onset or FTD diagnosis, factors including multiple service consultations, intermediate diagnoses such as mild cognitive impairment, and use of advanced diagnostic tools like MRI also contributed to longer TTDs. Factors associated with shorter TTD included older age at onset, noticeable impairment in activities of daily living, and access to specialist memory services. In young-onset cases, attending a dedicated diagnostic center reduced the time to diagnosis.
Olubunmi Kusoro of the Division of Psychiatry, Faculty of Brain Sciences at University College London, and coauthors noted "the lack of standardized criteria for measuring TTD in dementia, and the observed heterogeneity across studies such as variations in sample size, and different definitions of TTD." They added that policy and health care initiative recommendations are limited by the findings from the single studies that were included in the analysis.
Effective future research will, the authors concluded, "identify which socio-demographic, disease specific, and health care specific factors contribute to a longer TTD in dementia. Development of interventions that aim to reduce the diagnostic interval in dementia are urgently needed."
The authors reported no conflicts of interest.
Source: Geriatric Psychiatry
