Association between cancer and dementia risk in the UK Biobank: evidence of diagnostic bias - PubMed (original) (raw)
Association between cancer and dementia risk in the UK Biobank: evidence of diagnostic bias
Jingxuan Wang et al. Eur J Epidemiol. 2023 Oct.
Abstract
Epidemiological studies have identified an inverse association between cancer and dementia. Underlying methodological biases have been postulated, yet no studies have systematically investigated the potential for each source of bias within a single dataset. We used the UK Biobank to compare estimates for the cancer-dementia association using different analytical specifications designed to sequentially address multiple sources of bias, including competing risk of death, selective survival, confounding bias, and diagnostic bias. We included 140,959 UK Biobank participants aged ≥ 55 without dementia before enrollment and with linked primary care data. We used cancer registry data to identify cancer cases prevalent before UK Biobank enrollment and incident cancer diagnosed after enrollment. We used Cox models to evaluate associations of prevalent and incident cancer with all-cause dementia, Alzheimer's disease (AD), and vascular dementia. We used time-varying models to evaluate diagnostic bias. Over a median follow-up of 12.3 years, 3,310 dementia cases were diagnosed. All-site incident cancer was positively associated with all-cause dementia incidence (hazard ratio [HR] = 1.14, 95% CI: 1.02-1.29), but prevalent cancer was not (HR = 1.04, 95% CI: 0.92-1.17). Results were similar for vascular dementia. AD was not associated with prevalent or incident cancer. Dementia diagnosis was substantially elevated in the first year after cancer diagnosis (HR = 1.83, 95% CI: 1.42-2.36), after which the association attenuated to null, suggesting diagnostic bias. Following a cancer diagnosis, health care utilization or cognitive consequences of diagnosis or treatment may increase chance of receiving a dementia diagnosis, creating potential diagnostic bias in electronic health records-based studies.
Keywords: Alzheimer’s disease; Dementia; Diagnostic bias; cancer.
© 2023. Springer Nature B.V.
Figures
Figure 1:. Flow diagram of inclusion criteria
Figure 2:. Age-specific all-cause dementia incidence rates
Age-specific incidence rates were calculated by dividing the number of all-cause dementia cases in each age group by the number of person-years of observation in that group. Participants were at risk and contributed person-years from study baseline until the time of first dementia diagnosis, death from any cause, or censoring date. For each age group, a 95% CI for the age-specific incidence rate was calculated assuming a Poisson distribution for the number of cases in that group.
References
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