Long-term medical costs of Alzheimer's disease: matched cohort analysis

Objectives Medical costs associated with Alzheimer's disease (AD) are characterised by uncertainty and are often presented in a format unsuitable for decision modelling. We set out to estimate long-term medical costs attributable to AD compared to the general population for use in decision modelling. Methods We used multiple logistic regressions to generate propensity scores to match 26,951 incident cases of AD with 26,951 people without AD, identified from Danish hospital and medication registries. Costs were available for up to 11 years for each individual, representing costs for 10 years before and 5 years after diagnosis. Generalised estimating equations were employed to investigate the effect of having AD on primary care, medication, hospital and total costs in the matched cohort. We also explored the impact of other socio-economic and demographic factors on healthcare costs. Results We report costs by year to diagnosis, from 10 years before to 5 after. AD was associated with significantly higher costs, driven by medication and hospital costs, especially around the time of diagnosis. Mean total medical cost was €4996 higher for AD than for the control group in year of diagnosis, after which primary and hospital costs decreased to prediagnostic levels. AD had higher attributable primary care costs in years preceding diagnosis. Conclusions Reporting AD-attributable costs by year to diagnosis can be useful for use in decision modelling. Medical costs attributed to AD are driven by diagnostic procedures and medication, and the impact of AD on medical costs may not be as high or prolonged as previously suggested.