Nuclear medical imaging as part of dementia diagnostics in psychiatric day-care clinics and inpatient care settings

Background Current guidelines support the use of nuclear medical imaging (NMI) techniques for differential diagnostics of certain cases of dementia. Aims We aimed at studying the association between using NMI and the accuracy of dementia diagnoses. Additionally, we evaluated the effect of conducting NMI on the duration of hospital treatment. Methods This study was based on data collected according to §21 of the German hospital remuneration law, including relevant diagnostic and procedural codes for NMI in dementia patients. In total, more than 7.2 million cases treated in German psychiatric and somatic hospitals between 2015 and 2017 were included. Associations between the frequency of NMI and the accuracy of dementia diagnoses in terms of specific vs. unspecific diagnostic codes were analyzed using Fischer’s exact test. Results In total, 351,106 cases with a dementia diagnosis were encoded during the study period. NMI was performed in 1.03% or 0.15% of all patients with dementia in psychiatric or somatic clinics, respectively. In psychiatric clinics, the proportion of unspecific dementia diagnoses decreased from 20.86% in 2015 to 17.73% in 2017. NMI was mainly performed within psychiatric day-care settings. Interestingly, patients receiving NMI stayed shorter within day-care settings (8.1 ± 16.0 days) compared to inpatient settings (38.3 ± 44.7 days). Conclusions Nuclear medical imaging is often performed in psychiatric day-care settings. Further studies are warranted to understand the predictive diagnostic value of NMI in dementia diagnosis compared with clinical, CSF and structural imaging in different healthcare settings.