Prevalence and Ascertainment of Dementia Cases in the Malmö Diet and Cancer Study

Abstract

Background: Register diagnoses, both hospital-based and from open clinic care, are often used in research studies in Sweden. The validity of such diagnoses has been debated and a validation assessment can improve the diagnostic accuracy for use in research studies. Objective: The aim of this study was to investigate the quality of register-derived dementia diagnoses in the Malmö Diet and Cancer population study (MDCS) and to validate these diagnoses using systematic criteria. Methods: MDCS is a population-based prospective study comprising 30,446 participants. Register diagnoses of dementia for the MDCS population were derived from the Swedish National Patient Register (NPR) and validated through re-evaluation of available medical records by physicians. Results: In the MDCS cohort, 2,206 participants were diagnosed with dementia according to the NPR during a mean follow-up of 18.1 years. The general dementia diagnosis was valid in 96% of the cases, but 40% of the specific dementia diagnoses were changed during the process of reevaluation. The diagnostic validity varied between 25.2% and 82.9% for the different diagnoses. The results from the validity assessment per diagnostic category revealed that the validity of the NPR diagnoses was higher for the more specific diagnoses and lower for unspecified dementia. The major diagnostic shift during the re-evaluation was from unspecified dementia to more specific diagnoses. Conclusion: Validation of dementia diagnoses using medical records results in more precise diagnoses. Dementia diagnoses derived from registers should be validated in order to study associations between influential factors and different dementia diagnoses.

Polygenic risk of type 2 diabetes is associated with incident vascular dementia: a prospective cohort study

“…the second highest level on a four-level scale (a vast majority of the data indicating a specific diagnosis), or definite was higher; 88% for Alzheimer’s disease, 91% for mixed dementia and 76% for vascular dementia. 25 Taken together with the fact that 76% of the dementia cases were diagnosed by a specialist in cognitive disorders (which is unusually high in this population), as well as the fact that 40% of the register-based diagnoses were changed after validation, we believe that these aspects indicate a relatively high diagnostic precision in general of the dementia diagnoses.…”

“…The validation process of dementia diagnoses in the MDCS cohort has previously been described. 24 , 25 The validity was assessed using data from medical records by trained medical doctors at the Memory Clinic, Skåne University Hospital in Malmö. National Patient Register (NPR) diagnoses of dementia from the baseline examination until 31 December 2014 were obtained ( n = 2206), covering 99% of inpatient medical diagnoses during the study period, and from 2001 also outpatient diagnoses, 26 although not diagnoses from primary care facilities.…”

Comparison of DBFS with MoCA and MMSE tools for MCI screening

“…Mild cognitive impairment (MCI) is regarded as the transitional period between the normal cognitive decline of healthy ageing and dementia. Some of the risk factors for developing MCI include diabetes, depression, and stroke [ 1 , 2 , 3 , 4 ]. The MCI prevalence ranged from 7% to 25% among the older population of age ranging from 60-85 years [ 5 ].…”