Validity of Dementia Diagnoses in the Danish Hospital Registers
ABSTRACT The validity of dementia diagnoses in the Danish nationwide hospital registers was evaluated to determine the value of these registers in epidemiological research about dementia.
Two hundred patients were randomly selected from 4,682 patients registered for the first time with a dementia diagnosis in the last 6 months of 2003. The patients' medical journals were reviewed to evaluate if they fulfilled ICD-10 and/or DSM-IV criteria for dementia and specific dementia subtypes. The patients who were still alive in 2006 were invited to an interview.
One hundred and ninety-seven journals were available for review and 51 patients were interviewed. A registered diagnosis of dementia was found to be correct in 169 (85.8%) cases. Regarding dementia subtypes, the degree of agreement between the registers and the results of the validating process was low with a kappa of 0.36 (95% CI 0.24-0.48).
The validity of dementia syndrome in the Danish hospital registers was high and allows for epidemiological studies about dementia. Alzheimer's disease, although underregistered, also had a good validity once the diagnosis was registered. In general, other ICD-10 dementia subtypes in the registers had a low validity and are less suitable for epidemiological research.
- SourceAvailable from: Christian Fynbo Christiansen
[Show abstract] [Hide abstract]
- "Several Danish studies have estimated the PPV of selected diagnoses included in the Charlson comorbidity index (e.g. acute myocardial infarction , cerebrovascular disease [28,29], dementia , rheumatoid arthritis , liver cirrhosis , diabetes mellitus , cancer , haematological malignancies  and HIV ) in the NRP and generally report of lower PPV's than in our study. These studies validated diagnoses using strict diagnostic criteria, requiring for example specific clinical investigations. "
ABSTRACT: The Charlson comorbidity index is often used to control for confounding in research based on medical databases. There are few studies of the accuracy of the codes obtained from these databases. We examined the positive predictive value (PPV) of the ICD-10 diagnostic coding in the Danish National Registry of Patients (NRP) for the 19 Charlson conditions. Among all hospitalizations in Northern Denmark between 1 January 1998 and 31 December 2007 with a first-listed diagnosis of a Charlson condition in the NRP, we selected 50 hospital contacts for each condition. We reviewed discharge summaries and medical records to verify the NRP diagnoses, and computed the PPV as the proportion of confirmed diagnoses. A total of 950 records were reviewed. The overall PPV for the 19 Charlson conditions was 98.0% (95% CI; 96.9, 98.8). The PPVs ranged from 82.0% (95% CI; 68.6%, 91.4%) for diabetes with diabetic complications to 100% (one-sided 97.5% CI; 92.9%, 100%) for congestive heart failure, peripheral vascular disease, chronic pulmonary disease, mild and severe liver disease, hemiplegia, renal disease, leukaemia, lymphoma, metastatic tumour, and AIDS. The PPV of NRP coding of the Charlson conditions was consistently high.BMC Medical Research Methodology 05/2011; 11(1):83. DOI:10.1186/1471-2288-11-83 · 2.17 Impact Factor
[Show abstract] [Hide abstract]
- "First, the validity of the ICD-10 diagnosis of dementia in the DNHR and the DPCR has been found to be high with a correct register diagnosis in 85.8% of cases compared with research-based diagnoses (Phung et al. 2007). The ICD-10 subtype diagnosis of dementia was rather low, but AD, although under registered, also had a good validity once the diagnosis was registered. "
ABSTRACT: Purpose: To investigate whether normal tension glaucoma (NTG) is associated with increased risk of developing dementia/Alzheimer disease (AD). Methods: A total of 69 patients with NTG were identified in the case note files in the Glaucoma Clinic, University Hospital of Copenhagen (Rigshospitalet), Denmark from 1980 to 2001. The rate of a subsequent diagnosis of dementia as recorded in nationwide health care registers from 1980 to 2005 was estimated and compared with the rate for the general population [standard mortality rate (SMR) = observed number of cases of dementia/expected number of cases of dementia]. Results: The 69 patients had a median age of 64 years (quartiles 57 and 73) at the time of the diagnosis, and the average follow-up period was 12.7 years. The SMRdementia was 0.20 (95% CI 0.01–1.11). No patient developed AD. Conclusion: Normal tension glaucoma was not associated with an increased risk of developing dementia/AD.Acta ophthalmologica 02/2011; 90(7). DOI:10.1111/j.1755-3768.2011.02125.x · 2.51 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Investigates the electromigration performances of selective CVD tungsten filled vias under DC and AC stressing currents. The authors' results show that the electromigration failure always occurred in metal 2 layer at the via area. The AC lifetimes of the test structure are found to be much longer (more than 1000X) than DC lifetimes under same peak stressing current density. No obvious electromigration induced damage was observed in metal 1 in the test structure we studiedVLSI Multilevel Interconnection Conference, 1991, Proceedings., Eighth International IEEE; 07/1991