Empowering knowledge generation through international data network: the IMeCCHI-DATANETWORK.

INTRODUCTION: The International Methodology Consortium for Coded Health Information (IMeCCHI) is a collaboration of health services researchers who promote methodological advances in coded health information. The IMeCCHI-DATANETWORK initiative focuses on developing a multi-purpose distributed data infrastructure and common data model (CDM) to enable cross-border data sharing and international comparisons. METHODS: IMeCCHI consortium partners from six different countries - Canada, Denmark, Italy, New Zealand, South Korea, and Switzerland - used a questionnaire to describe their original databases which differ in size, structure, content and coding systems. To standardize these data, they agreed on a CDM and mapped their population-based databases to meet the CDM specifications. At the end of this process, local data had a more homogenous content and structure, which made them syntactically and semantically interoperable. Data transformation was performed using a common data management software called TheMatrix. RESULTS: The CDM encompasses four tables of structured data (person characteristics, hospitalizations, outpatient prescription medication and death), linked at the individual level through a person identifier. It can be used to answer research questions across countries using locally converted databases, which facilitates study replication in a distributed fashion. As a proof-of-concept study, an initial research question was addressed using an agreed protocol. Local data were transformed in csv files in the CDM structure and TheMatrix was tested to transform the standardized data from each partner into local analytical datasets. This allowed results to be shared between countries, whilst maintaining local control over each region's data. CONCLUSION: The IMeCCHI-DATANETWORK, a model of a distributed data network, demonstrated that it is feasible to analyze international data using standardized analytical methods that enable independent analyses by regions, without relocating datasets thereby protecting local confidentiality obligations. The distributed data infrastructure can produce results that can be generalized to several countries, while facilitating cross-border data sharing and international comparisons. KEYWORDS: Common data model, international comparison, cross-border data sharing, interoperability, observational data.

Evolution of glomerular filtration rate in HIV-infected, HIV-HBV-coinfected and HBV-infected patients receiving tenofovir disoproxil fumarate.

We aimed to compare the evolution of estimated glomerular filtration rate (eGFR) in HIV-, HIV-HBV- and HBV-infected patients treated with tenofovir disoproxil fumarate (TDF). Three groups of patients receiving TDF > 12 months were recruited: 194 HIV-infected patients, 85 HIV-HBV-coinfected patients and 50 HBV-infected patients. eGFR was estimated using the Modification of the Diet in Renal Disease (MDRD) equation. Multivariate regression models were constructed to estimate factors associated with eGFR decrease from baseline. A total of 329 patients were studied. Median follow-up was 2.7 years. Median eGFR decrease was -4.9 (-16.6 to +7.2) mL/min/1.73 m(2) . After multivariate stepwise regression analysis, age (P = 0.0002), non-African origin (P < 0.0001), baseline eGFR (P < 0.0001) and TDF duration (P = 0.02) were associated with eGFR decrease in the whole population, while hypertension, diabetes and type of infection were not. Age (P < 0.0001), non-African origin (P = 0.0004), baseline eGFR (P < 0.0001) and TDF duration (P = 0.007) remained associated with eGFR decline in HIV and HIV-HBV-infected patients, while other variables including HIV risk factor, CDC stage, CD4 and HIV-RNA levels were not. Age (P = 0.03), non-African origin (P = 0.004), baseline eGFR (P < 0.0001) and baseline HBV-DNA > 2000 IU/mL (P = 0.04) were associated with eGFR decline in HBV and HIV-HBV-infected patients, while other variables including HBV risk factor and fibrosis stage were not. Estimated glomerular filtration rate decline under TDF therapy appears mainly associated with older age, non-African origin, higher baseline eGFR and longer TDF administration but not with the type of viral infection. Regular follow-up of renal function, especially tubular function is recommended during TDF therapy.

[Evaluation of anterior knee laxity on MRI]. / Évaluation de la laxité antérieure du genou en IRM: la laxi-IRM.

PURPOSE: Evaluation of the ACL and anterior knee laxity on MR during anterior tibial translation. PATIENTS AND METHODS: Three groups were identified based on clinical and arthrometric (KT-1000) data: normal ACL (n=12), complete tear (n=10) and partial tear (n=20). MRI was performed without and with anterior tibial translation (pneumatic device) with morphological and laximetric analysis: drawer tests and dynamic evaluation of ligamentous tension. RESULTS: Intra- and inter-observer reproducibility was excellent, correlated to arthrometric data and clinical tests (Lachman, pivot shift). The difference between the drawer signs of normal subjects and patients with ACL tear was significant for a threshold value of 1,1mm for the anterior drawer (sensitivity: 93.33%, specificity: 91.7%) and 2.8 mm for the posterior drawer (sensitivity: 86.7%, specificity: 100%). Dynamic evaluation of ligamentous tension was also reproducible, statistically correlated to the MR drawer tests and reliable for the diagnosis of ACL lesions. In this preliminary study, the distinction between complete and partial ACL tears could not be detected. CONCLUSION: Anterior cruciate ligament function can be demonstrated on MR. The predictive value of this morphological and functional association should be determined in the management of patients with partial tears.