The nationwide Finnish anticoagulation in atrial fibrillation (FinACAF): study rationale, design, and patient characteristics

Atrial fibrillation (AF) is a major cause of ischemic stroke and the number of AF patients is increasing. Thus, up-to-date multifaceted data about the characteristics of AF patients, their treatments, and outcomes are urgently needed. The Finnish anticoagulation in atrial fibrillation (FinACAF) study has collected comprehensive data on all Finnish AF patients from 1st January 2004 to 31st December 2018. The aim of this paper is to describe the study rationale, the process of integrating data from the applied resources and to define the study cohort. Using national unique personal identification number, individual patient data is linked from nationwide health care registries (primary, secondary, and tertiary care), drug purchases, education, and socio-economic status as well as places of domicile, incomes, and taxes. Six regional laboratory databases (~ 282,000, 77% of the patients) are also included. The study cohort comprises of a total of 411,000 patients. Since the introduction of the national primary care register in 2012, 9% of all AF patients were identified outside hospital care registers. The prevalence of AF in Finland—4.1% of whole population—is for the first time now established. The FinACAF study allows a unique possibility to investigate the epidemiology and socio-medico-economic impact of AF as well as the cost effectiveness of different AF management strategies in a completely unselected, nationwide population. This article provides the rationale and design of the study together with a summary of the characteristics of the cohort.

Declining incidence of meningococcal disease in Denmark, confirmed by a capture–recapture analysis for 1994 and 2002

SUMMARYDenmark has in the past 10 years experienced a decrease in the number of notified cases of meningococcal disease. In 1994 the completeness of the Notification System for Meningococcal Disease (NSMD) was estimated as 96% (95% CI 93–98). To answer the question whether the observed decrease reflects a real decrease in the incidence; we estimated the completeness of the notification system in 2002. We estimated the completeness of registration by a capture–recapture analysis. As the first data source, we used the national NSMD, which is an integrated surveillance system between the Department of Epidemiology and the Neisseria Reference Laboratory. The second independent source was the National Patient Registry (NPR). In 2002, the completeness of the NSMD was estimated as 96% (95% CI 95–98) and for the NPR as 84% (95% CI 82–85). The ‘real’ incidence rate was 1·9/100 000 population, which compared to 4·4/100 000 population in 1994. We concluded that the observed decrease in incidence rate is real. The NSMD in Denmark functions well and captures almost all cases of meningococcal disease. The complete registration which includes a unique personal identification number serves as an outstanding source for nationwide registry linkage studies.

SmiNet-2: Description of an internet-based surveillance system for communicable diseases in Sweden

Electronic systems for communicable diseases surveillance enhance quality by simplifying reporting, improving completeness, and increasing timeliness. In this article we outline the ideas and technologies behind SmiNet-2, a new comprehensive regional/national system for communicable disease surveillance in Sweden. The system allows for reporting from physicians (web form) and laboratories (direct from lab data system) over the internet. Using a unique personal identification number, SmiNet-2 automatically merges clinical and laboratory notifications to case records. Privileged users, at national and county level, work against a common central server containing all notifications and case records. In addition, SmiNet-2 has separate county servers with tools for outbreak investigations, contact tracing and case management. SmiNet-2 was first used in September 2004. Individual counties receive up to 90% of all notifications electronically. In its first year, SmiNet-2 received 54 980 clinical notifications and 32 765 laboratory notifications, which generated 58 891 case records. Since most clinicians in Sweden have easy access to the internet, a general web-based reporting has been feasible, and it is anticipated that within a few years all reporting to SmiNet-2 will be over the internet. In this context, some of the major advantages of SmiNet-2 when compared with other systems are timeliness in the dataflow (up to national level), the full integration of clinical and laboratory notifications, and the capability to handle more than 50 diseases with tailor-made notification forms within one single system.