Information for researchers

Relevant patient care data registered by general practitioners (GPs) in their Health Information System (HIS) are included in the AHON database. Sensitive information is pseudonymized and can’t be traced back to individual patients. The following details are available in our database:

• Morbidity, including presenting complaints, symptoms and diagnoses, encoded using International Classification of Primary Care (ICPC) codes;
• Medication prescriptions, encoded according to the Anatomical Therapeutic Chemical (ATC) classification;
• Medical investigations, including diagnostic, biometric and laboratory results;
• Referrals (partly): referrals enter the HIS in the form of a referral letter. We do not have these letters in our database. We only have registration data on referrals if the practice subsequently registers the referral information from the letters in the system itself.

Any researcher can request a dataset for scientific research with the intention of publication in a national or international journal. Direct applications from pharmaceutical or other industry will not be considered.

• Research using solely registration data does not, in principle, require ethical approval according to the Medical Research Involving Human Subjects Act (WMO);
• Before submitting an application, we advise that you ensure the information included by GPs in a HIS is suitable for your research. In case of questions, you can contact [email protected]; include a short description of your research idea and the data needed to answer your research questions;
• You will need to pay a one-time fee to cover administration costs, as well as ongoing charges for a research environment in which you will be working with the data. Contact us at [email protected] to request an indication of the costs.

You can request an application form for a dataset via [email protected]. In this form, you will be asked to give a brief description of key aspects of the study, such as the planned research question, the proposed methodology, and the dataset required. We request that you send relevant supporting information as attachments.

For support, contact Karina Sulim, Datasteward AHON-database: 06 25 65 13 57 or [email protected].

After submitting your request, several steps will be completed before the data becomes available in the secure research environment:

• Application review by the AHON committee - this takes an average of four weeks (depending on a possible waiting list).
• DTA and quotation – the signing process for the DTA (Data Transfer Agreement) and quotation.
• Query phase – in this phase, the data request is further operationalized. The time required depends on how specific and complete the request has been formulated by the researcher, and how complex the request is. The AHON manual and a data specification fill-in template help researchers to operationalize a research question into an effective extraction from the healthcare registration data.
• Data extraction and preparation in the secure research environment – the requested data is retrieved from the database and securely placed in the research environment. The time required for this step depends on the size of the dataset and how complex the extraction queries are.
• Please note that the entire process can easily take three months or longer.

The Committee is composed of representatives from affiliated registration practices and from the UMCG Department of Primary- and Long-term Care. The goal of the AHON-committee is to promote high quality research in general practice. This is achieved by assessing research applications for relevance, feasibility, workload, quality, and methodology. In this way, the committee represents the interests of GPs in the AHON.

We can link datasets when additional data are needed for an investigation. The new data won’t be included in the AHON Database. ZorgTTP acts as Trusted Third Party for all data linkage in these instances. Please note that the linking of datasets involves additional time and costs. You might need to ask for ethical approval, and you will need to arrange official documents such as Data Transfer Agreements, before the linkage can occur. Contact [email protected] to discuss whether the linkage is possible; include a short description of your research idea, and whether you have already had contact with the other data source with which you want to link.

The infrastructure of the AHON-database was developed in collaboration with the GP registration networks of the University Medical Centers (UMC) in Utrecht, Amsterdam, and Maastricht. The primary care departments at these UMCs use the same data model and have entered a partnership called the Intercity Network to facilitate joint research. AHON datasets can thereby be scaled nationally to withhold healthcare data of approximately one million patients if a study needs to include data from other parts of the Netherlands.