Data Source

Registry

Type of Study

Cross-section, regular

Data gathering method

Registries

Registries, based on GP-files

Ease

Data cannot be downloaded directly.

Conditions of access

Formal agreements (e.g. fees, research contracts, institutional agreements, etc.)

Access to data requires: (1) Access fee (2) Official authorisation (CCS); (3) Authorisation of register holder is required.

Time elapsed between application and reception of data

Months

Type of available data (e.g. anonymised microdata, aggregated tables, etc.)

Anonymised microdata

Formats available

SPSS (default)

Language issues

Documentation is only available in Dutch.

Years of collection, reference years, and sample sizes

Data regarding diagnoses was first collected between 2002 and 2010; data regarding contacts was first collected between 2006 and 2010. The sample size used was 84 practices and around 350,000 individuals. For both cases, data collection is ongoing and is scheduled to continue at some point in the future (data collected in 2011 should be released in May/June 2013).

First year of collection

2002

Stratification if applicable

Not applicable

Base used for sampling

Not applicable

Geographical coverage and breakdowns

Patients of GP-practices. (nearly whole population)

Age range

No age restrictions

Statistical representativeness

Representative for patients of GP-practices.

Coverage of main and cross-cutting topics

Detailed study of: General Practitioner (GP) visits, frequency, diagnosis, prescriptions, referrals.

Possibility of linkage among databases

Limited linkage key: about 85% of patients can be linked

Consistency of terminology or coding used during collection

Consistent time series

Strengths: Registry provides information on a patient level. Weaknesses: The database is, however, not integral.