The core study has been conducted at eight sites in five countries (Belgium, Germany, Italy, the Netherlands and Switzerland).
The materials and methods of the core study have been published previously [ 13, 14] and will be briefly summarized here.
This study was part of an ongoing epidemiological core study among men and women attending the Latin American Center for Sexually Transmitted Diseases (CLETS, by its initials in Spanish), located in San Juan, Puerto Rico A full description of the methodology used in the core study has been described elsewhere [ 25].
DCCT/EDIC core studies have been the foundation for many collaborations, each initiative advancing our understanding of the multisystem effects of diabetes and guiding future clinical and basic science investigations (Fig. 1).
In the core study, surgery had been performed under local anaesthesia following a standard surgical procedure.
The "intent-to-treat population" (ITT) consisted of all randomized patients who signed informed consent, received at least 1 dose of study drug in the core study, and had a core study baseline and at least 1 extension study efficacy measurement from the same scale.
Patients who completed the core study and had serum ferritin levels ≥500 μg/l could elect to enter an extension study, which was initially intended to be 3 years, but was extended to 4 years after a protocol amendment.
To be included, reviewed articles were required to have sufficient empirical data for analysis (eg, conference proceedings were excluded), the educational intervention was required to include patient safety as core content and the study had to include an evaluation of the educational intervention.
Tissue cores used in this study had a length of about 3 mm.
The two apple core collections used in this study had been previously constituted by choosing the individuals that maximized the genetic diversity based on a set of 24 microsatellite markers in the INRA Angers germplasm collection of dessert and cider apple cultivars.
