The first major achievement of the present project is having finalised a most difficult multi-centre study protocol. The project has first been running as a pilot study; this has shown clearly that the question posed was scientifically relevant and approachable from the practical point of view. Experience learned from this pilot phase, has permitted to adapt practical aspects that were considered too difficult by a number of centres. The final protocol that emerged out of this learning period has proven to be rather good as judged from comments at international meetings and symposia devoted to the topic. That the project is feasible was shown by inclusion of almost 1600 patients in an 18 month period. A second achievement is the new format to bring in the data. Although sheet forms are available, data can be entirely brought in by computer and the information can be sent to the coordination centre either by post, electronic mail or by EARN. A third achievement is that the techniques to record blood pressure have largely been standardised and that the reading of the data can be transferred either to a MS-DOS or a MacIntosh computer.