We feel that it is extremely important to have a standardised methodology for post-introduction observation of new technologies. The assessment methodology set forth in this guideline is a preliminary proposal on the relevant aspects to be borne in mind when considering the implementation of post-introduction observation, the outcome indicators to be used, and the way in which the information is to be obtained. This proposal has been agreed upon by a national group of HTA experts and is, to a great extent, based on experience gained at a regional level (Galicia). We should however like to stress the fact that this is an initial proposal which will have to be further developed and modified, as and when more information on the operational performance of post-introduction observation systems is forthcoming. In its current form, only the basic aspects of the outcome indicators are reflected, without data-analysis and -interpretation being explored in any great depth.

Despite being intended as a guideline, the proposed outcome indicators serve as a point of reference for identifying and evaluating important deviations in the impact of new technologies once these have spread throughout the health system, and for identifying problems of effectiveness or safety. Detecting important deviations from the current standards renders it possible for timely corrective measures to be applied, thereby serving to enhance the quality and efficiency of health services. The use of a common methodology to obtain results also enables comparisons to be made among different centres, areas and regions, and possible shortcomings or, on the contrary, areas of excellence to be identified.

In our opinion, the proposed assessment methodology is valid for any centre, body or institution, national or international, which may envisage initiating post-introduction observation activities. The outcome indicators established are based on essential data that are usually collected in daily clinical practice and would entail no extra work for health-care professionals. However, we recognise the fact that the feasibility of this proposal may, in great part, depend on the availability and quality of the information existing at the level of the various health systems. For instance, the possibility of using electronic medical records as a data source depends on a number of factors, such as: 1) the model of electronic clinical history implemented (overall, exclusively at a specialised level, primary care, etc.); 2) the degree of use of such e-histories in the health organisation and/or system (sole data- collection source, data also recorded in paper format, etc.); 3) the data recorded (completeness, quality, coding); and 4) the software available for data-collection and -transfer. With respect to case registries, their viability has been observed to be dictated, to a large extent, by the collaboration of clinicians. Involving clinicians in planning and data-collection is a difficult task that calls, on the one hand, for an awareness as to the need for assessing new technologies post-introduction, and on the other hand, for appropriate institutional, structural and technical support.