Contents of the RELIS database were analysed to illustrate how questions were answered. Two periods of 6 years were compared (1995–2000 and 2001–2006). QAPs published in the public database in the respective periods were used. They reflect the process of answering better than QAPs unsuited for publication as described above. Overall publication frequency in the period (1995–2006) was 80% (range 66%–95% between individual centres). Relevant data from QAPs, including question number, were transferred to SPSS V.17.0 (SPSS Inc.) for analysis and subjected to a randomisation procedure in the application. From a total of 9697 QAPs, a randomised sample of 963 QAPs was used for further analysis. Each QAP was compared with the information in the associated paper version (all documents and information on answering the question) saved in the respective RELIS centre. The paper version contained the day the question was received and the corresponding day an answer was provided. One hundred and twenty-one QAPs were excluded because the questions concerned nutritional or herbal medicine (n=65), non-medical products from pharmacies, homeopathy, medical equipment, disinfection or chemicals (n=26), or questions that were answered solely by a previous answer or by sending copies of relevant scientific articles (n=30). Exclusion of these QAPs was based on the notion that DICs primary function and resources (personnel and available drug information sources) are directed to answer questions concerning drugs. Thus, based on a sequence of selection criteria (publication or not, randomisation to 10% and the final exclusion), 842 QAPs were included in the study. They were analysed for the number of drugs involved in the question, complexity, the type of literature search performed, use of references (the number of references used and/or use of the RELIS database as a reference) and the time needed for providing an answer (in days). The number of drugs involved in the queries were categorised as one, two or three or more. Questions concerning groups of drugs, for example, antipsychotics, were categorised as three or more drugs. Judgemental and/or patient-related questions were defined as complex. Factual questions, such as the therapeutic dose of a drug or its half-life, can easily be located in textbooks, monographs or databases. Judgemental questions require by definition the integration of data or knowledge and experience in the process of making a decision regarding a specific therapeutic problem.6 (link) The original definition assumed that answers to judgemental questions could not be given in any single reference source, but this assumption has been excluded in the present and other studies.7 (link) Judgemental questions are frequently patient-related because they involve drug information applied to a clinical situation associated with patient-specific characteristics. They can, however, also represent a more general drug-related problem. If the question was answered without searching the literature and without consulting colleagues, the literature search was categorised as none. If it was necessary to search the RELIS database, databases containing monographs like the Micromedex, the Summary of Product Characteristics for the drug, reference books and/or colleagues/other health professionals only, the search was categorised as simple. If searches in databases like Medline, Embase or Cochrane to obtain original articles were necessary, the search was categorised as advanced. The number of questions received each year were analysed by use of the statistical function in the database. This function allows RELIS to quantify the activity in the centres (eg, the number of questions from physicians or pharmacists from a particular county from a particular time period to a particular RELIS can be retrieved). The number of employees in the centres in the respective periods was estimated but did not include all cases of maternity leave, leave of absence and vacant positions. The mean number of questions per employee per year was calculated from data corresponding to the start (year) and end (year) of each period. Figure 1 summarises the present RELIS model together with the study sample and design.