Aims To explore the usefulness of data derived from observational studies on adverse drug reactions (ADRs) in de®ning and preventing the risk of pharmacological interventions in children in different health care settings. Methods A systematic review of studies on ADRs in hospitalized children, in outpatient children, and on ADRs causing paediatric hospital admissions was performed. Studies were identi®ed through a search of the MEDLINE and EMBASE databases. The inclusion criteria required that the population was not selected for particular conditions or drug exposure and prospective monitoring was used for identifying ADRs. Data were analysed by a random-effects model. Results Seventeen prospective studies were included. In hospitalized children, the overall incidence of ADRs was 9.53% (95% con®dence interval [CI], 6.81,12.26); severe reactions accounted for 12.29% (95%CI, 8.43,16.17) of the total. The overall rate of paediatric hospital admissions due to ADRs was 2.09% (95%CI, 1.02,3.77); 39.3% (95%CI, 30.7,47.9) of the ADRs causing hospital admissions were life threatening reactions. For outpatient children the overall incidence of ADRs was 1.46% (95%CI, 0.7,3.03).Conclusions The results show that ADRs in children are a signi®cant public health issue. The completeness and accuracy of prescription reporting as well as clinical information from studies was a rarity, making it dif®cult for health practitioners to implement evidence based preventive strategies. Further, methodologically sound drug surveillance studies are necessary for an effective promotion of a safer use of drugs in children.

Objective: To assess the reliability of healthcare information on the world wide web and therefore how it may help lay people cope with common health problems. Methods: Systematic search by means of two search engines, Yahoo and Excite, of parent oriented web pages relating to home management of feverish children. Reliability of information on the web sites was checked by comparison with published guidelines. Main outcome measures:Minimum temperature of child that should be considered as fever, optimal sites for measuring temperature, pharmacological and physical treatment of fever, conditions that may warrant a doctor's visit. Results: 41 web pages were retrieved and considered. 28 web pages gave a temperature above which a child is feverish; 26 pages indicated the optimal site for taking temperature, most recommending rectal measurement; 31 of the 34 pages that mentioned drug treatment recommended paracetamol as an antipyretic; 38 pages recommended non-drug measures, most commonly tepid sponging, dressing lightly, and increasing fluid intake; and 36 pages gave some indication of when a doctor should be called. Only four web pages adhered closely to the main recommendations in the guidelines. The largest deviations were in sponging procedures and how to take a child's temperature, whereas there was a general agreement in the use of paracetamol. Conclusions: Only a few web sites provided complete and accurate information for this common and widely discussed condition. This suggests an urgent need to check public oriented healthcare information on the internet for accuracy, completeness, and consistency.

The principal dilemma of the internet is that, while its anarchic nature is desirable for fostering open debate without censorship, this raises questions about the quality of information available, which could inhibit its usefulness. While the internet allows "medical minority interest groups to access information of critical interest to them so that morbidity in these rare conditions can be lessened,"1 it also gives quacks such as the "cancer healer" Ryke Geerd Hamer a platform (http:// www.geocities.com/HotSprings/3374/index.htm). 2-4Quality is defined as "the totality of characteristics of an entity that bear on its ability to satisfy stated and implied needs."5 For quality to be evaluated, these needs have to be defined and translated into a set of quantitatively or qualitatively stated requirements for the characteristics of an entity that reflect the stated and implied needs. So how can we define consumers' "needs" in the case of medical information on the internet?The quality of medical information is particularly important because misinformation could be a matter of life or death.6 Thus, studies investigating the "quality of medical information" on the various internet venues-websites, 7 mailing lists and newsgroups, 8 9 and in email communication between patients and doctors 10 -are mostly driven by the concern of possible endangerment for patients by low quality medical information. Thus, quality control measures should aim for the Hippocratic injunction "first, do no harm."Most papers published so far about the problem of quality of medical internet information focus on assessing reliability, but, as box 1 shows, this should be only one aspect of quality measures aiming for "first, do no harm." Another should be to provide context. Although these two problems are different in nature and different measures may be proposed to solve them, we discuss a common measure that could solve both aspects at the same time: assigning "metadata" to internet information; both evaluative metadata to help consumers assess reliability and descriptive metadata to provide context. BenchmarksIdeally, the success of methods of quality control and evaluation would be tested by their impact on morbidity, mortality, and quality of life. Such benchmarks would, however, be extremely difficult to measure.12 Therefore, measures of process and structure 13 could be used as more indirect indicators of quality-for example, reliability, provision of context, qualification of authors, use or acceptance of this information by consumers, etc. Table 1 shows different systems for quality control of information on the internet. If quality control at the time of production is not possible or not desirable, 14 it could be decentralised and consist of selecting the products complying to the quality requirements of a consumer. Such selection may consist of downstream filtering (by consumers) and upstream filtering (by an intermediary). Filtering and selecting information Summary pointsThe quality of information on the internet is extremely vari...