M. Haugh

Efficacy indices do not contain the same information although they are all combinations of the same two quantities. Therefore, one should choose the proper index. Actually, none is entirely appropriate. Each more or less meets the specifications, depending on the underlying effect model for the therapy considered. However, one can say that the absolute benefit is more appropriate from the patient's point of view, the relative from the scientific point of view and the number of patients to treat from the policy maker's point of view. Nevertheless, this classification needs to be considered with caution. Finally, it emerges from the review that none is fully relevant to express the efficacy of a therapy, even in the most suitable condition, the acute illness.

PURPOSE: To describe the quality of oncology guidelines developed in different countries. METHODS: The Appraisal of Guidelines and Research and Evaluation (AGREE) Instrument was used to assess the quality of 100 guidelines (including 32 oncology guidelines) from 13 countries. The criteria of the instrument are grouped into six quality domains: scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, and editorial independence. RESULTS: Oncology guidelines had significantly higher scores on rigor of development than nononcology guidelines (42.2% v 29.4%; P =.02). In particular, systematic methods to search for evidence were more often used (P =.01); the methods for formulating the recommendations were more clearly described (P =.02); and health benefits, risks, and side effects were more often considered in formulating the recommendations (P =.03). Although the standardized scores for the other domains were not significantly different, the oncology guidelines had significantly higher scores for items measuring inclusion of all relevant professional groups (P =.05), consideration of patient views (P =.04), and presentation of different options (P =.05). Only three organizations producing oncology guidelines had standardized scores more than 60% for more than three domains. CONCLUSION: The quality of clinical practice guidelines (CPGs) is modest in general, but for certain domains, oncology guidelines seem to be of better quality than others. The experience of the organization may explain higher scores for some items. Research projects and training aimed at improving the quality of guidelines should be developed. The AGREE instrument could provide a basis for defining steps in a shared development approach to produce high-quality CPGs.

OBJECTIVE: To determine whether prophylactic treatment with low molecular weight heparin reduces the incidence of thrombosis in patients who have had general or orthopaedic surgery. DESIGN: Meta-analysis of results from 52 randomised, controlled clinical studies (29 in general surgery and 23 in orthopaedic surgery) in which low molecular weight heparin was compared with placebo, dextran, or unfractionated heparin. SUBJECTS: Patients who had had general or orthopaedic surgery. INTERVENTION: Once daily injection of a low molecular weight heparin compared with placebo, dextran, or unfractionated heparin. MAIN OUTCOME MEASURES: Incidence of deep venous thrombosis, pulmonary embolism, major haemorrhages, and death. RESULTS: The results confirm that low molecular weight heparins are more efficacious for the prophylactic treatment of deep venous thrombosis than placebo (common odds ratio 0.31, 95% confidence interval 0.22 to 0.43; p < 0.001) and dextran (0.44, 0.30 to 0.65; p < 0.001). The results suggest that low molecular weight heparins are also more efficacious than unfractionated heparin (0.85, 0.74 to 0.97; p = 0.02), with no significant difference in the incidence of major haemorrhages (1.06, 0.93 to 1.20; p = 0.62). CONCLUSIONS: Low molecular weight heparins seem to have a higher benefit to risk ratio than unfractionated heparin in preventing perioperative thrombosis. However, it remains to be shown in a suitably powered clinical trial whether low molecular weight heparin reduces the risk of fatal pulmonary embolism compared with heparin.