[Clinical trials in Norway--completion and reporting are not satisfactory]. / Klinisk legemiddelutprøvning i Norge--gjennomføring og rapportering er ikke tilfredsstillende.

OBJECTIVE: To investigate how drug trials are carried out and reported in Norway and to what extent they are published. MATERIAL AND METHODS: All drug trials notified in 1996 were included in the study. Data were obtained from the standard notification form, correspondence with investigators, end-of-study reports, and a questionnaire designed for this study. RESULTS: A total of 208 drug trials were notified. Most trials were initiated by the pharmaceutical industry (85%) and international multicenter studies constituted a major part (73%). Mandatory end-of-study reports were submitted to the health authorities on 48 (23%) of the trials. Out of a total of 159 trials for which we have data, 39 (25%) were interrupted or not started. Out of a total of 143 trials for which we have data on publishing, 77 (54%) were not published. Trials with a positive conclusion (54%) were more likely to be published than those with a negative conclusion (38%). INTERPRETATION: The reporting of drug trials is not satisfactory. Because of low reporting frequency, health authorities do not obtain a comprehensive overview. The pharmaceutical industry initiates the majority of the trials and clinical researchers in Norway increasingly participate in international multicentre trials. Many trials are not carried out as planned; less than half are published.

[Warfarin treatment and bleeding]. / Warfarinbehandling og blødninger.

BACKGROUND: Warfarin is involved in the majority of fatal adverse drug events in Norway. The aim of this study is to identify risk factors behind the haemorrhagic complications. MATERIAL AND METHODS: We analysed all adverse event reports involving bleeding related to warfarin that were received by the Norwegian Medicines Agency from 1990 to 2000. RESULTS: 713 reports were included; 71% of the patients were above 70 years of age. The most frequent diagnosis was atrial fibrillation (39%). Cerebral bleedings were reported in 57% of the cases, 73% of which were fatal, as were 39 % of gastrointestinal bleedings and 14% of other bleedings. International normalised ratio values (INR values) at the time of bleeding were reported in 83% of the cases; mean INR value was 4.4 (range 1.2 - > 8.0). INR values above recommended limits at the time of bleeding were found in 74% of the patients. In 63%, bleedings occurred during the first month; in 30% during the first five days. Median duration of treatment was shorter in fatal (16 days) than in non-fatal cases (24 days). INTERPRETATION: Our results show that haemorrhagic complications are associated with high INR values and initiation of treatment. Simple strategies for reducing bleedings include better monitoring of patients, careful dose adjustment, and INR values in the lower end of the recommended ranges.