In cancer research, hazard ratios are often used in clinical trials to measure survival at any point in time in a group of patients who have been given a specific treatment compared to a control group given another treatment or a placebo. A hazard ratio of one means that there is no difference in survival between the two groups. A hazard ratio of greater than one or less than one means that survival was better in one of the groups. National Cancer Institute
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The hazard ratio, sometimes called a relative hazard, is typically used to compare time to event data between two treatment groups. The hazard ratio of death for the intervention group compared with the control group was 0.46 (0.22 to 0.95). The hazard ratio was derived as the ratio of the hazard of death for the intervention group to the hazard of death for the placebo group across the study period. To derive the hazard of death for a treatment group, the study period was conceptually divided into very short time intervals.
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Interpreting hazard ratios. The impact of isoniazid prophylaxis on mortality and tuberculosis in children with HIV was investigated using a double blind placebo controlled trial. The intervention was isoniazid given with co-trimoxazole either daily or three times a week.
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hazard ratio listen (HA-zurd RAY-shee-oh) A measure of how often a particular event happens in one group compared to how often it happens in another group, over time.
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Examples of the variable relationship between the hazard ratio and median ratio with clinical trials of antiviral agents as examples. While more than one drug dose was tested in two of the examples, outcomes were similar, and the statistics shown could ...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC478551/
Interpreting hazard ratios. 1  a) When calculating the hazard ratio of death, it was assumed that the death rate was constant during follow-up for each treatment group. 2  b) The intervention group had a 54% lower risk of mortality than the control group at any time during follow-up.
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The hazard ratio of death for the intervention group compared with the control group was 0.46 (0.22 to 0.95), which is smaller than unity (1.0). Therefore, the hazard of death in the isoniazid prophylaxis group was less than that in the control group.
http://www.bmj.com/content/351/bmj.h4631
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http://www.bmj.com/content/351/bmj.h4631
NCI Dictionary of Cancer Terms. The NCI Dictionary of Cancer Terms features 8,108 terms related to cancer and medicine. We offer a widget that you can add to your website to let users look up cancer-related terms. Get NCI’s Dictionary of Cancer Terms Widget.
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The hazard ratio is a clinical trial statistic that allows the physician to say with confidence that healing is faster with the new drug. The hazard ratio must be >1 and the lower limit of the 95% confidence interval of the hazard ratio must be >1, which was the case in this example.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC478551/
hazard ratios
The hazard ratio, sometimes called a relative hazard, is typically used to compare time to event data between two treatment groups.