ArticleBritish journal of clinical pharmacology2008
Clinically informative measures of the effect of drugs or other interventions.
Article in British journal of clinical pharmacology, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
1 citing paper in PubMed, 4 citations in OpenAlex.
- Drug regulation & therapeutic efficacy.British journal of clinical pharmacology · 2008Article
Corrections and comments
- Commented on by
Authors and funding
4 authors at 2 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
what is already known about this subjectSeveral comparative measures (ratios, differences, or the number needed to treat) are used to express the effect of a drug or another intervention. These measures can vary in the way they are affected by the background risk measured from the reference group. WHAT THIS STUDY ADDS: This paper reviews the formulation, interpretation and limitations of measures of effect. We describe a little-known parameter, the attained effect or clinical result ratio, a positive reformulation of the relative risk difference, and suggest how available parameters can be best used to summarize results of studies of the effect of drugs. AIMS Measures to compare two drugs are often affected by the background risk in the reference group; a ceiling effect results when the background risk is small. We review measures of the effect of drugs, including a special formulation of the relative risk difference, the attained effect or clinical result ratio, that addresses background risk and ceiling effect.
methodsExisting measures are the risk and odds ratios, the absolute and relative risk differences, and the number needed to treat. The attained effect is defined as the observed gain in success (the difference of proportion of success between the two interventions), divided by the maximum attainable gain, the maximum proportion of success one can expect. We illustrate the relationship between these measures with published results of two meta-analyses.
resultsIn studies of the effectiveness of cell salvage, the baseline risk ranged between 8 and 95%. This variability affected the risk difference and number needed to treat, while the attained effect, with a ceiling residual risk of 2%, showed that the gain in success was half the maximum attainable gain. In studies of the effectiveness of therapy in patients infected by the human immunodeficiency virus, where the baseline risk was less variable, and there was no ceiling effect, the maximum attained effect indicated that the gain could be much smaller.
conclusionThe attained effect, interpreted as the proportion of effectiveness that remains to gain for future interventions, can usefully complete the number needed to treat as a clinically informative effect measure.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.