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Medications
Published in Henry J. Woodford, Essential Geriatrics, 2022
The ARR can be used to calculate the number needed to treat (NNT). This can give a number that is easier to understand when assessing the risks and benefits of prescribing a medication. For the example given above:
Basic Science and Molecular Oncology
Published in Manit Arya, Taimur T. Shah, Jas S. Kalsi, Herman S. Fernando, Iqbal S. Shergill, Asif Muneer, Hashim U. Ahmed, MCQs for the FRCS(Urol) and Postgraduate Urology Examinations, 2020
Paul Cleaveland, Vijay Sangar, Noel Clarke
Prevalence is the number of people with a given disease, including new and previously diagnosed, in a specific population, at a given time point. Incidence is the number of events in a defined population over a given time period. NNT – number needed to treat, is the number of people needed to be treated to prevent one bad outcome. This is defined as 1/Absolute risk reduction or (events in control group) – (events in intervention group). Absolute risk reduction is the difference in the rate of events between the control and intervention group. Relative risk reduction is the proportion by which the intervention reduces the event rate. It tells you by how much the treatment reduced the risk of unfavourable outcomes compared to the group that did not have treatment.
Analyzing and integrating a body of knowledge: Systematic reviews and meta-analysis of evidence
Published in Milos Jenicek, Foundations of Evidence-Based Medicine, 2019
As explained in Chapter 9, number needed to treat (NNT) is a reciprocal of the absolute risk reduction (ARR); in other words, of risk difference or attributable risk. Given the fact that relative risk reduction can also be calculated as 1—relative risk or 1—odds ratio, NNTs can be derived from odds ratios or relative risks provided by systematic reviews. McQuay and Moore52 give formulas for the calculation of the number needed to treat from odds ratios and control event rates for preventive interventions as well as for treatment (Table 11.4).
Provider-directed analgesia for dental pain
Published in Expert Review of Clinical Pharmacology, 2023
The number-needed-to-treat (NNT) is a statistical measurement of the impact of a medication by estimating the number of patients that need to be treated in order to have an effect [69]. Numerical values are calculated per single agent or combination therapy, in which a lower NNT number indicates greater medical impact [69]. Along the same lines, the number-needed-to-treat-to-harm (NNH) provides a statistical estimate for the risk of harm (adverse side effects) if such medication(s) is/are prescribed [70]. Weil et al. [71] found, following a systematic review of the literature that acetaminophen is an effective and safe drug to treat postoperative pain following the removal of lower wisdom teeth at a dose of 1 g every 6 hours (4 g/day). The NNT and NNH were 3 and 33, respectively, for this regimen [71]. Deshpande et al. [72] suggested a dosage of 500 mg every 8 hours (1.5 g/day) for effective pain control following routine, uncomplicated extractions. Although the safest, efficacious regimen of acetaminophen to treat dental pain remains to be established, findings from Deshpande et al. [72] and Weil et al. [71] studies provide guidance.
Effectiveness of topical glyceryl trinitrate in treatment of tendinopathy – systematic review and meta-analysis
Published in Disability and Rehabilitation, 2022
Mikhail Saltychev, Jouni Johansson, Viljami Kemppi, Juhani Juhola
An SMD is not an intuitively understandable type of effect size as it does not have any meaningful unit. However, it can be converted into meaningful estimates like the number needed to treat (NNT). The NNT around 2.5 was considered the indicator of effective treatment with moderate improvement over controls and NNT around 10 was considered pointing at mild effect. There is no consensus on the cut-offs for NNT, which can be used in all possible cases. The adequacy of NNT varies widely, depending on a clinical situation, a desirable outcome, the seriousness of the problem, etc. The cut-offs for NNT in this study were based on the authors’ experience and familiarity with published research on the topic. In this study, NNT, which defines the number of patients that should be treated to observe one favorable outcome was calculated using an online calculator available at https://rpsychologist.com/cohend/.
Differential Risk of Cancer Associated with Glucagon-like Peptide-1 Receptor Agonists: Analysis of Real-world Databases
Published in Endocrine Research, 2022
The association between categorical variables was examined using the Chi-square test. The adjusted OR (aOR) for various cancers in Explorys was calculated using multivariable logistic regression, with sex, age, smoking status, alcohol abuse history, hemoglobin A1c and BMI as covariates. The adjusted number needed to treat (NNT) was calculated using aOR and unexposed event rate (UER). The aOR for various cancers in FDA FAERS was calculated with Cochran-Mantel-Haenszel method with sex as the confounding factor. Pearson correlation test was performed to determine the significance of a trend. All tests were two-sided and p-value ≤ 0.05 was considered statistically significant. Statistical calculations including meta-analysis were made using R statistical software version 3.6.1 (R Foundation for Statistical Computing, Vienna, Austria). Graphs were generated using Prism 7 (GraphPad Software, San Diego, CA, USA).