# study interpretation

**URL:** https://discourse.datamethods.org/c/resmeth/studyinterp/31.md

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## [About the study interpretation category](https://discourse.datamethods.org/t/about-the-study-interpretation-category/54)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 0

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Interpretation of particular study results

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## [RCT & Synthetic Data Generating Processes](https://discourse.datamethods.org/t/rct-synthetic-data-generating-processes/28859)

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**Author:** [@llynn](https://discourse.datamethods.org/u/llynn)\
**Replies:** 0\
**Last updated:** [September 13, 2026, 1:09am UTC](https://discourse.datamethods.org/t/rct-synthetic-data-generating-processes/28859 "2026-09-13T01:09:07Z")

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Clinicians are increasing fatigued by trialists continued use of synthetic data generating processes (SDGPs) in RCT. Many years ago, in this forum, I called these “fake measurements” but that was too generous. A Synthe…

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## [Problems with NNT](https://discourse.datamethods.org/t/problems-with-nnt/195)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 37\
**Last updated:** [August 10, 2025, 9:45pm UTC](https://discourse.datamethods.org/t/problems-with-nnt/195 "2025-08-10T21:45:14Z")

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In talking to a patient or in making grand policy decisions, when the likely benefit of a treatment is being considered, it is wise to utilize both relative (e.g., hazard ratio) and absolute treatment effects. For the l…

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## [Non Inferiority vs Non significant](https://discourse.datamethods.org/t/non-inferiority-vs-non-significant/24002)

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**Author:** [@Lawrence\_Lynn](https://discourse.datamethods.org/u/Lawrence_Lynn)\
**Replies:** 17\
**Last updated:** [December 19, 2024, 10:07pm UTC](https://discourse.datamethods.org/t/non-inferiority-vs-non-significant/24002 "2024-12-19T22:07:39Z")

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I am trying to understand the conclusion of this PettyBone RCT published in JAMA Here Medpage Today summarizes the results as a potential guideline changing breakthrough for using PCT (an expensive biomarker) to guide…

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## [Immortal-time-bias vs. selection bias](https://discourse.datamethods.org/t/immortal-time-bias-vs-selection-bias/9447)

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**Author:** [@mksp](https://discourse.datamethods.org/u/mksp)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 2:23pm UTC](https://discourse.datamethods.org/t/immortal-time-bias-vs-selection-bias/9447 "2024-04-07T14:23:53Z")

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Esteemed Experts ! This is the definition of Immortal time bias on the Catalog of Bias “Immortal time bias: A distortion that modifies an association between an exposure and an outcome, caused when a cohort study is d…

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## [Language for communicating frequentist results about treatment effects](https://discourse.datamethods.org/t/language-for-communicating-frequentist-results-about-treatment-effects/934)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 200\
**Last updated:** [January 9, 2024, 11:32am UTC](https://discourse.datamethods.org/t/language-for-communicating-frequentist-results-about-treatment-effects/934 "2024-01-09T11:32:21Z")

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Correct interpretation of p \> 0.05: The current sample size did not yield sufficient evidence to reject, at the incredibly arbitrary 0.05 level, the supposition that the treatment does nothing, assuming data model M (de…

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## [Article: JAMA meta-analysis of Placebo response and cannabis based therapies for pain](https://discourse.datamethods.org/t/article-jama-meta-analysis-of-placebo-response-and-cannabis-based-therapies-for-pain/6255)

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**Author:** [@R\_cubed](https://discourse.datamethods.org/u/R_cubed)\
**Replies:** 2\
**Last updated:** [December 3, 2022, 12:16pm UTC](https://discourse.datamethods.org/t/article-jama-meta-analysis-of-placebo-response-and-cannabis-based-therapies-for-pain/6255 "2022-12-03T12:16:28Z")

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I came across a recently published meta-analysis that got some attention in the mainstream media: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2799017?utm\_source=For\_The\_Media&utm\_medium=referral&utm\_cam…

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## [Language regarding confidence in "negative" results](https://discourse.datamethods.org/t/language-regarding-confidence-in-negative-results/6094)

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**Author:** [@Elias\_Eythorsson](https://discourse.datamethods.org/u/Elias_Eythorsson)\
**Replies:** 0\
**Last updated:** [October 5, 2022, 10:58am UTC](https://discourse.datamethods.org/t/language-regarding-confidence-in-negative-results/6094 "2022-10-05T10:58:49Z")

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Exposure E is known to be a rare cause of a common condition C, which has many other possible causes. When C is caused by E, this is defined as a new clinical entity EC. To confirm EC an invasive and costly test is neede…

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## [Should adverse effects be adjusted for multiple comparisons?](https://discourse.datamethods.org/t/should-adverse-effects-be-adjusted-for-multiple-comparisons/5660)

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**Author:** [@KuTA](https://discourse.datamethods.org/u/KuTA)\
**Replies:** 4\
**Last updated:** [May 24, 2022, 3:11am UTC](https://discourse.datamethods.org/t/should-adverse-effects-be-adjusted-for-multiple-comparisons/5660 "2022-05-24T03:11:58Z")

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RCTs are powered for primary end points and adjustments for multiple comparisons are usually used for secondary end points but not for adverse effects. However, underpowered studies are prone to false positive or false n…

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## [Understanding "BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting\]"](https://discourse.datamethods.org/t/understanding-bnt162b2-mrna-covid-19-vaccine-in-a-nationwide-mass-vaccination-setting/5277)

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**Author:** [@felixw](https://discourse.datamethods.org/u/felixw)\
**Replies:** 0\
**Last updated:** [January 18, 2022, 6:49pm UTC](https://discourse.datamethods.org/t/understanding-bnt162b2-mrna-covid-19-vaccine-in-a-nationwide-mass-vaccination-setting/5277 "2022-01-18T18:49:53Z")

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Dear community, I am having a hard time to understand the statistical analyis in the often-cited work BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting and I was hoping that you can assist me. My …

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## [Delphi Method Consensus](https://discourse.datamethods.org/t/delphi-method-consensus/5162)

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**Author:** [@adr21](https://discourse.datamethods.org/u/adr21)\
**Replies:** 0\
**Last updated:** [December 9, 2021, 3:04am UTC](https://discourse.datamethods.org/t/delphi-method-consensus/5162 "2021-12-09T03:04:29Z")

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Hey all. I am running a Delphi study and after the first round I have consensus (Cronbach’s = 0.916 \> 0.80). Can I just stop here or do I need more rounds?

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## [Interpretation of the REGEN-COV trial](https://discourse.datamethods.org/t/interpretation-of-the-regen-cov-trial/4970)

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**Author:** [@eliast](https://discourse.datamethods.org/u/eliast)\
**Replies:** 22\
**Last updated:** [November 1, 2021, 12:57pm UTC](https://discourse.datamethods.org/t/interpretation-of-the-regen-cov-trial/4970 "2021-11-01T12:57:07Z")

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In the report of the trial comparing two doses of REGEN-COV vs. placebo, in which the composite of 29 days covid-19 related hospitalization or death was the primary outcome, the following statement summarised the primary…

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## [Mathematical behavior of the primary endpoint](https://discourse.datamethods.org/t/mathematical-behavior-of-the-primary-endpoint/2520)

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**Author:** [@llynn](https://discourse.datamethods.org/u/llynn)\
**Replies:** 13\
**Last updated:** [March 2, 2021, 8:59pm UTC](https://discourse.datamethods.org/t/mathematical-behavior-of-the-primary-endpoint/2520 "2021-03-02T20:59:20Z")

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I previously discussed critical care summation score of the APACHE class the discussion on CITRIS-ALI. I you missed the discussion I present some of the basics of APACHE class scoring in sections 18-20. I was in trainin…

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## [Making sense of significant interaction with null main effect in RCT](https://discourse.datamethods.org/t/making-sense-of-significant-interaction-with-null-main-effect-in-rct/3961)

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**Author:** [@MAR](https://discourse.datamethods.org/u/MAR)\
**Replies:** 3\
**Last updated:** [December 24, 2020, 4:20pm UTC](https://discourse.datamethods.org/t/making-sense-of-significant-interaction-with-null-main-effect-in-rct/3961 "2020-12-24T16:20:05Z")

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In a clinical trial comparing two interventions for patients with a disease that has been classified into two previously well-defined subgroups, we find that the main effect of intervention B compared to intervention A o…

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## [What are credible priors and what are skeptical priors?](https://discourse.datamethods.org/t/what-are-credible-priors-and-what-are-skeptical-priors/580)

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**Author:** [@Sander](https://discourse.datamethods.org/u/Sander)\
**Replies:** 62\
**Last updated:** [June 9, 2020, 8:43pm UTC](https://discourse.datamethods.org/t/what-are-credible-priors-and-what-are-skeptical-priors/580 "2020-06-09T20:43:48Z")

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A few weeks ago Dan Scharfstein asked a group of colleagues about how to report an odds ratio of 1.70 with 95% confidence limits of 0.96 and 3.02. Back-calculating from these statistics gives a two-sided P of 0.06 or 0.0…

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## [Lower limit of the confidence interval for measuring the magnitude of clinical benefit](https://discourse.datamethods.org/t/lower-limit-of-the-confidence-interval-for-measuring-the-magnitude-of-clinical-benefit/3181)

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**Author:** [@albertoca](https://discourse.datamethods.org/u/albertoca)\
**Replies:** 8\
**Last updated:** [April 17, 2020, 12:21pm UTC](https://discourse.datamethods.org/t/lower-limit-of-the-confidence-interval-for-measuring-the-magnitude-of-clinical-benefit/3181 "2020-04-17T12:21:05Z")

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Now there are many people rethinking the magnitude of therapeutic effects in oncology. One of the proposed tools is the ESMO clinical benefit scale. One of the controversial aspects of this scale is that the magnitude o…

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## [Very small effect size wih significant p-value](https://discourse.datamethods.org/t/very-small-effect-size-wih-significant-p-value/3160)

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**Author:** [@mamaru\_ayenew](https://discourse.datamethods.org/u/mamaru_ayenew)\
**Replies:** 9\
**Last updated:** [April 5, 2020, 8:33am UTC](https://discourse.datamethods.org/t/very-small-effect-size-wih-significant-p-value/3160 "2020-04-05T08:33:11Z")

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I did a statistical analysis to see the effect of lifestyle factors (physical activity, dietary intake and other covariates) on longitudinal weight gain among women using linear mixed models. The data were collected at s…

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## [What to interpret when observed effect size is smaller but statistically significant than expected effect size](https://discourse.datamethods.org/t/what-to-interpret-when-observed-effect-size-is-smaller-but-statistically-significant-than-expected-effect-size/675)

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**Author:** [@Madhu](https://discourse.datamethods.org/u/Madhu)\
**Replies:** 18\
**Last updated:** [January 29, 2020, 2:38pm UTC](https://discourse.datamethods.org/t/what-to-interpret-when-observed-effect-size-is-smaller-but-statistically-significant-than-expected-effect-size/675 "2020-01-29T14:38:25Z")

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I read a recent clinical trial where the researchers powered their study (80%) for an expected effect size of 4% absolute risk reduction. With the same sample size, they, however, report an absolute risk reduction of 3%,…

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## [Prophetic variable in survival analysis - or not?](https://discourse.datamethods.org/t/prophetic-variable-in-survival-analysis-or-not/2527)

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**Author:** [@tamas.ferenci](https://discourse.datamethods.org/u/tamas.ferenci)\
**Replies:** 3\
**Last updated:** [January 3, 2020, 9:25pm UTC](https://discourse.datamethods.org/t/prophetic-variable-in-survival-analysis-or-not/2527 "2020-01-03T21:25:38Z")

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Problems with using “prophetic” variables in survival analysis are well known. Just to fix concepts, let me quote Terry Therneau: This particular incorrect analysis is re-discovered every few years in oncology. (Or I s…

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## [Drawing inferences from frequentist point estimates with wide confidence intervals](https://discourse.datamethods.org/t/drawing-inferences-from-frequentist-point-estimates-with-wide-confidence-intervals/2785)

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**Author:** [@Doc\_Ed](https://discourse.datamethods.org/u/Doc_Ed)\
**Replies:** 2\
**Last updated:** [December 10, 2019, 4:14pm UTC](https://discourse.datamethods.org/t/drawing-inferences-from-frequentist-point-estimates-with-wide-confidence-intervals/2785 "2019-12-10T16:14:21Z")

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Dear community, Recently, the ICU-ROX trial reported its findings. This trial was an RCT randomising 1000 patients between conservative and usual oxygen in intensive care units. A post-hoc subgroup analysis investigati…

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## [Comparing Beta coefficients](https://discourse.datamethods.org/t/comparing-beta-coefficients/2491)

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**Author:** [@Theresac](https://discourse.datamethods.org/u/Theresac)\
**Replies:** 4\
**Last updated:** [October 11, 2019, 10:17am UTC](https://discourse.datamethods.org/t/comparing-beta-coefficients/2491 "2019-10-11T10:17:25Z")

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Hello Wanted to find out if Its ok to compare beta coefficients of a predictor variable from two different regression models. Is there a way to standardise them before comparing or can i just go ahead and compare them. …

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## [Fragility Index](https://discourse.datamethods.org/t/fragility-index/1920)

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**Author:** [@Doc\_Ed](https://discourse.datamethods.org/u/Doc_Ed)\
**Replies:** 31\
**Last updated:** [August 24, 2019, 4:34am UTC](https://discourse.datamethods.org/t/fragility-index/1920 "2019-08-24T04:34:45Z")

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There are a growing number of research papers that are proposing the use of the “Fragility Index” to be published alongside RCTs. Unsurprisingly, when this has been investigated in surgery, critical care (pubmed 26963326…

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## [Updates to NEJM Statistical Guidelines for Authors](https://discourse.datamethods.org/t/updates-to-nejm-statistical-guidelines-for-authors/1888)

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**Author:** [@f2harrell](https://discourse.datamethods.org/u/f2harrell)\
**Replies:** 20\
**Last updated:** [August 11, 2019, 1:03pm UTC](https://discourse.datamethods.org/t/updates-to-nejm-statistical-guidelines-for-authors/1888 "2019-08-11T13:03:54Z")

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The highly revered statistical consultants to the New England Journal of Medicine in conjunction with senior medical leaders have revised guidelines for statistical reporting in the journal. The new guidelines may be se…

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## [Interpreting the results of two non-inferiority trials](https://discourse.datamethods.org/t/interpreting-the-results-of-two-non-inferiority-trials/1877)

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**Author:** [@paulpharoah](https://discourse.datamethods.org/u/paulpharoah)\
**Replies:** 14\
**Last updated:** [July 31, 2019, 3:36pm UTC](https://discourse.datamethods.org/t/interpreting-the-results-of-two-non-inferiority-trials/1877 "2019-07-31T15:36:54Z")

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This is my first post on datamethods so I hope it is appropriate and of some interest. Colleagues of mine recently published a trial as one of two back-to-back papers in the Lancet (1, 2). The trials were addressing th…

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## [GRADE guidelines and effect estimate & CIs](https://discourse.datamethods.org/t/grade-guidelines-and-effect-estimate-cis/1283)

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**Author:** [@aleksi](https://discourse.datamethods.org/u/aleksi)\
**Replies:** 19\
**Last updated:** [July 10, 2019, 11:19am UTC](https://discourse.datamethods.org/t/grade-guidelines-and-effect-estimate-cis/1283 "2019-07-10T11:19:44Z")

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The GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) is very widely used tool to evaluate the certainty of evidence in healthcare. The GRADE approach is usually associated to meta-analy…

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## [Uncovering Waste in U.S. Healthcare](https://discourse.datamethods.org/t/uncovering-waste-in-u-s-healthcare/1763)

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**Author:** [@R\_cubed](https://discourse.datamethods.org/u/R_cubed)\
**Replies:** 0\
**Last updated:** [June 14, 2019, 3:03pm UTC](https://discourse.datamethods.org/t/uncovering-waste-in-u-s-healthcare/1763 "2019-06-14T15:03:09Z")

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I found this interesting: Uncovering Waste in U.S. Healthcare From the Abstract: Blockquote Outcomes are related to different types of treatment intensity, however: patients assigned to hospitals with high levels of…

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## [CREOLE Trial: Interpretation of results doesn't line up with statistical plan?](https://discourse.datamethods.org/t/creole-trial-interpretation-of-results-doesnt-line-up-with-statistical-plan/1530)

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**Author:** [@StanKogan](https://discourse.datamethods.org/u/StanKogan)\
**Replies:** 7\
**Last updated:** [March 30, 2019, 5:52pm UTC](https://discourse.datamethods.org/t/creole-trial-interpretation-of-results-doesnt-line-up-with-statistical-plan/1530 "2019-03-30T17:52:58Z")

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Hey all, this is my first post on this board. I was referred by Dr. Brian Byrd from Twitter. I would really appreciate any thoughts on how to interpret this recent paper: https://www.nejm.org/doi/full/10.1056/NEJMoa19011…

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## [Most reasonably hypothesised effects cannot be exactly zero?](https://discourse.datamethods.org/t/most-reasonably-hypothesised-effects-cannot-be-exactly-zero/1041)

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**Author:** [@TimWatkins](https://discourse.datamethods.org/u/TimWatkins)\
**Replies:** 13\
**Last updated:** [March 29, 2019, 11:00pm UTC](https://discourse.datamethods.org/t/most-reasonably-hypothesised-effects-cannot-be-exactly-zero/1041 "2019-03-29T23:00:42Z")

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A few authors over the years have suggested that, in most cases, effects (and all effects are causal by definition) cannot be exactly zero, at least in fields like health and the social sciences. For example: “All we kn…

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## [Treatment effect heterogeneity: or is it?](https://discourse.datamethods.org/t/treatment-effect-heterogeneity-or-is-it/1510)

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**Author:** [@byrdjb](https://discourse.datamethods.org/u/byrdjb)\
**Replies:** 12\
**Last updated:** [March 28, 2019, 1:19pm UTC](https://discourse.datamethods.org/t/treatment-effect-heterogeneity-or-is-it/1510 "2019-03-28T13:19:47Z")

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I frequently see the claim that humans respond differently to the same medication, and I believe this is true. Can we discuss how one would prove this & quantify it? You enroll 500 participants with BP \> 150/90 mm Hg, …

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## [What does it mean when a test/predictor is 'predictive on the aggregate level but not on the individual level'](https://discourse.datamethods.org/t/what-does-it-mean-when-a-test-predictor-is-predictive-on-the-aggregate-level-but-not-on-the-individual-level/1342)

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**Author:** [@duplex](https://discourse.datamethods.org/u/duplex)\
**Replies:** 3\
**Last updated:** [March 6, 2019, 2:39pm UTC](https://discourse.datamethods.org/t/what-does-it-mean-when-a-test-predictor-is-predictive-on-the-aggregate-level-but-not-on-the-individual-level/1342 "2019-03-06T14:39:36Z")

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I recently listened to the episode ‘What’s Wrong with the IAT? (with Jesse Singal)’ of the podcast ‘Two Psychologists Four Beers’ (https://fourbeers.fireside.fm/13). The hosts together with their guest Jessy Singal disc…

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