58 Matching Annotations
  1. Last 7 days
    1. Meta-analysis statistical procedures provide a measure of the difference between two groups thatis expressed in quantitative units that are comparable across studies

      The units are only "comparable across studies" if there weren't any mishaps (eg, clinical or methodological heterogeneity). If there's clinical heterogeneity, then we're probably comparing apples to oranges (ie, either participants, interventions, or outcomes are different among studies). If there's methodological heterogeneity, then that means there's a difference in study design

    1. PDF summary by Cochrane for planning a meta-analysis at the protocol stage. Gives guidance on how to anticipate & deal with various types of heterogeneity (clinical, methodological , & statistical). Link to paper

      Covers - ways to assess heterogeneity - courses of action if substantial heterogeneity is found - methods to examine the influence of effect modifiers (either to explore heterogeneity or because there's good reason to suggest specific features of participants/interventions/study types will influence effects of the intervention. - methods include subgroup analyses & meta-regression

    2. Statistical heterogeneity is the term given to differences in the effects of interventions and comesabout because of clinical and/or methodological differences between studies (ie it is a consequenceof clinical and/or methodological heterogeneity). Although some variation in the effects ofinterventions between studies will always exist, whether this variation is greater than what isexpected by chance alone needs to be determined.

      If the statistical heterogeneity is larger that what's expected by chance alone, then what does that imply? That there's either clinical or methodological heterogeneity within the pooled studies.

      What's the impact of the presence of clinical heterogeneity? The statistical heterogeneity (variation of effects/results of interventions) becomes greater than what's expected by chance alone

      What's happens if methodological heterogeneity is present? The statistical heterogeneity (variation of effects/results of interventions) becomes greater than what's expected by chance alone

  2. Aug 2022
  3. Apr 2022
  4. Mar 2022
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  6. Oct 2021
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  8. Aug 2021
    1. Rogers, J. P., Watson, C. J., Badenoch, J., Cross, B., Butler, M., Song, J., Hafeez, D., Morrin, H., Rengasamy, E. R., Thomas, L., Ralovska, S., Smakowski, A., Sundaram, R. D., Hunt, C. K., Lim, M. F., Aniwattanapong, D., Singh, V., Hussain, Z., Chakraborty, S., … Rooney, A. G. (2021). Neurology and neuropsychiatry of COVID-19: A systematic review and meta-analysis of the early literature reveals frequent CNS manifestations and key emerging narratives. Journal of Neurology, Neurosurgery & Psychiatry, jnnp-2021-326405. https://doi.org/10.1136/jnnp-2021-326405

  9. Jun 2021
  10. May 2021
    1. Chen, X., Chen, Z., Azman, A. S., Deng, X., Sun, R., Zhao, Z., Zheng, N., Chen, X., Lu, W., Zhuang, T., Yang, J., Viboud, C., Ajelli, M., Leung, D. T., & Yu, H. (2021). Serological evidence of human infection with SARS-CoV-2: A systematic review and meta-analysis. The Lancet Global Health, 0(0). https://doi.org/10.1016/S2214-109X(21)00026-7

  11. Mar 2021
  12. Feb 2021
  13. Jan 2021
    1. Weingarten. E., Chen. Q., McAdams., Yi. J., (2016). From Primed Concepts to Action: A Meta-Analysis of the BehavioralEffects of Incidentally Presented Words. Psychological Bulletin 2016 (142) pp 472-497.

  14. Nov 2020
  15. Sep 2020
    1. Siemieniuk, R. A., Bartoszko, J. J., Ge, L., Zeraatkar, D., Izcovich, A., Kum, E., Pardo-Hernandez, H., Rochwerg, B., Lamontagne, F., Han, M. A., Liu, Q., Agarwal, A., Agoritsas, T., Chu, D. K., Couban, R., Darzi, A., Devji, T., Fang, B., Fang, C., … Brignardello-Petersen, R. (2020). Drug treatments for covid-19: Living systematic review and network meta-analysis. BMJ, 370. https://doi.org/10.1136/bmj.m2980

  16. Aug 2020
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  18. Jun 2020
    1. Chu, D. K., Akl, E. A., Duda, S., Solo, K., Yaacoub, S., Schünemann, H. J., Chu, D. K., Akl, E. A., El-harakeh, A., Bognanni, A., Lotfi, T., Loeb, M., Hajizadeh, A., Bak, A., Izcovich, A., Cuello-Garcia, C. A., Chen, C., Harris, D. J., Borowiack, E., … Schünemann, H. J. (2020). Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: A systematic review and meta-analysis. The Lancet, 0(0). https://doi.org/10.1016/S0140-6736(20)31142-9

  19. May 2020
    1. While somewhat modest in size, the literature on chronic tolerance to nicotine in humans is reasonably consistent in showing clear evidence of tolerance to subjective mood effects but little or no tolerance to cardiovascular, performance or other nicotine effects

      This is what I'd expect for tobacco, but it tells me little about nicotine. Most of the subjective effects are not from tobacco, so It's still plausible that nicotine does not develop tolerance. Indeed, the effects that don't go away are the effects expected from nicotine.

  20. Apr 2020
    1. Jefferson, T., Jones, M., Al Ansari, L. A., Bawazeer, G., Beller, E., Clark, J., Conly, J., Del Mar, C., Dooley, E., Ferroni, E., Glasziou, P., Hoffman, T., Thorning, S., & Van Driel, M. (2020). Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 1 - Face masks, eye protection and person distancing: Systematic review and meta-analysis [Preprint]. Public and Global Health. https://doi.org/10.1101/2020.03.30.20047217

  21. Jul 2018
  22. Feb 2018
  23. Apr 2016