Differential effects play a special role in certain observational studies in which treatments are not assigned to subjects at random, where differing outcomes may reflect biased assignments rather than effects caused by the treatments.
Definition
editFor two treatments, differential effects is the effect of applying one treatment in lieu of the other.[1] Differential effects are not immune to differential biases, whose possible consequences are examined by sensitivity analysis.
Methods
editIn statistics and data science, causality is often tested via regression analysis. Several methods can be used to distinguish actual differential effects from spurious correlations. First, the balancing score (namely propensity score) matching method can be implemented for controlling the covariate balance.[2] Second, the difference-in-differences (DID) method with a parallel trend assumption (2 groups would show a parallel trend if neither of them experienced the treatment effect) is a useful method to reduce the impact of extraneous factors and selection bias.[3] The differential effect of treatments (DET) was explored using several examples and models.
In the biomedicine area, differential effects of early hippocampal pathology[4] were investigated on episodic and semantic memory. The differential effects of apolipoproteins E3 and E4 were also examined on neuronal growth in vitro.[5]
See also
editReferences
edit- ^ Rosenbaum PR (1 September 2006). "Differential effects and generic biases in observational studies". Biometrika. 93 (3): 573–586. doi:10.1093/biomet/93.3.573. ISSN 1464-3510.
- ^ Yu H, Wang Y, Wang JN, Chiu YL, Qiu H, Gao M (July 2020). "Causal Effect of Honorary Titles on Physicians' Service Volumes in Online Health Communities: Retrospective Study". Journal of Medical Internet Research. 22 (7): e18527. doi:10.2196/18527. PMC 7380898. PMID 32673232.
- ^ Yu HY, Chen JJ, Wang JN, Chiu YL, Qiu H, Wang LY (June 2019). "Identification of the Differential Effect of City-Level on the Gini Coefficient of Health Service Delivery in Online Health Community". International Journal of Environmental Research and Public Health. 16 (13): 2314. doi:10.3390/ijerph16132314. PMC 6651774. PMID 31261952.
- ^ Vargha-Khadem F, Gadian DG, Watkins KE, Connelly A, Van Paesschen W, Mishkin M (July 1997). "Differential effects of early hippocampal pathology on episodic and semantic memory". Science. 277 (5324): 376–380. doi:10.1126/science.277.5324.376. PMID 9219696.
- ^ Nathan BP, Bellosta S, Sanan DA, Weisgraber KH, Mahley RW, Pitas RE (May 1994). "Differential effects of apolipoproteins E3 and E4 on neuronal growth in vitro". Science. 264 (5160): 850–852. Bibcode:1994Sci...264..850N. doi:10.1126/science.8171342. PMID 8171342.
