A Proxy Outcome Approach for Causal Effect in Observational Studies: A Simulation Study
MetadataShow full item record
This article is published under the Open Access publishing model and distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0/. Please refer to the licence to obtain terms for any further reuse or distribution of this work.
Background: Known and unknown/unmeasured risk factors are the main sources of confounding effects in observational studies and can lead to false observations of elevated protective or hazardous effects. In this study, we investigate an alternative approach of analysis that is operated on field-specific knowledge rather than pure statistical assumptions. Method: The proposed approach introduces a proxy outcome into the estimation system. A proxy outcome possesses the following characteristics: (i) the exposure of interest is not a cause for the proxy outcome; (ii) causes of the proxy outcome and the study outcome are subsets of a collection of correlated variables. Based on these two conditions, the confounding-effect-driven association between the exposure and proxy outcome can then be measured and used as a proxy estimate for the effects of unknown/unmeasured confounders on the outcome of interest. Performance of this approach is tested by a simulation study, whereby 500 different scenarios are generated, with the causal factors of a proxy outcome and a study outcome being partly overlapped under low-to-moderate correlations. Results: The simulation results demonstrate that the conventional approach only led to a correct conclusion in 21% of the 500 scenarios, as compared to 72.2% for the alternative approach. Conclusion: The proposed method can be applied in observational studies in social science and health research that evaluates the health impact of behaviour and mental health problems.
Showing items related by title, author, creator and subject.
Liang, Wenbin; Chikritzhs, Tanya (2013)Background. The frequently reported protective effects of moderate alcohol consumption in observational studies may be due to unadjusted bias. Aim. To examine two new approaches that account for unknown confounding factors ...
Examining the relationship between heavy alcohol use and assaults: With adjustment for the effects of unmeasured confoundersLiang, Wenbin; Chikritzhs, Tanya (2015)Background. Experimental studies suggest that alcohol can lead to aggression in laboratory settings; however, it is impossible to test the causal relationship between alcohol use and real-life violence among humans in ...
Parsons, Miles James Gerard (2009)Techniques of single- and multi-beam active acoustics and the passive recording of fish vocalisations were employed to evaluate the benefits and limitations of each technique as a method for assessing and monitoring fish ...