Greedy caliper propensity score matching can yield variable estimates of the treatment‐outcome association—A simulation study
Purpose Greedy caliper propensity score (PS) matching is dependent on randomness, which can ultimately affect causal estimates. We sought to investigate the variation introduced by this randomness. Methods Based on a literature search to define the simulation parameters, we simulated 36 cohorts of d...
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Published in | Pharmacoepidemiology and drug safety Vol. 30; no. 7; pp. 934 - 951 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Inc
01.07.2021
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Purpose
Greedy caliper propensity score (PS) matching is dependent on randomness, which can ultimately affect causal estimates. We sought to investigate the variation introduced by this randomness.
Methods
Based on a literature search to define the simulation parameters, we simulated 36 cohorts of different sizes, treatment prevalence, outcome prevalence, treatment‐outcome‐association. We performed 1:1 caliper and nearest neighbor (NN) caliper PS‐matching and repeated this 1000 times in the same cohort, before calculating the treatment‐outcome association.
Results
Repeating caliper and NN caliper matching in the same cohort yielded large variations in effect estimates, in all 36 scenarios, with both types of matching. The largest variation was found in smaller cohorts, where the odds ratio (OR) ranged from 0.53 to 10.00 (IQR of ORs: 1.11‐1.67). The 95% confidence interval was not consistently overlapping a neutral association after repeating the matching with both algorithms. We confirmed these findings in a noninterventional example study.
Conclusion
Caliper PS‐matching can yield highly variable estimates of the treatment‐outcome association if the analysis is repeated. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1053-8569 1099-1557 1099-1557 |
DOI: | 10.1002/pds.5232 |