Table 2.
Percent Reduction (Increase) in Sample Mean Difference (Treated–Untreated) from PS Methods for the Measured Covariate XM, and the Independent Portions of the Unmeasured Covariates Affecting Treatment Choice R1, R3, and R4
Scenario 1 | Scenario 2 | Scenario 3 | Scenario 4 | Scenario 5 | Scenario 6 | Scenario 7 | Scenario 8 | |
---|---|---|---|---|---|---|---|---|
XM | ||||||||
Binning* | 95.5% | 95.7% | 93.5% | 94.9% | 91.1% | n/a | n/a | n/a |
Matching† | 85.7 | 95.4 | 98.9 | 97.7 | 99.1 | 99.2% | 99.0% | 98.4% |
Weighting | 100.8 | 101.3 | 122.6 | 100.0 | 61.3 | 22.7 | 16.8 | 15.0 |
R1 | ||||||||
Binning* | −4.4 | −20.0 | −81.5 | −42.0 | −157.4 | n/a | n/a | n/a |
Matching† | −3.9 | −19.6 | −76.1 | −40.0 | −130.2 | −323.5 | −720.0 | −2,200.0 |
Weighting | −4.6 | −21.9 | −117.9 | −53.3 | −88.6 | −75.0 | −33.3 | −66.7 |
R3 | ||||||||
Binning* | −4.5 | −20.3 | −82.8 | −41.5 | −155.1 | n/a | n/a | n/a |
Matching† | −3.8 | −19.7 | −75.6 | −28.0 | −134.9 | −343.8 | −730.0 | −2,300.0 |
Weighting | −4.6 | −21.4 | −111.0 | −51.6 | −101.2 | −71.9 | −70.0 | −40.0 |
R4 | ||||||||
Binning* | −4.2 | −19.9 | −83.3 | −41.3 | −155.3 | n/a | n/a | n/a |
Matching† | −4.2 | −18.5 | −74.4 | −38.5 | −131.4 | −334.4 | −740.0 | −2,500.0 |
Weighting | −4.9 | −21.6 | −111.3 | −53.8 | −95.3 | −68.8 | −60.0 | −70.0 |
Average across 5 PS-quintile “bins,” n/a when not all five bins contained patients.
For match tolerance value = 0.01 (for matched portion of total sample only).