Table 2

The output of the Laupacis et al’s NNT estimators for a simulated ‘panss_survival.csv’ dataset

 NNT CI TR L CI TR U CI DL L CI DL U CI NBS L CI NBS U CI PBS L CI PBS U NNT-KM(7) 4.05 2.32 15.89 1.03 7.07 2.92 6.65 NA NA NNT-COX(7) 4.21 1.84 Inf 1.00 9.63 3.46 5.39 3.09 5.32 NNT(7|100) 2.30 1.00 Inf 1.00 24.14 1.90 2.89 1.70 2.90
• NNT: point estimate of the NNT.

• The output of the Laupacis et al’s NNT estimates for a simulated ‘panss_survival.csv’ dataset. The chosen fixed timepoint for adjustment is seven (ie, 7 months after the treatment admission), and the adjusted value of the baseline PANSS is 100. The table presents the point estimates of the unadjusted Kaplan-Meier NNT (NNT-KM(7)), marginal Cox NNT (NNT-COX(7)) and adjusted (NNT(7|100)) Laupacis et al’s NNT for a survival time until the discontinuation of the treatment. Additionally, the table presents the corresponding transformation-based (TR), delta-method-based (DL), non-parametric-bootstrap-based (NBS) and parametric-bootstrap-based (PBS) 95% CIs. Inf, infinity. For the unadjusted NNT point estimator, the PBS-based CI limits are not available (NA) since the NNT-KM is a non-parametric estimator.

• CI DL L, the lower limit of the 95% level delta-method-based CI; CI DL U, the upper limit of the 95% level delta-method-based CI; CI NBS L, lower limit of the 95% level non-parametric-bootstrap-based CI; CI NBS U, the upper limit of the 95% level non-parametric-bootstrap-based CI; CI PBS L, the lower limit of the 95% level parametric-bootstrap-based CI; CI PBS U, the upper limit of the 95% level parametric-bootstrap-based CI; CI TR L, the lower limit of the 95% level transformation-based CI; CI TR U, the upper limit of the 95% level transformation-based CI; Inf, Infinity; NA, Not available; NNT, number needed to treat; NNT(7|100), Cox regression-based estimator of the adjusted NNT for timepoint 7 and covariate value of 100; NNT-COX(7), Cox regression-based estimator of the marginal NNT for timepoint 7; NNT-KM(7), the Kaplan-Meier-based non-parametric maximum likelihood estimator of the unadjusted NNT for timepoint 7; PANSS, Positive and Negative Syndrome Scale.