Peto-Peto generalized Wilcoxon test

Shown in the app as peto_peto. Part of the method reference, under Survival and censored data.

When to use

Compare a censored continuous outcome across 2+ groups when detection limits overlap observed values (not rank-determinable).

What you provide

• Outcome: one numeric column.
• Group: one categorical column.

Options

Missing data

• Complete case (listwise deletion)

Multiple comparisons

• Holm
• Benjamini-Hochberg (false discovery rate)
• Bonferroni
• None (unadjusted)

Related methods

Other methods under Survival and censored data:

• Censored regression (Tobit-style)
• Kaplan-Meier (log-rank test)
• Cox proportional-hazards regression
• Weibull accelerated failure time regression
• Factors associated with outcome (time-to-event outcome)

Guides that discuss this method

• How to analyse values below the detection limit

Worked example

Celeus's result on a published or illustrative dataset, next to an independent computation and, where one exists, a published value. The data themselves are not reproduced here.

synthetic left-censored lab example (Peto-Peto test)

• Source: Illustrative or synthetic example data
• Licence: synthetic (no third-party content)
• Reference: Hand-authored synthetic example for the Peto-Peto test; not published data

Quantity	Celeus	Independent computation	Published value	Agrees
Test statistic	7.12991	7.12991	-	Yes
p-value	0.00758084	0.00758084	-	Yes

Validation report

References

1. Peto, R., Peto, J. (1972). Asymptotically efficient rank invariant test procedures. Journal of the Royal Statistical Society, Series A 135: 185-207. doi:10.2307/2344317 doi:10.2307/2344317
2. Helsel, D. R. (2012). Statistics for Censored Environmental Data Using Minitab and R. John Wiley & Sons, 2nd edition.