Table 1.

Change point Cox PH simulation results. Covariates X and Y are generated from Uniform[0, 1]. Parameters in hazard function are λ₀ = 0.01, β₁ = 3, β₂₀ = 0.1, and β₂₁ = 15. The change point τ = 8.59 is selected such that C_TX = C_TY = 0.655 based on 100,000 simulations. Parameters λ for exponential censoring and c₂ for uniform (0, c₂) censoring are chosen to achieve the desired censoring proportions.

Censoring distribution / n	% censor	ĈTX	ĈTY	ĈTX − ĈTY	% Reject H0 at α = 5%	% Reject H0 at α = 10%
Exponential n=100	0%	0.655	0.655	0.000	5.6%	10.7%
	10%	0.661	0.642	0.020	7.6%	13.3%
	20%	0.669	0.627	0.042	12.7%	20.3%
	33%	0.679	0.604	0.075	24.6%	35.4%
	50%	0.694	0.575	0.119	41.8%	54.2%
n=200	0%	0.655	0.655	0.000	5.5%	10.3%
	10%	0.661	0.642	0.019	8.9%	15.7%
	20%	0.668	0.627	0.041	19.0%	27.9%
	33%	0.678	0.604	0.075	41.5%	53.6%
	50%	0.693	0.571	0.123	70.7%	80.9%
n=500	0%	0.655	0.655	0.000	4.7%	9.8%
	10%	0.661	0.642	0.019	12.6%	20.8%
	20%	0.668	0.627	0.041	37.1%	50.3%
	33%	0.679	0.604	0.075	79.3%	87.6%
	50%	0.694	0.569	0.125	97.7%	99.1%
Uniform n=100	10%	0.661	0.641	0.020	8.1%	13.8%
	20%	0.669	0.625	0.044	13.1%	21.4%
	33%	0.679	0.602	0.077	26.9%	37.5%
	50%	0.697	0.568	0.129	51.5%	62.9%
n=200	10%	0.661	0.642	0.019	8.8%	15.3%
	20%	0.669	0.626	0.043	20.7%	30.3%
	33%	0.68	0.602	0.077	44.7%	56.6%
	50%	0.698	0.563	0.135	80.1%	87.7%
n=500	10%	0.661	0.642	0.019	12.7%	21.1%
	20%	0.669	0.626	0.042	40.7%	52.9%
	33%	0.679	0.603	0.077	81.6%	89.1%
	50%	0.697	0.562	0.135	99.3%	99.7%