Table 2.

Comparison of median survival (natural deaths) by laboratory. Overall comparison between all laboratories and pairwise comparisons between each laboratory pair are shown

Laboratory	N (observed)	Median	SE	95% CI	Overall	Pairwise comparisons of
		survival			p-value	median survival time
						between laboratories
Lab A	20	82	8.2	67–98	<0.0001	Lab A vs. Lab B (p < 0.001)
Lab B	34	44	2.2	37–47		Lab A vs. Lab C (p = NS)
Lab C	67	84	10.3	61–93		Lab A vs. Lab D (p < 0.001)
Lab D	16	34	5.3	24–39		Lab B vs. Lab C (p < 0.001)
						Lab B vs. Lab D (p = 0.03)
						Lab C vs. Lab D (p < 0.001)