Table 4. Comparisons among different statistical tests for testing independence between stage at initial diagnosis and response to treatment in a previously treated lung cancer patient population.

Methods	P value	Clinical Interpretation
Chi-squared test	0.14	Initial diagnosis stage is not significantly associated with response rate
Gamma statistics	0.03	A significant negative monotone trend (Gamma statistics = −0.22, 95% confidence interval, −0.42 to −0.03) was observed in response rate as the initial diagnosis stage advances
Cochran-Armitage trend test	0.02	A significant negative linear trend was observed in response rate as the initial diagnosis stage advances