Answer Happy

The Log Rank Test O tests for significant risk factors associated with the event of interest O tests if the proportion surviving at time zero = 1.0 O tests if there is a significant difference in the Hazard Ratios between two groups O tests if the correlation coefficient = 0
The chart below shows Kaplan-Meier curves for the cumulative risk of dementia among elderly persons who frequently played board games such as chess, checkers, backgammon, or cards at baseline as compared with subjects who rarely played such games. 1.0 0.9 0.8 0.7 Played frequently (n=103) 0.6 Proportion Surviving Free of Dementia 0.5 0.4 0.3 Played Rarely (n=366) 0.2 0.1 0.0 0 5 10 15 20 Years of follow-up The chart indicates: O The median time to suffer dementia for subjects who played games frequently is about 7.5 years O Subjects who rarely played games take longer to suffer dementia than those that played frequently O Subjects who rarely played games have the same Hazard ratio as those that played frequently O Subjects who frequently played games take longer to suffer dementia than those that rarely played