A Study Prospectively Examined Whether Sleep-Disordered Breathing Was Associated with an Increased

Multiple Choice

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6294 men and women participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe) . The counts of deaths over the course of the study are reported for each group in the following two-way table:
$$\begin{array}{l}\begin{array} { | l | r r r r | } \hline &&& { \text { sleep-disordered breathing } } \\& \text { none } & \text { mild } & \text { moderate } & \text { severe } &\text { total } \\\hline \text { death } & 476 & 320 & 165 & 86 &1047\\\text { no death } & 2953 & 1477 & 562 & 255 &5247\\\hline \text { total } & 3429 & 1797 & 727 & 341 \\\hline\end{array}\\\begin{array} { l } \end{array}\end{array}$$ What is the best comparison group for the proportion of people who died among those with no sleep-disordered breathing?

A) Only about half the proportion who died among those with severe sleep-disordered breathing
B) Approximately twice the proportion who died among those with severe sleep-disordered breathing
C) Only about one-tenth of the proportion who died among those with severe sleep-disordered breathing
D) Approximately 10 times the proportion who died among those with severe sleep-disordered breathing