A study examines participation in cardiac rehabilitation in patients following their first-ever episode of myocardial infarction in Oakland County, Michigan, from 1991-2010. The following graphs are reported: Which of the following is the best statement based on the information presented?

Question

A study examines participation in cardiac rehabilitation in patients following their first-ever episode of myocardial infarction in Oakland County, Michigan, from 1991-2010.  The following graphs are reported:  Which of the following is the best statement based on the information presented?

Quizplus · Accepted Answer

Explanation: Based on the second graph, a larger percentage of men than women participate in cardiac rehabilitation, and the trend appears to be toward less participation over time. In contrast, participation seems lower among women and has a different trend compared to men. If no measure of statistical significance had been given, it would have been difficult to comment on the statistical significance of these differences over time. However, the p-value for the sex*year interaction is <0.05 and supports the interpretation that there are significant gender differences in the participation trend. A significant p-value for sex only would indicate that there are significant differences in participation between men and women, but it would not provide enough information to comment on the differences at different time points. Similarly, a significant p-value for year only would indicate that there are overall significant differences in participation over time, but it would not provide enough information to comment on the differences between men and women. (Choice A) Based on the first graph, only the young patients appear to show a decline in cardiac rehabilitation participation over time; participation does not seem to decline sharply for elderly patients (appears to have increased over time instead). (Choice B) It is difficult to establish a trend in women's participation in cardiac rehabilitation. There may be a trend toward increased participation but there is not enough information to comment on its statistical significance. Participation seems to have dropped in 2001-2005 compared to 1996-2000. (Choice C) There is no information provided regarding the benefits of participation in cardiac rehabilitation. (Choice E) The graphs do not give enough information about men and women in different age groups. Furthermore, higher participation among men would not necessarily be a reflection of higher motivation. Educational objective: Look for measures of statistical significance in order to interpret trends on graphs.

A Study Examines Participation in Cardiac Rehabilitation in Patients Following