A Finnish study of coronary heart disease between 1978-1980 and 20002001 reported decreased prevalence of coronary heart disease among men and women aged 45 to 64 years, no change in prevalence among men and women aged 65 to 74 and increased incidence among people aged 75 and over (Kattainen, A. et al. 2004). Our results may reflect similar trends in age-related incidence of heart disease.
The second row of the table shows a significant increase in the survival rate to the next survey for people admitted to a hospital with cardiovascular disease. The survival rate increased by 4.3 percentage points, or about 7.5 percent. By itself, this would have led to an increase in disability from cardiovascular disease. This effect is overwhelmed, however, by the substantial reduction in disability among survivors, shown in the third row of the table. The share of CVD survivors who are disabled fell from 48 percent in 1989 to 39 percent in 1999, a 19 percent reduction. It is this massive reduction in event-specific disability that needs to be explained. canadian health and care mall
Before estimating formal statistical models to address the role of medical care in reduced CVD-related disability, we consider a less structural analysis of the role of medical care. Specifically, we look at how disability changed in the period shortly after the cardiovascular disease event relative to the period several years later. If the reduction in disability followed immediately after the cardiovascular event, it strongly suggests that medical treatment of the acute event was the major factor responsible for the reduction in disability. A disability reduction further out in time might be attributable to medical intervention, but other factors, such as better coping with limitations due to improved environmental factors, could be important as well.
Figure 4 shows the change in disability rates for people whose cardiovascular disease event happened within 6 months of the survey, by type of event. The rate of disability declined from 1984-1989 cohort to the 1994-1999 cohort for people with hospitalizations for ischemic heart disease, heart failure and arrhythmia, stroke and other cardiovascular disease. For heart failure and arrhythmia patients as well as other cardiovascular diseases, there were increases in the disability rate from the 1984-1989 to 1989-1994 cohorts that need further explanation. Overall, though, it seems that medical advances could have some role in this change decline in disability between 1984-1989 and 1994-1999.
To examine the role of medical technology changes in event-related reductions in disability more formally, we estimate regression models for the health of patients who have been admitted to a hospital with cardiovascular disease. Our sample is formed from each of the three cohorts. We select people who were admitted to a hospital with cardiovascular disease in the 1984-89 period, the 1989-94 period, and the 1994-99 period. In each case, the sample includes all people for whom we know health status at the beginning and end of the 5-year period. There are three possible health states at the end of each period, i.e. at the time of follow-up survey: dead; alive and non-disabled; and alive and disabled. We denote these possible outcomes with the subscript k.