Background and purpose: Coronary artery angiography (CAG) and percutaneous transluminal coronary angioplasty (PTCA) are important procedures for the diagnosis and treatment of patients with coronary artery disease. However, long-term trends in the frequency of CAG and PTCA use and their relation to gender have not been clearly determined in the Asian population. The purpose of this study was to investigate gender differences in the patterns of CAG and PTCA use in a university hospital in Taiwan during the period of 1983 through 1996.
Methods: We studied the monthly data of all patients who underwent CAG or PTCA in a university hospital in Taipei from 1983 through 1996. A time series analysis was used to estimate gender differences in the patterns of CAG and PTCA use.
Results: The frequency of CAG and PTCA increased significantly during this period. Before 1990, only a small number of patients underwent PTCA. However, this number increased steadily after 1990. Men were more likely to undergo CAG and PTCA than women. A time series analysis with fitted models was used to create an integrated moving average model. For CAG, the value of the estimated intercept for men was 2.5 times greater than that for women. In the PTCA series, the value of the intercept in men was 4.4 times greater than that in women. The patterns of trend change showed greater increases in men than in women, and a greater increase in the PTCA than in the CAG series. By transfer function modeling and intervention analysis, we found that the effect of CAG on the frequency of PTCA in men was 1.8 times greater than its effect in women. The estimated influence of the use of a new catheterization room (added in 1993) was 2.8 times greater in men than in women. The fitted model correlated well with the observed values in the next 12 months for both genders.
Conclusions: We concluded that women had fewer CAG and PTCA procedures than men, and the influence of CAG on the PTCA series was significantly higher in men than in women.