Browsing by Author "Vainio, Suvi"

In this thesis the mortality after coronary artery bypass surgery (CABG) is studied. The scope of the analysis are the perioperative 60 days. Aim of the analysis is to recognize and analyse the differences between the hospitals in mortality after sex, age, and most common comorbidities and complications have been controlled for. Data for the thesis is from Care Register for Health Care HILMO, also referred to as Hospital Discharge Register, administered by Institute for Health and Welfare (THL). Procedures are queried from the years 2014 to 2017. First CABG procedure per patient is included in the analysis. Comorbidities are queried from 10 years preceeding the operation and complications are queried from the period after the operation. All in all the data covers the operation for 6 766 patients and 217 deaths. Survival methods were used in the analysis, in particular Kaplan-Meier estimators and Cox regression. To concretize the results and the uncertainty Bootstrap-sampling is used. Analyses were performed with R-program. In absolute numbers death occurs seldom, in the data 3 % of the patients died within 60 days after the operation. There are differences between the hospitals in mortality: Compared to the hospital with smallest number the number of deaths is 1.3 to 2.4 times higher in the other hospitals, when a reference patient without comorbidities and complications is considered. As has been noted in previous studies also in this analysis women had a higher mortality after CABG surgery eventhough they comprise minority of the patients. One goal of the analysis was to assess whether the reporting register data could be refined following foosteps taken in the analysis. As the number of events is small, four years were combined into the analysis dataset. Time frame of the analysis, four years, is better suitable for research purposes than yearly reporting. The data could be extended with the help of other registers. Also the diagnosis codes for comorbidities and complications should be examined with care.