Fig. 2

Population base and number of surgeries by year of surgery. Number of persons, age 65 y or older living in the studied healthcare regions and number of surgeries performed, incidence rate, OR for having surgery, and corresponding p-value by year of surgery. # - n of persons, age 65 y or older (bars); ¤ - n of surgeries performed (line); $ - incidence rate of surgery per 100,000 for each year; £ - OR for having surgery from univariate logistic regression with 1999 as index year. p-value for the regression < 0.001