Table 2: Mixed model analysis showing the effects of year of residency, number of previously performed procedures and type of operation on scores for GRS I and II. All estimates are significant (p < 0.001). The intercept can be interpreted as the mean of the outcome when all independent variables are zero. The estimates can be interpreted the same way as the estimates (coefficients) of predictors in a linear regression. GRS scores increase with 8.1 and 9.3 respectively per year of residency, and with 0.14 and 0.13 points respectively per number of previously performed arthroscopies. Scores for ACL-procedures are on average 12.5 and 13.0 points lower that KA scores.

Estimate (95% CI) Estimate (95% CI)
Intercept 34.4 (25.7-43.1) 29.4 (20.1-38.7)
Year of residency 8.1 (6.3-9.4) 9.3 (7.4-11.2)
No of arthroscopies 0.14 (0.1-0.2) 0.13 (0.1-0.2)
ACL-procedure -12.5 (-17.2- -7.8) -13.0 (-17.8- -7.8)

s.e.: standard error; CI: confidence interval.