Lagerbäck T, Fritzell P, Hägg O, et al. - Data from the national spine registers in Sweden, Denmark and Norway during 2011–2013 were pooled, and 9,965 individuals, aged 18–65 years, of which 6,468 had one-year follow-up data, were involved in the study in order to investigate whether variations in surgical incidence were related to disparities in preoperative patient features as well as patient-reported outcomes. In the outcome variables, the mean improvement surpassed formerly defined minimal clinical significant variation in all countries. In Sweden, Denmark, and Norway, the mean final scores of the Oswestry Disability Index were 18, 19 and 15, respectively. Corresponding outcomes of EQ-5D-3L were 0.74, 0.73 and 0.75. Results of Numerical Rating Scale leg and back pain functioned likewise. The findings were not substantially modified by Case-mix adjustment. Therefore, no clear relationship between the incidence of surgery for lumbar disc herniation and preoperative patient features as well as the outcome was discovered, and compared with the minimal clinical significant variation in all outcomes, the disparities between the countries were lower.