The evidence of effectiveness of operative treatment of lumbar disc herniation (LDH) is based on findings from RCTs published during the last couple of decades. The applicability of these findings to clinical practise has not previously been evaluated by comparison with nationwide registry data. Our purpose was to assess the clinical homogeneity of the randomised controlled trials, to evaluate the applicability of the findings to the clinical reality utilizing FinSpine registry data and to propose ways to improve the applicability in the future.

A systematic literature search was undertaken to find the RCTs. The benchmarking method compatible with the CONSORT statement was used to document and compare the characteristics of the RCTs and FinSpine registry population.

Six RCTs comparing operative treatment of LDH to different methods of conservative treatment showed heterogeneity of patients’ clinical characteristics in trial protocols and in actual experiments and a poor adherence to intervention groups. Patient groups were not representative of the catchment area in any of the RCTs. The completeness of documentation of clinically relevant characteristics was limited in all of the RCTs. Despite the deficiencies, the RCT results on operative treatment were comparable with FinSpine registry results.

The clinical heterogeneity of the RCTs, non-representative patient populations, incomplete reporting of patient characteristics and poor adherence to treatment groups limit generalizability and applicability of the existing RCTs’ results. Our findings mark a need for future pragmatic RCTs as well as clinical registry-based studies to improve the evidence for decision making in real-life settings.