Background and purpose: An evidence-based clinical practice guideline for laryngeal carcinomas was introduced in the Netherlands late 1999. The objective of this guideline was to ensure uniformity in the diagnosis, treatment, and follow-up. We retrospectively evaluated whether clinical practice changed according to the recommendations of this guideline and whether it succeeded in its aim.
Material and methods: In five out of eight Dutch university hospitals, chart data of 459 patients treated before the guideline introduction were compared to data of 363 patients treated after the guideline introduction.
Results: Patient and tumour characteristics were comparable among both groups. In general, the guideline recommendations were properly complied with. The patients treated before the guideline introduction were actually also for a large part already treated according to the guideline's recommendations. After its introduction, several changes according to the guideline were observed: increased rates of reassessment of biopsy samples taken in local hospitals, psychological screening (although still only performed in 10.5% of patients), application of accelerated radiotherapy schedules, clinical trial treatments, function-preserving treatments, and decreased rates of total laryngectomy, and annual chest X-rays during follow-up.
Conclusions: Although a causal relationship cannot be established in this kind of observational studies, several positive changes were observed after the introduction of the guideline, and therefore the guideline seems to have contributed to more uniformity. The largest changes were seen for the guideline recommendations based on the highest levels of evidence.