Abstract
Background: Clinical practice guidelines (cpgs) are systematically developed statements designed to assist practitioners and patients in making decisions about appropriate heath care interventions. Clinical practice guidelines are expensive and time-consuming to create. A cpg on concurrent chemotherapy with radiation therapy (ccrt) was developed in Ontario at a time when treatment approaches for head-and-neck cancer were changing significantly. Methods: An assessment of treatments and outcomes based on electronic and chart data obtained from a population-based study of 571 patients with oropharynx cancer treated in Ontario (2003–2004) was combined with a review of relevant knowledge transfer (publications and presentations at major meetings) to understand variation in adherence to a cpg. Results: In 9 Ontario cancer treatment centres, ccrt was used for 55% of all patients with oropharyngeal cancer; however, at the centres individually, that proportion ranged from 82% to 39%. Furthermore, there was no agreement on the chemotherapy regimen: 2–4 years later (a period during which newer regimens were emerging), only 4 of 9 centres were following the guideline for most patients. When outcomes of treated patients were compared for centres with “higher” and “lower” use of ccrt, no difference in survival was observed (p = 0.64). Conclusions: At a time of treatment evolution, the new guideline was controversial, and there are many reasons for the mixed adherence. An estimation of adherence should be included during both development and review of guidelines.