Poor Adherence to National Clinical Management Guidelines: A Population-Based, Cross-Sectional Study of the Surgical Management of Melanoma in New South Wales, Australia.

Abstract

Standardization of the clinical management of melanoma through the formulation of national guidelines, based on interpretation of the existing evidence and consensus expert opinion, seeks to improve quality of care; however, adherence to national guidelines has not been well studied. A population-based, cross-sectional study of the clinical management of all patients with newly notified primary melanomas in the state of New South Wales, Australia, during 2006/2007 was conducted using cancer registry identification and questionnaires completed by treating physicians. Surgical margin guidelines were adhered to in 35% of cases; 45% were over treated and 21% were undertreated. Factors independently associated with non-concordance on multivariate analysis were lower Breslow thickness, lower socio-economic status of the physician's practice location, older physician age, lower physician caseload, and physicians who biopsied the lesion and then referred for definitive management. Complications were not related to over- or under-treatment on multivariate analysis (p=0.72). Sentinel lymph node biopsy was performed in 17% of patients with invasive melanoma, with the main determinant for selection being a Breslow thickness>0.75mm. The low level of concordance with national guidelines for surgical management of melanoma resulted in overtreatment of many patients. However, a fifth of patients were undertreated, which is likely to have resulted in increased locoregional recurrence rates. The better concordance achieved by physicians treating>30 melanomas per year suggests that a minimum caseload threshold for physicians treating melanoma patients would be desirable. High guideline concordance will ensure patients receive optimal care and minimize morbidity and health service costs.