Background: Skin cancer is common in Australia and its increasing incidence has been matched by an increase in specifically focused skin cancer clinics staffed by general practitioners. This study compares the management of skin cancer in general practice with that of skin cancer clinic networks.
Methods: Analysis of billing data relating to management of skin cancer from 1 July 2005 to 30 June 2006 in three Queensland general practices (metropolitan, provincial, and rural) representing 23 100 patients and 23 doctors. As far as possible, methods were matched to those used in two published studies of skin cancer clinics.
Results: Of the 1417 skin cancers: 31 melanomas and 1361 nonmelanoma skin cancers (NMSC) were treated by excision, and 25 NMSC were treated nonsurgically. The biopsy to treatment ratio in general practice was 0.7 and the number needed to treat (NNT) was 39, compared with 3.1 and 29 in one skin cancer clinic network and 0.5 and 24 in the other. Eighty-seven percent of skin cancer excisions were closed by primary repair and 54% of all excised lesions were malignant, compared with 42 and 60% in one network and 76 and 46% in the other, respectively.
Discussion: The benign to malignant excision rate was similar in general practice and the skin cancer clinic networks, but one network reported very different rates of biopsy and complex wound closure. This raises questions as to whether outcomes are improved by these measures. These results demonstrate the usefulness of three billing data outcome measures in comparing activity in different clinical settings. However, the billing based NNT may not be a useful measure.