Skin cancer clinics in Australia: workload profile and performance indicators from an analysis of billing data
Authors: Alvin L K Chia and Stephen Shumack
Published online: 21 August 2006
To the Editor: We read with alarm the skin cancer clinic profile published recently in the Journal.1 This article publicly states what has been privately suggested for some time — that doctors in skin cancer clinics provide a service no better than the average Australian general practitioner.
Surely, if these doctors are calling themselves skin cancer “experts”, the aim of their practice should be to reduce the skin biopsy rate. This is obviously not the case. They report a consultation to biopsy ratio of 1.79. Thus, 56% of all their consultations result in a skin biopsy. The biopsy to treatment ratio of 3.1 is also very high. In addition, they report that only 32% of all biopsies yield a non-melanoma skin cancer. This figure indicates either no additional diagnostic ability on the part of the skin cancer clinic doctors compared with the average Australian GP (who, according to a recent retrospective study, can clinically diagnose a basal cell carcinoma 34% of the time2) or an effort to maximise income.
Similarly, the article describes a number needed to treat (NNT) of 28.6. This means that for every 29 benign lesions excised and sent for histological examination to exclude melanoma, only one melanoma is detected. The authors concede that this figure is equivalent to that observed in mainstream general practice. We therefore question the motives of doctors at these clinics in presenting themselves as skin cancer “experts”.
However, perhaps the greatest indicator of their seeming intent to maximise financial gain can be demonstrated by an analysis of skin flap item numbers. The article indicates that the total number of excisions was 8055, of which 116 were melanomas and 4709 were non-melanoma skin cancers (ie, 4825 cancers were excised). If one assumes that a suspicious or benign mole biopsy is never closed with a skin flap repair (standard clinical practice), then, of the 4825 skin cancers excised, 2651 (55%) were closed with a flap procedure, and of these, 55% were either “complicated” or “site-specific” flap repairs. There were only 111 skin grafts performed out of the 4825 cancers excised (2.3%). Thus, more than half of the skin cancers excised were closed with a flap repair! Moreover, more than half of the flaps used were “complicated” or “site-specific” flaps, with 24 flaps performed for every skin graft! Surely, no one can argue that these figures are reasonable or consistent with good clinical practice. In comparison, current Australian Medicare data indicate that dermatologists and specialist surgeons close large skin cancer excisions (lesions > 2 cm on the trunk [item number 31290]) with skin flaps at rates of 15% and 17%, respectively (Andrew Miller, Australian Medical Association Skin Representative Group, personal communication). Large lesions normally require a higher skin flap closure rate than smaller lesions. Hence, a flap repair rate of 55% — for lesions of all sizes and sites — reported by the skin cancer clinic doctors is all the more extraordinary.
We believe that the above suggests that many skin cancer clinic practitioners are more concerned with maximising income than improving patient care.
References
- Wilkinson D, Askew DA, Dixon A. Skin cancer clinics in Australia: workload profile and performance indicators from an analysis of billing data. Med J Aust 2006; 184: 162-164.
- Tran H, Chen K, Lim A, et al. Assessing diagnostic skill in dermatology: a comparison between general practitioners and dermatologists. Australas J Dermatol 2005; 46: 230-234. 0_pgfId-1120120