Skin cancer clinics in Australia: workload profile and performance indicators from an analysis of billing data

Objective: To describe the workload profile in a network of Australian skin cancer clinics. Design and setting: Analysis of billing data for the first 6 months of 2005 in a primary-care skin cancer clinic network, consisting of seven clinics and staffed by 20 doctors, located in the Northern Territory, Queensland and New South Wales. Main outcome measures: Consultation to biopsy ratio (CBR); biopsy to treatment ratio (BTR); number of benign naevi excised per melanoma (number needed to treat [NNT]). Results: Of 69780 billed activities, 34 622 (49.6%) were consultations, 19 358 (27.7%) biopsies, 8055 (11.5%) surgical excisions, 2804 (4.0%) additional surgical repairs, 1613 (2.3%) non-surgical treatments of cancers and 3328 (4.8%) treatments of premalignant or non-malignant lesions. A total of 6438 cancers were treated (116 melanomas by excision, 4709 non-melanoma skin cancers [NMSCs] by excision, and 1613 NMSCs non-surgically); 5251 (65.2%) surgical wounds were repaired by direct suture, 2651 (32.9%) by a flap (of which 44.8% were simple flaps), 42 (0.5%) by wedge excision and 111 (1.4%) by grafts. The CBR was 1.79, the BTR was 3.1 and the NNT was 28.6. Conclusions: In this network of Australian skin cancer clinics, one in three biopsies identified a skin cancer (BTR, 3.1), and about 29 benign lesions were excised per melanoma (NNT, 28.6). The estimated NNT was similar to that reported previously in general practice. More data are needed on health outcomes, including effectiveness of treatment and surgical repair.

Niveo-eolian Sediment Deposits in Coastal South Victoria Land, Antarctica: Indicators of Regional Variability in Weather and Climate

A 35 year chronology from 1965 to 2000 of the deposition of wind-blown sediment is constructed from snowpits for coastal southern Victoria Land, Antarctica. Analysis of local meteorology, contemporary eolian sedimentation, and mineralogy confirm a Victoria Valley provenance, while the presence of volcanic tephra is ascribed to an Erebus volcanic province source. Winter foelm winds associated with anticyclonic circulation are considered responsible for transporting fine-grained sediment from the snow- and ice-free Victoria Valley east toward the coast, while cyclonic storms transport tephra north along the Scott Coast. No trend could be identified in the occurrence of either tephra or wind-blown sediments sourced from the Victoria Valley and retrieved from the snowpits; excavated on the Victoria Lower and Wilson Piedmont Glaciers. We infer this to indicate that the region has not undergone a significant change in weather patterns for at least the last 35 years. Our results also confirm the McMurdo Dry Valleys as a regionally significant source of wind-blown sediment.

A bibliographic snapshot of the telemedicine citation literature

There appear to have been no previous literature-based or literature-oriented studies in telemedicine which have analysed raw citation data. Using a simple search strategy, the Web of Science was analysed up to the end of 2005 to give a snapshot of the field, and to identify matters which would need to be considered in larger scale bibliometric studies. Of the 3673 telemedicine documents retrieved, 2213 (60%) had been cited. Of 56,875 citation records, 32,460 unique citation formats were found. The most-cited paper, and the paper with the greatest annual citation rate, was Perednia and Allen's review article in JAMA, 1995. The two specialist telemedicine journals published 40% of all papers retrieved. In the general literature (i.e. excluding the two specialist journals) there were 1556 citations to their 1374 'citable' articles, apportioned in the ratio 76:24, almost exactly in accordance with the distribution of the articles themselves. However, each of the two specialist telemedicine journals cited itself in a proportion higher than its share of original articles, with an 'excess' of self-citations of 14% in the journal of Telemedicine and Telecare, and 19% in the Telemedicine journal and E-Health. Despite certain technical difficulties, there is considerable scope for bibliometric research in telemedicine.

Linking riparian vegetation spatial structure in Australian tropical savannas to ecosystem health indicators: semi-variogram analysis of high spatial resolution satellite imagery

Government agencies responsible for riparian environments are assessing the combined utility of field survey and remote sensing for mapping and monitoring indicators of riparian zone health. The objective of this work was to determine if the structural attributes of savanna riparian zones in northern Australia can be detected from commercially available remotely sensed image data. Two QuickBird images and coincident field data covering sections of the Daly River and the South Alligator River - Barramundie Creek in the Northern Territory were used. Semi-variograms were calculated to determine the characteristic spatial scales of riparian zone features, both vegetative and landform. Interpretation of semi-variograms showed that structural dimensions of riparian environments could be detected and estimated from the QuickBird image data. The results also show that selecting the correct spatial resolution and spectral bands is essential to maximize the accuracy of mapping spatial characteristics of savanna riparian features. The distribution of foliage projective cover of riparian vegetation affected spectral reflectance variations in individual spectral bands differently. Pan-sharpened image data enabled small-scale information extraction (< 6 m) on riparian zone structural parameters. The semi-variogram analysis results provide the basis for an inversion approach using high spatial resolution satellite image data to map indicators of savanna riparian zone health.

Mapping indicators of riparian vegetation health using IKONOS and Landsat-7 ETM+ image data in Australian tropical savannas

Government agencies responsible for riparian environments are assessing the utility of remote sensing for mapping and monitoring environmental health indicators. The objective of this work was to evaluate IKONOS and Landsat-7 ETM+ imagery for mapping riparian vegetation health indicators in tropical savannas for a section of Keelbottom Creek, Queensland, Australia. Vegetation indices and image texture from IKONOS data were used for estimating percentage canopy cover (r2=0.86). Pan-sharpened IKONOS data were used to map riparian species composition (overall accuracy=55%) and riparian zone width (accuracy within 4 m). Tree crowns could not be automatically delineated due to the lack of contrast between canopies and adjacent grass cover. The ETM+ imagery was suited for mapping the extent of riparian zones. Results presented demonstrate the capabilities of high and moderate spatial resolution imagery for mapping properties of riparian zones, which may be used as riparian environmental health indicators