C. D’Arcy J. Holman

OBJECTIVE: To investigate the lifetime risk of first-time incident pelvic organ prolapse (POP) surgery with the intention of updating previous risk estimates that have been based on members of managed-care populations. METHODS: Age-specific incidence rates of first-time prolapse surgery between 1981 and 2005 were calculated based on 44,728-incident cases. We estimated the lifetime risk as the cumulative incidence to age 85 years based on a life-table method and using the most recent cross-sectional incidence rates for the period 2001-2005. Age-standardized rates by calendar year were also calculated to show the secular trend in prolapse surgery. RESULTS: The lifetime risk of surgery for POP in the general female population was 19% based on the most recent cross-sectional rates, a figure higher than the 11-12% reported from U.S. managed-care populations. CONCLUSION: There is a relatively high likelihood that a woman in Western Australia will undergo surgery for POP during her lifetime. If, as our results suggest, the burden of genital prolapse in general populations is higher than previously thought, there is justification for a stronger evidence base for prevention, early detection and intervention to reduce the personal and societal costs of these gynecological conditions. LEVEL OF EVIDENCE: II.

OBJECTIVES: The report describes the strategic design, steps to full implementation and outcomes achieved by the Western Australian Data Linkage System (WADLS), instigated in 1995 to link up to 40 years of data from over 30 collections for an historical population of 3.7 million. Staged development has seen its expansion, initially from a linkage key to local health data sets, to encompass links to national and local health and welfare data sets, genealogical links and spatial references for mapping applications. APPLICATIONS: The WADLS has supported over 400 studies with over 250 journal publications and 35 graduate research degrees. Applications have occurred in health services utilisation and outcomes, aetiologic research, disease surveillance and needs analysis, and in methodologic research. BENEFITS: Longitudinal studies have become cheaper and more complete; deletion of duplicate records and correction of data artifacts have enhanced the quality of information assets; data linkage has conserved patient privacy; community machinery necessary for organised responses to health and social problems has been exercised; and the commercial return on research infrastructure investment has exceeded 1000%. Most importantly, there have been unbiased contributions to medical knowledge and identifiable advances in population health arising from the research.

Evidence associating malignant melanoma with semiquantitative and questionnaire indicators of past sunlight exposure is presented from a case-control study of 511 patients and 511 matched control subjects in Western Australia. That melanoma is related to sun exposure was supported by associations with actinic skin damage graded by cutaneous microtopography, history of nonmelanotic skin cancer, duration of residence of migrants to Australia, and mean annual hours of bright sunshine received at locations where the subjects had resided. Separate analyses of histogenetic subtypes revealed that Hutchinson's melanotic freckle melanoma had the strongest associations with indicators of sunlight exposure. For superficial spreading melanoma, a specific relationship was observed with age at arrival as against duration of residence in Australia. Migrants arriving before age 10 years appeared to have a risk similar to that of native-born Australians, whereas the estimated incidence in those arriving after age 15 years was around one-quarter of the native-born rate, with arrival at later ages giving no additional advantage. Control subjects arriving in Australia before age 10 years had an increased number of nevi on their arms, suggesting that sun exposure in early life may be a factor in nevus production and, therefore, a determinant of later potential to develop superficial spreading melanoma.