Number, incidence, and projections of distal forearm fractures admitted to hospital in Australia.

BACKGROUND: This study documents the number, incidence, and relative risk (RR) of distal forearm fractures requiring admission to hospital in Australia in 1997 and estimates of the projected numbers for 2021. METHODS: Distal forearm fracture numbers from 1993 to 1998 were obtained. The incidence and RR were calculated by gender and 5-year age groups for 1997. Projected numbers for 2021 were estimated using population projection data. RESULTS: In 1997, fracture numbers were 12357 for male patients and 19319 for female patients. The incidence was 152 per 100000 for male patients and 157 per 100000 for female patients. The highest incidence and RR was in the 10- to 14-year age group for male patients and in the 85 years and over age group for female patients. If fracture incidence remains constant (on the basis of predicted population changes in Australia), by 2021, it is estimated that fracture numbers for people 50 years of age and over will increase by 81%, compared with 11% for people under 50. In the older age group, the number for women will be 4.7 times higher than for men. CONCLUSION: This study quantifies the potential disproportionate increase in distal forearm fractures requiring admission in Australia, particularly for female patients, because of an aging population.

Confidence limits of arteriovenous fistula flow rate measured by the "on-line" thermodilution technique.

BACKGROUND: A method is presented for estimating the confidence limits (CLs), or accuracy, of the arteriovenous fistula flow rate measured at haemodialysis by the "on-line" thermodilution technique. METHODS: This was by derivation of an expression to estimate what variance a set of repeated measures of flow would yield, using values pertaining to a single measure of flow. (Laws of variance were applied to the formula used to calculate flow, to account for its variables' values and measurement errors.) This enabled CLs of a single measure to be estimated. RESULTS: The variance estimated from a single measure was compared with that actually observed upon immediately taking a second measurement; differences in 189 pairs were not significantly different from zero (P=0.56). Applying the results demonstrated that measured flow values of 430-570 ml/min typically had associated 95% CLs that included 500 ml/min; therefore, true flow could not be said to be either side of 500 ml/min. The same was the case for 500-700 ml/min with regard to 600 ml/min. CLs widened considerably with the magnitude of flow rate, limiting the accurate measurement of higher flows and the detection of falls in flow. CONCLUSION: A method to estimate CLs of flow rate measured by the thermodilution technique is presented and validated. Application demonstrates an accurate measurement of low flow, but limitations at higher flow and in detecting falls in flow. Appreciating the magnitude of such is critical to informed clinical decision making when using flow rate in an access surveillance programme.