Relative survival: a useful tool to assess generalisability in longitudinal studies of health in older persons

Background  

Generalisability of longitudinal studies is threatened by issues such as choice of sampling frame, representativeness of the initial sample, and attrition. To determine representativeness, cohorts are often compared with the population of interest at baseline on demographic and health characteristics. This study illustrates the use of relative survival as a tool for assessing generalisability of results from a cohort of older people among whom death is a potential threat to generalisability.     

Inhaled heparin in cystic fibrosis.

Cystic fibrosis (CF) is characterised by inspissated airway secretions and chronic endobronchial infection associated with exuberant neutrophilic inflammation. Unfractionated heparin may be mucolytic and has demonstrated a number of anti-inflammatory properties; however, further safety data are needed in these subjects who are at risk of airway bleeding. The current study aimed to assess the medium-term safety and tolerability of moderately high-dose inhaled heparin in CF adults and to explore possible in vivo mucolytic and anti-inflammatory outcomes. A randomised, double-blind, placebo-controlled crossover study of twice daily inhalation of 50,000 IU of heparin for 2 weeks was undertaken in CF adults, with a 1-week washout period. Eighteen subjects were randomised and 14 (mean+/-sd age 23+/-7.8 yrs and percentage-predicted forced expiratory volume in one second 52.1+/-15.56%) completed the study protocol. Heparin neither affected blood coagulation parameters nor resulted in any increase in adverse events. Heparin inhalation had no significant effect upon forced expiratory volume in one second, symptoms of sputum clearance or sputum inflammatory markers. The current pilot study demonstrated no evidence of improved sputum clearance with 50,000 IU of inhaled heparin given twice daily to adult cystic fibrosis subjects. However, inhaled heparin was safe and the future evaluation of larger doses over a longer period may be warranted.     

Predictive diagnosis of multiple endocrine neoplasia (MEN 1) in four Australian kindreds

Background: Multiple endocrine neoplasia type 1 (MEN 1) is a tumour predisposition syndrome that usually manifests in the first four decades of life. It has an autosomal dominant mode of inheritance which means that any new member of a MEN1 kindred has roughly a 50% chance of developing the disorder during their lifetime. The localisation of the MEN1 gene to a small region of chromosome band llql3 has led to the development of DNA-based predictive diagnosis for this disease. Aims: To establish a polymerase chain reaction (PCR)-based system, using simple tandem repeat polymorphisms (STRPs), to predict gene carriers in four Australian MEN 1 kindreds. Funding: This work was supported by the National Health and Medical Research Council of Australia and the Princess Alexandra Hospital Foundation. Methods: Six STRP markers flanking the MEN1 region of chromosome band 11q13 were used to screen individuals for a common haplotype in order to determine carrier status. Results: The accuracy of prediction was calculated to be >95% in informative individuals. Conclusions: DNA-based presymptomatic detection of affected members of MEN 1 kindreds could facilitate their care and reduce the inconvenience and expense of repeated testing of unaffected members. However, due to occasional recombination events or uninformativeness of markers in certain individuals, carrier status cannot always be predicted.     

Monitor position and the accuracy and speed of ultrasound-guided nerve blocks

Ultrasound is rapidly becoming an essential skill for all anaesthetists with an interest in regional anaesthesia. Using a single-blinded cross-over trial design, we assessed the accuracy and speed of simulated ultrasound-guided nerve blockade with the monitor either in direct line-of-sight or perpendicular to the line-of-sight. Thirty-one anaesthetists participated in the study. Times taken to reach the targets were similar 18.4 (14.6) s with the monitor 'in-line' and 22.4 (26.7) s with the monitor perpendicular to the target. Needle placement was significantly more accurate when anaesthetists had the monitor in front of them (29 acceptable) than to the side (22 acceptable). For anaesthetists with limited ultrasound experience, the accuracy, but not speed, of ultrasound guided regional anaesthesia can be improved by aligning the monitor in the line of sight of the operator.