Protocol for north of England and Scotland study of tonsillectomy and adeno-tonsillectomy in children (NESSTAC). A pragmatic randomised controlled trial comparing surgical intervention with conventional medical treatment in children with recurrent sore throats

BACKGROUND: Uncertainties surrounding the effectiveness and cost-effectiveness of childhood tonsillectomy for recurrent sore throat led the NHS Health Technology Assessment Programme to commission this research to evaluate the effectiveness and cost-effectiveness of tonsillectomy and adeno-tonsillectomy in comparison with standard non-surgical management in children aged under 16 with recurrent throat infections. The aim is to evaluate if tonsillectomy and adeno-tonsillectomy reduces the number of episodes of sore throats among children to a clinically significant extent. METHODS/DESIGN: A simple prospective pragmatic randomised controlled trial with economic analysis and prospective cohort study of non-trial participants comparing surgical intervention with conventional medical treatment. The treatment arm will receive tonsillectomy and adeno-tonsillectomy while in the control arm non-surgical conventional medical treatment only will be used. The primary outcome measure will be reported number of episodes of sore throat over two years with secondary outcomes measures of reported number of episodes of sore throat, otitis media and upper respiratory tract infection which invoke a GP consultation; reported number of symptom-free days; reported severity of sore throats and surgical and anaesthetic morbidity. The study will take place in five hospitals in the UK. The trial population will be 406 children aged 4–15 on their last birthday with recurrent sore throat referred by primary care to the 5 otolaryngology departments. The duration of the study is seven years (July 2001- July 2008). DISCUSSION: As with all pragmatic randomised controlled trials it is impossible to control the external environment in which the research is taking place. Since this trial began a number of factors have arisen which could affect the outcome including; a reduction in the incidence of respiratory tract infections, marked socio-economic differences in consultation rates, the results from the National Prospective Tonsillectomy Audit and the Government's waiting list initiatives

Elemental composition and productivity of cyanobacterial mats in an arid zone estuary in north Western Australia

Extensive cyanobacterial mats are a feature of the high intertidal zone in the Exmouth Gulf, Western Australia. This study provides a description of the position of the mats within the intertidal zone and of the mats elemental composition and productivity. We found that the mats occupied 40 cm elevational range within the intertidal zone. They have a mean organic matter content of 1,600 g m(-2). Mean concentrations of nitrogen (N) were 1.82 g kg(-1) and phosphorus (P) 205 mg kg(-1). N:P ratio was 19.7 indicating P limitation, but N:P was variable. Rates of photosynthesis and biomass production were similar to those reported for mats in hypersaline conditions at other sites. When photosynthetic production was scaled-up for the region our data suggest that cyanobacterial mats are an important contributor to the carbon budget in the Exmouth Gulf, contributing between 5 and 15% of the total carbon fixed by primary producers. Additionally mats were observed to be a source of soluble carbohydrates in tidal waters indicating that fixed carbon from high intertidal cyanobacterial mats may enter near shore food webs through this pathway