Randomised trial investigating the relationship of response rate for blood sample donation to site of biospecimen collection, fasting status and reminder letter: The 45 and Up Study

BACKGROUND Various options exist for collecting biospecimens and biomarkers from cohort study participants, and these have important logistic, resource and scientific implications. Evidence on how different collection methods affect participation and data quality is lacking. This parallel-design randomised trial, the Link-Up Study, involved blood sample donation and other data collection among participants in an existing cohort study, The 45 and Up Study. It aimed to investigate the relation of fasting status, reminder letters and data collection site to response rates, data quality and biospecimen yield. METHODS Individuals aged 45 and over participating in The 45 and Up Study and living ≤ 20 km from central Wagga Wagga, NSW (regional area) or ≤ 10 km from central Parramatta, NSW (urban area) (n=2340) were randomised, stratified by area of residence, to be invited to give a blood sample and additional data by attending either a clinic established specifically for the trial, with an appointment time ("dedicated clinic", n=1336) or an existing local commercial pathology centre (n=1004). Within dedicated clinic groups, participants were randomised into fasting (n=668) or non-fasting (n=668) and, at the Parramatta pathology centre site, reminder letter after two weeks (n=336) or no reminder (n=334). RESULTS Overall, 33% (762/2340) of invitees took part in the Link-Up Study; 41% (410/1002) among regional and 26% (352/1338) among urban-area residents (p<0.0001). At the dedicated clinics, response rates were 38% (257/668) not fasting and 38% fasting (257/668) (participation rate ratio (RR) =1.00, 95%CI 0.91-1.08, p=0.98). The response rate was 22% among individuals randomised to attend the Parramatta pathology centre without a reminder and 23% among those sent a reminder letter (RR=1.01, 0.93-1.09, p=0.74). In total, the response rate was 38% (514/1336) at the dedicated clinics and 25% (248/1004) at the pathology centres (RR=0.67, 0.56-0.78, p<0.01); measures of height, weight and systolic and diastolic blood pressure did not vary materially between these groups, nor did the median number of aliquots of plasma, buffy coat and red cells collected. CONCLUSIONS Among cohort study participants, response rates for an additional study involving biospecimen collection, but not data quality or average biospecimen yield, were considerably higher at dedicated clinics than at existing commercial pathology sites.This specific project was funded by The Cancer Council NSW. Emily Banks is supported by the National Health and Medical Research Council

Hydrogen thermal conductivity at temperatures from 2000 to 4000 deg F Final report

Hydrogen thermal conductivity at temperatures from 2000 to 4600 deg

The Establishment of a Preliminary Weight Profile for the 257 Table Birds within the Sheepdrove Organic Farm Organic Silvo-Poultry System.

A preliminary weight profile was produce for the organic silvo-poultry system on Sheepdrove organic farm. Seven batches (each of 20 hens and 20 cocks) were weighed over a two month period (January/February 2003). No current organic silvo-poultry weight profile was available but the weights achieved were found to exceed those of the nearest suggested profile (ISA 657) but were beneath the weights required for Sheepdroves markets. There was great and inconsistent variation between the batches and between sheds. This suggested that environment and management of particular houses could be having a large impact on final chicken weights