Predicting risk among non-respondents in prospective studies

Potential non-response bias was investigated in a follow-up study of 2,011 chronically disabled patients. 82.5% and 73.3% of the study subjects responded to self-administered mail questionnaires respectively at 6-month and 1-year follow-up. Information on employment status, the outcome of interest, of approximately 90% of the non-respondents was obtained from indirect sources. Employment rate was lower among the non-respondents than the respondents. Non-response was associated with age, social class, previous employment record, and the type of disability; but none of these characteristics were associated with the outcome. Out of the five known independent risk factors for unemployment, only one (incompletion of rehabilitation course) was associated with non-response. The employment rate among the respondents was also assessed according to the delay in response, that is the number of reminders sent to achieve response. The outcome among- the late respondents was similar to that among the nonrespondents. These data suggest that (a) risk estimates may be biased even when the response rate is greater than 80%, (b) the prevalence of risk factors among non-respondents may not indicate the presence or the degree of non-response bias, but (c) reliable estimates can be obtained from extrapolations of the rates among the respondents according to the delay in response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42663/1/10654_2004_Article_BF00152716.pd

Measurement of Pressure Dependent Fluorescence Yield of Air: Calibration Factor for UHECR Detectors

In a test experiment at the Final Focus Test Beam of the Stanford Linear Accelerator Center, the fluorescence yield of 28.5 GeV electrons in air and nitrogen was measured. The measured photon yields between 300 and 400 nm at 1 atm and 29 deg C are Y(760 Torr, air) = 4.42 +/- 0.73 and Y(760 Torr, nitrogen) = 29.2 +/- 4.8 photons per electron per meter. Assuming that the fluorescence yield is proportional to the energy deposition of a charged particle traveling through air, good agreement with measurements at lower particle energies is observed.Comment: 22 pages, 14 figures, 2 tables, submitted to Astroparticle Physic

The impact of residential and respite care on the behaviour of older people with dementia: literature review

Aim. The aim of this review was to examine the impact of residential respite care on the behaviour displayed by older people with dementia. Background. Relocation of older people with dementia to a different care setting could have a negative impact on their behaviour. If such a response is anticipated, a short-term admission to a residential aged care facility for respite care would appear to be futile for the older person and their home caregiver. Therefore, it is important to know what the outcomes of residential respite care are in relation to behaviour for older people with dementia. Methods. A literature search was undertaken and papers emerged from a range of disciplines. The search terms ‘respite’; ‘respite care’; ‘residential respite care’; ‘short-stay’, ‘short-term’, ‘overnight stays/admissions’, ‘behav*’ and various combinations of these terms were used to find relevant publications in English from Ageline, CINAHL, Medline and, Psychinfo databases dating from 1966. Other key publications were located when searching through the reference lists of retrieved publications. A limited body of literature on residential respite care for older people with dementia was revealed. Results. Six studies were identified, which met the criteria of residential respite care as the intervention and behaviour as an outcome. Conclusions. The studies had a variety of methodological limitations and produced contradictory findings. The strength of the studies was the reporting of outcomes for respite recipients who are usually overlooked in the outcomes for respite research. Relevance to clinical practice. Residential respite care has great anecdotal support but more empirical and evaluative research is needed on outcomes for the respite recipients