Cross-sectional study of 24-hour urinary electrolyte excretion and associated health outcomes in a convenience sample of Australian primary schoolchildren: the salt and other nutrients in children (SONIC) study protocol

BACKGROUND: Dietary sodium and potassium are involved in the pathogenesis of cardiovascular disease. Data exploring the cardiovascular outcomes associated with these electrolytes within Australian children is sparse. Furthermore, an objective measure of sodium and potassium intake within this group is lacking. OBJECTIVE: The primary aim of the Salt and Other Nutrient Intakes in Children ("SONIC") study was to measure sodium and potassium intakes in a sample of primary schoolchildren located in Victoria, Australia, using 24-hour urine collections. Secondary aims were to identify the dietary sources of sodium and potassium, examine the association between these electrolytes and cardiovascular risk factors, and assess children's taste preferences and saltiness perception of manufactured foods. METHODS: A cross-sectional study was conducted in a convenience sample of schoolchildren attending primary schools in Victoria, Australia. Participants completed one 24-hour urine collection, which was analyzed for sodium, potassium, and creatinine. Completeness of collections was assessed using collection time, total volume, and urinary creatinine. One 24-hour dietary recall was completed to assess dietary intake. Other data collected included blood pressure, body weight, height, waist and hip circumference. Children were also presented with high and low sodium variants of food products and asked to discriminate salt level and choose their preferred variant. Parents provided demographic information and information on use of discretionary salt. Descriptive statistics will be used to describe sodium and potassium intakes. Linear and logistic regression models with clustered robust standard errors will be used to assess the association between electrolyte intake and health outcomes (blood pressure and body mass index/BMI z-score and waist circumference) and to assess differences in taste preference and discrimination between high and low sodium foods, and correlations between preference, sodium intake, and covariates. RESULTS: A total of 780 children across 43 schools participated. The results from this study are expected at the end of 2015. CONCLUSIONS: This study will provide the first objective measure of sodium and potassium intake in Australian schoolchildren and improve our understanding of the relationship of these electrolytes to cardiovascular risk factors. Furthermore, this study will provide insight into child taste preferences and explore related factors. Given the cardiovascular implications of consuming too much sodium and too little potassium, monitoring of these nutrients during childhood is an important public health initiative.

Screening pregnant women for chlamydia : what are the predictors of infection?

Objectives: To determine the risk factors associated with chlamydial infection in pregnancy and the sensitivity and specificity of these when used for selective screening.

Methods: A prospective, cross-sectional study of pregnant women aged 16–25 years attending four major public antenatal services across Melbourne, Australia. Between October 2006 and July 2007, women were approached consecutively and asked to complete a questionnaire and to provide a first-pass urine specimen for Chlamydia trachomatis testing using PCR.

Results: Of 1180 eligible women, 1087 were approached and 1044 (88%) consented to participate. Among the 987 women for whom a questionnaire and a definitive diagnostic assay were available, the prevalence of chlamydia was 3.2% (95% CI 1.8 to 5.9). In a multiple logistic regression model, more than one sexual partner in the past year (AOR 11.5; 95% CI 7.1 to 18.5) was associated with chlamydia infection. The use of any antibiotic within 3 months (AOR 0.2; 95% CI 0.1 to 0.6) was associated with a decreased risk of infection. Screening restricted to women who reported more than one sexual partner in the past year would have detected 44% of infections in women aged 16–25 years and would have required only 7% of women to be screened. The addition of those women aged 20 years and under would have required 27% of women to be screened and detection of 72% of infections.

Conclusions: Selective chlamydia screening of pregnant women based on risk factors can improve the yield from screening. However, the potential harm of missed infections among excluded women would need to be considered.

Climate-related spatial and temporal variation in bill morphology over the past century in Australian parrots

Aim: Allen's rule posits that the appendages of endothermic organisms will be larger in warmer climates to allow for dumping of heat loads. Given a link between appendage size and climate, we tested the prediction that climate change has driven the evolution of larger bills in birds, resulting in measurable changes over the recent past. Location: Australia. Methods: We explored geographical and temporal variation in bill surface area of five Australian parrot species to determine whether individuals from warmer climates have larger bills, and whether there have been increases in bill surface area over time, consistent with climatic warming. Measurements were obtained from museum specimens dating from 1871 to 2008. These data were then related to geographical location, collection date and locality-specific climate data, in order to construct and compare models of spatio-temporal and climate-related variation in bill morphology. Results: There have been increases in bill surface area in mulga parrots (Psephotus varius), gang-gang cockatoos (Callocephalon fimbriatum), red-rumped parrots (Psephotus haematonotus) and male crimson rosellas (Platycercus elegans), equating to a c. 4-10% increase in bill surface area since 1871. Average maximum summer temperature in the 5 years prior to specimen collection also positively predicted bill surface area in mulga parrots, red-rumped parrots and crimson rosellas, consistent with Allen's rule. With the exception of red-rumped parrots, however, models with geographical location and year of collection were still better predictors of bill surface area than local climate at the date of collection. Main conclusions: Our analysis provides evidence that four species of parrot have exhibited adaptive change in bills over the past century potentially mitigating the thermal stress caused by climatic warming. Although consistent with the predicted effects of climate change, the temporal patterns we observe may have additional causes, however, such as changes in primary productivity, habitat or food availability.

Accuracy and usefulness of select methods for assessing complete collection of 24-hour urine: a systematic review.

Twenty-four-hour urine collection is the recommended method for estimating sodium intake. To investigate the strengths and limitations of methods used to assess completion of 24-hour urine collection, the authors systematically reviewed the literature on the accuracy and usefulness of methods vs para-aminobenzoic acid (PABA) recovery (referent). The percentage of incomplete collections, based on PABA, was 6% to 47% (n=8 studies). The sensitivity and specificity for identifying incomplete collection using creatinine criteria (n=4 studies) was 6% to 63% and 57% to 99.7%, respectively. The most sensitive method for removing incomplete collections was a creatinine index <0.7. In pooled analysis (≥2 studies), mean urine creatinine excretion and volume were higher among participants with complete collection (P<.05); whereas, self-reported collection time did not differ by completion status. Compared with participants with incomplete collection, mean 24-hour sodium excretion was 19.6 mmol higher (n=1781 specimens, 5 studies) in patients with complete collection. Sodium excretion may be underestimated by inclusion of incomplete 24-hour urine collections. None of the current approaches reliably assess completion of 24-hour urine collection.

Direct processing of clinically relevant large volume samples for the detection of sexually transmitted infectious agents from urine on a microfluidic device

Urine is a preferred specimen for nucleic acid-based detection of sexually transmitted infections (STIs) but represents a challenge for microfluidic devices due to low analyte concentrations. We present an extraction methodology enabling rapid on-chip nucleic acid purification directly from clinically relevant sample volumes up to 1 ml and subsequent PCR amplification detection.

A comparison of collection techniques for gene expression analysis of human oral taste tissue

Variability in human taste perception is associated with both genetic and environmental factors. The influence of taste receptor expression on this variability is unknown, in part, due to the difficulty in obtaining human oral tissue that enables quantitative expression measures of taste genes. In a comparison of six current techniques (Oragene RNeasy Kit, Isohelix swab, Livibrush cytobrush, tongue saliva, cheek saliva collection, and fungiform papillae biopsy), we identify the fungiform papillae biopsy is the optimal sampling technique to analyse human taste gene expression. The fungiform papillae biopsy resulted in the highest RNA integrity, enabling amplification of all the assessed taste receptor genes (TAS1R1, TAS1R2, TAS1R3, SCNN1A and CD36) and taste tissue marker genes (NCAM1, GNAT3 and PLCβ2). Furthermore, quantitative expression was observed in a subset of taste genes assessed from the saliva collection techniques (cheek saliva, tongue saliva and Oragene RNA kit). These saliva collection techniques may be useful as a non-invasive alternative sampling technique to the fungiform papillae biopsy. Identification of the fungiform papillae biopsy as the optimal collection method will facilitate further research into understanding the effect of gene expression on variability in human taste perception.

An experimental examination of fiber reinforcing effect with a novel composite specimen

This paper introduces a simple fiber/tape composite that is easy to prepare and structurally more uniform. This novel composite provides a good alternative standard composite sample for experimental study of various phenomena and issues in fiber reinforced composite behaviors. Experimental results in the present work demonstrate how the fiber fragmentation, fiber-reinforcing effect and the gauge length effect can be successfully evaluated by using this novel composite specimen.

Online versus postal data collection methods: an examination of issues and a comparison of results

New communications technologies often allow new ways of conducting market research. Determining the advantages of a new data collection method over established alternatives is difficult without thorough comparative testing. Computer-mediated marketing research is one such example of a new technology that has been enthusiastically embraced by marketing organisations and those servicing them. While researchers using the Internet (Net) and World Wide Web (Web) in its early years reported benefits such as high response levels, there is little in the way of comparative evidence to support any claimed advantages. This paper reports on the outcomes of three separate studies in which members (subscribers) of various organisations have been surveyed using both postal and online (email invitation and HTML Web form) data collection methods. The conclusion here is that it would be unwise to assume that one method can be directly substituted for another and obtain the same response. Differences in both the response pattern and demographic profile of respondents between the groups are consistently noticed, such as to warrant further examination of the methods used in online marketing research, and to suggest the need for further study.

Clinical research 5: quantitative data collection and analysis

This six-part research series is aimed at clinicians who wish to develop research skills, or who have a particular clinical problem that they think could be addressed through research. The series aims to provide insight into the decisions that researchers make in the course of their work, and to also provide a foundation for decisions that nurses may make in applying the findings of a study to practice in their own Unit or Department. The series emphasises the practical issues encountered when undertaking research in critical care settings; readers are encouraged to source research methodology textbooks for more detailed guidance on specific aspects of the research process.

A couple of points:

1. It is artificial to describe research as qualitative or quantitative. Studies often include both dimensions. However, for the purposes of this paper/series, this distinction is drawn for clarity of writing.

2. It is common practice for quantitative studies to refer to study ‘subjects’ and qualitative studies to refer to study ‘participants’. For ease of reading, the latter term will be used throughout this series.

Timed voiding for the management of urinary incontinence in adults (Review)

Background
Timed voiding is a fixed time interval toileting assistance program that has been promoted for the management of people with urinary incontinence who cannot participate in independent toileting. For this reason, it is commonly assumed to represent current practice in residential aged care settings.
Objectives
To assess the effects of timed voiding for the management of urinary incontinence in adults who cannot participate in independent toileting.
Search strategy
We searched the Cochrane Incontinence Group Specialised Register (28 February 2007), MEDLINE (January 1966 to November 2003), EMBASE (January 1980 to Week 18 2002), CINAHL (January 1982 to February 2001), PsycINFO (January 1972 to August 2002), Biological Abstracts (January 1980 to December 2000), Current Contents (January 1993 to December 2001) and the reference lists of relevant articles. We also contacted experts in the field, searched relevant websites and hand searched journals and conference proceedings.
Selection criteria
We selected all randomised and quasi-randomised trials that addressed timed voiding in an adult population and that had an alteration in continence status as a primary outcome. We included those trials that had assessed timed voiding delivered either alone or in combination with another intervention and compared it with either usual care, or no timed voiding, or another intervention.
Data collection and analysis
Data extraction and quality assessment were undertaken by at least two people working independently of each other. Any differences were resolved by discussion until agreement was reached. The relative risk for dichotomous data were calculated with 95% confidence intervals. Where data were insufficient to support a quantitative analysis, a narrative overview was undertaken.
Main results
Two trials with a total of 298 participants met the inclusion criteria. Both compared timed voiding plus additional intervention with usual care. In one of these timed voiding was combined with continence products, placement of a bedside commode for each participant, education to staff on transfer techniques, feedback and encouragement to staff, praise to participants for "successful responses" and administration of oxybutynin in small doses. The mean percentage who were incontinent when checked daily was 20% in the intervention group compared with 80% in the control group. No further between group analysis was possible from the data reported. The other trial combined timed voiding with a medical assessment and individualised medical management that was based on clinical data. Reduction in the number of participants with daytime and night-time incontinence was greater in the intervention group but this difference was statistically significant only for night-time wetting. There was no difference in the volume of urine lost as determined by pad weighing.
The methodological quality of these trials was not high based on the quality appraisal criteria of the Cochrane Incontinence Group. In particular, there was a lack of clarity regarding levels of blinding. It was not possible to combine data from trials. In both trials, the fixed schedule of toileting was combined with other interventions. The extent to which the results reflect the contribution of timed voiding is unknown because the trials' design did not allow assessment of the effects of the fixed schedule of toileting separately from other components of the interventions.
Authors' conclusions
The data were too few and of insufficient quality to provide empirical support for or against the intervention of timed voiding.

Online and postal data collection methods: a comparative study

Computer-mediated marketing research has been enthusiastically embraced by marketing organisations and those servicing them, for many reasons. While researchers using the Internet (Net) and World Wide Web (Web) in its early years reported benefits such as high response levels, there are now issues in this regard. This paper reports on the outcomes of a probabilistic study involving football club members (subscribers) involving both postal and online (e-mail invitation and HTML Web form) data collection methods. The paper reports differences in both the response pattern and demographic profile of respondents between the groups such as to warrant further examination of the methods used in online marketing research, and to suggest the need for further study.

Online versus postal data collection : a re-examination of the response differences using demographically matched data

Past research has identified differences between online and mail collected responses to the same survey, but differences in the demographics of respondents had also been noted making the cause of the variation unclear. In the research reported here, responses to the same questionnaire, delivered via mail and internet surveys, were demographically matched across a range of variables. This removed the impact of response differences caused by age, gender, type of product consumed and length of customer relationship. Across all the different question types and response scales, significant differences were still found between mail and online respondents, even when data were ipsatised. Notably, online respondents were far less likely to use the end-points of the scale, perhaps indicating issues with the online collection methodology. The conclusion is that the two methods of data collection can not be assumed to be directly inter-changeable, and that the method used can lead to different results if not managed carefully.