In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications

Tryptophan-like fluorescence (TLF) is an indicator of human influence on water quality as TLF peaks are associated with the input of labile organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time measurement of TLF could be particularly useful for monitoring water quality at a higher temporal resolution than available hitherto. However, current understanding of TLF quenching/interference is limited for field deployable sensors. We present results from a rigorous test of two commercially available submersible tryptophan fluorometers (ex ∼ 285, em ∼ 350). Temperature quenching and turbidity interference were quantified in the laboratory and compensation algorithms developed. Field trials were then undertaken involving: (i) an extended deployment (28 days) in a small urban stream; and, (ii) depth profiling of an urban multi-level borehole. TLF was inversely related to water temperature (regression slope range: -1.57 to -2.50). Sediment particle size was identified as an important control on the turbidity specific TLF response, with signal amplification apparent <150 NTU for clay particles and <650 NTU for silt particles. Signal attenuation was only observed >200 NTU for clay particles. Compensation algorithms significantly improved agreement between in situ and laboratory readings for baseflow and storm conditions in the stream. For the groundwater trial, there was an excellent agreement between laboratory and raw in situ TLF; temperature compensation provided only a marginal improvement, and turbidity corrections were unnecessary. These findings highlight the potential utility of real time TLF monitoring for a range of environmental applications (e.g. tracing polluting sources and monitoring groundwater contamination). However, in situations where high/variable suspended sediment loads or rapid changes in temperature are anticipated concurrent monitoring of turbidity and temperature is required and site specific calibration is recommended for long term, surface water monitoring.

A high-dose preparation of lactobacilli and bifidobacteria in the prevention of antibiotic-associated and Clostridium difficile diarrhoea in older people admitted to hospital: a multicentre, randomised, double-blind, placebo-controlled, parallel arm trial (PLACIDE)

BACKGROUND

Antibiotic-associated diarrhoea (AAD) occurs most commonly in older people admitted to hospital and within 12 weeks of exposure to broad-spectrum antibiotics. Although usually a mild and self-limiting illness, the 15-39% of cases caused by Clostridium difficile infection [C. difficile diarrhoea (CDD)] may result in severe diarrhoea and death. Previous research has shown that probiotics, live microbial organisms that, when administered in adequate numbers, are beneficial to health, may be effective in preventing AAD and CDD.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of a high-dose, multistrain probiotic in the prevention of AAD and CDD in older people admitted to hospital.

DESIGN

A multicentre, randomised, double-blind, placebo-controlled, parallel-arm trial.

SETTING

Medical, surgical and elderly care inpatient wards in five NHS hospitals in the UK.

PARTICIPANTS

Eligible patients were aged ≥ 65 years, were exposed to one or more oral or parenteral antibiotics and were without pre-existing diarrhoeal disorders, recent CDD or at risk of probiotic adverse effects. Out of 17,420 patients screened, 2981 (17.1%) were recruited. Participants were allocated sequentially according to a computer-generated random allocation sequence; 1493 (50.1%) were allocated to the probiotic and 1488 (49.9%) to the placebo arm.

INTERVENTIONS

Vegetarian capsules containing two strains of lactobacilli and two strains of bifidobacteria (a total of 6 × 10(10) organisms per day) were taken daily for 21 days. The placebo was inert maltodextrin powder in identical capsules.

MAIN OUTCOME MEASURES

The occurrence of AAD within 8 weeks and CDD within 12 weeks of recruitment was determined by participant follow-up and checking hospital laboratory records by research nurses who were blind to arm allocation.

RESULTS

Analysis based on the treatment allocated included 2941 (98.7%) participants. Potential risk factors for AAD at baseline were similar in the two study arms. Frequency of AAD (including CDD) was similar in the probiotic (159/1470, 10.8%) and placebo arms [153/1471, 10.4%; relative risk (RR) 1.04; 95% confidence interval (CI) 0.84 to 1.28; p = 0.71]. CDD was an uncommon cause of AAD and occurred in 12/1470 (0.8%) participants in the probiotic and 17/1471 (1.2%) in the placebo arm (RR 0.71; 95% CI 0.34 to 1.47; p = 0.35). Duration and severity of diarrhoea, common gastrointestinal symptoms, serious adverse events and quality of life measures were also similar in the two arms. Total health-care costs per patient did not differ significantly between the probiotic (£8020; 95% CI £7620 to £8420) and placebo (£8010; 95% CI £7600 to £8420) arms.

CONCLUSION

We found no evidence that probiotic administration was effective in preventing AAD. Although there was a trend towards reduced CDD in the probiotic arm, on balance, the administration of this probiotic seems unlikely to benefit older patients exposed to antibiotics. A better understanding of the pathogenesis of AAD and CDD and the strain-specific effects of probiotics is needed before further clinical trials of specific microbial preparations are undertaken. Evaluation of the effectiveness of other probiotics will be difficult where other measures, such as antibiotic stewardship, have reduced CDD rates.

TRIAL REGISTRATION

This trial is registered as ISRCTN70017204.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 57. See the NIHR Journals Library website for further project information.

An observational study of public and private general practitioner consultations in the Republic of Ireland

BACKGROUND

The reasons why patients visit their general practitioner (GP) is vital information for fund holders and policy makers. GP consultations in the Republic of Ireland are either paid by the patient on a fee-per-service basis (private patients) or by the state [general medical service (GMS) card holders], and information related to primary care consultations is limited.

OBJECTIVES

The aim of this study was to conduct an observational study of GMS and private consultations within general practice in Ireland.

DESIGN

This is a cross-sectional study of general practitioner consultations.

METHODS

GPs within existing Continued Medical Education (CME) groups were invited to participate. Participating GPs gathered data on 100 consecutive consultations between September 2008 and April 2010.

RESULTS

There were 16,899 consultations recorded; 53.8 % (9,095) were GMS patients. Patients ≥65 years accounted for 23.69 % of consultations (n = 3,822). Respiratory illnesses accounted for the highest proportion of consultations (3,886, 23.0 %), followed by routine check-ups (15.4 %). GMS patients were more likely to consult for a repeat prescription (OR = 4.04, 95 % CI 2.93-5.57) and were also more likely to consult to review their treatment (OR = 2.33, 95 % CI 1.68-3.22) compared to private patients.

CONCLUSION

This study displays the consultation behaviour of patients in Ireland. It suggests that inequalities may exist in access to primary care services in ROI; however, more research is required to examine this further. There is insufficient information available on primary healthcare utilisation. Key issues such as the lack of unique patient identifiers and the lack of extractable data from GP practices in ROI need to be addressed.

Static and predictive tomographic reconstruction for wide-field multi-object adaptive optics systems

Multi-object adaptive optics (MOAO) systems are still in their infancy: their complex optical designs for tomographic, wide-field wavefront sensing, coupled with open-loop (OL) correction, make their calibration a challenge. The correction of a discrete number of specific directions in the field allows for streamlined application of a general class of spatio-angular algorithms, initially proposed in Whiteley et al. [J. Opt. Soc. Am. A15, 2097 (1998)], which is compatible with partial on-line calibration. The recent Learn & Apply algorithm from Vidal et al. [J. Opt. Soc. Am. A27, A253 (2010)] can then be reinterpreted in a broader framework of tomographic algorithms and is shown to be a special case that exploits the particulars of OL and aperture-plane phase conjugation. An extension to embed a temporal prediction step to tackle sky-coverage limitations is discussed. The trade-off between lengthening the camera integration period, therefore increasing system lag error, and the resulting improvement in SNR can be shifted to higher guide-star magnitudes by introducing temporal prediction. The derivation of the optimal predictor and a comparison to suboptimal autoregressive models is provided using temporal structure functions. It is shown using end-to-end simulations of Raven, the MOAO science, and technology demonstrator for the 8 m Subaru telescope that prediction allows by itself the use of 1-magnitude-fainter guide stars.

Guidance on the use of respiratory and facial protection equipment

Infectious micro-organisms may be transmitted by a variety of routes, and some may be spread by more than one route. Respiratory and facial protection is required for those organisms that are usually transmitted via the droplet/airborne route, or when airborne particles have been artificially created, such as during ‘aerosol-generating procedures’. A range of personal protective equipment that provides different degrees of facial and respiratory protection is available. It is apparent from the recent experiences with severe acute respiratory syndrome and pandemic (H1N1) 2009 influenza that healthcare workers may have difficulty in choosing the correct type of facial and respiratory protection in any given clinical situation. To address this issue, the Scientific Development Committee of the Healthcare Infection Society established a short-life working group to develop guidance. The guidance is based upon a review of the literature, which is published separately, and expert consensus.

Determining in-patient diabetes treatment satisfaction in the UK--the DIPSat study

AIMS

To measure in-patient diabetes treatment satisfaction and its relationship to in-patient diabetes care.

METHODS

In a cross-sectional study, diabetes in-patient specialist nurses at 58 UK hospitals asked insulin-treated in-patients with diabetes to complete the recently updated Diabetes Treatment Satisfaction Questionnaire for In-patients and a general questionnaire; 1319 in-patients completed these questionnaires.

RESULTS

Satisfaction with the general diabetes treatment items in the Diabetes Treatment Satisfaction Questionnaire for In-patients was high, but there were high levels of extreme dissatisfaction with meal choices, meal quality and lack of similarity of hospital meals to normal domestic choices--23% would never or rarely have made similar meal choices at home. Hyperglycaemia or hypoglycaemia was reported for much of the in-patient stay (20% and 7%, respectively) and 26% reported at least one severe hypoglycaemic episode; these groups had lower satisfaction with the timing of medication in relation to meals (P < 0.003). More frequent in-patient hyperglycaemia or hypoglycaemia were associated with significantly poorer overall satisfaction scores and negative well-being scores (both P < 0.0001). Previous experience of a multiple daily insulin injection regimen was associated with more dissatisfaction than other regimens (P < 0.01). Multiple regression models explained 36% of variability in overall treatment satisfaction, with most (22.4%) accounted for by satisfaction with time spent with a diabetes in-patient specialist nurse (P < 0.0001). Self-administration of insulin was independently associated with higher treatment satisfaction (P < 0.006) in this model.

CONCLUSIONS

The DIPSat programme describes the complex relationships between diabetes in-patient treatment satisfaction and in-patient diabetes care.

Exploring robust methods for evaluating treatment and comparison groups in chronic care management programs

Evaluation of chronic care management (CCM) programs is necessary to determine the behavioral, clinical, and financial value of the programs. Financial outcomes of members who are exposed to interventions (treatment group) typically are compared to those not exposed (comparison group) in a quasi-experimental study design. However, because member assignment is not randomized, outcomes reported from these designs may be biased or inefficient if study groups are not comparable or balanced prior to analysis. Two matching techniques used to achieve balanced groups are Propensity Score Matching (PSM) and Coarsened Exact Matching (CEM). Unlike PSM, CEM has been shown to yield estimates of causal (program) effects that are lowest in variance and bias for any given sample size. The objective of this case study was to provide a comprehensive comparison of these 2 matching methods within an evaluation of a CCM program administered to a large health plan during a 2-year time period. Descriptive and statistical methods were used to assess the level of balance between comparison and treatment members pre matching. Compared with PSM, CEM retained more members, achieved better balance between matched members, and resulted in a statistically insignificant Wald test statistic for group aggregation. In terms of program performance, the results showed an overall higher medical cost savings among treatment members matched using CEM compared with those matched using PSM (-$25.57 versus -$19.78, respectively). Collectively, the results suggest CEM is a viable alternative, if not the most appropriate matching method, to apply when evaluating CCM program performance.

Assessing the impact of diabetes on the quality of life of older adults living in a care home: validation of the ADDQoL Senior

AIMS

Around a quarter of UK care-home residents have diabetes. Diabetes is known to impact quality of life but existing diabetes-specific quality of life measures are unsuitable for elderly care-home residents. We aimed to develop and evaluate a new measure for use with older adults, to be particularly suitable for use with care-home residents: the Audit of Diabetes-Dependent Quality of Life (ADDQoL) Senior*.

METHODS

Content and format changes were made to the 19-domain ADDQoL, informed by related measures for people with visual impairments (12 domain-specific items were retained, four items were revised/added and three items were removed). This revision was modified further following cognitive debriefing interviews with three older adults living in a care home. Psychometric evaluation of the newly developed 17-domain ADDQoL Senior was conducted using data from 90 care-home residents with diabetes who took part in a broader intervention study.

RESULTS

The life domains most impacted by diabetes were 'independence' and 'freedom to eat as I wish'. The ADDQoL Senior demonstrated good factor structure and internal consistency (Cronbach's alpha = 0.924). Domain scores were, as expected, significantly intercorrelated.

CONCLUSIONS

The ADDQoL Senior measures the perceived impact of diabetes on quality of life in older adults, and has been found to be suitable for those living in care homes if administered by interview. The scale has demonstrated acceptability and excellent psychometric properties. It is anticipated that the number of items may be reduced in the future if our current findings can be replicated.

Guidelines for transoesophageal echocardiographic probe cleaning and disinfection from the British Society of Echocardiography

The clinical utility of transoesophageal echocardiography (TOE) is well established. Being a semi-invasive procedure, however, the potential for transmission of infection between sequential patients exists. This has implications for the protection of both patients and medical staff. Guidelines for disinfection during gastrointestinal endoscopy (GIE) have been in place for many years.(1,2) Unfortunately, similar guidance is lacking with respect to TOE. Although traversing the same body cavities and sharing many similarities with upper GIE, there are fundamental structural and procedural differences with TOE which merit special consideration in establishing a decontamination protocol. This document provides recommendations for TOE probe decontamination based on the available evidence, expert opinion, and modification of the current British Society of Gastroenterology guidelines.

LABORATORY AND FIELD EVALUATIONS OF BEAUVERIA BASSIANA (BALSAMO) VUILLEMIN AGAINST GRASSHOPPERS AND LOCUSTS IN AFRICA

Two isolates of the fungus Beauveria bassiana (Balsamo) Vuillemin, GHA and BF, were evaluated in Cape Verde in 1991 and 1992 for infectivity to the Senegalese grasshopper, Oedaleus senegalensis (Krauss), and the migratory locust, Locusta migratoria migratorioides (Reiche and Fairmaire). Evaluations included laboratory bioassays and small-scale field trials. Laboratory bioassays evaluated five different formulations. Four of the formulations tested showed strong dose–response patterns and significantly higher mortality than the untreated control or carriers minus spores. All four formulations achieved high mortality levels when applied at economically feasible dose rates. The GHA and BF isolates, formulated in an oil carrier with an emulsifier, were equally infectious to migratory locust nymphs. Six different formulations of GHA were evaluated in field trials. Field trials evaluated both direct effects (treatment of field plots infested with O. senegalensis) and indirect effects (treatment of plots without grasshoppers, after which grasshoppers were introduced). In both cases, all six formulations showed good biocontrol potential. Grasshoppers exposed to treated plots up to 72 h after application exhibited comparatively high mortality levels, indicating that large numbers of spores remained viable in the field for at least 3 days. This was confirmed by analysis of the viability of conidia from vegetation samples obtained in the field following treatment. In open-plot, small-scale field trials, two different formulations (oil and clay-based) of GHA resulted in high rates of infection and approximately 45% reductions in grasshopper densities in the treated plots 7 days after application, even though density-reduction results were "diluted" by grasshopper migration into and out of the test plots. Results of the Cape Verde evaluations demonstrate that biopesticides developed from B. bassiana represent a promising alternative to chemical pesticides for grasshopper and locust control.

A computer based, automated analysis of process and outcomes of diabetic care in 23 GP practices

The predicted prevalence of diabetes in Ireland by 2015 is 190,000. Structured diabetes care in general practice has outcomes equivalent to secondary care and good diabetes care has been shown to be associated with the use of electronic healthcare records (EHRs). This automated analysis of EHRs in 23 practices took 10 minutes per practice compared with 15 hours per practice for manual searches. Data was extracted for 1901 type II diabetics. There was valid data for >80% of patients for 6 of the 9 key indicators in the previous year. 543 (34%) had a Hba1c > 7.5%, 142 (9%) had a total cholesterol >6 mmol/l, 83 (6%) had an LDL cholesterol >4 mmol/l, 367 (22%) had Triglycerides > 2.2 mmol/l and 162 (10%) had Blood Pressure > 160/100 mmHg. Data quality and key indicators of care compare well with manual audits in Ireland and the U.K. electronic healthcare records and automated audits should be a feature of all chronic disease management programs.