Predictors of physicians' satisfaction with their management of uncertainty during a decision-making encounter with a simulated advanced stage cancer patient

OBJECTIVES

To optimize their training, predictors of physicians' satisfaction with their management of uncertainty should be examined. This study investigated these predictors by using a simulated advanced stage cancer patient.

METHODS

Physicians (n=85) rated their satisfaction with their management of uncertainty (Visual Analog Scale-100mm) after a decision-making encounter. Communication predictors were examined with the: Observing Patient Involvement scale (OPTION), Multidimensional analysis of Patient Outcome Predictions (MD.POP) and Communication Content Analysis Software (LaComm). Psychological predictors were assessed with the: Intolerance of Uncertainty Inventory (IUI), Physicians' Reactions to Uncertainty scale (PRU), Decisional Conflict Scale (DCS), and Jefferson Scale of Physician Empathy (JSPE).

RESULTS

Physicians' satisfaction (mean=67mm; standard deviation=17mm) was not predicted by their communication, but by their anxiety due to uncertainty (PRU) (β=-.42; p=<.001) and their perceived empathy (JSPE) (β=.26; p=.009). These variables accounted for 25% of variance in physicians' satisfaction.

CONCLUSIONS

Physicians' satisfaction with their management of uncertainty was not affected by their communication performance, but by their psychological characteristics.

PRACTICE IMPLICATIONS

Training programs should increase physicians' awareness regarding the communication performance required in decision-making encounters under conditions of uncertainty.

Sludge drying reed beds for septage treatment: towards design and operation recommendations

This paper focuses on the feasibility of septage treatment by sludge drying reed beds (SDRB). Different designs and operation conditions of SRDB pilot-scales were tested on system efficiencies such as the top filtration layer (sand or compost) and the organic load (30 and 50 kg SSm(-2)y(-1)). Results focus on the obtained performances considering sludge characteristics, filtration efficiencies, percolate qualities, and sludge deposit properties. Although results show better filtration efficiency for activated sludge (e.g. SS removal around 98.4%) than for septage (e.g. SS removal around 87.5%), the feasibility of septage treatment with SDRB has been demonstrated with, at 50 kg SSm(-2)y(-1) sludge accumulation, and dry matter about 7.9 cm y(-1) and 70% (summer period), respectively. Further design and operation condition recommendations for SDRB treating septage are proposed.

Sludge drying reed beds: full- and pilot-scale study for activated sludge treatment

Sludge drying reed beds have been used for dewatering and mineralization of sludge since the beginning of the 90s, but their insufficient performances in terms of Dry Matter [DM] content and mineralization of the sludge have made necessary new studies. Therefore, 8 pilots of 2 m2 each and a full-scale plant (13,000 p.e, 8 beds of 470 m2 in operation for 4 years) have been monitored to examine the influence of the sludge loading rate, the sludge quality and the loading frequency on the dewatering and mineralization efficiencies. Two filtration layers and two loading rhythms were tested on pilots which were fed at a loading rate of 25-30 kg DM m(-2) yr(-1) during the first year of operation (commissioning period). Hydraulic behaviour (infiltration rate, outflow), O2 and CO2 relative concentrations in the filtration media, redox potential, pollutants removal and dry matter content were assessed during all the study. The rheological quality of the extracted sludge from full scale beds was assessed and showed that its mechanical behaviour exceed those of sludge of comparable dry matter content, making its spreading easier. Therefore, this sludge could easily claim the status of solid and stabilized sludge according to the French regulation. Design and management recommendations (number of beds, loading rates, feeding/rest period) gained from the experiments results are suggested.

Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds

French legislation requires the control of private on-site sanitation systems by local authorities. This will result in a large increase of the quantity of sludge from septic tanks to be treated. Nevertheless, large wastewater treatment plants are not systematically able to treat this sludge because they may have reached their nominal load or they are not so numerous in rural zone to avoid too long transportation. The study concerns both the feasibility of sludge reed beds devoted to the treatment of septage and the assessment of a simultaneous treatment with aerated sludge. The experiments have been carried out on eight pilot-scale drying reed beds (2 m(2)) planted with Phragmites australis. Two filtration layers of either vegetal compost or sand were tested. The study is focused on the commissioning period (first vegetative year) with a loading rate of 30 kg SS m(-2) yr(-1). According to these operational conditions, dewatering efficiencies reached approx. 30% DM during summer but less than 20% DM in winter for each filtration layer and sludge. High removal efficiencies, with an average of 96%, 92% and 89% for SS, COD and TKN respectively, were achieved with septage whereas they were lower for the mixture of aerated sludge and septage. The dewaterability of septage and its filtration behaviour were assessed by several parameters (Capillary Suction Time, bound water) which may be some interesting tools for an optimised loading strategy.

Factors that influence cancer patients' anxiety following a medical consultation: impact of a communication skills training programme for physicians

BACKGROUND

No study has yet assessed the impact of physicians' skills acquisition after a communication skills training programme on the evolution of patients' anxiety following a medical consultation. This study aimed to compare the impact, on patients' anxiety, of a basic communication skills training programme (BT) and the same programme consolidated by consolidation workshops (CW), and to investigate physicians' communication variables associated with patients' anxiety.

PATIENTS AND METHODS

Physicians, after attending the BT, were randomly assigned to CW or to a waiting list. The control group was not a non-intervention group. Consultations with a cancer patient were recorded. Patients' anxiety was assessed with the State Trait Anxiety Inventory before and after a consultation. Communication skills were analysed according to the Cancer Research Campaign Workshop Evaluation Manual.

RESULTS

No statistically significant change over time and between groups was observed. Mixed-effects modelling showed that a decrease in patients' anxiety was linked with screening questions (P = 0.045), physicians' satisfaction about support given (P = 0.004) and with patients' distress (P < 0.001). An increase in anxiety was linked with breaking bad news (P = 0.050) and with supportive skills (P = 0.013). No impact of the training programme was observed.

CONCLUSIONS

This study shows the influence of some communication skills on the evolution of patients' anxiety. Physicians should be aware of these influences.

Effect of reeds and feeding operations on hydraulic behaviour of vertical flow constructed wetlands under hydraulic overloads

Vertical flow constructed wetlands (VFCWs) have been very successful in France over the last 5 years. The sizing of VFCWs is still roughly based on organic load acceptance with slight clear water intrusion into the sewerage system which is often wrong in the context of small communities. To specify the hydraulic limits would be of great help to Water Authorities in deciding at what point is it preferable to build separate sewers rather than adapt the wastewater treatment plant. The study of the hydraulic limits of reed beds, based on the knowledge of hydrodynamics in unsaturated porous media, shows the ability of the system to accept flow overloads. Measuring different parameters (flow, pollutant removal, infiltration rate (IR), pressure head profiles) in pilot and full-scale studies, we explain the hydraulic behaviour of the filter, and the role of reeds and batch frequency on the IRs. Consequently, new hydraulic limits with accompanying sizing rules and operational recommendations according to the level of deposit on the filter surface are suggested. The study shows the robustness of reed beds systems as designed in France to accept hydraulic overloads. Overloads up to ten times the dry weather flow are possible whilst still complying with the European standards.

Capacités de traitement d'un effluent de synthèse en infiltration percolation

Dans cet article, nous présentons des travaux mettant en évidence les capacités de traitement biologique des eaux résiduaires urbaines au sein des milieux poreux de textures différentes. Une étude comparative du développement de la biomasse couplé aux mécanismes généraux de transferts gazeux à travers deux réacteurs biologiques est menée. Des lits d’infiltration percolation sont simulés par des colonnes garnies de sables d’origine et de structures différentes. Ils sont alimentés périodiquement via un automate de commande avec un influent d’une charge de 525 mgDCO/l et de 54 mgNK/l. Les résultats obtenus établissent le fait qu’un développement équilibré de la biomasse incluant les phases de croissance et de régression est intrinsèquement lié à la nature physique du matériau support. A l’aide des carottes prélevées sur les massifs filtrants et des sondes d’oxymétrie introduites à différentes hauteurs des lits d’infiltration, nous montrons que la répartition verticale du biofilm dans les colonnes ainsi que l’oxygénation des milieux poreux lors des périodes de repos sont également corrélées à la structure des supports pourtant de diamètres moyens similaires. L’efficacité de traitement biologique du carbone est supérieure pour un sable d’origine alluvionnaire comparativement à un sable concassé ; la tendance s’inversant significativement lorsqu’il s’agit de la diminution de l’azote.

Apatite as an interesting seed to remove phosphorus from wastewater in constructed wetlands

Intensive use of phosphates has resulted in high P levels in surface waters and therefore eutrophication problems. Over the last decade many studies have revealed the advantage of using specific materials with efficient phosphorus retention capacities. Recent studies state that Ca materials are of particular interest for long-term retention of P, but can induce negative effects. To improve P retention and avoid negative counter-effects we tested the potential of natural apatites. Apatite sorption was evaluated using batch and open reactor experiments. Batch experiments identify sorption mechanisms and the influence of the ionic characteristics of the solution; open reactor experiments evaluate sorption capacities in relation to the ionic composition of the solution and biomass development. In parallel, observation of the material by electron microscopy was used to give more precision information about the mechanisms involved. This work reveals the strong chemical affinity between apatites and phosphorus. Compared to other calcareous materials apatite is better able to maintain low outlet P levels. After more than 550 days feeding, sorption was still present and low P outlet levels were still being obtained when sufficient contact time and calcium content in the solution were ensured. This work demonstrates the advantages of using apatites for phosphorus removal in constructed wetlands. The behaviour of apatite in phosphorus retention is explained and its suitability for use in such extensive systems defined.

Phosphorus retention in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions

Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible for P uptake. Two media (calcite and recycled crushed concrete (RCC)) were examined in batch and continuous systems. Batch experiments show attractive sorption capacities, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality. RCC is sensitive to a strong dissolution leading to a quick phosphorus precipitation but induces high conductivity and pH values in the treated water. Calcite efficiency depends on the carbonate equilibrium of the solution. Microscopic observations of the calcite surface show crystal growth of phosphorus precipitate. Crystallisation seems to be the main P uptake once a material's surface is covered.

Modelling of a recirculating granular medium filter's processes

The effluents of French small farm factories will soon be submitted to regulation. Only a few treatment techniques are available to deal with these kind of effluent (high concentration and small daily volumes). To allow the treatment, in the particular economic context of small food processing industries, Cemagref is trying to adapt a treatment based on attached growth cultures on fine media, a system known to be easy to operate and relatively inexpensive. A model, based on four sub-models (hydrodynamic characteristics, oxygen transport, solute transport in the mobile and immobile phases and bacterial evolution) describes this process. Based on wastewater concentration, hydraulic load, applied organic loads, feeding/rest cycles and recycling phases number, this model predicts: eliminated organic loads and the discharge concentration as a function of time, oxygen and biomass contents as a function of time and depth. The determination of the model's parameters is based on a comparison between simulations and performances achieved on experimental columns. This model would be helpful in sizing full-scale filters treating different types of agro-food wastewater. The aim of this article is to present the model's structure, to give all parameter values and to compare the simulations with the results obtained on pilot and full scale plants.

Use of recycling through medium size granular filters to treat small food processing industry effluents

Currently there are no suitable wastewater treatment systems for effluents from small food processing industries (dairy, cheese, wine production). Such raw sewages are characterized by high organic matter concentrations (about 10 g COD L-1) and relatively low daily volumes (about 2 m3). An adaptation of attached-growth cultures on fine media processes, known to be easy and inexpensive to use, could fit both the technical and economical context of those industries. Coarser filter particle size distributions than those normally used allow a better aeration and reduce clogging risk. The transit time of the effluent through the porous filter materials is shortened and requires recycling to increase the contact time between the biomass and the substrate. A pilot plant was built to compare the efficiency of two kinds of filter materials, gravel (2-5 mm) and pozzolana (3-7 mm). Two measurement campaigns were undertaken on a full-scale unit dealing with cheese dairy effluents. Both pilot-scale and full-scale plants show high COD removal rates (> 95%). Pilot-scale experiments show that accumulation of organic matter leads to the clogging of the recycling filter. To prevent early clogging, a better definition of feeding cycles is needed.

Choice of the sand for sand filters used for secondary treatment of wastewater

In a range from 100 to about 1,000 People Equivalent (PE), Secondary Wastewater Sand Filters (SWSF) are used by a lot of rural communities in France. A series of case studies however point out that several criteria concerning global and detailed design and implementation of these systems have to be approached scientifically, in order to obtain the expected results on a long-term basis. The choice of the sand constituting the infiltration bed, core of the biological reactor, is of course one of the key elements and is the main subject of this article. It must have a sufficient initial permeability in order to ensure an adapted infiltration speed, after colonisation by the purifying biomass. The d10 fines content and degree of uniformity mainly control this permeability. The quarry or the aggregate extractor, who masters his production this way, usually gives these elements, based on granulometric analysis. However the adjustment of an infiltration test with clear water is essential to check on site the conformity of the deliveries.