Combination antidepressants : use by GPs and psychiatrists

Background : Current treatment of depression fails to achieve remission in 50% of patients. Combinations of two antidepressants are used by some Australian psychiatrists.

Objective : This article investigates the pros and cons of combination antidepressant therapy and provides suggestions for when to consider their use, which combinations to choose, and how to introduce combination antidepressant therapies.

Discussion : Combining two antidepressants is a controversial strategy, with supporters and critics arguing its efficacy and safety from opposing perspectives. The use of combination antidepressant therapies may facilitate remission from depression. However, there is limited evidence supporting these treatments, and safety concerns are often cited. There is some support for combination therapies in selected cases from international bodies. After considering risks and benefits on a case-by-case basis, careful use of selected combination antidepressant therapy may be one of a range of effective treatments for some individuals suffering from depression.

The place of information and communication technology-mediated consultations in primary care : GPs' perspectives

Background: New information and communication technologies such as email and text messaging have been shown to be useful in some aspects of primary care service delivery. Little is known about Scottish GPs’ attitudes towards the adoption of these technologies as routine consultation tools.

Objectives: To explore GPs’ perceptions of the potential place of new non-face-to-face consultation technologies in the routine delivery of primary care; to explore GPs’ perceived barriers to the introduction of these technologies and to identify the processes by which GPs feel that new consultation technologies could be incorporated into routine primary care.

Methods: Qualitative interview study: 20 in-depth semi-structured interviews carried out with maximum variation sample of GPs across Scotland.

Results: Whilst the face-to-face consultation was seen as central to much of the clinical and diagnostic work of primary care, many GPs were conditionally willing to consider using new technologies in the future, particularly to carry out administrative or less complex tasks and therefore maximize practice efficiency and patient convenience. Key considerations were access to appropriate training, IT support and medico-legal guidance.

Conclusions: GPs are conditionally willing to use new consultation media if clinically appropriate and if medico-legal and technical support is available.

A novel monotonic fixed-point algorithm for l1-regularized least square vector and matrix problem

Least square problem with l₁ regularization has been proposed as a promising method for sparse signal reconstruction (e.g., basis pursuit de-noising and compressed sensing) and feature selection (e.g., the Lasso algorithm) in signal processing, statistics, and related fields. These problems can be cast as l₁-regularized least-square program (LSP). In this paper, we propose a novel monotonic fixed point method to solve large-scale l₁-regularized LSP. And we also prove the stability and convergence of the proposed method. Furthermore we generalize this method to least square matrix problem and apply it in nonnegative matrix factorization (NMF). The method is illustrated on sparse signal reconstruction, partner recognition and blind source separation problems, and the method tends to convergent faster and sparser than other l₁-regularized algorithms.

A flexible receiver-driven cache replacement scheme for continuous media objects in best-effort networks

In this paper, we investigate the potential of caching to improve quality of reception (QoR) in the context of continuous media applications over best-effort networks. Specifically, we investigate the influence of parameters such as loss rate, jitter, delay and area in determining a proxy's cache contents. We propose the use of a flexible cost function in caching algorithms and develop a framework for benchmarking continuous media caching algorithms. The cost function incorporates parameters in which, an administrator and or a client can tune to influence a proxy's cache. Traditional caching systems typically base decisions around static schemes that do not take into account the interest of their receiver pool. Based on the flexible cost function, an improvised Greedy Dual (GD) algorithm called GD-multi has been developed for layered multiresolution multimedia streams. The effectiveness of the proposed scheme is evaluated by simulation-based performance studies. Performance of several caching schemes are evaluated and compared with those of the proposed scheme. Our empirical results indicate GD-multi performs well despite employing a generalized caching policy.

SAS macros for point and interval estimation of area under the receiver operating characteristic curve for non-proportional and proportional hazards Weibull models

Aims and objectives  For prediction of risk of cardiovascular end points using survival models the proportional hazards assumption is often not met. Thus, non-proportional hazards models are more appropriate for developing risk prediction equations in such situations. However, computer program for evaluating the prediction performance of such models has been rarely addressed. We therefore developed SAS macro programs for evaluating the discriminative ability of a non-proportional hazards Weibull model developed by Anderson (1991) and that of a proportional hazards Weibull model using the area under receiver operating characteristic (ROC) curve.

Method  Two SAS macro programs for non-proportional hazards Weibull model using Proc NLIN and Proc NLP respectively and model validation using area under ROC curve (with its confidence limits) were written with SAS IML language. A similar SAS macro for proportional hazards Weibull model was also written.

Results  The computer program was applied to data on coronary heart disease incidence for a Framingham population cohort. The five risk factors considered were current smoking, age, blood pressure, cholesterol and obesity. The predictive ability of the non-proportional hazard Weibull model was slightly higher than that of its proportional hazard counterpart. An advantage of SAS Proc NLP in terms of the example provided here is that it provides significance level for the parameter estimates whereas Proc NLIN does not.

Conclusion  The program is very useful for evaluating the predictive performance of non-proportional and proportional hazards Weibull models.

Making decisions about fertility : three facts GPs need to communicate to women

Background Average annual fertility rates in industrialised countries have been below two children per woman for the past 3 decades. The reasons behind women’s childbearing behaviour are complex. However, a lack of awareness regarding the consequences of delayed childbearing and the inability of reproductive technologies to overcome the ‘biological clock’ may be contributory factors.

Objective A narrative review guided by the research question: What do women need to know about the consequences of delayed childbearing in order to make informed decisions about their fertility?

Discussion There are three facts that women need to know in order to make informed decisions around their fertility: Some women want to have more children than they are able to have because they postpone childbearing; there can be medical consequences to delaying childbearing and; some women’s ideas about their fertility don’t match the ‘the scientific facts’. General practitioners are well placed to play a strategic role in the provision of timely, relevant information to help women make informed decisions about their fertility. Further research is needed to identify the most appropriate ways for GPs to communicate this information.