On the computation of zone and double zone diagrams

Classical objects in computational geometry are defined by explicit relations. Several years ago the pioneering works of T. Asano, J. Matousek and T. Tokuyama introduced "implicit computational geometry", in which the geometric objects are defined by implicit relations involving sets. An important member in this family is called "a zone diagram". The implicit nature of zone diagrams implies, as already observed in the original works, that their computation is a challenging task. In a continuous setting this task has been addressed (briefly) only by these authors in the Euclidean plane with point sites. We discuss the possibility to compute zone diagrams in a wide class of spaces and also shed new light on their computation in the original setting. The class of spaces, which is introduced here, includes, in particular, Euclidean spheres and finite dimensional strictly convex normed spaces. Sites of a general form are allowed and it is shown that a generalization of the iterative method suggested by Asano, Matousek and Tokuyama converges to a double zone diagram, another implicit geometric object whose existence is known in general. Occasionally a zone diagram can be obtained from this procedure. The actual (approximate) computation of the iterations is based on a simple algorithm which enables the approximate computation of Voronoi diagrams in a general setting. Our analysis also yields a few byproducts of independent interest, such as certain topological properties of Voronoi cells (e.g., that in the considered setting their boundaries cannot be "fat").Comment: Very slight improvements (mainly correction of a few typos); add DOI; Ref [51] points to a freely available computer application which implements the algorithms; to appear in Discrete & Computational Geometry (available online

Pharmacists in Pharmacovigilance: Can Increased Diagnostic Opportunity in Community Settings Translate to Better Vigilance?

The pharmacy profession has undergone substantial change over the last two to three decades. Whilst medicine supply still remains a central function, pharmacist’s roles and responsibilities have become more clinic and patient focused. In the community (primary care), pharmacists have become important providers of healthcare as Western healthcare policy advocates patient self-care. This has resulted in pharmacists taking on greater responsibility in managing minor illness and the delivery of public health interventions. These roles require pharmacists to more fully use their clinical skills, and often involve diagnosis and therapeutic management. Community pharmacists are now, more than ever before, in a position to identify, record and report medication safety incidents. However, current research suggests that diagnostic ability of community pharmacists is questionable and they infrequently report to local or national schemes. The aim of this paper is to highlight current practice and suggest ways in which community pharmacy can more fully contribute to patient safety

Quality assessment of patients’ self-monitoring of blood glucose in community pharmacies

Objective: To evaluate diabetes patients’ self-monitoring of blood glucose using a community pharmacy-based quality assurance procedure, to investigate whether the procedure improved the quality of the patient performance of self monitoring of blood glucose, and to examine the opinions of the patients taking part in the study. Methods: The results of patient blood glucose measurements were compared to the results obtained with HemoCue Glucose 201+ by pharmacy employees in 16 Norwegian community pharmacies. Patient performance was monitored using an eight item checklist. Patients whose blood glucose measurements differed from pharmacy measurements by more than 20% were instructed in the correct use of their glucometer. The patients then re-measured their blood glucose. If the results were still outside the set limits, the control procedure was repeated with a new lot of glucometer strips, and then with a new glucometer. The patients returned for a follow-up visit after three months. Results: During the first visit, 5% of the 338 patients had measurements that deviated from pharmacy blood glucose values by more than 20% and user errors were observed for 50% of the patients. At the second visit, there was no significant change in the analytical quality of patient measurements, but the percentage of patients who made user errors had decreased to 29% (p < 0.001). Eighty-five percent of the patients reported that they used their blood glucose results to adjust medication, exercise or meals. Fifty-one percent of the patients reported a greater trust in their measurements after the second visit. Eighty percent of patients wished to have their measurements assessed yearly. Of these patients, 83% preferred to have the assessment done at the community pharmacy. Conclusion: A community pharmacy-based quality assessment procedure of patients’ self monitoring of blood glucose significantly reduced the number of user errors. The analytical quality of the patients’ measurements was good and did not improve further during the study. The high analytical quality might be explained by a selection bias of participating patients. Patients also reported increased confidence in their blood glucose measurements after their measurements had been assessed at the pharmacy

Does pharmacist-led medication review help to reduce hospital admissions and deaths in older people? A systematic review and meta-analysis

We set out to determine the effects of pharmacist-led medication review in older people by means of a systematic review and meta-analysis covering 11 electronic databases. Randomized controlled trials in any setting, concerning older people (mean age > 60 years), were considered, aimed at optimizing drug regimens and improving patient outcomes. Our primary outcome was emergency hospital admission (all cause). Secondary outcomes were mortality and numbers of drugs prescribed. We also recorded data on drug knowledge, adherence and adverse drug reactions. We retrieved 32 studies which fitted the inclusion criteria. Meta-analysis of 17 trials revealed no significant effect on all-cause admission, relative risk (RR) of 0.99 [95% confidence interval (CI) 0.87, 1.14, P = 0.92], with moderate heterogeneity (I2 = 49.5, P = 0.01). Meta-analysis of mortality data from 22 trials found no significant benefit, with a RR of mortality of 0.96 (95% CI 0.82, 1.13, P = 0.62), with no heterogeneity (I2 = 0%). Pharmacist-led medication review may slightly decrease numbers of drugs prescribed (weighted mean difference = -0.48, 95% CI -0.89, -0.07), but significant heterogeneity was found (I2 = 85.9%, P < 0.001). Results for additional outcomes could not be pooled, but suggested that interventions could improve knowledge and adherence. Pharmacist-led medication review interventions do not have any effect on reducing mortality or hospital admission in older people, and can not be assumed to provide substantial clinical benefit. Such interventions may improve drug knowledge and adherence, but there are insufficient data to know whether quality of life is improved