Some considerations on the design of population pharmacokinetic studies

The goal of this manuscript is to introduce a framework for consideration of designs for population pharmacokinetic orpharmacokinetic-pharmacodynamic studies. A standard one compartment pharmacokinetic model with first-order input and elimination is considered. A series of theoretical designs are considered that explore the influence of optimizing the allocation of sampling times, allocating patients to elementary designs, consideration of sparse sampling and unbalanced designs and also the influence of single vs. multiple dose designs. It was found that what appears to be relatively sparse sampling (less blood samples per patient than the number of fixed effects parameters to estimate) can also be highly informative. Overall, it is evident that exploring the population design space can yield many parsimonious designs that are efficient for parameter estimation and that may not otherwise have been considered without the aid of optimal design theory.

Evaluation of the Western Australian Department of Health telehealth project

In 1999, the Department of Health in Western Australia began a telehealth project, which finished in 2004. The 75 videoconferencing sites funded by the project were part of a total state-wide videoconference network of 104 sites. During the period from January 2002 to December 2003, a total of 3266 consultations, case reviews and patient education sessions took place. Clinical use grew to 30% of all telehealth activity. Educational use was approximately 40% (1416 sessions) and management use was about 30% (1031 sessions). The average overhead cost per telehealth session across all regions and usage types was $A192. Meaningful comparisons of the results of the present study with other public health providers were difficult, because many of the available Websites on telehealth were out of date. Despite the successful use of telehealth to deliver clinical services in Western Australia, sustaining the effort in the post-project phase will present significant challenges.

Realtime telemedicine for paediatric otolaryngology pre-admission screening

We conducted a feasibility study to examine whether a paediatric patient at a regional hospital could be assessed by an ear, nose and throat (ENT) specialist via videoconference, therefore saving at least one journey to the tertiary hospital for a pre-admission appointment. A video-otoscope was used with standard videoconference equipment, and realtime images were transmitted at a bandwidth of 384 kbit/s. In all, 13 telepaediatric ENT clinics were conducted between November 2003 and April 2005, and 98 consultations were facilitated for 64 patients. The main reasons for referral were recurrent tonsillitis (25%) and obstructive sleep apnoea (23%). Of the 64 patients examined by telemedicine, 42 (66%) were recommended for surgery and placed on the surgical waiting list. About 12 patients (19%) required travel to the tertiary centre for further investigations and tests not available locally, while four patients (6%) were reviewed via videoconference during a scheduled clinic. Six patients (9%) required no further follow-up after their initial telepaedliatric consultation. Videoconferencing is an effective method of assessing ENT conditions of paediatric patients and for pre-screening potential surgical admissions to a tertiary hospital. Careful consideration of a number of economic and logistical factors needs to be made before large investments are made to expand the service.

An e-health needs assessment of medical residents in Cameroon

Medical residents from Yaounde I University in Cameroon are required to spend periods of time in rural or remote locations to complete their training. To determine if e-health might lessen their isolation and enhance patient care, a needs assessment of the residents was performed using a brief questionnaire (five items) about the situation in which residents found themselves outside their medical school environment. We gave the questionnaires to 45 residents. Seventeen questionnaires had been returned at the time of the site visit, a response rate of 38%. Most residents indicated that the ability to contact a mentor would have either made them feel more confident (16, or 94%) or altered their handling of recent cases (15, or 88%). All residents had access to a mobile phone, and many (11, or 65%) had used it to contact a medical colleague for guidance. A low-cost and technologically simple telemedicine solution that maximized use of mobile phone capability, provided access to medical and health-care information, and permitted exchange of images would be an appropriate response to the identified needs.

Purchasing behaviour for non-prescription medicines

Background: The non-prescription medicine, market is constantly challenges. With changes to scheduling and market dynamics, a need for current Australian data on medicines purchasing behaviour was identified. Objectives: This survey aimed to report on the purchasing behaviour of non-prescription medicine customers, the medicines bought and influences on medicine sales. Methods: Researchers were stationed in 15 community pharmacies in southeast Queensland during mid-August 2004. Interview and observational data were collected for all eligible medicine purchases -over approximately 35 hours per pharmacy. Results: Data were collected for 3017 medicines purchased by 2583 customers. Most purchases were made by females (65%) and customers aged 26-35 years (25.8%). Pharmacy assistants alone provided advice in 58% of sales. Two thirds of purchases were for self use. In two thirds of cases, customers had a particular brand in mind; this was highly correlated with previous purchases. Pharmacy staff were highly influential in first time purchases. Conclusions: This study reports a high level of involvement and influence of pharmacy staff in medicine selection.

A survey of e-mentoring among New Zealand midwives

Mentoring is a strategy that may assist the midwifery profession to support new graduates and midwives working in rural and remote areas. We conducted a survey of 1577 New Zealand midwives about their opinions and experiences of mentoring. The questionnaire comprised 33 questions, nine of which were open questions. There was a 44% response rate. While the telephone was commonly utilized by mentors (37%) and mentored midwives (37%), the Internet and email played only a small part. Participants acknowledged the potential of these avenues for communication, but midwives felt that mentoring could be provided only by immediate, face-to-face contact. Nevertheless, e-mentoring could be a viable option and requires further investigation. About one-third of midwives identified geographical isolation as a barrier to being a mentor (38%) and being mentored (36%). The use of e-mentoring could remove the barrier of location and allow the midwife to chose a mentor who meets her needs, rather than because she is the only mentor available.

Pharmacokinetic-pharmacodynamic modelling of QT interval prolongation following citalopram overdoses

Aims To develop a pharmacokinetic-pharmacodynamic model describing the time-course of QT interval prolongation after citalopram overdose and to evaluate the effect of charcoal on the relative risk of developing abnormal QT and heart-rate combinations. Methods Plasma concentrations and electrocardiograph (ECG) data from 52 patients after 62 citalopram overdose events were analysed in WinBUGS using a Bayesian approach. The reported doses ranged from 20 to 1700 mg and on 17 of the events a single dose of activated charcoal was administered. The developed pharmacokinetic-pharmacodynamic model was used for predicting the probability of having abnormal combinations of QT-RR, which was assumed to be related to an increased risk for torsade de pointes (TdP). Results The absolute QT interval was related to the observed heart rate with an estimated individual heart-rate correction factor [alpha = 0.36, between-subject coefficient of variation (CV) = 29%]. The heart-rate corrected QT interval was linearly dependent on the predicted citalopram concentration (slope = 40 ms l mg(-1), between-subject CV = 70%) in a hypothetical effect-compartment (half-life of effect-delay = 1.4 h). The heart-rate corrected QT was predicted to be higher in women than in men and to increase with age. Administration of activated charcoal resulted in a pronounced reduction of the QT prolongation and was shown to reduce the risk of having abnormal combinations of QT-RR by approximately 60% for citalopram doses above 600 mg. Conclusion Citalopram caused a delayed lengthening of the QT interval. Administration of activated charcoal was shown to reduce the risk that the QT interval exceeds a previously defined threshold and therefore is expected to reduce the risk of TdP.