Prescribing in the prehospital environment: a review of the pharmaceutical Module 501 on UK Military Exercise SAIF SAREEA 3. Can such analysis assist with the scaling of healthcare assets?

INTRODUCTION: Module 501 provides core medications which are fundamental to the capability of a prehospital treatment team (PHTT). The quantities of each medication in the module inventory undergo regular review, but these do not correspond to a population at risk (PAR) figure or deployment length for which they intend to be used. This article proposes how the quantities of Module 501 drugs can be scaled for a given deployment, in this example using statistics taken from static PHTTs on Exercise Saif Sareea 3 (SS3). METHODS: The statistics were gathered using a custom-built search of electronic records from the Deployed Defence Medical Information Capability Programme in addition to written record-keeping, which were aligned to the weekly PAR at each PHTT location throughout their full operational capability periods. A quotient was then derived for each module item using a formula. RESULTS: Among the 10 most commonly prescribed drugs were four analgesics and three antimicrobials. 42 of the 110 studied drugs were not prescribed during SS3. DISCUSSION: The data from SS3 reflect the typical scope of disease encountered in the deployed land setting. Employing these data, the use of a formula to estimate the drug quantities needed to sustain a Strike Armoured Infantry Brigade over a 28-day period is demonstrated. RECOMMENDATIONS: Further study of Module 501 across varied deployment environments would be valuable in evolving this approach to medicinal scaling if proven effective for the warm desert climate. It could then be applied to other modules to further inform future Strike medical planning. LIMITATIONS: Several considerations when drawing deductions from the data are mentioned, including the inaccuracy of predictor variables taken from the EpiNATO-2 reports. CONCLUSION: The proposed formula provides an evidence-based framework for scaling drug quantities for a deployment planning. This may improve patient safety and confer logistical, storage and fiscal benefits.

Factors controlling volatile organic compounds in dwellings in Melbourne, Australia.

This study characterized indoor volatile organic compounds (VOCs) and investigated the effects of the dwelling characteristics, building materials, occupant activities, and environmental conditions on indoor VOC concentrations in 40 dwellings located in Melbourne, Australia, in 2008 and 2009. A total of 97 VOCs were identified. Nine VOCs, n-butane, 2-methylbutane, toluene, formaldehyde, acetaldehyde, d-limonene, ethanol, 2-propanol, and acetic acid, accounted for 68% of the sum of all VOCs. The median indoor concentrations of all VOCs were greater than those measured outdoors. The occupant density was positively associated with indoor VOC concentrations via occupant activities, including respiration and combustion. Terpenes were associated with the use of household cleaning and laundry products. A petroleum-like indoor VOC signature of alkanes and aromatics was associated with the proximity of major roads. The indoor VOC concentrations were negatively correlated (P < 0.05) with ventilation. Levels of VOCs in these Australian dwellings were lower than those from previous studies in North America and Europe, probably due to a combination of an ongoing temporal decrease in indoor VOC concentrations and the leakier nature of Australian dwellings.

Postcopulatory selection for dissimilar gametes maintains heterozygosity in the endangered North Atlantic right whale.

Although small populations are expected to lose genetic diversity through genetic drift and inbreeding, a number of mechanisms exist that could minimize this genetic decline. Examples include mate choice for unrelated mates and fertilization patterns biased toward genetically dissimilar gametes. Both processes have been widely documented, but the long-term implications have received little attention. Here, we combined over 25 years of field data with high-resolution genetic data to assess the long-term impacts of biased fertilization patterns in the endangered North Atlantic right whale. Offspring have higher levels of microsatellite heterozygosity than expected from this gene pool (effect size = 0.326, P < 0.011). This pattern is not due to precopulatory mate choice for genetically dissimilar mates (P < 0.600), but instead results from postcopulatory selection for gametes that are genetically dissimilar (effect size = 0.37, P < 0.003). The long-term implication is that heterozygosity has slowly increased in calves born throughout the study period, as opposed to the slight decline that was expected. Therefore, this mechanism represents a natural means through which small populations can mitigate the loss of genetic diversity over time.

Considerations for safe use of statins: liver enzyme abnormalities and muscle toxicity.

Statins play an important role in the care of patients with cardiovascular disease and have a good safety record in clinical practice. The risk of hepatic injury caused by statins is estimated to be about 1 percent, similar to that of patients taking a placebo. Patients with transaminase levels no more than three times the upper limit of normal can continue taking statins; often the elevations will resolve spontaneously. Coexisting elevations of transaminase levels from nonalcoholic fatty liver disease and stable hepatitis B and C viral infections are not contra- indications to statin use. Although myalgias are common with statin use, myositis and rhabdomyolysis are rare. When prescribed at one-half the recommended maximal dosage or less, statins are associated with an incidence of myopathy similar to that of placebo; therefore, rou- tine monitoring of creatine kinase levels in asymptomatic patients is not recommended. Myopathic symptoms usually resolve approximately two months after discontinuing the statin, and the same statin can be restarted at a lower dosage, or patients can try a different statin. Clinically important drugs that interact with statins and increase the risk of adverse effects include fibrates, diltiazem, verapamil, and amiodarone.

The low prevalence Rh antigen Be(a) (Rh36) is associated with RHCE*ce 662C>G in exon 5, which is predicted to encode Rhce 221Arg.

BACKGROUND AND OBJECTIVES: The low prevalence antigen, Be(a), is produced by a complex that also produces weak c, e and f (ce). We report here the molecular basis associated with Be(a) antigen expression. MATERIALS AND METHODS: Peripheral blood samples from four Be(a+) probands were tested. Haemagglutination, gDNA extraction, PCR-based assays, reticulocyte RNA isolation, Rh-cDNA analyses, and sequencing were performed by standard procedures. RESULTS: RBCs from Probands 1 and 3 were D-C-E-c+e+, and from Probands 2 and 4 were D+C+E-c+(W)e+. In proband 1, cDNA sequencing of RHCE revealed heterozygosity of nucleotide (nt) 662C/G in exon 5 of RHCE*ce. No other nucleotide changes were observed. As the 662C>G nucleotide change ablates a MscI restriction enzyme cleavage site, PCR-RFLP analysis was performed and the RHCE*ce nt 662C/G heterozygosity was detected on gDNA from the four probands and two children from both Proband 3 and Proband 4. CONCLUSION: The low prevalence Rh antigen, Be(a), is associated with a single nucleotide change in exon 5 of RHCE*ce; that of 662C>G and this change is predicted to alter proline at amino acid position 221 of Rhce to arginine. The fundamental differences in the properties of these two amino acids may impose a steric and/or charge-related effect on the protein, and thereby provide an explanation for the weakened expression of c, e and f (ce) antigens in the Be(a) phenotype.

Clinical assessment and treatment of ADHD in children.

Attention-deficit/hyperactivity disorder is a highly diagnosed psychiatric disorder in children. This widespread and complex condition requires extensive evaluation involving clinicians, parents and teachers. Proper management involves individual assessment and treatment. Psychostimulants remain the primary medication of choice as they have been shown to be efficacious for this condition. Newer, long-acting medications are providing expanded options for children and their caregivers. Failure to assess and treat can lead to serious long-term effects later in life.

An on-line exact small-sample test of significance for extended matching tasks.

An extension of the traditional matching paradigm that enables researchers to test a variety of new experimental hypotheses is outlined. An on-line computer program that provides an exact small-sample test of hypotheses in the extended matching paradigm is described. The program, which has an intuitive graphical interface, may be accessed and executed via the Internet by using an ordinary browser.

Sample size determination for a t test given a t value from a previous study: A FORTRAN 77 program.

When uncertain about the magnitude of an effect, researchers commonly substitute in the standard sample-size-determination formula an estimate of effect size derived from a previous experiment. A problem with this approach is that the traditional sample-size-determination formula was not designed to deal with the uncertainty inherent in an effect-size estimate. Consequently, estimate-substitution in the traditional sample-size-determination formula can lead to a substantial loss of power. A method of sample-size determination designed to handle uncertainty in effect-size estimates is described. The procedure uses the t value and sample size from a previous study, which might be a pilot study or a related study in the same area, to establish a distribution of probable effect sizes. The sample size to be employed in the new study is that which supplies an expected power of the desired amount over the distribution of probable effect sizes. A FORTRAN 77 program is presented that permits swift calculation of sample size for a variety of t tests, including independent t tests, related t tests, t tests of correlation coefficients, and t tests of multiple regression b coefficients.

Size distribution and sources of aerosol in Launceston, Australia, during winter 1997.

As part of a pilot study into the chemical and physical properties of Australian fine particles, a suite of aerosol samples was collected at Ti Tree Bend in Launceston, Tasmania, during June and July 1997. This period represents midwinter in the Southern Hemisphere, a period when aerosol sources in Launceston are dominated by smoke from domestic wood burning. This paper describes the results from this measurement campaign, with the aim of assessing the effect of wood smoke on the chemical and physical characteristics of ambient aerosol. A micro orifice uniform deposit impactor (MOUDI) was used to measure the size distributions of the aerosol from 0.05 to 20 microns aerodynamic diameter. Continuous measurements of fine particle mass were made using a PM2.5 tapered element oscillating microbalance (TEOM) and light scattering coefficients at 530 nm were measured with nephelometers. Mass size distributions tended to be bimodal, with the diameter of the dominant mode tending to smaller sizes with increases in total mass. Non-sea salt potassium and polycyclic aromatic hydrocarbons (PAHs) were used as chemical tracers for wood smoke. Wood smoke was found to increase absolute particle mass (enough to regularly exceed air quality standards), and to concentrate mass in a single mode below 1 micron aerodynamic diameter. The acid-base equilibrium of the aerosol was altered by the wood smoke source, with free acidity hydrogen ion, non-sea salt sulfate, and ammonium concentrations being higher and the concentration of all species, including nitrate (to differing extents), focused in the fine particle size ranges. The wood smoke source also heavily influenced the aerosol scattering efficiency, adding to a strong diurnal cycle in both mass concentration and light scattering.

Determination of nicotine in water by gradient ion chromatography.

A sensitive gradient ion chromatographic method has been demonstrated for determination of nicotine in aqueous solution. The method provides an improvement in detection limit, plus a reduction in analysis time, compared with a previously published ion chromatographic method.

Dental emergence among urban Zambian school children: an assessment of the accuracy of three methods in assigning ages.

In situations where birth records are unavailable and stated ages are unreliable, the emergence of the permanent dentition can serve as an indicator of age. Due to substantial variation in the timing of tooth emergence, a sample (n = 721) of Zambian school children, with known ages, was examined to provide a tooth emergence reference standard for the area. Three methods for assigning ages were utilized and their accuracy assessed. A random test sample was withheld from the original study in order to further evaluate the methods' accuracy. The three methods-1) number of teeth, 2) regression and 3) probit analysis-were applied to Zambian children, and estimates of age were made. Predicted ages were compared to actual ages to determine the percentage of accuracy in three categories-(+/-) .5, +/- 1.0 and +/- 2.0 years- and paired t-tests were conducted. Each of the three methods was then applied to the test sample, and their accuracy was evaluated in the same manner. Methods 1 and 2 were found to provide the higher percentage of correct ages within +/- .5 years, assigning roughly 39% of both male and female children within this increment. This was also the case at the next increment, with methods 1 and 2 assigning a higher percentage (66-76%) of children to the +/- 1.0 year category, while the accuracy of method 3 was quite a bit lower. The results for the test sample were very similar to those of the main sample. The overall accuracy of methods 1 and 2 was very similar in both the main and test samples, while method 3 had lower accuracy and t-tests indicated significant differences. Therefore, due to ease of application in the field setting, method 1, mean age per number of teeth emerged, is the method of choice.

Testing hypotheses about working memory capacity.

When an individual is engaged in sampling from a finite population, an assessment of their working memory for previously sampled objects is often desired. An extension of the classical occupancy distribution provides a framework for testing hypotheses about working memory capacity, based on a general model of working memory in which the individual retains a record of m previous inspections (and hence does not make the mistake of resampling these objects) and samples with replacement objects outside the current memory set. The buffer size m provides a common metric for assessing the effect of variables on performance in search tasks involving different numbers of items, or locations.

Problems in the diagnosis of pituitary adenoma (Cushing's syndrome) in horses.

Thyrotropin releasing hormone (TRH) stimulation tests were carried out on a number of horses, including one clinically affected horse whose age and clinical signs suggested that a pituitary adenoma was most unlikely. The results of these tests indicated that, according to criteria published overseas, the majority of these horses had pituitary adenomas. The fact that clinically normal or affected horses may have marked increases in cortisol concentrations indicates that the TRH stimulation test is not suitable for the diagnosis of pituitary adenoma. Other tests, including alterations in glucose metabolism and, if available, ACTH measurements, are probably more useful for diagnosis. However, most diagnoses will probably rely upon the characteristic clinical signs.

Choice autonomy and memory for spatial locations in six-year-old children.

Six-year-old children were presented with 12 identically labelled locations in a room and required to search non-redundantly for the six that contained rewards. On each day they could commit Across-Trial Memory (ATM) errors by visiting non-rewarded locations, or Within-Trial Memory (WTM) errors by revisiting locations previously visited that day. Groups were trained for nine days, either walking or pushed in a wheelchair, and with or without freedom of choice. They were then tested, walking with freedom of choice. Performance of the task improved significantly across training days in groups allowed free choice, whether walking or transported, and was superior at test to that of non-choosing groups. Throughout training and testing, the ATM component of performance was superior in groups allowed free choice. WTM was more accurate than would be expected by chance in all subjects at all stages of the experiment, but did not differ between groups. The problem of comparing WTM scores in groups differing in ATM accuracy was discussed. It was concluded that the primary benefit of free choice in spatial memory tasks is that it promotes accurate environmental segmentation, and that WTM is little affected by training or environmental familiarity.

A study of respiratory infections in a healthy adult population during the 1987 Australian winter.

During the 1987 Australian winter, respiratory illness patterns were studied in a population of 454 healthy adults, aged 18-59, over a period of 45 days. These patterns were matched with data obtained from laboratory diagnoses for respiratory viruses, Mycoplasma pneumoniae and bacteria. Influenza B/1/86 was by far the most prevalent pathogen but other viruses including influenza A, paramyxoviruses, respiratory syncytial virus and coronavirus OC-43 were also present, either alone or in combination during the sampling period. Overall, 92 males and 101 females experienced one episode, 12 males and 22 females experienced two episodes and four females experienced three episodes. However, there were only 52 instances of viral or M. pneumoniae infections, of which 37 had a defined aetiology, while the remainder were clinically silent. No bacterial pathogens could be detected from throat swabs taken from 15 of 37 volunteers in whom a viral infection was detected, or from 43 of 70 volunteers who did not experience such infections. The study indicates that major deficiencies in our understanding of the aetiology of respiratory viral illness are probably due to methodological problems in obtaining laboratory diagnoses for many respiratory viruses, and that great difficulties exist in establishing an aetiology for respiratory infections based upon clinical symptoms alone.

Prescriptions for medical research. I--Management within the Medical Research Council.

In their submission to the government in advance of the white paper on science policy in the United Kingdom the Medical Research Council commends the MRC's own approach to managing directly funded research. But a series of semi-structured interviews with the directors of some of the MRC's units suggests a gap between the MRC's model of managed research and the reality. Although such units are theoretically managed from MRC head office (and units are charged an overhead for this), in practice each unit runs its own affairs. Between major reviews average contact time with the head office contact person is seven hours a year. The first paper argues that a purchaser-provider split would recognise the benefits of decentralisation and allow units to bid for research funds from several sources, the successful ones guaranteeing their survival through a rolling series of research programmes. The second paper criticises the MRC's cumbersome peer review system. Reliance on outside experts atrophies the scientific skills of head office staff and builds delays into decision making. A purchaser-provider model would allow the head office scientific staff to act like commercial research and development managers, commissioning research, and using the outcome, rather than peer review, as a criterion for continued funding.