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This study aims to identify the extent of terminal digit bias in routinely recorded blood pressures (BP) across a number of different general practices and report on changes in terminal digit bias over a 10-year period. It also explores the effect this may have had on the mean recorded BP in this population. BP records were taken from The Health Improvement Network database containing anonymized patient records from information entered by UK general practices in the financial years 1996–1997 to 2005–2006. The proportion of measurements ending in zero and the mean BP readings were calculated for each practice and for each year of data. Over this 10-year period the percentage of systolic BPs with zero terminal digits fell from 71.2 to 36.7% and mean recorded BP fell from 152.3 to 145.3 mm Hg. Correcting the BPs to remove terminal digit bias indicates a 2–3 mm Hg underestimation of the mean population systolic BP over this period. The between-practice variation in the percentage of zero terminal digit readings increased from 3.5 to 6.5 s.d. Although it is welcome to see a reduction in terminal digit bias, it is worrying to see the increase in variation between practices. There is evidence that terminal digit bias may lead to potential misclassification and inappropriate treatment of hypertensive patients. The increase in variation observed may therefore lead to an increased variation in the quality of care given to patients.

This paper aims to identify how many young adults on antihypertensive treatment have been misclassified as hypertensive. We identified subjects aged under 35 on antihypertensive treatment, from the Health Surveys for England, 1998-2004. Pretreatment systolic and diastolic blood pressures were calculated by adjusting on-treatment blood pressures for the effects of treatment. Treatment effects were derived from meta-analysis. Subjects were classified as hypertensive if pretreatment blood pressure wasor=160/100 mm Hg, or wasor=140/90 mm Hg in conjunction with high cardiovascular risk. We then identified the proportion of treated subjects on antihypertensive treatment who were truly eligible for treatment. From the survey data we identified 65 adults (25 men and 40 women) under 35 on diuretics, beta-blockers, angiotensin converting enzyme inhibitors, calcium blockers or other antihypertensives. Average pretreatment blood pressure was 164/100 mm Hg in those eligible for treatment, and 136/79 mm Hg in those not eligible. The analysis indicated that 29.2% of adults aged 16-34 (95% confidence interval (CI): 18.6-41.8%) were truly eligible for antihypertensive treatment: 32.0% (95% CI: 14.9-53.5%) of men and 25.0% (95% CI: 12.7-41.2%) of women. A total of 73.7% (14 of 19) of subjects eligible and 41.3% (19 of 46) of subjects not eligible for treatment either had a body mass index30 kg m(-2) or kidney disease (chi(2)-test P=0.018). Because of biological variation in blood pressure, most young adults on treatment for hypertension have been misclassified as hypertensive. Most who have been correctly diagnosed are either clinically obese or have kidney disease.

Local childhood obesity monitoring data can be a valuable resource for health communities and provide useful feedback for schools. However care must be taken in how the data are used. What role can a school nurse play to help improve school children’s health?

Kerogens isolated from nine samples from a single marl bed of the Gessoso-solfifera formation in the Vena del Gesso basin (Upper Miocene, Italy) were treated with CrCl 2 and Li/EtNH 2 to remove inorganic and organic sulphur, respectively. The untreated and “desulphurized” (CrCl 2 and Li/EtNH 2 ) kerogens were qualitatively and quantitatively analyzed by flash pyrolysis-gas chromatography-mass spectrometry. Typically, significant variations in the relative contributions and abundances of n -alk-1-enes/ n -alkanes, alkylated pyrroles, thiophenes and supposedly S-bound moieties released as phytenes and sterenes were observed. The first series of products ( n -hydrocarbons) contributed relatively more to the pyrolyzates of the desulphurized kerogens, suggesting an enrichment of microalgal-derived aliphatic macromolecules. These marine micro-organisms are thought to belong in part to the class of Eustigmatophyceae. Alkylated pyrroles were barely detectable in the untreated kerogen pyrolyzates, whereas they contributed significantly to those from the treated kerogens. Similar treatment of a porphyrin, octaethylporphyrin, revealed that alkyl porphyrins are thermally too stable to be cleaved upon pyrolysis. However, Li/EtNH 2 treatment reduced the porphyrin standard, such that it could generate mainly monopyrroles upon pyrolysis. It is concluded that Li/EtNH 2 treatment reduced tetrapyrrole moieties bound to the desulphurized kerogen network.

Kerogens of nine samples from a single marl bed of the Gessoso-solfifera Formation in the Vena del Gesso basin (Messinian, Italy) were qualitatively and quantitatively studied by analytical pyrolysis. Relationships between the nature of the pyrolysis products and the source organisms were determined. The high abundance of (i) algal-derived components (n-alkanes and n-alk-1-enes) and (ii) sulphur-containing and sulphur-bound products signifying a high degree of early diagenetic sulphurization were observed. Presence of photic zone anoxia during the deposition of these sediments was discussed via the presence of 1,2,3,4-tetramethylbenzene in the pyrolysates. Unusual distributions were found for three series of pyrolysis products (i.e. C13 and C14n-alkylated thiophenes and thiolanes and C12 and C13n-1,3-alkadienes were by far the major products of these series) in the pyrolysates of two samples corresponding to the middle of the cycle (samples 3 and 5) which also have the highest δ13CTOC values and the highest pyrolysis yields. Therefore, the contribution of organisms biosynthesizing resistant algal biopolymer was considered as much more important during the deposition of the sediments associated with samples 3 and 5. We finally proposed partial structural elements from which the specific low molecular weight compounds of samples 3 and 5 can be derived upon pyrolysis.

Lithium in ethylamine ( Li EtNH 2 ) treatment has been carried out on sulphur-rich kerogens from 10 sub-samples of the cycle IV marl from the Vena del Gesso evaporitic sediments (Upper Miocene, Italy). The treatment releases, after chromatography of the resulting solvent extracts, up to 30% of the kerogen total organic carbon. The biomarkers released are dominated by components of algal origin. The concentrations of the aliphatic hydrocarbons obtained are of the same order of magnitude as the bound alkanes released upon desulphurization of polar fractions from organic extracts and show similar distributions. The presence of diaromatic isoprenoids derived from Chlorobiaceae indicates that photic zone anoxia occurred during the deposition of the cycle IV marl, such conditions being more prevalent at the middle of the section. Polar material makes up by far most of the organic material released and contains in particular alcohols and amides which may result from the cleavage of ester bonds present in these immature kerogens, the amides being secondary products formed by reaction with the EtNH2. In the case of the alcohols, however, these components could also arise from cleavage of sulphide-bound moieties.

Background Historically there has been a wide variation in the proportion of inadequate smears between general practices. Cervical screening in the UK is undergoing a fundamental change by moving from conventional to liquid based cytology (LBC). The main driver for this change has been a predicted reduction in the proportions of inadequate samples. This study investigates the effect of LBC on the variation in the proportion of inadequate samples between general practices using Shewhart's theory of variation and control charts. Methods Routinely collected cervical cytology data was obtained for all general practices in two localities in South Staffordshire for periods before and after the introduction of liquid based cytology. Control charts of the proportion of inadequate smears were plotted for the practices stratified by laboratory. A standardised measure of variation for all of the practices in each laboratory and each time period was also calculated. Results Following the introduction of liquid based cytology the overall proportion of inadequate samples in the two localities fell from 11.8 to 1.3% (p < 0.05). This fall was associated with a reduction in the average variation between the GP practices in the two localities from 1.6 to 1.0 standard deviations. There has also been a reduction in the number of practices showing special cause variation from eight to one following the introduction of liquid based cytology. Conclusion A reduction in the proportion of inadequate samples has been realised in these localities. The reduction in the overall proportion of inadequate samples has also been accompanied by a reduction in variation between GP practices.

Although the majority of publications on the epidemiology of hypertension are on North American and European populations, high blood pressure and its health consequences are worldwide phenomena. For several reasons, good epidemiological data on blood pressure in the population are essential to understanding high blood pressure. Firstly, epidemiological studies inform our understanding of the extent of the problem. What are mean blood pressures in a population? How many individuals are likely to require treatment for hypertension? An understanding of the extent of the problem is essential if we are to plan and develop health services to deal with the clinical needs that are associated with high blood pressure. This includes the management of hypertension, the treatment of stroke and the treatment of cardiovascular disease.

Background Inadequate cervical smears cannot be analysed, can cause distress to women, are a financial burden to the NHS and may lead to further unnecessary procedures being undertaken. Furthermore, the proportion of inadequate smears is known to vary widely amongst providers. This study investigates this variation using Shewhart's theory of variation and control charts, and suggests strategies for addressing this. Methods Cervical cytology data, from six laboratories, serving 100 general practices in a former UK Health Authority area were obtained for the years 2000 and 2001. Control charts of the proportion of inadequate smears were plotted for all general practices, for the six laboratories and for the practices stratified by laboratory. The relationship between proportion of inadequate smears and the proportion of negative, borderline, mild, moderate or severe dyskaryosis as well as the positive predictive value of a smear in each laboratory was also investigated. Results There was wide variation in the proportion of inadequate smears with 23% of practices showing evidence of special cause variation and four of the six laboratories showing evidence of special cause variation. There was no evidence of a clinically important association between high rates of inadequate smears and better detection of dyskaryosis (R2 = 0.082). Conclusions The proportion of inadequate smears is influenced by two distinct sources of variation – general practices and cytology laboratories, which are classified by the control chart methodology as either being consistent with common or special cause variation. This guidance from the control chart methodology appears to be useful in delivering the aim of continual improvement.