Slowing down of adult body mass index trend increases in England: a latent class analysis of cross-sectional surveys (1992-2010).

BACKGROUND: The prevalence of excess body weight, commonly measured as body mass index (BMI)≥25 kg m(-2), has increased substantially in many populations worldwide over the past three decades, but the rate of increase has slowed down in some western populations. OBJECTIVE: We address the hypothesis that the slowing down of BMI trend increases in England reflects a majority sub-population resistant to further BMI elevation. DESIGN: Pseudo-panel data derived from annual cross-sectional surveys, the Health Surveys for England (1992-2010). Trends in median BMI values were explored using regression models with splines, and gender-specific mixture model (latent class analysis) were fit to take an account of increasing BMI distribution variance with time and identify hidden subgroups within the population. SUBJECTS: BMI was available for 164 155 adults (men: 76 382; women: 87 773). RESULTS: Until 2001, the age-adjusted yearly increases in median BMI were 0.140 and 0.139 kg m(-2) for men and women, respectively, decreasing thereafter to 0.073 and 0.055 kg m(-2) (differences between time periods, both P-values<0.0001). The mixture model identified two components--a normal BMI and a high BMI sub-population--the proportions for the latter were 23.5% in men and 33.7% in women. The remaining normal BMI populations were 'resistant' with minimal increases in mean BMI values over time. By age, mean BMI values in the normal BMI sub-population increased greatest between 20 and 34 years for men; for women, the increases were similar throughout age groups (slope differences, P<0.0001). CONCLUSION: In England, recent slowing down of adult BMI trend increases can be explained by two sub-populations--a high BMI sub-population getting 'fatter' and a majority 'resistant' normal BMI sub-population. These findings support a targeted, rather than a population-wide, policy to tackle the determinants of obesity.

IMPACT: a generic tool for modelling and simulating public health policy.

BACKGROUND: Populations are under-served by local health policies and management of resources. This partly reflects a lack of realistically complex models to enable appraisal of a wide range of potential options. Rising computing power coupled with advances in machine learning and healthcare information now enables such models to be constructed and executed. However, such models are not generally accessible to public health practitioners who often lack the requisite technical knowledge or skills. OBJECTIVES: To design and develop a system for creating, executing and analysing the results of simulated public health and healthcare policy interventions, in ways that are accessible and usable by modellers and policy-makers. METHODS: The system requirements were captured and analysed in parallel with the statistical method development for the simulation engine. From the resulting software requirement specification the system architecture was designed, implemented and tested. A model for Coronary Heart Disease (CHD) was created and validated against empirical data. RESULTS: The system was successfully used to create and validate the CHD model. The initial validation results show concordance between the simulation results and the empirical data. CONCLUSIONS: We have demonstrated the ability to connect health policy-modellers and policy-makers in a unified system, thereby making population health models easier to share, maintain, reuse and deploy.

The high prevalence of unrecognized anaemia in patients with diabetes and chronic kidney disease: a population-based study.

BACKGROUND: Anaemia occurs early in the course of diabetes-related chronic kidney disease (CKD). There is little evidence about the prevalence of anaemia in people with diabetes. The aim of this study was to assess the prevalence of anaemia, by stage of CKD, in the general diabetic population. METHODS: Haemoglobin (Hb) was measured on all glycated haemoglobin (HbA1c) samples and the most recent (< 4 months) estimated glomerular filtration rate (eGFR) was obtained. Anaemia (at treatment level) was defined as Hb < 110 g/l or the use of erythropoetic stimulating agents (ESA). RESULTS: Twelve per cent (10-14%) of people had Hb < 110 g/l. The prevalence of anaemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anaemia; 18% (95% CI 13-24%) had Hb < 110 g/l. Those with eGFR < 60 ml/min/1.73 m2 and not on ESA or dialysis were four (2-7) times more likely than patients with better renal function to have Hb < 110 g/l. The relation between Hb and eGFR became approximately linear below an eGFR of 83 ml/min/1.73 m2, where, for every 1 ml/min/1.73 m2 fall in eGFR, there was a 0.4 (0.3-0.5) g/l fall in haemoglobin. CONCLUSIONS: This study demonstrates that anaemia, at levels where treatment is indicated, occurs commonly in people with diabetes and CKD stage 3 or worse. The screening for anaemia in current diabetes management should be extended.

Cardiorespiratory fitness and body mass index of 9-11-year-old English children: a serial cross-sectional study from 1998 to 2004.

OBJECTIVE: To examine the changes over time in cardiorespiratory fitness and body mass index (BMI) of children. DESIGN: Serial cross-sectional, population-based study. SETTING: Primary schools in Liverpool, UK. PARTICIPANTS: A total of 15,621 children (50% boys), representing 74% of eligible 9-11-year olds in the annual school cohorts between 1998/9 and 2003/4, who took part in a 20m multi-stage shuttle run test (20mMST). MAIN OUTCOME MEASURES: Weight, height, BMI (kg/m(2)) and obesity using the International Obesity Taskforce definition. RESULTS: Median (95% confidence interval) 20mMST score (number of runs) fell in boys from 48.9 (47.9-49.9) in 1998/9 to 38.1 (36.8-39.4) in 2003/4, and in girls from 35.8 (35.0-36.6) to 28.1 (27.2-29.1) over the same period. Fitness scores fell across all strata of BMI (P<0.001). Moreover, BMI increased over the same 6-year period even among children in fittest third of 20mMST. CONCLUSION: In a series of uniform cross-sectional assessments of school-aged children, BMI increased whereas cardiorespiratory fitness levels decreased within a 6-year period. Even among lean children, fitness scores decreased. Public health measures to reduce obesity, such as increasing physical activity, may help raise fitness levels among all children - not just the overweight or obese.

Body mass index has risen more steeply in tall than in short 3-year olds: serial cross-sectional surveys 1988-2003.

OBJECTIVE: To monitor the changing relationship between body mass index (BMI) and height in young children. DESIGN: Annual cross-sectional surveys using health-visitor-collected routine data 1988-2003. SETTING: Wirral, England. PARTICIPANTS: Fifty thousand four hundred and fifty-five children (49% female) each measured once at the age of 3 years. MAIN OUTCOME MEASURES: Weight, height and derived BMI (weight/height(2)) adjusted for age and sex (British 1990 revised reference) using standard deviation scores. RESULTS: From 1988 to 2003, mean BMI increased by 0.7 kg/m(2), whereas mean height fell by 0.5 cm. Over the same period, the weight-height correlation rose from 0.59 to 0.71 (P<0.0001) owing to BMI increasing faster in the taller than the shorter children. Among the shortest 10% of children, mean BMI rose by 0.12 (95% confidence interval: -0.05-0.28) kg/m(2) as against 1.38 (1.19-1.56) kg/m(2) among the tallest 10%, a 12-fold difference. Adjustment for age, sex, seasonality, birth-weight and deprivation did not alter the findings. CONCLUSIONS: Among 3-year-old children in Wirral, where BMI has been rising for 16 years, the largest increase in BMI has occurred in the tallest children, whereas in the shortest BMI has hardly changed. Tall stature has, therefore, become important for child obesity. It suggests a drive to increasing adiposity in young children that involves both growth and appetite, with fast growing and hungrier children now more exposed to the 'obesogenic' environment.

WAX ActiveLibrary: a tool to manage information overload.

WAX Active-Library (Cambridge Centre for Clinical Informatics) is a knowledge management system that seeks to support doctors' decision making through the provision of electronic books containing a wide range of clinical knowledge and locally based information. WAX has been piloted in several regions in the United Kingdom and formally evaluated in 17 GP surgeries based in Cambridgeshire. The evaluation has provided evidence that WAX Active-Library significantly improves GPs' access to relevant information sources and by increasing appropriate patient management and referrals this might also lead to an improvement in clinical outcomes.

Exchanging clinical knowledge via Internet.

The need for effective and efficient exchange of clinical knowledge is increasing. Paper based methods for managing clinical knowledge are not meeting the demand for knowledge and this has undoubtedly contributed to the widely reported failures of clinical guidelines. Internet affords both opportunities and dangers for clinical knowledge. Systems such as Wax have demonstrated the importance of intuitive structure in the management of knowledge. We report on a new initiative for the global management of clinical knowledge.

Local clinical guidelines: description and evaluation of a participative method for their development and implementation.

BACKGROUND: National guidelines are rarely followed by immediate change in clinical behaviour. We present our experience of an active educational method for local development and implementation of a guideline. OBJECTIVE: To evaluate the effectiveness of a participative method for developing local clinical guidelines. METHODS: A trial in a district of the effect of guideline development incorporating active participation of intended recipients on subsequent relevant prescribing. It was carried out in Wirral Family Health Services Authority district (the Wirral peninsula) comprising 69 general practices covering a population of 345,763. An exemplar guideline on 'hypertension in the elderly' was developed by the method described. The principal recommended drug was bendrofluazide 2.5 mg once daily. The differences in prescribed daily doses (PDD) of bendrofluazide 2.5 mg tablets per quarter per 1000 prescribing units (age-weighted population) between the intervention district and England as a whole was measured. RESULTS: Comparison of the intervention district with England data demonstrates a median difference of 122.49 PDD before and 206.34 PDD after guideline production, this change is statistically highly significant (Mann-Whitney two-tailed P < 0.0001; 95% CI = 36.51-104.77). Grouped regression analysis shows no significant difference (0.89) in slope gradients before guideline production (P = 0.35, 95% CI = -3.97-5.76), but the difference in slope gradients after (12.95) is statistically highly significant (P < 0.0001; 95% CI = 8.17-17.73). The data suggests that the change in clinical behaviour persisted for at least two years. CONCLUSION: Participation of intended recipient general practitioners and local specialists in the development of a guideline by an active educational method as described was followed by a favourable change in clinical behaviour which persisted for at least two years.

Vascular reactivity to noradrenaline and neuropeptide Y in the streptozotocin-induced diabetic rat.

The study aimed to assess vascular reactivity to noradrenaline with and without neuropeptide Y in diabetic rats, and to determine whether any abnormality could be attributed to insulin deficiency or to hyperglycaemia per se. The authors compared non-diabetic rats (n = 9) and rats with streptozotocin-induced diabetes that were either untreated (n = 10), or treated with insulin (n = 9) or food restriction (n = 8) to restore near-normoglycaemia. After 4 weeks of diabetes, contractile responses to noradrenaline (0.24-48 mumol L-1), without and with neuropeptide Y (0.1 mumol L-1), were assessed using an isometric myograph in two mesenteric arteries from each rat. Vessels from untreated diabetic rats were significantly more reactive to noradrenaline than the control vessels when tested without (P < 0.0001) but not with (P = NS) neuropeptide Y. Diabetic rats rendered nearly normoglycaemic through food restriction showed dose-response curves that were very similar to the untreated diabetic group (P = NS). By contrast, insulin-treated diabetic vessels showed reduced sensitivity to noradrenaline, with and without neuropeptide Y, compared with both the diet-restricted and untreated vessels (both P < 0.0001). The authors conclude that vascular sensitivity to noradrenaline, without or with neuropeptide Y, is reduced over a wide dose range in vessels taken from rats treated in vivo with insulin; furthermore, vessels taken from diabetic rats not treated with insulin (hypoinsulinaemic) tended to be more reactive than either control vessels or those taken from the insulin-treated rats. The latter group of rats were probably hyperinsulinaemic for much of the time; the results may therefore support the hypothesis that insulin acts as a vasodilator.

Path.Finder: an interactive clinical information system. The day-to-day management of patients requires unified information sources.

Presents Path.Finder, a locally managed health care information system built in response to the need for better communication of current research evidence and clinical practice guidelines. Concludes that this system will improve patient care by providing up-to-date, clinically useful information which is relevant locally. The technology and the information management system have been developed in parallel.

Drug interactions in arthritic patients.

The drug treatment of 100 consecutive new patients admitted to a regional rheumatology centre was reviewed. Potential drug interactions actions were sought according to appendix one of the British National Formulary (September 1989) and identified in 55 of 100 patients. The clinical and laboratory features of these patients were then reviewed, showing that only 11 displayed clinical manifestations of a drug interaction. Five patients had drug induced drowsiness, which was easily corrected, five a raised serum creatinine, which was less easily corrected, and one both. Although there is considerable potential for drug interaction in patients with severe arthritis, the proportion of patients who display clinical manifestations of this is small.