Predicting childhood overweight and obesity using maternal and early life risk factors: a systematic review.

BACKGROUND: Childhood obesity is a serious public health challenge, and identification of high-risk populations with early intervention to prevent its development is a priority. We aimed to systematically review prediction models for childhood overweight/obesity and critically assess the methodology of their development, validation and reporting. METHODS: Medline and Embase were searched systematically for studies describing the development and/or validation of a prediction model/score for overweight and obesity between 1 to 13 years of age. Data were extracted using the Cochrane CHARMS checklist for Prognosis Methods. RESULTS: Ten studies were identified that developed (one), developed and validated (seven) or externally validated an existing (two) prediction model. Six out of eight models were developed using automated variable selection methods. Two studies used multiple imputation to handle missing data. From all studies, 30,475 participants were included. Of 25 predictors, only seven were included in more than one model with maternal body mass index, birthweight and gender the most common. CONCLUSION: Several prediction models exist, but most have not been externally validated or compared with existing models to improve predictive performance. Methodological limitations in model development and validation combined with non-standard reporting restrict the implementation of existing models for the prevention of childhood obesity.

Predicting AKI in emergency admissions: an external validation study of the acute kidney injury prediction score (APS).

OBJECTIVES: Hospital-acquired acute kidney injury (HA-AKI) is associated with a high risk of mortality. Prediction models or rules may identify those most at risk of HA-AKI. This study externally validated one of the few clinical prediction rules (CPRs) derived in a general medicine cohort using clinical information and data from an acute hospitals electronic system on admission: the acute kidney injury prediction score (APS). DESIGN, SETTING AND PARTICIPANTS: External validation in a single UK non-specialist acute hospital (2013-2015, 12 554 episodes); four cohorts: adult medical and general surgical populations, with and without a known preadmission baseline serum creatinine (SCr). METHODS: Performance assessed by discrimination using area under the receiver operating characteristic curves (AUCROC) and calibration. RESULTS: HA-AKI incidence within 7 days (kidney disease: improving global outcomes (KDIGO) change in SCr) was 8.1% (n=409) of medical patients with known baseline SCr, 6.6% (n=141) in those without a baseline, 4.9% (n=204) in surgical patients with baseline and 4% (n=49) in those without. Across the four cohorts AUCROC were: medical with known baseline 0.65 (95% CIs 0.62 to 0.67) and no baseline 0.71 (0.67 to 0.75), surgical with baseline 0.66 (0.62 to 0.70) and no baseline 0.68 (0.58 to 0.75). For calibration, in medicine and surgical cohorts with baseline SCr, Hosmer-Lemeshow p values were non-significant, suggesting acceptable calibration. In the medical cohort, at a cut-off of five points on the APS to predict HA-AKI, positive predictive value was 16% (13-18%) and negative predictive value 94% (93-94%). Of medical patients with HA-AKI, those with an APS ≥5 had a significantly increased risk of death (28% vs 18%, OR 1.8 (95% CI 1.1 to 2.9), p=0.015). CONCLUSIONS: On external validation the APS on admission shows moderate discrimination and acceptable calibration to predict HA-AKI and may be useful as a severity marker when HA-AKI occurs. Harnessing linked data from primary care may be one way to achieve more accurate risk prediction.

Haemodiafiltration, haemofiltration and haemodialysis for end-stage kidney disease.

BACKGROUND: Renal replacement therapy (RRT) for end-stage kidney disease (ESKD) can be achieved by several interventions including haemodialysis (HD), peritoneal dialysis (PD) and kidney transplantation. HD, haemofiltration (HF), haemodiafiltration (HDF) and acetate-free biofiltration (AFB) are extracorporeal RRT methods. It has been suggested that HF and HDF may reduce the frequency and severity of intradialytic and post-dialytic adverse symptoms and may be more effective than HD in the removal of high molecular weight molecules. OBJECTIVES: To compare convective modes of extracorporeal RRT (HF, HDF or AFB) with HD and to establish if any of these techniques is superior to each other in patients with ESKD. SEARCH STRATEGY: We searched MEDLINE (1966-2006), EMBASE (1980-2006), Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library issue 2, 2006) and CINAHL (1872-2006). Authors of included studies were contacted, reference lists of identified RCTs and relevant narrative reviews were screened. SELECTION CRITERIA: RCTs comparing HF, HDF, AFB and HD for ESKD were included. Trials enrolling any patient undergoing RRT for ESKD were included. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes or weighted mean difference (MD) for continuous data with 95% confidence intervals (CI). Heterogeneity was measured using the Chi-square (chi(2)) and I(2) statistic. MAIN RESULTS: Twenty studies (657 patients) were included. Seventeen studies compared HF, HDF or AFB with HD, two compared HDF with AFB and one compared HF with HDF. The studies were generally small with suboptimal quality. Convective modalities (HF, HDF, AFB) did not differ significantly from HD for mortality (RR 1.68, 95% CI 0.23 to 12.13; chi(2)= 2.58, P = 0.11, I(2) = 61.2%), number of hospital admissions/year (MD 0.20, 95% CI -0.07 to 0.47) and dialysis adequacy (Kt/V: MD 0.09, 95% CI 0.02 to 0.17; chi(2) = 3.73, P = 0.29, I(2) = 19.6%). No study assessed number of dialysis treatments associated with "any adverse symptoms", sessions that were stopped early, change of dialysis modality or dialysis-related amyloidosis. AUTHORS' CONCLUSIONS: We were unable to demonstrate whether convective modalities (either HF, HDF or AFB) have significant advantages over HD with regard to clinically important outcomes of mortality, dialysis-related hypotension and hospitalisation. More adequately-powered good quality RCTs assessing clinically important outcomes (mortality, hospitalisation, quality of life) are needed.

Trends in adult renal replacement therapy in the UK: 1982-2002.

BACKGROUND: Following the introduction of dialysis and transplantation for the treatment of established renal failure (ERF) 40 years ago, the UK failed to match the achievements of many other countries. AIM: To review progress with treatment for ERF in the UK in the past 20 years. DESIGN: Review of four cross-sectional national studies, and 1997-2002 annual UK Renal Registry data. METHODS: Data on UK patients on renal replacement treatment (RRT) were collated from three sources: European Registry reports for 1982-1990, surveys carried out within the UK in 1993, 1996, 1998 and 2002, and the UK Renal Registry database (1997-2002). Trends in acceptance and prevalence rates, median age, cause of ERF, and treatment modality were analysed and compared with current data from other countries. RESULTS: The UK annual acceptance rate for RRT increased from 20 per million population (pmp) in 1982 to 101 pmp in 2002. This growth was largely in those aged over 65 years, and in those with co-morbidity. Annual acceptance rates for ERF due to diabetes rose from 1.6 to 18 pmp. The prevalence of RRT increased from 157 pmp in 1982 to 626 pmp in 2002. Hospital haemodialysis has become the main modality, and is increasingly being provided in satellite units. Although rising, UK acceptance and prevalence rates are still lower than in many developed countries. DISCUSSION: Despite significant expansion in RRT services for adults in the UK over the last 20 years, there is evidence of unmet need, and need is expected to rise, due to demographic changes and trends in type 2 diabetes. Continuing growth in the already substantial investment in RRT will be needed, unless efforts to prevent the occurrence of ERF are successful.

Psychosocial interventions for depression in dialysis patients.

BACKGROUND: Depression is the most common psychological problem in the dialysis population. The diagnosis of depression in dialysis patients is confounded by the fact that several symptoms of uraemia mimic the somatic components of depression. It affects the physical, psychological and social well being of the dialysis population in several ways. OBJECTIVES: The aim of this systematic review was to assess the effectiveness of psychosocial interventions in the treatment of depression in patients who are dialysed for end-stage renal disease. SEARCH STRATEGY: A comprehensive search strategy was employed to identify all randomised controlled trials (RCTs) relevant to the treatment of depression in dialysis patients. The following databases were searched - MEDLINE (1966 - October 2003), EMBASE (1980 - October 2003), PsycINFO (1872 - October 2003) and The Cochrane Library (issue 3, 2003). Authors of potential studies were contacted, reference lists of identified RCTs and relevant narrative reviews were screened. SELECTION CRITERIA: RCTs comparing any psychosocial intervention with control intervention or no intervention in depressed dialysis patients. DATA COLLECTION AND ANALYSIS: Data were to be abstracted by two investigators independently onto a standard form and entered into Review Manager 4.2. Relative risk (RR) for dichotomous data and a (weighted) mean difference (MD) for continuous data were to be calculated with 95% confidence intervals (CI). MAIN RESULTS: Despite extensive searching, no RCTs were identified. AUTHORS' CONCLUSIONS: Data were not available to draw conclusions about the effectiveness of psychosocial interventions in the treatment of depression in the chronic dialysis population, as we did not find any RCTs of psychosocial interventions to treat depression in dialysis patients. This review highlights the need for commencing and completing adequately powered RCTs to address the issue of psychosocial interventions for depression in dialysis patients.

Dependent censoring in piecewise exponential survival models.

There are often reasons to suppose that there is dependence between the time to event and time to censoring, or dependent censoring, for survival data, particularly when considering medical data. This is because the decision to treat or not is often made according to prognosis, usually with the most ill patients being prioritised. Due to identifiability issues, sensitivity analyses are often used to assess whether independent censoring can lead to misleading results. In this paper, a sensitivity analysis method for piecewise exponential survival models is presented. This method assesses the sensitivity of the results of standard survival models to small amounts of dependence between the time to failure and time to censoring variables. It uses the same assumption about the dependence between the time to failure and time to censoring as previous sensitivity analyses for both standard parametric survival models and the Cox model. However, the method presented in this paper allows the use of more flexible models for the marginal distributions whilst remaining computationally simple. A simulation study is used to assess the accuracy of the sensitivity analysis method and identify the situations in which it is suitable to use this method. The study found that the sensitivity analysis performs well in many situations, but not when the data have a high proportion of censoring.

Positive association between self-reported fatty food consumption and factor VII coagulant activity, a risk factor for coronary heart disease, in 4246 middle-aged men.

Raised levels of factor VII coagulant activity (VIIc) have been reported to increase the incidence of CHD. Preliminary evidence from observational and experimental studies suggests that dietary fat intake is positively associated with VIIc. We explored this further in 4,246 men aged 45-69, who were found to be free of major CHD when screened for a primary prevention trial of antithrombotic medication. All men were asked about their consumption of fatty foods and changes in consumption in the last month. In the 9% of men who reported avoidance of fatty foods in the month before interview, age adjusted VIIc was 7.8% of standard (95% CI 5.1-10.6%) lower than in the remainder. Serum cholesterol and body mass index (BMI) were also significantly lower. The extent to which fat consumed in the past month had deviated from usual intake was significantly and positively related with VIIc, serum cholesterol and BMI. Thus, the VIIc difference between those eating much less fatty food than usual and those eating much more than usual was 11% of standard, with those eating their usual amount having an intermediate level. This study adds to the evidence that dietary fat intake influences VIIc and coagulability. The effect is rapid, so that much of the benefit of dietary fat reduction on thrombogenic risk in CHD is likely to occur within a short time. Thus, the results reinforce the value of a low fat diet, even in individuals with advanced atheroma, in whom dietary intervention has sometimes been considered unlikely to be effective.

Extra-cranial bleeding and other symptoms due to low dose aspirin and low intensity oral anticoagulation.

Data from the early stages of the thrombosis prevention trial (TPT) have been used to establish and quantify the risk of extracranial bleeding due to low dose aspirin (75 mg) and low intensity oral anticoagulation with warfarin (international normalised ratio, INR, 1.5) singly or in combination, in men aged between 45 and 69 who are at high risk of ischaemic heart disease (IHD). The design of the trial is factorial, the four treatments being combined low dose aspirin and low intensity anticoagulation (WA), low intensity anticoagulation alone (W), low dose aspirin alone (A) and double placebo treatment (P). The trial is being carried out through the Medical Research Council's General Practice Research Framework, with participating practices throughout the United Kingdom. Results are based on the first 3,667 men entered. The risk of major gastrointestinal bleeding due to active treatment is probably about 1 in 500 man-years of treatment, there currently being no difference between the three active regimes (WA, W, A). Intermediate and minor bleeding episodes occur more frequently with WA than with W or A on their own, the excess being mainly due to minor nose bleeds and bruises. In turn, both W and A on their own cause more such minor episodes than placebo treatment, P. There is no evidence that any of the three active regimens increases the risk of peptic ulceration, nor do they increase reports of indigestion. Aspirin increases reports of constipation and reduces reports of blurred vision. Minor bleeding occurs less frequently in smokers than in non-smokers but is not influenced by age. The antithrombotic regimes used are feasible and acceptable.

Causes of end-stage renal failure in black patients starting renal replacement therapy.

In the United States, blacks are more frequently diagnosed than whites with end-stage renal failure (ESRF) from primary hypertension or diabetic nephropathy. We performed a validation retrospective case-note study of all blacks with ESRF who started renal replacement therapy (RRT) at three teaching hospitals in London, England, during 1991 to 1995 to investigate and validate the causes of primary renal disease using standard criteria. We identified 144 black patients with a mean age of 52.0 +/- 16.0 (SD) years; 59% were men and 32% had renal histological data. One hundred forty-four whites who were matched for age, sex, and onset of RRT (42% with renal histological data) underwent a similar validation exercise. Before the validation, the principal working diagnosis in the black patients had been diabetic nephropathy in 35% (89%, type 2; 11%, type 1); primary hypertension, 19%; glomerulonephritis (GN), 18%; and uncertain cause, 15%. After validation analysis, this changed to diabetes, 38% (16% biopsy proven); uncertain, 24%; GN, 20%; and primary hypertension, only 10% (28% biopsy proven). Among the uncertain cases (n = 34), 19 patients had hypertension, but this could not be established as the primary disease; 94% of all blacks had hypertension, accelerated in 21%. Among whites, only 3.5% had primary hypertension, and this proportion was not changed by the validation study. Type 2 diabetes is the most common single cause of ESRF in black patients in London, and although hypertension is more common and more severe in blacks, the proportion of renal failure attributed to primary hypertension is overestimated, and the diagnosis is often made using inadequate criteria.

The provision of renal replacement therapy for adults in England and Wales: recent trends and future directions.

We assessed the level of provision of renal replacement therapy for adults in England and Wales. All autonomous main renal units in England (n = 52) and Wales (n = 5) were surveyed in 1996. Data for England were compared to the 1993 National Renal Review. The acceptance rate in England 1995 was 82 (80-85) per million population (p.m.p.) compared with 67 (65-70) p.m.p. in 1991-2. The rate in 1995 in Wales was 109 (98-122) p.m.p. The prevalence rate in England was 476 p.m.p. at end-1995 compared to 393 p.m.p. in 1993, in Wales it was 487 p.m.p. The number of main renal units in England did not rise between 1993 and 1995; capacity was increased by use of more treatment shifts and temporary haemodialysis stations, and by opening more satellite units. The main growth was in hospital haemodialysis. There was an uneven geographical distribution of services. Patients accepted were older with more comorbidity. The use of better-quality processes of dialysis increased. The steady-state position for RRT will not be reached for over a decade. Health authorities will face continued pressure to fund increases in quantity and quality improvements. A stronger evidence base of the effectiveness of therapies, and a national registry to monitor the equity and cost-effectiveness of services are needed.

The need and demand for renal replacement therapy in ethnic minorities in England.

STUDY OBJECTIVE: The study aimed to determine the relative risk of being accepted for renal replacement treatment of black and Asian populations compared with whites in relation to age, sex, and underlying cause. The implications for population need for renal replacement therapy in these populations and for the development of renal services were also considered. DESIGN/SETTING: This was a cross sectional retrospective survey of all patients accepted for renal replacement treatment in renal units in England in 1991 and 1992. PATIENTS: These comprised all 5901 patients resident in England with end-stage renal failure who had been accepted for renal replacement therapy in renal units in England and whose ethnic category was available from the units. Patients were categorised as white, Asian, black, or other. Population denominators for the ethnic populations were taken from the 1991 census. The census categories Indian, Pakistani, and Bangladeshi were aggregated to form the denominator for Asian patients, and black Caribbeans, black Africans, and black others were aggregated to form the denominator for black patients. MAIN RESULT: Altogether 7.7% of patients accepted were Asian and 4.7% were black; crude relative acceptance rates compared with whites were 3.5 and 3.2 respectively. Age sex specific relative acceptance ratios increased with age in both ethnic populations and were greater in females. Age standardised acceptance ratios were increased 4.2 and 3.7 times in Asian and black people respectively. The most common underlaying cause in both these populations was diabetes; relative rates of acceptance for diabetic end-stage renal failure were 5.8 and 6.5 respectively. The European Dialysis and Transplant Association coding system was inaccurate for disaggregating non-insulin and insulin dependent forms. "Unknown causes" were an important category in Asians with a relative acceptance of rate 5.7. The relative rates were reduced only slightly when the comparison was confined to the district health authorities with large ethnic minority populations, suggesting that geographical access was not a major factor in the high rates for ethnic minorities. CONCLUSION: Acceptance rates for renal replacement treatment are increased significantly in Asian and black populations. Although data inaccuracies and access factors may contribute to these findings, the main reason is probably the higher incidence of end-stage renal failure. This in turn is due to the greater prevalence of underlying diseases such as non-insulin dependent diabetes but possibly also increased susceptibility of developing nethropathy. The main implication is that these populations age demand for renal replacement treatment will increase. This will have an impact nationally but will be particularly apparent in areas with large ethnic minority populations. Future planning must take these factors into account and should include strategies for preventing chronic renal failure, especially that due to non-insulin dependent diabetes and hypertension. The data could not determine the extent to which population need was being met; further studies are required to estimate the incidence of end-stage renal failure in ethnic minority populations.

Population need for renal replacement therapy in Thames regions: ethnic dimension.

OBJECTIVES: To determine the use of renal replacement therapy by ethnic origin and to ascertain the variation in provision of such therapy and to relate this to the distribution of ethnic minority populations. DESIGN: Analysis of retrospective and cross sectional data from 19 renal units. SETTING: All four Thames regional health authorities. SUBJECTS: Patients resident in the Thames regions who were accepted as new patients for renal replacement therapy during 1991 and 1992 and the patients who were already undergoing such treatment between December 1992 and April 1993. MAIN OUTCOME MEASURES: Rates of acceptance for and prevalence of renal replacement therapy among white, black, and Asian people. RESULTS: The average annual acceptance rates per million in 1991-2 were 61 for white people, 175 for black people, and 178 for Asians, and the prevalences per million were 351, 918, and 957 respectively. The relative risks increased with age. A threefold increase in the acceptance rate occurred in people aged under 55 in both the black and Asian populations, suggesting that the higher rates are probably not due to factors related to access alone. Treatment rates varied considerably among districts, reflecting both the distribution of ethnic minority populations and access to services. CONCLUSION: Black and Asian people receive and have a greater need for renal replacement therapy, and the need will increase as these populations age. These findings have important implications for the provision of renal services in districts with a high proportion of ethnic minorities and for the management of diabetes mellitus and hypertension, two important causes of end stage renal failure in these populations.

Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance. The Infectious Intestinal Disease Study Executive.

OBJECTIVE: To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance. DESIGN: Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. SETTING: 70 general practices throughout England. PARTICIPANTS: 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients. MAIN OUTCOME MEASURES: Incidence of infectious intestinal disease in community and reported to general practice. RESULTS: 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified. CONCLUSIONS: Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered.

Evaluation of swabbing methods for estimating the prevalence of bacterial carriage in the upper respiratory tract: a cross sectional study.

OBJECTIVES: Bacterial carriage in the upper respiratory tract is usually asymptomatic but can lead to respiratory tract infection (RTI), meningitis and septicaemia. We aimed to provide a baseline measure of Streptococcus pneumoniae, Moraxella catarrhalis, Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae and Neisseria meningitidis carriage within the community. Self-swabbing and healthcare professional (HCP) swabbing were compared. DESIGN: Cross-sectional study. SETTING: Individuals registered at 20 general practitioner practices within the Wessex Primary Care Research Network South West, UK. PARTICIPANTS: 10,448 individuals were invited to participate; 5394 within a self-swabbing group and 5054 within a HCP swabbing group. Self-swabbing invitees included 2405 individuals aged 0-4 years and 3349 individuals aged ≥5 years. HCP swabbing invitees included 1908 individuals aged 0-4 years and 3146 individuals aged ≥5 years. RESULTS: 1574 (15.1%) individuals participated, 1260 (23.4%, 95% CI 22.3% to 24.5%) undertaking self-swabbing and 314 (6.2%, 95% CI 5.5% to 6.9%) undertaking HCP-led swabbing. Participation was lower in young children and more deprived practice locations. Swab positivity rates were 34.8% (95% CI 32.2% to 37.4%) for self-taken nose swabs (NS), 19% (95% CI 16.8% to 21.2%) for self-taken whole mouth swabs (WMS), 25.2% (95% CI 20.4% to 30%) for nasopharyngeal swabs (NPS) and 33.4% (95% CI 28.2% to 38.6%) for HCP-taken WMS. Carriage rates of S. aureus were highest in NS (21.3%). S. pneumoniae carriage was highest in NS (11%) and NPS (7.4%). M. catarrhalis carriage was highest in HCP-taken WMS (28.8%). H. influenzae and P. aeruginosa carriage were similar between swab types. N. meningitidis was not detected in any swab. Age and recent RTI affected carriage of S. pneumoniae and H. influenzae. Participant costs were lower for self-swabbing (£41.21) versus HCP swabbing (£69.66). CONCLUSIONS: Higher participation and lower costs of self-swabbing as well as sensitivity of self-swabbing favour this method for use in large population-based respiratory carriage studies.

The problems of monitoring tuberculosis in an inner-city health district: integrated information is required.

This paper discusses the difficulties in monitoring tuberculosis in an inner-city district health authority. Tuberculosis incidence was reviewed between 1981 and 1989 using several data sources: statutory notifications, hospital activity analysis, death certificates and chest clinic records. The overall notification rate declined but remained higher than national rates; the age-sex distribution was similar to national studies. However, interpretation was limited by the problems of small numbers, the difficulty in obtaining reliable numerator and denominator estimates of ethnic groups, the limited data available about sub-groups of concern such as the homeless, and finally by the incompleteness of the data. Improved methods of data linkage are required to facilitate more complete ascertainment and validation of the diagnosis.

The gastrointestinal toxicity of aspirin: an overview of randomised controlled trials.

The proven benefit of aspirin in the secondary prevention of cardiovascular disease and its possible value in primary prevention must be weighted against its potential hazards. This paper is an overview of the gastrointestinal toxicity of aspirin, its most serious complication after intracerebral haemorrhage. Information on toxicity has been drawn only from randomised trials, thus avoiding the potential biases of observational studies. All randomised placebo controlled trials listed in the Anti-platelet Trialists Collaboration where a direct aspirin-placebo comparison was possible were included. Twenty-one trials were included, all but one of secondary prevention. There were over 75,000 person years of aspirin exposure. The pooled odds ratios for categories of gastrointestinal bleeding (e.g. haematemesis, melaena) were between 1.5-2.0; fatal bleeds were very rare. The risk of peptic ulcers was 1.3 and of upper gastrointestinal symptoms 1.7. These risks were lower than those found in observational studies. Attributable disease rates are also presented. For haematemesis for example they varied from 0.2-1.0 per 1000 person years. Toxicity was dose related. Aspirin does have significant gastrointestinal toxicity, although this is rarely fatal. More recent work has demonstrated the efficacy of low doses of aspirin (75 mg daily) but there is limited information yet available on its toxicity.

Do risk factors change in men at high risk of coronary heart disease? Observations on the effect of health promotion in primary care.

BACKGROUND: There has been an increasing focus on the identification and modification of risk factors for coronary heart disease (CHD) in primary care. One approach is to concentrate activity on those at high risk of CHD. METHODS: This study was a prospective follow-up after CHD risk assessment and intervention designed to determine whether middle-aged men identified as being at high risk of CHD in primary care, who participated in a randomized controlled trial of antithrombotic medication, reduced their risk factor profile in response to the health promotion given in all practices, whatever their treatment allocation. We studied 4316 men aged 45-69 years (who had not suffered a previous myocardial infarction or stroke) identified at screening in 81 general practices in the UK as being at high risk of coronary heart disease. The changes in the prevalence of smoking and in blood pressure, serum cholesterol level, body mass index and plasma fibrinogen level were recorded for a period of up to 2 years after entry into the trial. The use of standard health education materials and of more intensive individual interventions was substantial. There were regular opportunities through nurses and consultations with general practitioners for continuing advice about risk factors. RESULTS: The prevalence of current smoking fell during the trial but it was still 37% at 2 years. There was a significant decrease in blood pressure due first to regression to the mean but then to the trial's treatment protocol and accommodation to measurement. There were small falls between screening and entry in body mass and levels of serum cholesterol and fibrinogen, again due largely to regression to the mean; subsequent changes in these characteristics were negligible. CONCLUSION: Sustained and quite intensive health promotion activity had only a limited effect in men identified as being at high risk of CHD. In particular, there was little change in body mass or serum cholesterol. Although improved blood pressure control and a moderate reduction in the prevalence of smoking can be achieved, further research is needed to determine the most effective methods of risk factor reduction in order to realize the full potential of the 'high-risk' approach to the prevention of CHD.

Developing the 'health-promoting school'--a national survey of healthy schools awards.

The concept of the 'Health Promoting School' has been widely advocated as an approach to enhancing public health through school based health promotion. In many areas 'Healthy Schools Award' schemes have been set up to support the development of this concept, but there is no information on how widespread this practice is in the UK, how standards are evaluated, and what effect Healthy Schools Awards may have on young peoples' health. This UK national survey aimed to determine the extent and nature of existing award schemes and how they were being evaluated. A postal questionnaire was sent to all 200 health promotion units in the UK; the response rate corrected for mergers of units was 78.5%. Sixty-eight respondents (51%) were involved with an award scheme and 28 (21%) were planning them. Current award schemes were mostly jointly run by the health and education sectors, encompassing 845 participating schools of which two-thirds were primary schools. The most common issues addressed were; standard chronic disease risk behaviour, the environment and health education in the national curriculum; less frequently addressed were mental health, accident prevention, staff health and developing links with the wider community. Evaluation was usually by target setting and assessment of progress over a two year period. However, evaluation was rarely external or independent, raising doubts about the standards obtained and validity of the approaches. This survey highlights the rapid growth of healthy schools award schemes and the need for wider exchange of information on good practice. In particular there is a need for more explicit and measurable standards of achievement to ensure the quality of award schemes, and further research into their effectiveness.

Evaluating screening policies for the early detection of retinopathy in patients with non-insulin dependent diabetes.

Retinopathy is a common complication of insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes, but serious visual loss may be prevented or delayed with sufficiently early diagnosis and treatment. Screening for early signs of retinopathy is clearly beneficial for some people, but there is no established consensus about who should be screened, by whom, by what technique and with what frequency, especially for NIDDM. The model described in this paper simulates the development of eye disease in a population of NIDDM patients and the effects of different screening schemes in terms of years of sight saved and the numbers of people prevented from suffering severe visual loss. The initial results indicate that blanket screening of all NIDDM patients may not be effective.

The study of infectious intestinal disease in England: socio-economic impact.

To assess the socio-economic impact of infectious intestinal disease (IID) on the health care sector, cases and their families, cases of IID ascertained from a population cohort component and those presenting to general practices were sent a socio-economic questionnaire 3 weeks after the acute episode. The impact of the illness was measured and the resources used were identified and costed. The duration, severity and costs of illness linked to viruses were less than those linked to bacteria. The average cost per case of IID presenting to the GP was Pound Sterling253 and the costs of those not seeing a GP were Pound Sterling34. The average cost per case was Pound Sterling606 for a case with salmonella, Pound Sterling315 for campylobacter, Pound Sterling164 for rotavirus and Pound Sterling176 for SRSV. The estimated cost of IID in England was Pound Sterling743m expressed in 1994/5 prices. The costs of IID are considerable and the duration of the illness was found to be longer than previous reports have suggested.