How predictive of future healthcare utilisation and mortality is data-driven population segmentation based on healthcare utilisation and chronic condition comorbidity?

BACKGROUND: In recent years data-driven population segmentation using cluster analyses of mainly health care utilisation data has been used as a proxy of future health care need. Chronic conditions patterns tended to be examined after segmentation but may be useful as a segmentation variable which, in combination with utilisation could indicate severity. These could further be of practical use to target specific clinical groups including for prevention. This study aimed to assess the ability of data-driven segmentation based on health care utilisation and comorbidities to predict future outcomes: Emergency admission, A&E attendance, GP practice contacts, and mortality. METHODS: We analysed record-linked data for 412,997 patients registered with GP practices in 2018-19 in Cwm Taf Morgannwg University Health Board (CTM UHB) area within the Secure Anonymised Information Linkage (SAIL) Databank. We created 10 segments using k-means clustering based on utilisation (GP practice contacts, prescriptions, emergency and elective admissions, A&E and outpatients) and chronic condition counts for 2018 using different variable compositions to denote need. We assessed the characteristics of the segments. We employed a train/test scheme (80% training set) to compare logistic regression model predictions with observed outcomes on follow-up in 2019. We assessed the area under the ROC curve (AUC) for models with demographic variables, with and without the segments, as well as between segmentation implementations (with/without comorbidity and primary care data). RESULTS: Adding the segments to the model with demographic covariates improved the prediction for all outcomes. For emergency admissions this increased discrimination from AUC 0.65 (CI 0.64-0.65) to 0.73 (CI 0.73-0.74). Models with the segments only performed nearly as well as the full models. Excluding comorbidity showed reduced predictive ability for mortality (similar otherwise) but most pronounced reduction when excluding all primary care variables. CONCLUSIONS: This shows that the segments have satisfactory predictive ability, even for varied outcomes and a broad range of events and conditions used in the segmentation. It suggests that the segments can be a useful tool in helping to identify specific groups of need to target with anticipatory care. Identification may be refined with selected diagnoses or more specialised tools such as risk stratification.

Dietary diversity and nutritional status of adolescents in Lagos, Nigeria.

Background/Objectives: Adolescents in low- and middle-income countries, such as Nigeria, are at increased risk of malnutrition, especially obesity, but there is limited data describing the risk. We assessed this risk by examining the nutritional status and associated factors such as dietary habits, dietary diversity, nutritional knowledge and sociodemographic characteristics among adolescents in Lagos, Nigeria. Methods: A descriptive cross-sectional study in which 682 adolescents were selected from their communities using a multistage sampling technique. Dietary habits were assessed using a food frequency questionnaire, and dietary diversity was assessed through nonquantifiable 24-h diet recall. Anthropometric measurements were taken to determine nutritional status. Data were analyzed using Epi-Info software version 7.2.3.1. Nutritional status was evaluated using WHO AnthroPlus software. Chi-square was used to test for an association between categorical variables, and P values ≤0.05 were considered statistically significant. Results: The mean age of the adolescents was 13.6 ± 2.3 years, and only 47.4% of them had good nutritional knowledge. Dietary habits were poor and dietary diversity was low. The prevalence of overweight and obesity was 13.4% and 7.0%. Eating dinner, dieting to control weight and daily consumption of foods outside the home were associated with overweight and obesity (P < 0.05). Conclusions: Dietary habits and diversity of the adolescents were poor, while overweight and obesity were high. Eating dinner and daily consumption of foods outside the home were factors associated with being overweight and obesity. Our findings emphasize the critical need for adolescent nutrition programs that address weight control, especially among those who eat outside their homes.

Cost-effectiveness of a whole-area testing pilot of asymptomatic SARS-CoV-2 infections with lateral flow devices: a modelling and economic analysis study.

BACKGROUND: Mass community testing for SARS-CoV-2 by lateral flow devices (LFDs) aims to reduce prevalence in the community. However its effectiveness as a public heath intervention is disputed. METHOD: Data from a mass testing pilot in the Borough of Merthyr Tydfil in late 2020 was used to model cases, hospitalisations, ICU admissions and deaths prevented. Further economic analysis with a healthcare perspective assessed cost-effectiveness in terms of healthcare costs avoided and QALYs gained. RESULTS: An initial conservative estimate of 360 (95% CI: 311-418) cases were prevented by the mass testing, representing a would-be reduction of 11% of all cases diagnosed in Merthyr Tydfil residents during the same period. Modelling healthcare burden estimates that 24 (16-36) hospitalizations, 5 (3-6) ICU admissions and 15 (11-20) deaths were prevented, representing 6.37%, 11.1% and 8.2%, respectively of the actual counts during the same period. A less conservative, best-case scenario predicts 2333 (1764-3115) cases prevented, representing 80% reduction in would-be cases. Cost -effectiveness analysis indicates 108 (80-143) QALYs gained, an incremental cost-effectiveness ratio of £2,143 (£860-£4,175) per QALY gained and net monetary benefit of £6.2 m (£4.5 m-£8.4 m). In the best-case scenario, this increases to £15.9 m (£12.3 m-£20.5 m). CONCLUSIONS: A non-negligible number of cases, hospitalisations and deaths were prevented by the mass testing pilot. Considering QALYs gained and healthcare costs avoided, the pilot was cost-effective. These findings suggest mass testing with LFDs in areas of high prevalence (> 2%) is likely to provide significant public health benefit. It is not yet clear whether similar benefits will be obtained in low prevalence settings or with vaccination rollout.

Social, demographic and behavioural determinants of SARS-CoV-2 infection: a case-control study carried out during mass community testing of asymptomatic individuals in South Wales, December 2020.

Between 21 November and 22 December 2020, a SARS-CoV-2 community testing pilot took place in the South Wales Valleys. We conducted a case-control study in adults taking part in the pilot using an anonymous online questionnaire. Social, demographic and behavioural factors were compared in people with a positive lateral flow test (cases) and a sample of negatives (controls). A total of 199 cases and 2621 controls completed a questionnaire (response rates: 27.1 and 37.6% respectively). Following adjustment, cases were more likely to work in the hospitality sector (aOR 3.39, 95% CI 1.43-8.03), social care (aOR 2.63, 1.22-5.67) or healthcare (aOR 2.31, 1.29-4.13), live with someone self-isolating due to contact with a case (aOR 3.07, 2.03-4.62), visit a pub (aOR 2.87, 1.11-7.37) and smoke or vape (aOR 1.54, 1.02-2.32). In this community, and at this point in the epidemic, reducing transmission from a household contact who is self-isolating would have the biggest public health impact (population-attributable fraction: 0.2). As restrictions on social mixing are relaxed, hospitality venues will become of greater public health importance, and those working in this sector should be adequately protected. Smoking or vaping may be an important modifiable risk factor.

SARS-CoV-2 sero-prevalence in the workforces of three large workplaces in South Wales: a sero-epidemiological study.

BACKGROUND: Sero-prevalence studies quantify the proportion of a population that has antibodies against SARS-CoV-2, and can be used to identify the extent of the COVID-19 pandemic at a population level. The aim of the study was to assess the sero-prevalence of SARS-CoV-2 antibodies in the workforce at three workplaces: a food factory, non-food factory and call-centre. METHODS: Nine hundred ninety-three participants were recruited from three workplaces in South Wales. Participants completed a questionnaire and had a lateral flow point-of-care SARS-CoV-2 antibody test administered by a healthcare professional. The data were analysed using multivariable logistic regression, both using complete records only and following multiple imputation. RESULTS: The sero-prevalence of SARS-CoV-2 antibodies ranged from 4% (n = 17/402) in the non-food factory to 10% (n = 28/281) in the food factory (OR 2.93; 95% CI 1.26 to 6.81). After taking account of confounding factors evidence of a difference remained (cOR comparing food factory to call centre (2.93; 95% CI 1.26 to 6.81) and non-food factory (3.99; 95% CI 1.97 to 8.08) respectively). The SARS-CoV-2 antibody prevalence also varied between roles within workplaces. People working in office based roles had a 2.23 times greater conditional odds (95% CI 1.02 to 4.87) of being positive for SARS-CoV-2 antibodies than those working on the factory floor. CONCLUSION: The sero-prevalence of SARS-CoV-2 antibodies varied by workplace and work role. Whilst it is not possible to state whether these differences are due to COVID-19 transmission within the workplaces, it highlights the importance of considering COVID-19 transmission in a range of workplaces and work roles.

Can cluster analyses of linked healthcare data identify unique population segments in a general practice-registered population?

BACKGROUND: Population segmentation is useful for understanding the health needs of populations. Expert-driven segmentation is a traditional approach which involves subjective decisions on how to segment data, with no agreed best practice. The limitations of this approach are theoretically overcome by more data-driven approaches such as utilisation-based cluster analysis. Previous explorations of using utilisation-based cluster analysis for segmentation have demonstrated feasibility but were limited in potential usefulness for local service planning. This study explores the potential for practical application of using utilisation-based cluster analyses to segment a local General Practice-registered population in the South Wales Valleys. METHODS: Primary and secondary care datasets were linked to create a database of 79,607 patients including socio-demographic variables, morbidities, care utilisation, cost and risk factor information. We undertook utilisation-based cluster analysis, using k-means methodology to group the population into segments with distinct healthcare utilisation patterns based on seven utilisation variables: elective inpatient admissions, non-elective inpatient admissions, outpatient first & follow-up attendances, Emergency Department visits, GP practice visits and prescriptions. We analysed segments post-hoc to understand their morbidity, risk and demographic profiles. RESULTS: Ten population segments were identified which had distinct profiles of healthcare use, morbidity, demographic characteristics and risk attributes. Although half of the study population were in segments characterised as 'low need' populations, there was heterogeneity in this group with respect to variables relevant to service planning - e.g. settings in which care was mostly consumed. Significant and complex healthcare need was a feature across age groups and was driven more by deprivation and behavioural risk factors than by age and functional limitation. CONCLUSIONS: This analysis shows that utilisation-based cluster analysis of linked primary and secondary healthcare use data for a local GP-registered population can segment the population into distinct groups with unique health and care needs, providing useful intelligence to inform local population health service planning and care delivery. This segmentation approach can offer a detailed understanding of the health and care priorities of population groups, potentially supporting the integration of health and care, reducing fragmentation of healthcare and reducing healthcare costs in the population.

Effects of Health-Related Food Taxes and Subsidies on Mortality from Diet-Related Disease in New Zealand: An Econometric-Epidemiologic Modelling Study.

BACKGROUND: Health-related food taxes and subsidies may promote healthier diets and reduce mortality. Our aim was to estimate the effects of health-related food taxes and subsidies on deaths prevented or postponed (DPP) in New Zealand. METHODS: A macrosimulation model based on household expenditure data, demand elasticities and population impact fractions for 18 diet-related diseases was used to estimate effects of five tax and subsidy regimens. We used price elasticity values for 24 major commonly consumed food groups in New Zealand, and food expenditure data from national Household Economic Surveys. Changes in mortality from cardiovascular disease, cancer, diabetes and other diet-related diseases were estimated. FINDINGS: A 20% subsidy on fruit and vegetables would result in 560 (95% uncertainty interval, 400 to 700) DPP each year (1.9% annual all-cause mortality). A 20% tax on major dietary sources of saturated fat would result in 1,500 (950 to 2,100) DPP (5.0%), and a 20% tax on major dietary sources of sodium would result in 2,000 (1300 to 2,700) DPP (6.8%). Combining taxes on saturated fat and sodium with a fruit and vegetable subsidy would result in 2,400 (1,800 to 3,000) DPP (8.1% mortality annually). A tax on major dietary sources of greenhouse gas emissions would generate 1,200 (750 to 1,700) DPP annually (4.0%). Effects were similar or greater for Maori and low-income households in relative terms. CONCLUSIONS: Health-related food taxes and subsidies could improve diets and reduce mortality from diet-related disease in New Zealand. Our study adds to the growing evidence base suggesting food pricing policies should improve population health and reduce inequalities, but there is still much work to be done to improve estimation of health impacts.

Endometriosis and associated symptoms among Nigerian women.

OBJECTIVE: To determine the prevalence of endometriosis and identify associated symptoms among Nigerian women. METHODS: A cross-sectional study was conducted at a center in Ibadan, Nigeria, between October 2008 and December 2010. All women aged 18-45 years scheduled for their first diagnostic laparoscopy for gynecologic indications were enrolled. Participants completed a previously validated self-administered questionnaire. Endometriosis was diagnosed on the basis of visual evidence. RESULTS: Among 239 women analyzed, 115 (48.1%) had endometriotic lesions. Endometriosis was more common among women reporting dysmenorrhea and pelvic pain than among those not reporting these symptoms (20/28 [71.4%] vs 95/211 [45.0%]; P=0.009). Women who reported dysmenorrhea were significantly more likely to have endometriosis than were those without dysmenorrhea (90/171 [52.6%] vs 25/68 [36.8%]; P=0.027). The risk of endometriosis was not significantly increased in women with one pain symptom (odds ratio [OR]1.69; 95% confidence interval [CI] 0.67-4.27), but was significantly increased in women with two (OR 2.70; 95% CI 1.13-6.52) or three (OR 4.87; 95% CI 1.88-12.82) pain symptoms (χ(2)trend=15.5; P<0.001). In a multivariate logistic regression model, only pain other than dysmenorrhea or dyspareunia independently predicted endometriosis (P=0.017). CONCLUSION: Endometriosis is fairly common among Nigerian women. Efforts to increase the awareness of endometriosis among the public, researchers, and clinicians are needed.

Systematic review and meta-analysis of the effect of increased vegetable and fruit consumption on body weight and energy intake.

BACKGROUND: Increased vegetable and fruit consumption is encouraged to promote health, including the maintenance of a healthy body weight. Population health strategies (e.g. 5-A-Day or similar campaigns and subsidies on vegetables or fruit) that emphasize increased consumption may theoretically lead to increased energy intake and weight gain. METHODS: We undertook a systematic review of trials that sought to increase vegetable and fruit consumption, in the absence of advice or specific encouragement to remove other foods from the diet, to understand the effect on body weight and energy intake. We included only randomised controlled trials. We pooled data using a random effects model for two outcomes: change in body weight and change in energy intake. Sensitivity and secondary analyses were also undertaken, including a one-study removed analysis and analysis by study sub-type to explore sources of heterogeneity. RESULTS: A total of eight studies, including 1026 participants, were identified for inclusion in the review. The mean study duration was 14.7 weeks (range four to 52 weeks). The mean difference in vegetable and fruit consumption between arms was 133 g (range 50 g to 456 g). The mean change in body weight was -0.54kg (95% CI: -1.05 to -0.04; n=8; I2 for heterogeneity = 73%, p<0.01) less in the 'high vegetable and fruit' intake arms than in the 'low vegetable and fruit intake' arms. There was no significant difference in measured change daily energy intake between the two arms (368 kJ; 95% CI: -27 to 762, comparing high vs low; n = 6; I2 = 42%, p = 0.07). CONCLUSION: Promoting increased fruit and vegetable consumption, in the absence of specific advice to decrease consumption of other foods, appears unlikely to lead to weight gain in the short-term and may have a role in weight maintenance or loss. Longer studies or other methods are needed to understand the long-term effects on weight maintenance and loss.

Potential cardiovascular mortality reductions with stricter food policies in the United Kingdom of Great Britain and Northern Ireland.

OBJECTIVE: To estimate how much more cardiovascular disease (CVD) mortality could be reduced in the United Kingdom through more progressive nutritional targets. METHODS: Potential reductions in CVD mortality in the United Kingdom between 2006 (baseline) and 2015 were estimated by synthesizing data on population, diet and mortality among adults aged 25 to 84 years. The effect of specific dietary changes on CVD mortality was obtained from recent meta-analyses. The potential reduction in CVD deaths was then estimated for two dietary policy scenarios: (i) modest improvements (simply assuming recent trends will continue until 2015) and (ii) more substantial but feasible reductions (already seen in several countries) in saturated fats, industrial trans fats and salt consumption, plus increased fruit and vegetable intake. A probabilistic sensitivity analysis was conducted. Results were stratified by age and sex. FINDINGS: The first scenario would result in approximately 12 500 fewer CVD deaths per year (range: 5500-30 300). Approximately 4800 fewer deaths from coronary heart disease and 1800 fewer deaths from stroke would occur among men, and 3500 and 2400 fewer, respectively, would occur among women. More substantial dietary improvements (no industrial trans fats, reduction in saturated fats and salt and substantial increases in fruit and vegetable intake) could result in approximately 30 000 fewer (range: 13 300-74 900) CVD deaths. CONCLUSION: Excess dietary trans fats, saturated fats and salt, along with insufficient fruits and vegetables, generate a substantial burden of CVD in the United Kingdom. Further improvements resembling those attained by other countries are achievable through stricter dietary policies.

Developing symptom-based predictive models of endometriosis as a clinical screening tool: results from a multicenter study.

OBJECTIVE: To generate and validate symptom-based models to predict endometriosis among symptomatic women prior to undergoing their first laparoscopy. DESIGN: Prospective, observational, two-phase study, in which women completed a 25-item questionnaire prior to surgery. SETTING: Nineteen hospitals in 13 countries. PATIENT(S): Symptomatic women (n = 1,396) scheduled for laparoscopy without a previous surgical diagnosis of endometriosis. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Sensitivity and specificity of endometriosis diagnosis predicted by symptoms and patient characteristics from optimal models developed using multiple logistic regression analyses in one data set (phase I), and independently validated in a second data set (phase II) by receiver operating characteristic (ROC) curve analysis. RESULT(S): Three hundred sixty (46.7%) women in phase I and 364 (58.2%) in phase II were diagnosed with endometriosis at laparoscopy. Menstrual dyschezia (pain on opening bowels) and a history of benign ovarian cysts most strongly predicted both any and stage III and IV endometriosis in both phases. Prediction of any-stage endometriosis, although improved by ultrasound scan evidence of cyst/nodules, was relatively poor (area under the curve [AUC] = 68.3). Stage III and IV disease was predicted with good accuracy (AUC = 84.9, sensitivity of 82.3% and specificity 75.8% at an optimal cut-off of 0.24). CONCLUSION(S): Our symptom-based models predict any-stage endometriosis relatively poorly and stage III and IV disease with good accuracy. Predictive tools based on such models could help to prioritize women for surgical investigation in clinical practice and thus contribute to reducing time to diagnosis. We invite other researchers to validate the key models in additional populations.

Is early age at menarche a risk factor for endometriosis? A systematic review and meta-analysis of case-control studies.

OBJECTIVE: To review published studies evaluating early menarche and the risk of endometriosis. DESIGN: Systematic review and meta-analysis of case-control studies. SETTING: None. PATIENT(S): Eighteen case-control studies of age at menarche and risk of endometriosis including 3,805 women with endometriosis and 9,526 controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Medline and Embase databases were searched from 1980 to 2011 to locate relevant studies. Results of primary studies were expressed as effect sizes of the difference in mean age at menarche of women with and without endometriosis. Effect sizes were used in random effects meta-analysis. RESULT(S): Eighteen of 45 articles retrieved met the inclusion criteria. The pooled effect size in meta-analysis was 0.10 (95% confidence interval -0.01-0.21), and not significantly different from zero (no effect). Results were influenced by substantial heterogeneity between studies (I(2) = 72.5%), which was eliminated by restricting meta-analysis to studies with more rigorous control of confounders; this increased the pooled effect size to 0.15 (95% confidence interval 0.08-0.22), which was significantly different from zero. This represents a probability of 55% that a woman with endometriosis had earlier menarche than one without endometriosis if both were randomly chosen from a population. CONCLUSION(S): There is a small increased risk of endometriosis with early menarche. The potential for disease misclassification in primary studies suggests that this risk could be higher.

Modelling the impact of a healthy diet on cardiovascular disease and cancer mortality.

BACKGROUND: Quantifying the potential health benefits of improvements in the nutritional quality of the average diet of a population would provide evidence for resource allocation between population-level interventions aimed at reducing chronic disease. METHODS: A model was built linking consumption of food components with biological risk factors (blood pressure, serum cholesterol and obesity) and subsequent mortality from coronary heart disease, stroke and cancer. Meta-analyses of individual-level studies that quantified the RR of increased consumption/increased risk factor level on disease outcomes were used to build the model. The sensitivity of the model to the results from the meta-analyses was assessed with Monte Carlo simulations. Country-specific estimates of current nutrient intake compared against dietary recommendations for the UK were used to demonstrate the model. RESULTS: Approximately 33 000 deaths per year would be avoided if UK dietary recommendations were met. The modelled reduction in deaths for coronary heart disease was 20 800 (95% credible interval 17 845-24 069), for stroke 5876 (3856-7364) and for cancer 6481 (4487-8353). Over 15 000 of the avoided deaths would be due to increased consumption of fruit and vegetables. CONCLUSIONS: The developed model estimates the impact of population-level dietary changes and is robust. Achieving UK dietary recommendations for fruit and vegetable consumption (five portions a day) would result in substantial health benefits-equivalent benefits would be achieved if salt intakes were lowered to 3.5 g per day or saturated fat intakes were lowered to 3% of total energy.

Impact of endometriosis on quality of life and work productivity: a multicenter study across ten countries.

OBJECTIVE: To assess the impact of endometriosis on health-related quality of life (HRQoL) and work productivity. DESIGN: Multicenter cross-sectional study with prospective recruitment. SETTING: Sixteen clinical centers in ten countries. PATIENT(S): A total of 1,418 premenopausal women, aged 18-45 years, without a previous surgical diagnosis of endometriosis, having laparoscopy to investigate symptoms or to be sterilized. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Diagnostic delay, HRQoL, and work productivity. RESULT(S): There was a delay of 6.7 years, principally in primary care, between onset of symptoms and a surgical diagnosis of endometriosis, which was longer in centers where women received predominantly state-funded health care (8.3 vs. 5.5 years). Delay was positively associated with the number of pelvic symptoms (chronic pelvic pain, dysmenorrhoea, dyspareunia, and heavy periods) and a higher body mass index. Physical HRQoL was significantly reduced in affected women compared with those with similar symptoms and no endometriosis. Each affected woman lost on average 10.8 hours (SD 12.2) of work weekly, mainly owing to reduced effectiveness while working. Loss of work productivity translated into significant costs per woman/week, from US$4 in Nigeria to US$456 in Italy. CONCLUSION(S): Endometriosis impairs HRQoL and work productivity across countries and ethnicities, yet women continue to experience diagnostic delays in primary care. A higher index of suspicion is needed to expedite specialist assessment of symptomatic women. Future research should seek to clarify pain mechanisms in relation to endometriosis severity.

Do geodemographic typologies explain variations in uptake in colorectal cancer screening? An assessment using routine screening data in the south of England.

BACKGROUND: Uptake of colorectal cancer (CRC) screening in UK is less than 60%. Geodemographic typologies are useful in describing patterns of individual preventive health behaviour but little is known of their value in assessing uptake of CRC screening, or how this compares to traditional measures of area deprivation. METHODS: We used data on CRC screening uptake in the South Central, South-East Coast and South-West England National Health Service regions in multilevel logistic regression to describe the effects of individual composition and contextual factors (area deprivation and geodemographic segments) on non-response to screening invitation. The relative impact of geodemographic segmentation and the index of multiple deprivation (IMD) 2007 was compared. The potential population impact of a targeted increase in uptake in specific geodemographic segments was examined. RESULTS: About 88 891 eligible adults were invited to be screened from 2006 to 2008. Uptake rate was 57.3% (CI: 57.0-57.7) and was lower amongst younger persons, men, residents of more deprived areas and people in specific geodemographic segments. Age and gender were significant determinants of uptake and contextual factors explained an additional 3% of the variation. Geodemographic segmentation reduced this residual contextual variation in uptake more than the IMD 2007 (72% vs. 53% reduction). The three geodemographic types that best predicted non-response were characterized by both ethnic mix and a higher than average proportion of single pensioner households renting council properties. Achieving average uptake in the 2.3% of the study population in these geodemographic segments would only increase the total population uptake rate by 0.5% (57.3-57.8%). CONCLUSION: Variation in the CRC screening uptake in Southern England is principally explained by characteristics of individuals but contextual factors also have a small but significant effect. This effect is captured in greater detail by geodemographic segmentation than by IMD 2007. This information could be used to inform the design of interventions aiming to improve uptake.

Modelling income group differences in the health and economic impacts of targeted food taxes and subsidies.

OBJECTIVE: To examine the effects, by income group, of targeted food taxes and subsidies on nutrition, health and expenditure in the UK. METHODS: A model based on consumption data and demand elasticity was constructed to predict the effects of four food taxation-subsidy regimens. Resulting changes in demand, expenditure, nutrition, cardiovascular disease (CVD) and cancer mortality were estimated. Data Expenditure data were taken from the Expenditure and Food Survey; estimates of price elasticities of demand for food were taken from a report based on the National Food Survey 1988-2000. Estimates of effect on CVD and cancer mortality of changing fat, salt, fruit and vegetable intake were taken from previous meta-analyses. RESULTS: (i) Taxing principal sources of dietary saturated fat is unlikely to reduce cardiovascular disease (CVD) or cancer mortality. (ii) Taxing 'less healthy' foods (defined by the WXYfm nutrient profiling model) could increase CVD and cancer deaths by 35-1300 yearly. (iii) Taxing 'less healthy' foods and subsidising fruits and vegetables by 17.5% could avert up to 2900 CVD and cancer deaths yearly. (iv) Taxing 'less healthy' foods and using all tax revenue to subsidize fruits and vegetables could avert up to 6400 CVD and cancer deaths yearly. Few obesity-related CVD deaths are averted by any of the regimens. All four regimens would be economically regressive and positive health effects will not necessarily be greater in lower-income groups where the need for dietary improvement is higher. CONCLUSIONS: A targeted food tax combined with the appropriate subsidy on fruits and vegetables could reduce deaths from CVD and cancer.

MULTI-CENTRE STUDIES OF THE GLOBAL IMPACT OF ENDOMETRIOSIS AND THE PREDICTIVE VALUE OF ASSOCIATED SYMPTOMS.

INTRODUCTION: Endometriosis can be difficult to diagnose clinically and models that use symptoms to predict whether the disease is present or not are based on limited patient populations. Endometriosis also influences health-related quality of life, but little is known about its impact across the world. We therefore initiated two integrated multicentre studies to collect prospective, standardised, epidemiological data, to 1) examine the global impact of endometriosis and relative effect of risk-factors, and 2) develop a symptom-based diagnostic tool. METHODS: The Global Study of Women's Health (GSWH) and the Women's Health Symptom Survey (WHSS) prospectively recruit 18-45 year old women having a laparoscopy across 23 and 19 centres, respectively, worldwide. Women with a previous surgical diagnosis of endometriosis are excluded. Multi-lingual patient questionnaires and a surgical questionnaire, incorporating validated instruments, are used to collect the data. The GSWH aims to recruit >2,000 women by December 2009; the WHSS to recruit 1,000 women in each of the two model-generating and validation stages. RESULTS: A six-week pilot study in Oxford, UK, established the feasibility of the study protocols. Of 32 eligible women, 27 participated (response rate - 84.4%); 26% completed the questionnaire online. Endometriosis was found in 47.4%. Extrapolating the recruitment rates from the pilot study, the target sample sizes for the GWSH and WHSS were deemed feasible. CONCLUSIONS: Using standardised data collection, the GSWH and WHSS will provide insight into the global impact of endometriosis and develop a validated, symptom-based, diagnostic tool. They have the potential to provide the basis for future, longitudinal, follow-up studies and a collaborative Endometriosis Biobank implementing standardised collection of DNA and tissue samples.