Tim Pearson

Do ‘food deserts’ influence fruit and vegetable consumption?—a cross-sectional study

Lack of access to affordable healthy foods has been suggested to be a contributory factor to poor diet. This study investigated associations between diet and access to supermarkets, transport, fruit and vegetable price and deprivation, in a region divergent in geography and socio-economic indices. A postal survey of 1000 addresses (response rate 42%) gathered information on family demographics, supermarket and shop use, car ownership, mobility and previous days fruit and vegetable intake. Postcode information was used to derive road travel distance to nearest supermarket and deprivation index. Fruit and vegetable prices were assessed using a shopping basket survey. Generalised linear regression models were used to ascertain predictors of fruit and vegetable intake. Male grocery shoppers ate less fruit than female grocery shoppers. Consumption of vegetables increased slightly with age. Deprivation, supermarket fruit and vegetable price, distance to nearest supermarket and potential difficulties with grocery shopping were not significantly associated with either fruit or vegetable consumption. These data suggest that the three key elements of a food desert, fruit and vegetable price, socio-economic deprivation and a lack of locally available supermarkets, were not factors influencing fruit or vegetable intake. We suggest that food policies aimed at improving diet should be orientated towards changing socio-cultural attitudes towards food.

Socioeconomic deprivation, travel distance, location of service, and uptake of breast cancer screening in North Derbyshire, UK

Background and aim: This study examined the association between socioeconomic deprivation, travel distance, urban-rural status, location and type of screening unit, and breast screening uptake. Screening was provided at 13 locations—1 fixed and 12 mobile (3 at non-health locations). Methods: The study examined data from 1998 to 2001 for 34 868 women aged 50–64 years, calculated road travel distance, used 1991 enumeration district level Townsend socioeconomic deprivation scores, and a ward level urban-rural classification. Results: Odds of attendance for screening decreased with increasing socioeconomic deprivation, with an adjusted odds ratio of 0.64 (95%CI 0.59 to 0.70) in the most deprived relative to the least deprived category. 87% of women lived within 8 km of their screening location. The odds ratio for a 10 km increase in distance was 0.87 (95%CI 0.79 to 0.95). The odds ratios were 1.18 (95%CI 1.08 to 1.28) for screening at a non-health relative to a health location, 1.00 (95%CI 0.94 to 1.07) for the fixed site relative to the mobile unit and 1.00 (95%CI 0.91 to 1.09) for mainly rural relative to mainly urban areas. Conclusions: Socioeconomic inequality in breast screening uptake seems to persist in an established service. There was a small decrease with increasing distance, no difference between fixed and mobile units, and no difference between urban and rural areas but uptake seemed to be higher at non-health sites. Further work is needed to identify effective methods of decreasing socioeconomic inequalities in uptake and to confirm if non-health locations are associated with higher screening uptake.

Outdoor Air Pollution and Stroke in Sheffield, United Kingdom: A Small-Area Level Geographical Study

Background and Purpose— Current evidence suggests that stroke mortality and hospital admissions should be higher in areas with elevated levels of outdoor air pollution because of the combined acute and chronic exposure effects of air pollution. We examined this hypothesis using a small-area level ecological correlation study. Methods— We used 1030 census enumeration districts as the unit of analysis and examined stroke deaths and hospital admissions from 1994 to 1998, with census denominator counts for people ≥45 years. Modeled air pollution data for particulate matter (PM10), nitrogen oxides (NOx), and carbon monoxide (CO) were interpolated to census enumeration districts. We adjusted for age, sex, socioeconomic deprivation, and smoking prevalence. Results— The analysis was based on 2979 deaths, 5122 admissions, and a population of 199 682. After adjustment for potential confounders, stroke mortality was 37% (95% CI, 19 to 57), 33% (95% CI, 14 to 56), and 26% (95% CI, 10 to 46) higher in the highest, relative to the lowest, NOx, PM10, and CO quintile categories, respectively. Corresponding increases in risk for admissions were 13% (95% CI, 1 to 27), 13% (95% CI, −1 to 29), and 11% (95% CI, −1 to 25). Conclusion— The results are consistent with an excess risk of stroke mortality and, to a lesser extent, hospital admissions in areas with high outdoor air pollution levels. If causality were assumed, 11% of stroke deaths would have been attributable to outdoor air pollution. Targeting policy interventions at high pollution areas may be a feasible option for stroke prevention.

Socioeconomic deprivation, urban-rural location and alcohol-related mortality in England and Wales

BackgroundMany causes of death are directly attributable to the toxic effects of alcohol and deaths from these causes are increasing in the United Kingdom. The aim of this study was to investigate variation in alcohol-related mortality in relation to socioeconomic deprivation, urban-rural location and age within a national context.MethodsAn ecological study design was used with data from 8797 standard table wards in England and Wales. The methodology included using the Carstairs Index as a measure of socioeconomic deprivation at the small-area level and the national harmonised classification system for urban and rural areas in England and Wales. Alcohol-related mortality was defined using the National Statistics definition, devised for tracking national trends in alcohol-related deaths. Deaths from liver cirrhosis accounted for 85% of all deaths included in this definition. Deaths from 1999-2003 were examined and 2001 census ward population estimates were used as the denominators.ResultsThe analysis was based on 28,839 deaths. Alcohol-related mortality rates were higher in men and increased with increasing age, generally reaching peak levels in middle-aged adults. The 45-64 year age group contained a quarter of the total population but accounted for half of all alcohol-related deaths. There was a clear association between alcohol-related mortality and socioeconomic deprivation, with progressively higher rates in more deprived areas. The strength of the association varied with age. Greatest relative inequalities were seen amongst people aged 25-44 years, with relative risks of 4.73 (95% CI 4.00 to 5.59) and 4.24 (95% CI 3.50 to 5.13) for men and women respectively in the most relative to the least deprived quintiles. People living in urban areas experienced higher alcohol-related mortality relative to those living in rural areas, with differences remaining after adjustment for socioeconomic deprivation. Adjusted relative risks for urban relative to rural areas were 1.35 (95% CI 1.20 to 1.52) and 1.13 (95% CI 1.01 to 1.25) for men and women respectively.ConclusionsLarge inequalities in alcohol-related mortality exist between sub-groups of the population in England and Wales. These should be considered when designing public health policies to reduce alcohol-related harm.

Impact of Outdoor Air Pollution on Survival After Stroke Population-Based Cohort Study

Background and Purpose— The impact of air pollution on survival after stroke is unknown. We examined the impact of outdoor air pollution on stroke survival by studying a population-based cohort. Methods— All patients who experienced their first-ever stroke between 1995 and 2005 in a geographically defined part of London, where road traffic contributes to spatial variation in air pollution, were followed up to mid-2006. Outdoor concentrations of nitrogen dioxide and particulate matter <10 &mgr;m in diameter modeled at a 20-m grid point resolution for 2002 were linked to residential postal codes. Hazard ratios were adjusted for age, sex, social class, ethnicity, smoking, alcohol consumption, prestroke functional ability, pre-existing medical conditions, stroke subtype and severity, hospital admission, and neighborhood socioeconomic deprivation. Results— There were 1856 deaths among 3320 patients. Median survival was 3.7 years (interquartile range, 0.1 to 10.8). Mean exposure levels were 41 &mgr;g/m3 (SD, 3.3; range, 32.2 to 103.2) for nitrogen dioxide and 25 &mgr;g/m3 (SD, 1.3; range, 22.7 to 52) for particulate matter <10 &mgr;m in diameter. A 10-&mgr;g/m3 increase in nitrogen dioxide was associated with a 28% (95% CI, 11% to 48%) increase in risk of death. A 10-&mgr;g/m3 increase in particulate matter <10 &mgr;m in diameter was associated with a 52% (6% to 118%) increase in risk of death. Reduced survival was apparent throughout the follow-up period, ruling out short-term mortality displacement. Conclusions— Survival after stroke was lower among patients living in areas with higher levels of outdoor air pollution. If causal, a 10-&mgr;g/m3 reduction in nitrogen dioxide exposure might be associated with a reduction in mortality comparable to that for stroke units. Improvements in outdoor air quality might contribute to better survival after stroke.

A comparison of methods for calculating general practice level socioeconomic deprivation

BackgroundA measure of the socioeconomic deprivation experienced by the registered patient population of a general practice is of interest because it can be used to explore the association between deprivation and a wide range of other variables measured at practice level. If patient level geographical data are available a population weighted mean area-based deprivation score can be calculated for each practice. In the absence of these data, an area-based deprivation score linked to the practice postcode can be used as an estimate of the socioeconomic deprivation of the practice population. This study explores the correlation between Index of Multiple Deprivation 2004 (IMD) scores linked to general practice postcodes (main surgery address alone and main surgery plus any branch surgeries), practice population weighted mean IMD scores, and practice level mortality (aged 1 to 75 years, all causes) for 38 practices in Rotherham UK.ResultsPopulation weighted deprivation scores correlated with practice postcode based scores (main surgery only, Pearson r = 0.74, 95% CI 0.54 to 0.85; main plus branch surgeries, r = 0.79, 95% CI 0.63 to 0.89). All cause mortality aged 1 to 75 correlated with deprivation (main surgery postcode based measure, r = 0.50, 95% CI 0.22 to 0.71; main plus branch surgery based score, r = 0.55, 95% CI 0.28 to 0.74); population weighted measure, r = 0.66, 95% CI 0.43 to 0.81).ConclusionPractice postcode linked IMD scores provide a valid proxy for a population weighted measure in the absence of patient level data. However, by using them, the strength of association between mortality and deprivation may be underestimated.

A system-wide approach to explaining variation in potentially avoidable emergency admissions: national ecological study

Background Some emergency admissions can be avoided if acute exacerbations of health problems are managed by the range of health services providing emergency and urgent care. Aim To identify system-wide factors explaining variation in age sex adjusted admission rates for conditions rich in avoidable admissions. Design National ecological study. Setting 152 emergency and urgent care systems in England. Methods Hospital Episode Statistics data on emergency admissions were used to calculate an age sex adjusted admission rate for conditions rich in avoidable admissions for each emergency and urgent care system in England for 2008–2011. Results There were 3 273 395 relevant admissions in 2008–2011, accounting for 22% of all emergency admissions. The mean age sex adjusted admission rate was 2258 per year per 100 000 population, with a 3.4-fold variation between systems (1268 and 4359). Factors beyond the control of health services explained the majority of variation: unemployment rates explained 72%, with urban/rural status explaining further variation (R2=75%). Factors related to emergency departments, hospitals, emergency ambulance services and general practice explained further variation (R2=85%): the attendance rate at emergency departments, percentage of emergency department attendances converted to admissions, percentage of emergency admissions staying less than a day, percentage of emergency ambulance calls not transported to hospital and perceived access to general practice within 48 h. Conclusions Interventions to reduce avoidable admissions should be targeted at deprived communities. Better use of emergency departments, ambulance services and primary care could further reduce avoidable emergency admissions.

Outdoor Air Pollution and Incidence of Ischemic and Hemorrhagic Stroke A Small-Area Level Ecological Study

Background and Purpose— Evidence linking outdoor air pollution and incidence of stroke is limited. We examined effects of outdoor air pollution on the incidence of ischemic and hemorrhagic stroke at the population level focusing on middle-aged and older people. Methods— We used a small-area level ecological study design and a stroke register set up to capture all incident cases of first-ever stroke occurring in a defined geographical area in south London (948 census output areas) where road traffic contributes to spatial variation in air pollution. Population-weighted averages were calculated for output areas using outdoor nitrogen dioxide and PM10 concentrations modeled at a 20-m resolution. Results— There were 1832 ischemic and 348 hemorrhagic strokes in 1995 to 2004 occurring among a resident population of 267 839. Mean (SD) concentration was 25.1 (1.2) &mgr;g/m3 (range, 23.3–36.4 &mgr;g/m3) for PM10 and 41.4 (3.0) &mgr;g/m3 (range, 35.4–68.0 &mgr;g/m3) for nitrogen dioxide. For ischemic stroke, adjusted rate ratios per 10-&mgr;g/m3 increase, for all ages, 40 to 64 and 65 to 79 years, respectively, were 1.22 (0.77–1.93), 1.12 (0.55–2.28), and 1.86 (1.10–3.13) for PM10 and 1.11 (0.93–1.32), 1.13 (0.86–1.50), and 1.23 (0.99–1.53) for nitrogen dioxide. For hemorrhagic stroke, the corresponding rate ratios were 0.52 (0.20–1.37), 0.78 (0.17–3.51), and 0.51 (0.12–2.22) for PM10 and 0.86 (0.60–1.24), 1.12 (0.66–1.90), and 0.78 (0.44–1.39) for nitrogen dioxide. Conclusions— Although there was no significant association between outdoor air pollutants and ischemic stroke incidence for all ages combined, there was a suggestion of increased risk among people aged 65 to 79 years. There was no evidence of increased incidence in hemorrhagic stroke.

Impact of NHS walk-in centres on primary care access times: ecological study.

Objective To examine whether walk-in centres contribute to shorter waiting times for a general practice appointment. Design Ecological study. Setting 2509 general practices in 56 primary care trusts in England; 32 walk-in centres within 3 km of one of these practices. Main outcome measure Waiting time to next available general practitioner appointment (April 2003 to December 2004), from national monthly primary care access survey. Results The percentage of practices achieving the target waiting time of less than 48 hours to see a general practitioner increased from 67% to 87% over the 21 month study period (adjusted odds ratio 1.07 (95% confidence interval 1.06 to 1.08) per increase in month). Achievement of the waiting time target decreased with increasing multiple deprivation (0.57 (0.49 to 0.67) for most versus least deprived third) and increased with increasing practice population size (1.02 (1.00 to 1.04) per 1000 increase). No evidence was found that increasing distance from a walk-in centre was associated with decreasing odds of achieving the waiting time target (1.00 (0.99 to 1.01) per km increase). Increasing “exposure” to a walk-in centre, modelled with a distance decay function based on attendance rates, also showed little evidence of association with achievement of the waiting time target (1.02 (0.97 to 1.08) for interquartile range increase). No evidence existed that the rate of increase in achieving the 48 hour target over time was enhanced by proximity or “exposure” to a walk-in centre. Results were similar when the analysis was rerun with data for 2003 only (done because pressure in 2004 to meet the governments deadline might have led to other changes that could have masked any walk-in centre effect). Conclusions No evidence existed that walk-in centres shortened waiting times for access to primary care, and the results do not support the use of walk-in centres for this purpose.

Hospital characteristics affecting potentially avoidable emergency admissions: National ecological study

Some emergency admissions can be avoided if acute exacerbations of health problems are managed by emergency and urgent care services without resorting to admission to a hospital bed. In England, these services include hospitals, emergency ambulance, and a range of primary and community services. The aim was to identify whether characteristics of hospitals affect potentially avoidable emergency admission rates. An age-sex adjusted rate of admission for 14 conditions rich in avoidable emergency admissions was calculated for 129 hospitals in England for 2008–2011. Twenty-two per cent (3,273,395/14,998,773) of emergency admissions were classed as potentially avoidable, with threefold variation between hospitals. Explanatory factors of this variation included those which hospital managers could not control (demand for hospital emergency departments) and those which they could control (supply in terms of numbers of acute beds in the hospital, and management of non-emergency and emergency patients within the hospital). Avoidable admission rates were higher for hospitals with higher emergency department attendance rates, higher numbers of acute beds per 1000 catchment population and higher conversion rates from emergency department attendance to admission. Hospital managers may be able to reduce avoidable emergency admissions by reducing supply of acute beds and conversion rates from emergency department attendance.