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Living in a conurbation, urban, or rural environment is an important determinant of health. For example, conurbation and rural living is associated with increased respiratory and allergic conditions, whereas a farm or rural upbringing has been shown to be a protective factor against this.
The objective of the study was to assess differences in general practice presentations of allergic and infectious disease in those exposed to conurbation or urban living compared with rural environments.
The population was a nationally representative sample of 175 English general practices covering a population of over 1.6 million patients registered with sentinel network general practices. General practice presentation rates per 100,000 population were reported for allergic rhinitis, asthma, and infectious conditions grouped into upper and lower respiratory tract infections, urinary tract infection, and acute gastroenteritis by the UK Office for National Statistics urban-rural category. We used multivariate logistic regression adjusting for age, sex, ethnicity, deprivation, comorbidities, and smoking status, reporting odds ratios (ORs) with 95% CIs.
For allergic rhinitis, the OR was 1.13 (95% CI 1.04-1.23;
Those living in conurbations or urban areas were more likely to consult a general practice for allergic rhinitis and upper respiratory tract infection. Both conurbation and rural living were associated with an increased risk of urinary tract infection. Living in rural areas was associated with an increased risk of asthma and lower respiratory tract infections. The data suggest that living environment may affect rates of consultations for certain conditions. Longitudinal analyses of these data would be useful in providing insights into important determinants.
There is a wide range of social determinants of health. Conurbation, urban, and rural living are important among these, although their different effects are still unclear [
Factors associated with urban and rural living contribute to differences in respiratory and allergic conditions. Pollution, climate change, and pollen exposure are all associated with increased respiratory and allergic conditions [
The UK Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) is one of the oldest sentinel networks and is in its 50th season of reporting infections and respiratory conditions [
We carried out this study to determine whether exposure to living in a conurbation (high-density living), urban (intermediate density, such as a city or town), or rural (least dense, such as the countryside) environment was associated with more presentations to a general practice (GP) of allergic (allergic rhinitis and asthma) or common infectious conditions. This investigation is the theme of the RSC’s annual report on diseases. The annual report also includes the annual weekly rates of GP presentations of all our monitored conditions (
We extracted data from 175 volunteer GPs that are members of the RCGP RSC, with a cohort of 1,602,366 patients registered for the first 6 months of the period of April 1, 2016 to March 31, 2017. All data are pseudonymized as close to source as possible. Data were coded with Read version 2 or Clinical Terms version 3 [
We determined a patient’s urban classification by using a UK Office for National Statistics (ONS) lookup tool [
Our outcome variables, presentation to a GP for allergic and infectious conditions, were a composite of similar conditions grouped together, a method we adopted for the 2016-2017 annual report. To identify our outcomes, we used Read version 2 codes and Clinical Terms version 3 codes to extract the data. These codes are based on
In exploring the association between living area and allergic and infectious diseases, we adjusted for age, sex, ethnicity, and socioeconomic status using the Index of Multiple Deprivation (IMD). The IMD is the official measure of relative deprivation for areas in England. It uses 7 domains of deprivation to produce an overall measure (income, employment, education, health, crime, housing and services, and living environment) [
From the cohort of 1,602,366 patients registered, we compiled and reported data on conurbation, urban, and rural living by age, sex, ethnicity, and IMD score. We also controlled for comorbid disease. We grouped comorbidities into the following groups: 0 comorbidities (reference), 1 to 2 comorbidities, and 3 or more comorbidities. We included the following as comorbidities: depression; hypertension; chronic obstructive pulmonary disease; rheumatoid arthritis; dementia; stroke or transient ischemic attack (grouped as cerebrovascular disease); acute myocardial infarction, angina, and coronary artery disease (grouped as ischemic heart disease); congestive cardiac failure; peripheral arterial disease; chronic kidney disease; diabetes mellitus; and atrial fibrillation. We also included and controlled for smoking status in our analysis, grouping smokers into active smokers (reference), ex-smokers, nonsmokers, and unknown, based on their latest recorded smoking habit. We used these comorbidities because they are quality and outcomes framework indicators that are used to rate GP performance [
To understand whether rural, urban, or conurbation living was associated with GP presentation for certain allergic or contagious diseases, we carried out a multivariate logistic regression, with rural, urban, or conurbation as the predictor variable and disease as the outcome variable. We report the odds ratio (OR) and 95% CI from the multivariate logistic regression [
In addition to the main effect of urban, rural, and conurbation living on GP presentation, we looked at the interaction of age band or sex and urban, rural, and conurbation living on GP presentation (see
The analysis presented in the annual report (
The RCGP RSC network population consists of 1,602,366 people. Older (>65 years: n=68,378, 25.01%), less deprived (IMD score ≥3: n=274,349, 25.62%), and less ethnically mixed (white: n=204,954, 20.8%; black: n=528, 1.00%) populations live in rural areas. In comparison, younger (25-44 years: n=182,322, 40.7%), ethnically mixed (black: n=44,690, 88.7%; Asian: n=30,827, 67.4%), and more deprived (IMD score <3: n=280,714, 52.81%) populations live in conurbations (see
Those living in a conurbation, in comparison with a rural area, had greater odds of presenting to a GP with allergic rhinitis (OR 1.29, 95% CI 1.19-1.41;
Those living in urban, compared with rural, areas had greater odds of presenting to a GP with allergic rhinitis (OR 1.13, 95% CI 1.04-1.23;
We found no interactions between sex and living area, although we did find 4 interactions for age band and living area, using rural and working age (18-64 years) as reference groups. Children aged 0 to 4 years living in urban areas were more likely to present to a GP with asthma than were adults aged 18 to 64 years living in rural areas (OR 1.42, 95% CI 1.20-1.68;
Odds ratios (ORs) and 95% CIs of the main effect of conurbation and urban living (rural is the reference) on the 6 conditions of interest.
Conditions of interest | Conurbation | Urban area | ||
OR (95% CI) | OR (95% CI) | |||
Allergic rhinitis | 1.29 (1.19-1.41)b | <.001b | 1.13 (1.04-1.23)b | .003b |
Asthma | 0.70 (0.67-0.73)c | <.001c | 0.97 (0.93-1.01) | .11 |
Lower respiratory tract infection | 0.94 (0.90-0.98)c | .005c | 1 (0.96-1.04) | .89 |
Upper respiratory tract infection | 1 (0.97-1.03) | .93 | 1.06 (1.03-1.08)b | <.001b |
Acute gastroenteritis | 1.04 (0.93-1.17) | .46 | 1.13 (1.01-1.25)b | .03b |
Urinary tract infection | 1.06 (1.00-1.13)b | .04b | 0.94 (0.89-0.99)c | .02c |
a
bOR>1 and significant adjusted
cOR<1 and significant adjusted
Forest plot showing odds ratios for various allergic and infectious diseases based on living area. AGE: acute gastroenteritis; LRTI: lower respiratory tract infection; ref: reference; URTI: upper respiratory tract infection; UTI: urinary tract infection.
From the results of the logistic regression (
Odds ratios (ORs) and 95% CIs of the main effect of urban (rural is the reference) and interaction terms of urban area with age band (18-64 years is the reference) on the 6 conditions of interest.
Conditions of interest | 0-4 years | 5-17 years | ≥65 years | |||
OR (95% CI) | OR (95% CI) | OR (95% CI) | ||||
Allergic rhinitis | 0.81 (0.63-1.04) | .09 | 0.93 (0.83-1.05) | .23 | 1.08 (0.94-1.25) | .29 |
Asthma | 1.42 (1.20-1.68) | <.001 | 1.05 (0.98-1.13) | .18 | 0.96 (0.91-1.02) | .18 |
Lower respiratory tract infection | 0.99 (0.91-1.08) | .85 | 1.11 (1.00-1.23) | .06 | 1.03 (0.99-1.09) | .17 |
Upper respiratory tract infection | 1.03 (0.99-1.08) | .16 | 1.06 (1.02-1.11) | .01 | 0.92 (0.88-0.97) | <.001 |
Acute gastroenteritis | 0.84 (0.72-0.98) | .03 | 1.01 (0.84-1.22) | .92 | 0.85 (0.72-0.99) | .04 |
Urinary tract infection | 1.100 (0.87-1.38) | .43 | 1 (0.86-1.17) | .97 | 0.98 (0.91-1.05) | .58 |
a
Odds ratios (ORs) and 95% CI of the main effect of conurbation (rural is the reference) and interaction terms of conurbation with age band (18-64 years is the reference) on the 6 conditions of interest.
Conditions of interest | 0-4 years | 5-17 years | ≥65 years | |||
OR (95% CI) | OR (95% CI) | OR (95% CI) | ||||
Allergic rhinitis | 0.84 (0.65-1.07) | .16 | 0.94 (0.83-1.05) | .27 | 0.99 (0.85-1.17) | .94 |
Asthma | 1.08 (0.90-1.29) | .43 | 1.14 (1.05-1.23) | .001 | 1.29 (1.21-1.39) | <.001 |
Lower respiratory tract infection | 0.98 (0.90-1.07) | .68 | 1.32 (1.18-1.47) | <.001 | 1.14 (1.08-1.21) | <.001 |
Upper respiratory tract infection | 1.25 (1.19-1.31) | <.001 | 1.25 (1.20-1.31) | <.001 | 1.02 0.97-1.08() | .40 |
Acute gastroenteritis | 0.94 (0.80-1.10) | .45 | 1.64 (1.36-1.98) | <.001 | 0.93 (0.78-1.12) | .45 |
Urinary tract infection | 1.13 (0.89-1.43) | .31 | 1.04 (0.89-1.22) | .61 | 1.02 (0.94-1.10) | .63 |
a
Patients living in conurbations or urban areas were more likely to consult for allergic rhinitis and URTI, after adjustment for age, sex, ethnicity, socioeconomic status, comorbid disease, and smoking status. The OR of presenting with allergic rhinitis increased with population density. While living in rural areas was associated with an increased risk of asthma and LRTI, both conurbation and rural living were associated with an increased risk of UTI.
Age and living environment interacted when predicting the GP presentation rates of these conditions. Children living in urban areas were more likely to consult for asthma (0-4 years) and URTI (5-17 years) than were 18- to 64-year-old adults living in rural areas (our reference group). Additionally, children living in conurbations were more likely than our reference groups to consult for URTI (0-17 years), LRTI, asthma, and AGE (5-17 years). Over-65-year-olds living in conurbations were also more likely than our reference group to consult for asthma. The risk of AGE was increased in 18- to 64-year-olds living in rural areas in comparison with 0- to 4-year-olds and over-65-year-olds living in urban areas. Rural living for 18- to 64-year-olds was associated with an increased risk of URTI compared with over-65-year-olds living in rural areas.
Conurbation and urban living was associated with increased presentation with allergic rhinitis to a GP. This is consistent with previous research finding that allergic rhinitis is more common in urban areas and conurbations [
Those living in conurbations had higher odds of consulting for UTI. Conurbation living is arguably very different from rural living. For example, the population density is higher [
The results also showed that those living in rural areas were more likely to present with LRTI and asthma. Some studies have found that urban living is associated with increased odds of developing asthma [
Infectious diseases are associated with population density [
Living in a conurbation or an urban area leads to an increased risk of allergic rhinitis and URTI in all people, and an increased risk of URTI, LRTI, asthma, and AGE in children. These results are in line with previous research, as densely populated areas have been associated with the rapid spread of infectious diseases such as the severe acute respiratory syndrome virus and avian flu [
Furthermore, population density and traffic in conurbations may increase the rates of allergic rhinitis and asthma [
We derived the data from a network of general practitioners in which the population in question is large and is representative of the whole of England. This large and representative population allows us to link morbidity to ethnicity, living environment, and socioeconomic status. Patterns found from this dataset can be applied to the whole population.
Further, data quality in the RCGP RSC for infections and allergic conditions is assured through data quality feedback to RSC member practices. More recently, we have introduced financially incentivized training and practice-specific comparative feedback via a dashboard [
The limitations of this study were that not everyone who has infectious or allergic diseases will go to their GP, meaning that actual rates of illness may have been higher in the general population. Furthermore, although we worked hard to ensure accuracy of our data, there were instances where conditions were not recorded accurately. Additionally, the allergic conditions we investigated tend to be chronic conditions, with peaks of exacerbations. We did not control for episode type in our analysis, which may have confounded rates of GP presentation for asthma and allergic rhinitis.
Overall, we found that different allergic and infectious conditions were associated with rural, urban and conurbation living. A longitudinal study of RCGP RSC data may provide insights, particularly around changes in pollutant emissions or other variations in exposure, on the effect of the environment on allergic and infectious conditions.
RCGP RSC Annual Report 2016-2017.
Data tables.
Additional figures.
Logistic regression output.
acute gastroenteritis
general practice
Index of Multiple Deprivation
lower respiratory tract infection
Office for National Statistics
odds ratio
Royal College of General Practitioners
Research and Surveillance Centre
upper respiratory tract infection
urinary tract infection
Thanks to the patients who consented to provide virology and other specimens in RCGP RSC practices, our member practices, Apollo Medical Systems for managing secure data extraction, Professor Mitch Blair for encouragement and support, and Nick Andrews for helpful comments on the manuscript. Requests for access to data should be addressed to SdeL, the data custodian of this study. Public Health England is the principal funder of the RCGP RSC.
SdeL created the idea for the study, proofread the work, was director and guarantor for the data, and assisted with clinical knowledge, system design, and problem solving. CM carried out data extraction and statistical analysis for this study and the supplementary report, and drafted the introduction, methods, and results sections. RW edited the introduction, methods, and results sections, wrote the discussion, and formatted the manuscript. MJ designed the statistical analysis method. AJE and GS reviewed the manuscript. RB designed and developed much of the database structure and carried out much of the data extraction. IY and MH acted as liaison with practices and provided coordination. FMF was project manager. IR was Joint Medical Director of RCGP Clinical Innovation and Research.
None declared.