Part 1: Developing MEDIx and MEDClass

1. Part 1: Developing MEDIx and MEDClass Richard Mitchell (PI), Niamh Shortt, Jamie Pearce, Elizabeth Richardson, Terry Dawson

2. Funding • NERC Environment and Human Health programme • Supported by: • NERC • EA • Defra • MOD • MRC • The Wellcome Trust • ESRC • BBSRC • EPSRC • HPA

3. Exploratory award: Multiple environmental classification of areas for researching health inequality Objectives: • To develop a measure of health-related multiple physical environmental deprivation for the UK (small-area level) • To determine its utility in researching spatial inequalities in health

4. Outline • Objective 1: To develop a measure of health-related multiple physical environmental deprivation for the UK (small-area level) • WHY? • HOW? • Over-arching principles • Identification of health-relevant dimensions of environmental deprivation • Dataset acquisition and processing • Construction of the summary measures: • Index • Classification

5. Why?

6. Spatial health inequalities Why? Standardised mortality rate 1999-2003 • Widening spatial inequalities in health 70 100 150

7. Spatial health inequalities Why? • Socioeconomic deprivation ‘explains’ much: • But, significant proportion remains unexplained… • … role of the physical environment? • How would we investigate this? • How would we measure ‘the physical environment’? Britain, males and females; Drawn from data in Shaw et al. (2005) Increasing life expectancy Increasing affluence

8. Socioeconomic deprivation Why? • Socioeconomic deprivation: • Multi-dimensional, e.g.: • Poverty • Housing conditions • Material possessions • Employment Measures of Multiple Socioeconomic Deprivation: • Carstairs score • Indices of Multiple Deprivation

9. Environmental deprivation Why? • Physical environmental deprivation: • Multi-dimensional, e.g.: • Air pollution • Climate • Radiation • Greenspace Measures of Multiple Physical Environmental Deprivation?

10. How?

11. Over-arching principles How? • Health-relevant • Scientifically credible • User-friendly and useful • Repeatable (Briggs, 2000; Corvalán et al., 2000; Nardo et al., 2008; Sol et al., 1995)

12. Development stages How? 1. Identify health-relevant dimensions of physical environmental deprivation 2. Identify and acquire datasets 3. Render to same geography 4. Develop summary measures 5. Test for associations with health outcomes

13. Identify dimensions of environmental deprivation How? • Air pollutants • Climate (temperature) • Solar UV radiation • Greenspace • Industrial facilities • Drinking water quality • Noise • ELF radiation (power lines) • RF radiation (transmitters) • Radon • Individual industrial pollutants • Nuclear facilities • Contaminated land • Food environment • Accidents • Scoping review • Grey literature • Reference databases  Long list • Systematic literature search • Appraisal of health-relevance: • Methodological rigour • Strength of association with health • Prevalence of health outcome • > 10% UK population exposure  ‘Wish list’

14. Evidence for wish-listed factors How? Wish list dimensions Detrimental? Beneficial? • Air pollutants  • Climate (temperature)  • Solar UV radiation   • Greenspace  • Certain industrial facilities  • Drinking water quality  • Noise 

15. Dataset acquisition and processing How? Wish list dimensions • Air pollutants National Atmospheric Emissions Inventory (NAEI) 1 km grids • Climate (temperature) Met Office, 5 km grids • Solar UV radiation UVB Index (Mo & Green, 1974) calculated from Met Office cloud cover data & latitude • Greenspace Generalised Land Use Database (GLUD) CORINE Land Cover Data (modelled %) • Industrial facilities European Pollutant Emission Register (EPER); facility type and grid ref • Drinking water quality • Noise

16. Summary of environmental data How? Geography = UK CAS wards: • n = 10,654 (in 2001) • Average population ~5,500 Detrimental factors: • Air pollutants • Proximity to industry • Cold climate Beneficial factors: • Solar UV radiation • Greenspace availability

17. Alternative summary measures Cold, Clean and Green How? 1. An index • a scale or ranking • increasing value reflects increasing environmental ‘burden’ 2. A classification • a label or category • groups areas that share the same specific types of environment Complementary uses: • Dose-response effect? • Health consequences of specific combinations of environments?

18. The Index How?

19. Constructing the index How? • Aim: • To represent relative ‘level’ of health-related environmental deprivation • To reflect both detrimental and beneficial environments • Unambiguous and easy to interpret

20. Constructing the index How? • How to identify better or worse environments? • A range of options… simplicity guided our choice: • Identify wards exposed to each environmental factor at a ‘detrimental’ (or ‘beneficial’) level • Index = balance of number of detrimental to number of beneficial exposures experienced by each ward

21. Constructing the index ‘health-relevant’ exposure 1 2 3 4 5 How? • Effect thresholds? • Arbitrary decision: ‘health-relevant’ level = highest exposure quintile (i.e., most exposed 20% of wards in the UK) No. of wards Increasing PM10

22. Constructing the index How?

23. Constructing the index III How?

24. Multiple Environmental Deprivation Index (MEDIx) How? MEDIx score -2 = Least environmentally deprived wards (‘healthiest’ places, theoretically) MEDIx score +3 = Most environmentally deprived wards (‘unhealthiest’ places)

25. The Classification How?

26. Constructing the classification Cold, Clean and Green How? • Aim: • Identify specific types of health-relevant environment • Group wards that share these environmental characteristics

27. Constructing the classification Environmental dimensions • Air pollutants • Climate (temperature) • Solar UV radiation • Greenspace • Certain industrial facilities How? Data reduction (PCA) Two-step classification Evaluate solutions Classification

28. Multiple Environmental Deprivation Classification (MEDClass) How? • Clusters = distinct ‘types’ of environment • Wards in cluster 7: • most greenspace • high UV levels • low air pollutant levels

29. Conclusion • Yes, it is possible to construct summary measures of multiple environmental deprivation. • Rigorous, well-documented process • Limitations, room for improvement… • Arbitrary decisions • Data limitations • Part 2: Testing the utility of MEDIx and MEDClass…

30. Any questions?

31. References • Briggs D, 2000, "Methods for building environmental health indicators", in Decision-making in environmental health Eds C Corvalán, D Briggs, G Zielhuis (E & FN Spon, London) pp 57-76 • Corvalán C, Briggs D, Kjellström T, 2000, "The need for information: environmental health indicators", in Decision-making in environmental health Eds C Corvalán, D Briggs, G Zielhuis (E & FN Spon, London) pp 25-56 • Nardo M, Saisana M, Saltelli A, Tarantola S, Hoffman A, Giovannini E, 2008 Handbook on constructing composite indicators: Methodology and user guide. EC Joint Research Centre & OECD Statistics Directorate and the Directorate for Science, Technology and Industry (OECD Publishing, Paris) • Mo T, Green AES: A climatology of solar erythema dose. Photochem Photobiol 1974, 20:483-496. • Shaw M, Davey Smith G, Dorling D, 2005, "Health inequalities and New Labour: how the promises compare with real progress" BMJ 330 1016-1021 • Sol V M, Lammers P E M, Aiking H, de Boer J, Feenstra J F, 1995, "Integrated environmental index for application in land-use zoning" Environmental Management 19 457-467