Multi-Sensor Board Analysis Plan

1. Multi-Sensor BoardAnalysis Plan Phil Hurvitz University of Washington College of Architecture and Urban Planning Urban Form Lab gis.washington.edu/phurvitz MEBI 591B Public Health Informatics Colloquium 2006.04.06

2. Confidentiality • Unpublished Data • Do Not Distribute Slide 2 (of 37)

3. Overview • Introduction/Background/Relevance • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 3 (of 37)

4. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 4 (of 37)

5. Source: CDC BRFSS (http://apps.nccd.cdc.gov/brfss/Trends/trendchart.asp) Introduction/Background • Obesity threatens personal health and may bankrupt the US health care system • Obesity incidence has increased dramatically over the last 20 years Slide 5 (of 37)

6. Introduction/Background: Obesity trends Slide 6 (of 37)

7. Introduction/Background • Health care system says, “Eat less, exercise more.” Slide 7 (of 37)

8. Introduction/Background • Increasing physical activity is important in the fight against obesity • The built environment can either promote or hinder physical activity, e.g., • Presence/absence of sidewalks • Presence/absence of utilitarian destinations (e.g., restaurants, retail stores, restaurants, banks) • How does physical activity vary with different compositions and configurations of environment? Slide 8 (of 37)

9. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 9 (of 37)

10. What is GIS? • A computer-based method for • Capture, • Storage, • Manipulation, • Analysis, and • Display of spatially referenced data Slide 10 (of 37)

11. What is GIS? • Any object or phenomenon that is or can be placed on a map can be stored, managed, and analyzed in a GIS. • Built environment features (streets, buildings, bus routes, restaurants, schools) • Households (address points, tax-lot polygons) • Individuals (points or travel lines/polygons) • Ground surface elevation or slope • Movement of objects through time and/or space • Demographics, socioeconomics • Patient residence, work, and school locations • Disease occurrence Slide 11 (of 37)

12. GIS combines coordinate (map) and attribute (tabular/statistical) data Slide 12 (of 37)

13. How GIS deals with spatial layers Slide 13 (of 37)

14. Introduction to GIS • Analytical techniques (a very simple list) • Spatial aggregation • Disease rates per census or zip code area • Buffering • How many fast food restaurants within 1 mile of schools? • Overlay analysis • How much of each census block group is affected by a toxic aerosol plume? • How many of each type of land use is within ½ mile of all locations visited within a day? • Surface generation, interpolation • Trend surfaces • Kriging Slide 14 (of 37)

15. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 15 (of 37)

16. Measuring Physical Activity • Subjective • Observation • Self-Report • Stanford 7-Day Activity Survey • International Physical Activity Questionnaire (IPAQ) • Travel Diaries • Objective • Pedometers • Accelerometers • New Generation Devices Slide 16 (of 37)

17. Measuring Physical Activity: Benefits & Drawbacks Slide 17 (of 37)

18. Measuring Physical Activity: New Generation Devices • Intelligent Device for Energy Expenditure and Activity (IDEAA) • sensors attached to skin (cumbersome) • relative accelerometry of different body parts • no locational capability • no external environmental cues • $4,000 per unit Slide 18 (of 37)

19. Measuring Physical Activity: New Generation Devices • IDEAA: recognizable activities Slide 19 (of 37)

20. Measuring Physical Activity: New Generation Devices • IDEAA: categorized activities by time Slide 20 (of 37)

21. Measuring Physical Activity: New Generation Devices • Multi-Sensor Board • UW/Intel invention, recent development • single sensing unit with data logger (iPAQ, phone) • easily worn • measures multiple environmental data streams • obtains XY locational data • estimated $100 per unit cost in large manufacturing run Slide 21 (of 37)

22. Measuring Physical Activity: New Generation Devices • Multi-Sensor Board • On-board sensors: • accelerometry • audio • IR / visible light • high-frequency light • barometric pressure • humidity, temperature • geophysical location • Multivariate data stream can be interpreted as a number of common activities using Hidden Markov Model Classifiers • Will be used in ECOR Pilot & Feasibility Study Slide 22 (of 37)

23. Classified Activity (by HMM) Walking Riding Riding Walking Riding a Driving Sitting Standing Walking Jogging down elevator elevator up stairs bicycle car stairs down up 89.8% 38.5% 0.5% 0.4% 33.4% Sitting 10.1% 50.8% 1.4% Standing 0.1% 7.4% 97.7% 5.2% 2.5% Walking 100.0% Jogging Precision 94.8% Walking up stairs Labeled Activities 0.5% 97.5% Walking down stairs 3.3% 99.6% Riding a bicycle 66.6% Driving car 100.0% Riding elevator down 100.0% Riding elevator up Measuring Physical Activity: New Generation Devices • Multi-Sensor Board Activity Classifier (overall accuracy > 95%) • Validated against videography Slide 23 (of 37)

24. Measuring Physical Activity: New Generation Devices • Multi-Sensor Board Classification of Activity90-minute interval Slide 24 (of 37)

25. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 25 (of 37)

26. Measuring the Built Environment • What to Measure? • Based on Research Question(s) • GIS Data Sources • Point Locations • Buffer Measures • Proximity Measures • Where to Measure? • Home-centered • Frank et al. 2005 • Moudon et al. 2005 • Where does activity take place in real time? Slide 26 (of 37)

27. Measuring the Built Environment: A GIS Based Approach • Point-centered Analysis of Location • Any number of different data sets can be quantified • Enumeration & relative proportion of different land uses • Parcel density • Street-block size • Total length of sidewalk • Number of intersections, lighted crosswalks • Area and count of parks • Distance to different built environment features • We should quantify & analyze all locations that are experienced during the day, not only the home location • Work & school environments may be key determinants of physical activity Slide 27 (of 37)

28. Measuring the Built Environment: A GIS Based Approach Slide 28 (of 37)

29. Measuring the Built Environment: A GIS Based Approach • GIS analysis results for each location buffer(count)measures proximitymeasures Slide 29 (of 37)

30. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 30 (of 37)

31. ECOR Funded Research • Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • MSB to capture • Activity type • Location • Walkable-Bikeable Communities GIS Software • Quantifying & analyzing the Built Environment Slide 31 (of 37)

32. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 32 (of 37)

33. Analysis Plan • MSB activity & location • Validity tests against diary (real-time location & activity), IPAQ (self-reported physical activity summary) • WBC location analysis of Built Environment Data overload? 15 h * 60 min/h * 60 s/min * 7 d * 40 subjects = 15,120,000 data points Slide 33 (of 37)

34. Analysis Plan • Sampling strategy for data reduction without loss of variability 10% sample → 1.5 million data points (time or distance?) Slide 34 (of 37)

35. Analysis Plan • This will be the first study to measure objectively • both physical activity types and Built Environment in a real-time, real-world setting with free-roaming individuals • Statistical associations? • Activity types/intensities & Built Environment types? • What do we gain if a pattern is discovered? • Policy recommendations • Quantitative urban design guidelines • A new “gold standard” for measurement of physical activity in real-time Slide 35 (of 37)

36. Overview • Introduction/Background • What is GIS, and what is its role in Public Health? • Measuring Physical Activity • Measuring the Built Environment • ECOR Funded Research: Assessing the reliability and validity of the Multi-Sensor-Board for the direct measurement of physical activity, environmental characteristics, and the built environment • Analysis Plan • Suggestions/Questions Slide 36 (of 37)

37. Suggestions/Questions Phil Hurvitz phurvitz@u.washington.edu gis.washington.edu/phurvitz Slide 37 (of 37)