scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Public transit, obesity, and medical costs: assessing the magnitudes.

Ryan D. Edwards1
01 Jan 2008-Preventive Medicine (Elsevier)-Vol. 46, Iss: 1, pp 14-21
TL;DR: While no silver bullet, walking associated with public transit can have a substantial impact on obesity, costs, and well-being.
About: This article is published in Preventive Medicine.The article was published on 2008-01-01 and is currently open access. It has received 127 citations till now. The article focuses on the topics: Population & Present value of costs.

Summary (2 min read)

Introduction

  • A topic of much recent interest is the degree to which public transportation may increase exercise through walking.
  • Because residents typically select their communities, much remains unclear about the causal influence of environment on activity (Handy and Mokhtarian, 2005; Ogilvie et al., 2006).
  • The amount of additional physical activity associated with public transportation appears potentially significant.

Methods

  • Estimating additional walking associated with public transit Part of the 2001 NHTS included a daily travel diary in which household respondents were asked to self-report all trips, their purposes, starting and ending times, and the means of transportation during an assigned travel day.
  • I can only compare my estimates to those of Wener and Evans (2007), who collect objective measures of extra walking using pedometers.
  • I interpret β as the additional walking associated with transit use.
  • Of the 105,942 individuals in the adult subsample, 39,782 filled out the entire survey and have a sample weight, and 28,771 records contain all covariates.

Forecasting obesity prevalence

  • These statistics are reported by Flegal et al. (2002) and Ogden et al. (2006), who examine data from the 1960–1962 National Health Examination Survey (NHES) and subsequent NHANES waves.
  • “College degree” includes the bachelor but not the associate.
  • It is convenient to combine the estimates of Sturm, who examines additional costs under age 65, with those of Lakdawalla et al., who explore costs over 70.
  • In each year of the projection, I apply the forecast obesity prevalence rate to the additional per capita spending associated with obesity.
  • In addition to increased medical costs, obesity also threatens the quality of health and well-being, most notably later in life, and I measure these costs as well.

Results

  • Additional walking through transit Table 1 describes the characteristics of the weighted NHTS sample of adults, where the observations are person-days.
  • An almost equally large share, 1.9%, reported walking as their sole means of transit on their travel day, but these were primarily recreational walkers rather than commuters.
  • Column 1 reports ordinary least squares estimates, while columns 2–6 re marginal effects of each Tobit are the partial derivatives of the expected value o significance, with ⁎⁎⁎ at the 1% level, ⁎⁎ at 5%, and ⁎ at the 10% level.
  • No el of daily walking time as shown in Eq. (1) in the text, with standard errors in port Tobit estimates under various alternative specifications, where the reported f the observed walking time variable.

Reductions in obesity

  • The distribution of excess energy stored reported by Hill et al. (2003) reveals that these levels of additional expenditure could eliminate weight gain in approximately 43%, 50%, or 60% of the population.
  • The assumed QALY weight of a life-year spent disabled is 0.8.

Obesity prevalence scenarios

  • An OLS regression line through the historical obesity prevalence data in Fig. 1 has a slope equal to roughly 0.5% per year, significant at the 1% level.
  • These three scenarios are depicted in the right-hand side of Fig. 1 beneath the baseline projection.
  • Present value per person depending on the intensity, and about 80% of the savings is public money.

Discussion

  • The objective of this paper was to explore the potential benefits of shifting an average U.S. citizen from driving to using public transit.
  • Results hinge on an unknown that is difficult to estimate with great confidence: the additional physical activity associated with public transit.
  • It seems unlikely that anyone rationally chooses to be obese (Cutler et al., 2003), so anti-obesity policies in general are unlikely to trigger rational behavior that directly counteracts the intent, as might be an issue with anti-smoking policies if addiction is rational.
  • It could be that public transit indeed causes more physical activity, but individuals offset the potential health effects by eating more.
  • I have chosen a simple linear extrapolation of the historical trend, which has been a 0.5% linear rate of increase since the inception of the NHES/NHANES survey in 1960.

Conclusion

  • Use of public transit is associated with more walking, by about 8.3 extra minutes per day.
  • This is not enough walking to halt the spread of obesity, but it could substantially reduce it.
  • The present value of medical expenditure savings per person could be $5500, while the value of reduced disability could be even greater.

Did you find this useful? Give us your feedback

Citations
More filters
Journal ArticleDOI
TL;DR: A meta-analysis of the built environment-travel literature existing at the end of 2009 is conducted in order to draw generalizable conclusions for practice, and finds that vehicle miles traveled is most strongly related to measures of accessibility to destinations and secondarily to street network design variables.
Abstract: Problem: Localities and states are turning to land planning and urban design for help in reducing automobile use and related social and environmental costs. The effects of such strategies on travel demand have not been generalized in recent years from the multitude of available studies. Purpose: We conducted a meta-analysis of the built environment-travel literature existing at the end of 2009 in order to draw generalizable conclusions for practice. We aimed to quantify effect sizes, update earlier work, include additional outcome measures, and address the methodological issue of self-selection. Methods: We computed elasticities for individual studies and pooled them to produce weighted averages. Results and conclusions: Travel variables are generally inelastic with respect to change in measures of the built environment. Of the environmental variables considered here, none has a weighted average travel elasticity of absolute magnitude greater than 0.39, and most are much less. Still, the combined effect o...

3,551 citations

Journal ArticleDOI
TL;DR: In this article, the authors systematically reviewed and graded the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use, including media and educational campaigns, labeling and consumer information, taxation, subsidies, and other economic incentives.
Abstract: Background—Poor lifestyle behaviors, including suboptimal diet, physical inactivity, and tobacco use, are leading causes of preventable diseases globally. Although even modest population shifts in risk substantially alter health outcomes, the optimal population-level approaches to improve lifestyle are not well established. Methods and Results—For this American Heart Association scientific statement, the writing group systematically reviewed and graded the current scientific evidence for effective population approaches to improve dietary habits, increase physical activity, and reduce tobacco use. Strategies were considered in 6 broad domains: (1) Media and educational campaigns; (2) labeling and consumer information; (3) taxation, subsidies, and other economic incentives; (4) school and workplace approaches; (5) local environmental changes; and (6) direct restrictions and mandates. The writing group also reviewed the potential contributions of healthcare systems and surveillance systems to behavior change...

476 citations

Journal ArticleDOI
TL;DR: The positive psychological wellbeing effects identified in this study should be considered in cost–benefit assessments of interventions seeking to promote active travel.

283 citations


Cites background from "Public transit, obesity, and medica..."

  • ...A partial explanation for our finding could be that public transport journeys typically feature physical activity when accessing bus stops or railway stations (Besser and Dannenberg, 2005; Edwards, 2008; Laverty et al., 2013; MacDonald et al., 2010;Morabia et al., 2010; Rissel et al., 2012)....

    [...]

Journal ArticleDOI
TL;DR: A systematic review of how much time is spent in physical activity among adults using public transport and the potential effect on the population level of physical activity if inactive adults in NSW, Australia, increased their walking through increased use of public transport is explored.
Abstract: Active travel, particularly walking and cycling, has been recommended because of the health benefits associated with increased physical activity. Use of public transport generally involves some walking to bus stops or train stations. This paper is a systematic review of how much time is spent in physical activity among adults using public transport. It also explores the potential effect on the population level of physical activity if inactive adults in NSW, Australia, increased their walking through increased use of public transport. Of 1,733 articles, 27 met the search criteria, and nine reported on absolute measures of physical activity associated with public transport. A further 18 papers reported on factors associated with physical activity as part of public transport use. A range of 8-33 additional minutes of walking was identified from this systematic search as being attributable to public transport use. Using "bootstrapping" statistical modelling, if 20% of all inactive adults increased their walking by only 16 minutes a day for five days a week, we predict there would be a substantial 6.97% increase in the proportion of the adult population considered "sufficiently active". More minutes walked per day, or a greater uptake of public transport by inactive adults would likely lead to significantly greater increases in the adult population considered sufficiently active.

276 citations


Cites background from "Public transit, obesity, and medica..."

  • ...(2008) [16] USA Cross-sectional n = 28,771...

    [...]

  • ...3 more minutes walking per day than did people who relied on cars [16]....

    [...]

Journal ArticleDOI
TL;DR: Generalized estimating equations, conducted on 5000 randomly chosen licensed drivers aged 25-64 in Salt Lake County, Utah, relate lower BMIs to older neighborhoods, components of a 6-category land use entropy score, and nearby light rail stops to healthy weight.

267 citations


Cites background from "Public transit, obesity, and medica..."

  • ...A recent cost benefit analysis estimated that rail stop users can accrue 8.3 min of walking per day walking to transit, which over time may prevent weight gain and prevent estimated expenditures of $5500 per person in additional health costs (Edwards, 2008)....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: Small physical activity increases may prevent weight gain in most populations but if the specific goal is to approach expending 420 kJ/d (100 kcal/d) through walking, the duration should be closer to 60 minutes for slow walking and 30 minutes for moderate or brisk walking.
Abstract: Small physical activity increases may prevent weight gain in most populations. Geneva residents completed validated quantitative physical activity frequency questionnaires from 1997 to 2001. Fifteen minutes per day of moderate or brisk walking, or 30 minutes per day of slow walking, could increase physical activity at the population level; however, if the specific goal is to approach expending 420 kJ/d (100 kcal/d) through walking, the duration should be closer to 60 minutes for slow walking and 30 minutes for moderate or brisk walking.

51 citations


"Public transit, obesity, and medica..." refers background or methods in this paper

  • ...First, I translate minutes of walking into kilocalories (kcal) of energy expended using the basal metabolic rates (BMR) reported by Morabia and Costanza (2004): slow walking expends 3.1 kcal/min, moderate walking 3.9 kcal/min, and fast walking 4.7 kcal/min....

    [...]

  • ...Walking expends 3.1, 3.9, or 4.7 kcal/min depending on whether the walking is slow, moderate, or brisk (Morabia and Costanza, 2004), so the 8.3 min of additional walking associated with transit use could represent 25.7, 32.4, or 39.0 additional kcal expended each day....

    [...]

01 Jan 2005
TL;DR: This paper found that the role of a paradigmatic built environment such as "suburban" or "urban" is less decisive in subjects' decisions to walk or drive than issues such as aesthetic appearance of the new neighborhood, alternatives to driving, increased safety, sociability between neighbors, accessibility to commercial services, and income.
Abstract: Although there is, in common understanding, a direct relation between driving, suburban areas, and obesity (as opposed to walking, urban areas, and a more healthful body-type), this article describes research recently conducted to find out just how decisive such correlative information might be. Since it was impossible for researchers to properly conduct an experiment with a control group and an experimental group by moving the experiment group between urban and suburban settings, they instead took results from a number of Northern California homes that were already planning on such a move, and deduced results from surveys acquired through them. They found that the role of a paradigmatic built environment such as “suburban” or “urban” is less decisive in subjects’ decisions to walk or drive than issues such as aesthetic appearance of the new neighborhood, alternatives to driving, increased safety, sociability between neighbors, accessibility to commercial services, and income.

29 citations


"Public transit, obesity, and medica..." refers background in this paper

  • ...Because residents typically select their communities, much remains unclear about the causal influence of environment on activity (Handy and Mokhtarian, 2005; Ogilvie et al., 2006)....

    [...]

01 Jan 2006
TL;DR: In this paper, the authors measured significant differences in stress levels among commuters who shifted to new transit services that reduced the number of transfers, and among commuters depending on whether they drove to work or used NJ TRANSIT rail service to New York City.
Abstract: This paper describes how it has long been theorized that there may be significant health risks for individuals who commute to work by driving in congested conditions. Conversely, it is widely thought that there may be commensurate benefits to individuals who take public transportation. A team of environmental psychologists have collected evidence that for the first time measured significant differences in stress levels among commuters who shifted to new transit services that reduced the number of transfers, and among commuters depending on whether they drove to work or used NJ TRANSIT rail service to New York City. This paper discusses two studies of New York-bound commuters using psychological and physiological indicators of stress in order to determine the effects of switching from a two-seat commuter rail trip to a one-seat ride using NJ TRANSIT’s Midtown Direct and Montclair Direct service. It also presents data on a third study that compared the stress levels of a sample of 122 auto commuters with those of a 164-member sample of rail commuters making similar trips to work. Results from the studies of Midtown Direct and Montclair Direct riders showed significant reductions in stress for those commuters who switched from a two-seat to a one-seat ride. The stress reduction benefit was found to be almost twice as significant for working mothers as compared to all others in the sample. For the study comparing auto and rail commuters, auto commuters showed significantly higher levels of reported stress, more negative mood, indicated the trip was significantly more effort, and felt that their trip was significantly less predictable compared to train commuters.

15 citations


"Public transit, obesity, and medica..." refers background in this paper

  • ...Substituting public transit for car commuting probably reduces stress (Wener et al., 2006)....

    [...]

Journal ArticleDOI
TL;DR: This study investigates the lifetime risks (costs) and benefits of smoking for a male individual and provides insight on the impact of delayed or postponed risks on consumption decisions which yield immediate benefits.
Abstract: Cigarette smoking has been an acceptable consumption activity since the seventeenth century. However, the relationship between health and cigarette smoking was not investigated to any great extent until the twentieth century. Researchers concluded that the three major smoking-related diseases were cancers, cardiovascular diseases, and respiratory diseases (Herdman, Hewitt, and Laschober 1993; Oster, Colditz, and Kelly 1984). According to the Office of Technology Assessment (OTA) smoking-related illnesses were responsible for nearly one in five U.S. deaths in 1990 and resulted in 417,000 deaths of U.S. residents (Herdman, Hewitt, and Laschober 1993). The report noted that this number was far greater than the total number of deaths due to automobile and other accidents, AIDS, suicide, and homicide. The total costs to society were $68 billion or $2.59 per pack of cigarettes ($1990). Domestic cigarette consumption has declined in the past two decades due to a variety of factors. They include "continued large hikes in cigarette wholesale prices, prospects for higher taxes, more and more social smoking restrictions, declining social acceptability of tobacco use in the United States and antismoking activities" (Grise 1991, 31). However, the percentage of the population that smokes has remained at 26 percent for the past three years so that cigarette smoking continues to remain a serious health problem (Herdman, Hewitt, and Laschober 1993). Existing policies in the United States mean that the individual is responsible for the decision to smoke or not to smoke provided that he or she can afford to do so. It is of interest, therefore, to examine the positive and negative consequences of cigarette smoking from the perspective of the individual. Of particular importance in such a comparison is the fact that the benefits and risks from smoking are incurred at different points in time. The individual, who smokes, receives benefits immediately while the negative consequences of smoking occur many years in the future. Thus, the individual's subjective rate of time preference as well as the value the individual attaches to a reduction in life expectancy will affect the internal risks from smoking. This study investigates the lifetime risks (costs) and benefits of smoking for a male individual. It differs from other analyses in its emphasis on internal as opposed to external or societal costs. It also differs from earlier studies in that the benefits from smoking are considered. The results of this analysis should provide information about the risks posed by cigarette smoking from the perspective of the individual and provide insight on the impact of delayed or postponed risks on consumption decisions which yield immediate benefits. REVIEW OF LITERATURE Costs of Smoking There have been several studies on the societal costs of smoking (Herdman, Hewitt, and Laschober 1993; Luce and Schweitzer 1978; Office of Technology Assessment 1985; Rice et al. 1986). Most of these studies used a similar procedure and obtained similar results. The costs of smoking were based on direct health care costs, indirect morbidity or productivity costs, and the indirect mortality costs at one point in time. Direct health care costs were costs associated with preventing, detecting, and treating smoking-related diseases while the indirect morbidity costs were the productivity losses to the economy due to time lost from work or from housekeeping. Productivity losses were based on earnings from work or housekeeping. The indirect mortality costs were based on the loss of future earnings of individuals due to premature death from smoking-related diseases. The most recent study by the Office of Technology Assessment (Herdman, Hewitt, and Laschober 1993) noted that six million life years were lost in 1990 due to premature mortality. Total costs amounted to $55.8 billion ($1985) of which $5.7 billion were direct health care costs, $17. …

9 citations


"Public transit, obesity, and medica..." refers background in this paper

  • ...Dardis and Keane (1995) have assessed welfare costs of quitting smoking among rationally addicted smokers; we need a similar analysis of transportation choices....

    [...]

Frequently Asked Questions (1)
Q1. What contributions have the authors mentioned in the paper "Public transit, obesity, and medical costs: assessing the magnitudes" ?

This paper assesses the potential benefits of increased walking and reduced obesity associated with taking public transit in terms of dollars of medical costs saved and disability avoided. Further research is warranted on the net impact of transit usage on all behaviors, including caloric intake and other types of exercise, and on whether policies can promote transit usage at acceptable cost.