Meta-Analysis of Heterogeneity in the Effects of Wildfire Smoke Exposure on Respiratory Health in North America
Abstract
:1. Introduction
2. Materials and Methods
- Were not related to wildfire exposure.
- Were not conducted in North America.
- Were case studies, meta-analyses, editorials, or commentaries.
- Were not of acute respiratory health outcomes including ED and/or hospital admissions.
- Did not report estimates of relative risk. We considered odds ratios to be estimates of relative risk (RR) under the rare outcome assumption.
- The shortest available lag time.
- If multiple estimates were available using different exposure periods (for example, during fire and postfire), we chose estimates associated with exposures during fire (compared to referent period/unit).
- Where possible, we chose models of combined admission types (both hospital and ED admissions). In the one study that reported separate models on hospital and ED admissions, we chose the outcome with highest number of events, which was ED admissions [26].
- If multiple predicted exposure definitions were used to produce relative risk estimates (for example, Gan et al. [23]), we chose the exposure definition that provided better reliability according to model fit, of surface measurements of PM2.5 (particulate matter of diameter less than 2.5 micrometers).
3. Results
3.1. Study Characteristics
3.2. Smoke Exposure Measurement and Exposure Contrast
3.2.1. Health Outcomes
3.2.2. Covariates
3.2.3. Lags
3.3. Stratified Estimates
4. Discussion
5. Conclusions
Author Contributions
Finanzierung
Conflicts of Interest
References
- Abatzoglou, J.T.; Williams, A.P. Impact of anthropogenic climate change on wildfire across western US forests. Proc. Natl. Acad. Sci. USA. 2016, 113, 11770–11775. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Dennison, P.E.; Brewer, S.C.; Arnold, J.D.; Moritz, M.A. Large wildfire trends in the western United States, 1984–2011. Geophys. Res. Lett. 2014, 41, 2928–2933. [Google Scholar] [CrossRef]
- Radeloff, V.C.; Helmers, D.P.; Kramer, H.A.; Mockrin, M.H.; Alexandre, P.M.; Bar-Massada, A.; Butsic, V.; Hawbaker, T.J.; Martinuzzi, S.; Syphard, A.D. Rapid growth of the US wildland-urban interface raises wildfire risk. Proc. Natl. Acad. Sci. USA. 2018, 115, 3314–3319. [Google Scholar] [CrossRef] [PubMed]
- Bowman, D.M.; Williamson, G.J.; Abatzoglou, J.T.; Kolden, C.A.; Cochrane, M.A.; Smith, A.M. Human exposure and sensitivity to globally extreme wildfire events. Nat. Ecol. Evol. 2017, 1, 0058. [Google Scholar] [CrossRef] [PubMed]
- Spracklen, D.V.; Mickley, L.J.; Logan, J.A.; Hudman, R.C.; Yevich, R.; Flannigan, M.D.; Westerling, A.L. Impacts of climate change from 2000 to 2050 on wildfire activity and carbonaceous aerosol concentrations in the western United States. J. Geophys. Res. Atmos. 2009, 114, D20. [Google Scholar] [CrossRef]
- Yue, X.; Mickley, L.J.; Logan, J.A.; Kaplan, J.O. Ensemble projections of wildfire activity and carbonaceous aerosol concentrations over the western United States in the mid-21st century. Atmos. Environ. 2013, 77, 767–780. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Hicke, J.A.; Johnson, M.C.; Hayes, J.L.; Preisler, H.K. Effects of bark beetle-caused tree mortality on wildfire. For. Ecol. Manag. 2012, 271, 81–90. [Google Scholar] [CrossRef] [Green Version]
- Urbanski, S.P.; Hao, W.M.; Baker, S. Chapter 4: Chemical composition of wildland fire emissions. In Developments in Environmental Science; Bytnerowicz, A., Arbaugh, M.J., Riebau, A.R., Andersen, C., Eds.; Elsevier: Amsterdam, The Netherlands, 2008; Volume 8, pp. 405–423. [Google Scholar]
- Jaffe, D.; Chand, D.; Hafner, W.; Westerling, A.; Spracklen, D. Influence of fires on O3 concentrations in the western US. Environ. Sci. Technol. 2008, 42, 5885–5891. [Google Scholar] [CrossRef]
- Jaffe, D.; Hafner, W.; Chand, D.; Westerling, A.; Spracklen, D. Interannual variations in PM2.5 due to wildfires in the Western United States. Environ. Sci. Technol. 2008, 42, 2812–2818. [Google Scholar] [CrossRef]
- Kim, Y.H.; Warren, S.H.; Krantz, Q.T.; King, C.; Jaskot, R.; Preston, W.T.; George, B.J.; Hays, M.D.; Landis, M.S.; Higuchi, M. Mutagenicity and lung toxicity of smoldering vs. flaming emissions from various biomass fuels: Implications for health effects from wildland fires. Environ. Health Perspect. 2018, 126, 017011. [Google Scholar] [CrossRef]
- Black, C.; Tesfaigzi, Y.; Bassein, J.A.; Miller, L.A. Wildfire smoke exposure and human health: Significant gaps in research for a growing public health issue. Environ. Toxicol. Pharmacol. 2017, 55, 186–195. [Google Scholar] [CrossRef] [PubMed]
- Adetona, O.; Reinhardt, T.E.; Domitrovich, J.; Broyles, G.; Adetona, A.M.; Kleinman, M.T.; Ottmar, R.D.; Naeher, L.P. Review of the health effects of wildland fire smoke on wildland firefighters and the public. Inhal. Toxicol. 2016, 28, 95–139. [Google Scholar] [CrossRef]
- Liu, J.C.; Pereira, G.; Uhl, S.A.; Bravo, M.A.; Bell, M.L. A systematic review of the physical health impacts from non-occupational exposure to wildfire smoke. Environ. Res. 2015, 136, 120–132. [Google Scholar] [CrossRef] [PubMed]
- Reid, C.E.; Brauer, M.; Johnston, F.H.; Jerrett, M.; Balmes, J.R.; Elliott, C.T. Critical review of health impacts of wildfire smoke exposure. Environ. Health Perspect. 2016, 124, 1334. [Google Scholar] [CrossRef] [PubMed]
- Eze, I.C.; Hemkens, L.G.; Bucher, H.C.; Hoffmann, B.; Schindler, C.; Künzli, N.; Schikowski, T.; Probst-Hensch, N.M. Association between ambient air pollution and diabetes mellitus in Europe and North America: Systematic review and meta-analysis. Environ. Health Perspect. 2015, 123, 381. [Google Scholar] [CrossRef] [PubMed]
- Pope, C.A.; Brook, R.D.; Burnett, R.T.; Dockery, D.W. How is cardiovascular disease mortality risk affected by duration and intensity of fine particulate matter exposure? An integration of the epidemiologic evidence. Air Qual. Atmos. Health 2011, 4, 5–14. [Google Scholar] [CrossRef]
- US Environmental Protection Agency. Integrated Science Assessment (ISA) for Particulate Matter (Final Report); US Environmental Protection Agency: Washington, DC, USA, 2009.
- Schweizer, D.; Cisneros, R. Forest fire policy: Change conventional thinking of smoke management to prioritize long-term air quality and public health. Air Qual. Atmos. Health 2017, 10, 33–36. [Google Scholar] [CrossRef]
- Agee, J.K.; Skinner, C.N. Basic principles of forest fuel reduction treatments. For. Ecol. Manag. 2005, 211, 83–96. [Google Scholar] [CrossRef] [Green Version]
- Williamson, G.; Bowman, D.M.S.; Price, O.F.; Henderson, S.; Johnston, F. A transdisciplinary approach to understanding the health effects of wildfire and prescribed fire smoke regimes. Environ. Res. Lett. 2016, 11, 125009. [Google Scholar] [CrossRef] [Green Version]
- Moher, D.; Liberati, A.; Tetzlaff, J.; Altman, D.G.; Prisma, G. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med. 2009, 6, e1000097. [Google Scholar] [CrossRef]
- Gan, R.W.; Ford, B.; Lassman, W.; Pfister, G.; Vaidyanathan, A.; Fischer, E.; Volckens, J.; Pierce, J.R.; Magzamen, S. Comparison of wildfire smoke estimation methods and associations with cardiopulmonary-related hospital admissions. GeoHealth 2017, 1, 122–136. [Google Scholar] [CrossRef] [Green Version]
- Rappold, A.G.; Cascio, W.E.; Kilaru, V.J.; Stone, S.L.; Neas, L.M.; Devlin, R.B.; Diaz-Sanchez, D. Cardio-respiratory outcomes associated with exposure to wildfire smoke are modified by measures of community health. Environ. Health 2012, 11, 71. [Google Scholar] [CrossRef]
- Rappold, A.G.; Stone, S.L.; Cascio, W.E.; Neas, L.M.; Kilaru, V.J.; Carraway, M.S.; Szykman, J.J.; Ising, A.; Cleve, W.E.; Meredith, J.T.; et al. Peat bog wildfire smoke exposure in rural North Carolina is associated with cardiopulmonary emergency department visits assessed through syndromic surveillance. Environ. Health Perspect. 2011, 119, 1415–1420. [Google Scholar] [CrossRef]
- Reid, C.E.; Jerrett, M.; Tager, I.B.; Petersen, M.L.; Mann, J.K.; Balmes, J.R. Differential respiratory health effects from the 2008 northern California wildfires: A spatiotemporal approach. Environ. Res. 2016, 150, 227–235. [Google Scholar] [CrossRef] [Green Version]
- Altman, D.G.; Bland, J.M. Interaction revisited: The difference between two estimates. BMJ 2003, 326, 219. [Google Scholar] [CrossRef]
- Higgins, J.P.; Thompson, S.G. Quantifying heterogeneity in a meta-analysis. Stat. Med. 2002, 21, 1539–1558. [Google Scholar] [CrossRef]
- Higgins, J.P.; Thompson, S.G.; Deeks, J.J.; Altman, D.G. Measuring inconsistency in meta-analyses. BMJ 2003, 327, 557. [Google Scholar] [CrossRef]
- Alman, B.L.; Pfister, G.; Hao, H.; Stowell, J.; Hu, X.F.; Liu, Y.; Strickland, M.J. The association of wildfire smoke with respiratory and cardiovascular emergency department visits in Colorado in 2012: A case crossover study. Environ. Health 2016, 15, 64. [Google Scholar] [CrossRef]
- Delfino, R.J.; Brummel, S.; Wu, J.; Stern, H.; Ostro, B.; Lipsett, M.; Winer, A.; Street, D.H.; Zhang, L.; Tjoa, T.; et al. The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003. Occup. Environ. Med. 2009, 66, 189–197. [Google Scholar] [CrossRef]
- Hutchinson, J.; Vargo, J.; Milet, M.; French, N.; Billmire, M.; Johnson, J.; Hoshiko, S. The San Diego 2007 wildfires and Medi-Cal emergency department presentations, inpatient hospitalizations, and outpatient visits: An observational study of smoke exposure periods and a bidirectional casecrossover analysis. PLoS Med. 2018, 15, e1002601. [Google Scholar] [CrossRef]
- Liu, J.C.; Wilson, A.; Mickley, L.J.; Ebisu, K.; Sulprizio, M.P.; Wang, Y.; Peng, R.D.; Yue, X.; Dominici, F.; Bell, M.L. Who among the elderly is most vulnerable to exposure to and health risks of fine particulate matter from wildfire smoke? Am. J. Epidemiol. 2017, 186, 730–735. [Google Scholar] [CrossRef]
- Resnick, A.; Woods, B.; Krapfl, H.; Toth, B. Health outcomes associated with smoke exposure in Albuquerque, New Mexico, during the 2011 Wallow fire. J. Public Health Manag. Pract. 2015, 21, S55–S61. [Google Scholar] [CrossRef]
- Tinling, M.A.; West, J.J.; Cascio, W.E.; Kilaru, V.; Rappold, A.G. Repeating cardiopulmonary health effects in rural North Carolina population during a second large peat wildfire. Environ. Health 2016, 15, 12. [Google Scholar] [CrossRef]
- Grell, G.A.; Peckham, S.E.; Schmitz, R.; McKeen, S.A.; Frost, G.; Skamarock, W.C.; Eder, B. Fully coupled “online” chemistry within the WRF model. Atmos. Environ. 2005, 39, 6957–6975. [Google Scholar] [CrossRef]
- Stein, A.; Draxler, R.R.; Rolph, G.D.; Stunder, B.J.; Cohen, M.; Ngan, F. NOAA’s HYSPLIT atmospheric transport and dispersion modeling system. Bull. Amer. Meteor. Soc. 2015, 96, 2059–2077. [Google Scholar] [CrossRef]
- Bey, I.; Jacob, D.J.; Yantosca, R.M.; Logan, J.A.; Field, B.D.; Fiore, A.M.; Li, Q.; Liu, H.Y.; Mickley, L.J.; Schultz, M.G. Global modeling of tropospheric chemistry with assimilated meteorology: Model description and evaluation. J. Geophys. Res. Atmos 2001, 106, 23073–23095. [Google Scholar] [CrossRef] [Green Version]
- Lassman, W.; Ford, B.; Gan, R.W.; Pfister, G.; Magzamen, S.; Fischer, E.V.; Pierce, J.R. Spatial and temporal estimates of population exposure to wildfire smoke during the Washington state 2012 wildfire season using blended model, satellite, and in situ data. GeoHealth 2017, 1, 106–121. [Google Scholar] [CrossRef] [Green Version]
- Higgins, J.P.; Green, S. Cochrane Handbook for Systematic Reviews of Interventions; Version 5.1.0; The Cochrane Collaboration: London, UK, 2011. [Google Scholar]
Citation | Standort | Study Period | Wildfire Event | Study Design | Age | Visit Types | Health Outcomes | ICD-9 Codes | Effect Modifiers | Referent | Lags | Exposure Contrast | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Alman et al. (2016) [30] | Colorado | 26 March–10 July 2012 | Statewide forest wildfire complex | Case crossover | all ages | ED and hospital admissions | All respiratory conditions, asthma, bronchitis, COPD, pneumonia, upper respiratory infection | 460–66, 480–88, 490–92, 496, 493–786.07, 460–5, 466.0, 466.1, 466.11, 466.19 | (1) age (0–18, 19–64, 65+) | grid-specific nonexposure | 0, 0–1, 0–1–2 | 5 µg/m3 |
2 | Delfino 2008 [31] | Southern California | 2003 | Region-wide forest wildfire complex | Time series | all ages | Hospital admissions | All respiratory conditions, asthma, bronchitis & bronchiolitis, COPD, pneumonia, upper respiratory infection | 493, 466, 491–92, 496, 480–87, 460–65 | (1) age (0–4, 5–19, 20–64, 65–99; COPD: 20–64, 65–99); (2) sex [not for all categories] | Prewildfire (compared to during and post) | 0–1 | 10 µg/m3 |
3 | Gan et al. (2017) [23] | WA State | 1 July–31 October 2012 | Statewide forest wildfire complex | "Time-stratified case crossover" | all ages | ED and hospital admissions | All respiratory conditions, asthma, bronchitis, COPD, pneumonia | 460–519, 480–86, 466 | (1) age (<15, 15+, 15–65); (2) sex | Subject-specific nonexposure | none, 0, 0–1, 0–2, 0–3, 0–4, 0–5 | 10 µg/m3 |
4 | Hutchinson et al. (2018) [32] | Southern California | 22 October–5 November 2007 | Region-wide forest wildfire complex | Case crossover | all ages | ED and hospital admissions | All respiratory conditions, asthma, bronchitis, pneumonia, upper respiratory infection | 277, 460–64, 466, 480–87, 490–96, 506, 508, 786 | (1) age (0–1, 2–4, 0–4, 5–17, 18–64) | Non-smoke exposed times; subject-specific nonexposure | none | 10 µg/m3 |
5 | Liu et al. (2017a) [33] | Western USA | 2004–2009 | Region-wide forest wildfire complex | Ecological | 65+ | Hospital admissions | All respiratory conditions | 490–492, 464–466, 480–487 | (1) age (65+, 65–74, 85+), (2) sex, (3) region (urban, rural, CA, NW, SW, Rocky Mountain), (4) education (>20%, <20% with bachelor degree), race (white, black, other), (5) poverty (<10%, 10–15%, 15%+) | Non-smoke exposed times | none | none |
6 | Rappold et al. (2011) [25] | North Carolina | 1 June–14 July 2008 | Peat wildfire in Pocosin Lakes National Wildlife Refuge | Ecological | all ages | ED admissions | All respiratory conditions | 465, 466, 480, 481, 482, 483, 484, 485, 486, 490, 491, 492, 493 | (1) age (all, 65+, <65); (2) sex; (3) region | Non-smoke exposed areas | 0–5 | none |
7 | Rappold et al. (2012) [24] | North Carolina | 1 June–14 July 2008 | Peat wildfire in Pocosin Lakes National Wildlife Refuge | Time series | 18+ | ED admissions | Asthma | 428, 493 | (1) health behaviors (tobacco use, diet/exercise, alcohol use, unsafe sex); (2) clinical care (access to care, quality of care); (3) SES (education, employment, income, family & social support, community safety); (4) physical environment (environmental quality, built environment) | Non-smoke exposed areas | 0, 1, 0–1 | 100 µg/m3 |
8 | Reid et al. (2016) [26] | Northern California | 2008 | Large wildfire complex | Time series | all ages | ED and hospital admissions | All respiratory conditions, asthma, COPD, pneumonia | 493 | (1) age (<20, 20–64, 65+); (2) sex; (3) race; (4) median income; (5) percent of the population with less than a high school diploma; (6) percent of owner–occupied housing units | Prewildfire (compared to during and post) | 0–1,0–2 | 5 µg/m3 |
9 | Resnick et al. (2013) [34] | Albuquerque, New Mexico | 2011 | Wallow Fire forest wildfire | Time series | all ages | ED admissions | All respiratory conditions, asthma, other diseases of respiratory system | 460–519 | (1) age (0–19, 20–64, 73+) | Prewildfire (compared to during and post) | none | 10 µg/m3 |
10 | Tinling et al. (2016) [35] | North Carolina | 5 May 5–15 June 2011 | Pains Bay peat wildfire | Time series | all ages | ED admissions | All respiratory conditions, asthma, COPD, upper respiratory infection, other chest/respiratory symptoms | 786 | (1) age (<18, 18–64, 18+, 65+); (2) sex | Non-smoke exposed times | 0–2 | 10 µg/m3 |
Study | Visit Type | Age | Lag | Female:Male | ||
---|---|---|---|---|---|---|
RR | 95% CI | I2 | ||||
All Respiratory | ||||||
Gan et al. 2017 | ED | Adult (15–64) | none | 0.998 | (0.947, 1.052) | |
Liu et al. 2017 | ED | Elderly (65+) | none | 0.929 | (0.786, 1.097) | |
Rappold et al. 2011 | ED | Ages 19+ | 0–5 | 1.124 | (0.764, 1.654) | |
Reid et al. 2016 | ED | All ages | 0–2 | 1.018 | (0.995, 1.041) | |
Tinling et al. 2016 | ED | Adult (18–64) | 0–2 | 1.029 | (0.939, 1.128) | |
Meta-RRR: | 1.015 | (0.994, 1.035) | 0.0% | |||
Asthma | ||||||
Delfino et al. 2008 | Hospital | Adult (20–64) | none | 1.056 | (1.000, 1.114) | |
Gan et al. 2017 | ED | Adult (15–64) | none | 0.998 | (0.895, 1.113) | |
Rappold et al. 2011 | ED | Ages 19+ | 0–5 | 1.900 | (0.941, 3.838) | |
Reid et al. 2016 | ED | Alle | 0–2 | 1.039 | (1.014, 1.065) | |
Tinling et al. 2016 | ED | Adult (18–64) | 0–2 | 0.919 | (0.796, 1.060) | |
Meta-RRR: | 1.038 | (1.016, 1.060) | 38.5% | |||
COPD | ||||||
Gan et al. 2017 | ED | Adult | none | 1.075 | (0.954, 1.212) | |
Rappold et al. 2011 | ED | Alle | 0–5 | 0.594 | (0.214, 1.648) | |
Reid et al. 2016 | ED | Alle | 0–2 | 1.017 | (0.992, 1.023) | |
Tinling et al. 2016 | ED | Adult | 0–2 | 1.017 | (0.981, 1.055) | |
Meta-RRR: | 1.018 | (1.003, 1.032) | 0.0% | |||
Pneumonia | ||||||
Gan et al. 2017 | ED | Adult | none | 0.987 | (0.892, 1.091) | |
Rappold et al. 2011 | ED | Alle | 0–5 | 0.877 | (0.468, 1.645) | |
Reid et al. 2016 | ED | Alle | 0–2 | 1.005 | (0.979, 1.032) | |
Meta-RRR: | 1.004 | (0.978, 1.030) | 0.0% |
Study | Visit Type | Age | Lag | Meta-RRR with Each Study Removed a | ||
---|---|---|---|---|---|---|
Meta-RRR | 95% CI | I2 | ||||
All Respiratory | ||||||
Gan et al. 2017 | ED | Adult | none | 1.017 | (0.995, 1.040) | 0.0% |
Liu et al. 2017 | ED | Elderly | none | 1.016 | (0.995, 1.037) | 0.0% |
Rappold et al. 2011 | ED | Alle | 0–5 | 1.014 | (0.004, 1.035) | 0.0% |
Reid et al. 2016 | ED | Alle | 0–2 | 1.002 | (0.959, 1.046) | 0.0% |
Tinling et al. 2016 | ED | Adult | 0–2 | 1.014 | (0.993, 1.035) | 0.0% |
Whole Group Meta-RRR: | 1.015 | (0.994, 1.035) | 0.0% | |||
Asthma | ||||||
Delfino et al. 2008 | Hospital | Adult | none | 1.034 | (1.010, 1.059) | 50.3% |
Gan et al. 2017 | ED | Adult | none | 1.039 | (1.017, 1.063) | 49.9% |
Rappold et al. 2011 | ED | Alle | 0–5 | 1.037 | (1.015, 1.060) | 18.0% |
Reid et al. 2016 | ED | Alle | 0–2 | 1.033 | (0.987, 1.082) | 53.6% |
Tinling et al. 2016 | ED | Adult | 0–2 | 1.041 | (1.018, 1.064) | 100.0% |
Whole Group Meta-RRR: | 1.038 | (1.016, 1.060) | 38.5% | |||
COPD | ||||||
Gan et al. 2017 | ED | Adult | none | 1.017 | (1.003, 1.031) | 0.0% |
Rappold et al. 2011 | ED | Alle | 0–5 | 1.018 | (1.004, 1.032) | 0.0% |
Reid et al. 2016 | ED | Alle | 0–2 | 1.021 | (0.986, 1.057) | 0.0% |
Tinling et al. 2016 | ED | Adult | 0–2 | 1.018 | (1.002, 1.033) | 0.0% |
Whole Group Meta-RRR: | 1.018 | (1.003, 1.032) | 0.0% | |||
Pneumonia | ||||||
Gan et al. 2017 | ED | Adult | none | 1.005 | (0.979, 1.032) | 0.0% |
Rappold et al. 2011 | ED | Alle | 0–5 | 1.004 | (0.979, 1.030) | 0.0% |
Reid et al. 2016 | ED | Alle | 0–2 | 0.984 | (0.891, 1.087) | 0.0% |
Whole Group Meta-RRR: | 1.004 | (0.978, 1.030) | 0.0% |
Study | Visit Type | Lag | Ratio of Relative Risks (RRR) | |||||
---|---|---|---|---|---|---|---|---|
Youth:Adult | 95% CI | Youth:Elderly | 95% CI | Elderly:Adult | 95% CI | |||
Alman et al. 2016 | ED | 0 | 0.966 | (0.938, 0.995) | 0.974 | (0.930, 1.021) | 1.009 | (0.967, 1.052) |
Delfino et al. 2008 | Hospital | 0 | 1.003 | (0.955, 1.053) | 0.997 | (0.950, 1.046) | 0.994 | (0.968, 1.021) |
Gan et al. 2017 | ED | 0 | 1.034 | (0.954, 1.120) | 1.011 | (0.938, 1.091) | 0.978 | (0.923, 1.037) |
Hutchinson et al. 2018 | ED | 0–5 | 0.983 | (0.638, 1.515) | ||||
Rappold et al. 2011 | ED | 0–5 | 1.050 | (0.874, 1.260) | ||||
Reid et al. 2016 | ED | 0–2 | 0.969 | (0.952, 0.985) | 0.977 | (0.959, 0.995) | 1.009 | (0.992, 1.025) |
Resnick et al. 2015 | ED | 0 | 0.805 | (0.667, 0.970) | 0.693 | (0.537, 0.894) | 0.861 | (0.680, 1.091) |
Tinling et al. 2016 | ED | 0–2 | 1.012 | (0.972, 1.054) | 1.066 | (1.017, 1.118) | 1.054 | (1.010, 1.099) |
Meta RRR: | 0.976 | (0.963, 0.989) | 0.987 | (0.973, 1.002) | 1.008 | (0.996, 1.020) | ||
I2: | 47.7% | 74.6% | 27.0% |
Study | Health Outcome | Ratio of Relative Risks (RRR) | |||||
---|---|---|---|---|---|---|---|
Low:Middle | 95% CI | Low:High | 95% CI | Middle:High | 95% CI | ||
Income a | |||||||
Reid et al. 2016 | All respiratory | 1.009 | (0.994, 1.022) | 1.019 | (1.004, 1.033) | 1.010 | (0.996, 1.024) |
Reid et al. 2016 | Asthma | 1.012 | (0.984, 1.039) | 1.021 | (0.990, 1.051) | 1.009 | (0.978, 1.040) |
Reid et al. 2016 | COPD | 1.020 | (0.982, 1.059) | 1.039 | (0.997, 1.082) | 1.018 | (0.976, 1.061) |
Reid et al. 2016 | Pneumonia | 1.009 | (0.977, 1.040) | 1.017 | (0.981, 1.054) | 1.009 | (0.977, 1.041) |
% Occupied Housing b | |||||||
Reid et al. 2016 | All respiratory | 0.999 | (0.986, 1.012) | 0.998 | (0.982, 1.014) | 0.999 | (0.983, 1.015) |
Reid et al. 2016 | Asthma | 0.989 | (0.962, 1.014) | 0.998 | (0.966, 1.031) | 1.010 | (0.978, 1.042) |
Reid et al. 2016 | COPD | 1.008 | (0.968, 1.048) | 1.036 | (0.985, 1.088) | 1.028 | (0.982, 1.075) |
Reid et al. 2016 | Pneumonia | 1.002 | (0.971, 1.033) | 1.004 | (0.969, 1.040) | 1.003 | (0.969, 1.036) |
% Population with High School Diploma c | |||||||
Liu et al. 2017 | All respiratory | 0.988 | (0.918, 1.062) | ||||
Reid et al. 2016 | All respiratory | 0.990 | (0.974, 1.004) | 0.991 | (0.974, 1.006) | 1.001 | (0.987, 1.014) |
Reid et al. 2016 | Asthma | 0.994 | (0.963, 1.025) | 0.996 | (0.965, 1.027) | 1.002 | (0.974, 1.029) |
Reid et al. 2016 | COPD | 0.982 | (0.943, 1.022) | 0.959 | (0.920, 0.997) | 0.976 | (0.939, 1.013) |
Reid et al. 2016 | Pneumonia | 0.967 | (0.935, 0.999) | 0.990 | (0.956, 1.025) | 1.024 | (0.993, 1.056) |
% Poverty d | |||||||
Liu et al. 2017 | All respiratory | 0.862 | (0.720, 1.032) | 1.160 | (1.000, 1.347) | 1.000 | (0.862, 1.161) |
Socioeconomic factors e | |||||||
Rappold et al. 2012 | All respiratory | 1.113 | (1.000, 1.347) | ||||
Race f | |||||||
Reid et al. 2016 | All respiratory | 0.992 | (0.979, 1.005) | 0.992 | (0.976, 1.008) | 1.000 | (0.984, 1.015) |
Reid et al. 2016 | Asthma | 0.986 | (0.959, 1.013) | 1.002 | (0.968, 1.038) | 1.017 | (0.983, 1.051) |
Reid et al. 2016 | COPD | 0.992 | (0.955, 1.030) | 1.008 | (0.965, 1.051) | 1.015 | (0.974, 1.057) |
Reid et al. 2016 | Pneumonia | 0.978 | (0.946, 1.009) | 0.997 | (0.962, 1.033) | 1.020 | (0.987, 1.053) |
White:Black | 95% CI | White:Other | 95% CI | Black:Other | 95% CI | ||
Liu et al. 2017 | All respiratory | 0.877 | (0.714, 1.076) | 1.029 | (0.915, 1.155) | 1.173 | (0.947, 1.452) |
Stratification Variables | Ratio of Relative Risks | 95% CI |
---|---|---|
Rappold et al. 2012 a | ||
Health Behaviors | 1.631 | (0.966, 2.752) |
Access to Care | 0.822 | (0.486, 1.391) |
Physical Environment | 0.712 | (0.405, 1.251) |
Liu et al. 2017 | ||
Urban: Less Urban | 0.955 | (0.810, 1.127) |
CA: Northwest | 0.813 | (0.616, 1.072) |
CA: Southwest | 0.954 | (0.440, 2.069) |
CA: Rocky Mountains | 1.000 | (0.699, 1.431) |
Northwest: Southwest | 1.174 | (0.520, 2.653) |
Northwest: Rocky Mountains | 1.231 | (0.793, 1.911) |
Southwest: Rocky Mountains | 1.048 | (0.450, 2.442) |
© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Share and Cite
Kondo, M.C.; De Roos, A.J.; White, L.S.; Heilman, W.E.; Mockrin, M.H.; Gross-Davis, C.A.; Burstyn, I. Meta-Analysis of Heterogeneity in the Effects of Wildfire Smoke Exposure on Respiratory Health in North America. Int. J. Environ. Res. Public Health 2019, 16, 960. https://doi.org/10.3390/ijerph16060960
Kondo MC, De Roos AJ, White LS, Heilman WE, Mockrin MH, Gross-Davis CA, Burstyn I. Meta-Analysis of Heterogeneity in the Effects of Wildfire Smoke Exposure on Respiratory Health in North America. International Journal of Environmental Research and Public Health. 2019; 16(6):960. https://doi.org/10.3390/ijerph16060960
Chicago/Turabian StyleKondo, Michelle C., Anneclaire J. De Roos, Lauren S. White, Warren E. Heilman, Miranda H. Mockrin, Carol Ann Gross-Davis, and Igor Burstyn. 2019. "Meta-Analysis of Heterogeneity in the Effects of Wildfire Smoke Exposure on Respiratory Health in North America" International Journal of Environmental Research and Public Health 16, no. 6: 960. https://doi.org/10.3390/ijerph16060960