University:
Boston University
Course:
SAR HP 151 | Introduction to Health Professions
Academic year:

2022
Views:

444

Pages:

19
Author:

Amari Owen

• Case-control study of 12 Results childhood leukemia cases diagnosed 1969-1979 of 1981 • No association with any particular Study exposure, family history, medical history • Elevated Standardized Incidence Ratio SIR=2.3, p=.007 (see Cutler JJ, et al. Childhood Leukemia in Woburn, Massachusetts. Public Health Reports 101(2):201-205, 1986) Harvard/FACE Study • Citizens and researchers conducted townwide telephone survey • Used Woburn water distribution model from Dept. of Env. Quality Engineering • Estimated exposure to contaminated wells G & H was two-fold higher in childhood leukemia cases diagnosed 1964-1983 (see Lagakos SW, et al. J Am Stat Assoc 81:583-596, 1986) Wells G and H Water Distribution DPH Follow-Up Study Case-control study of childhood leukemia diagnosed 1969-1986 (Costas, et al., 2002) • Used detailed water distribution model with estimates of G & H exposure by month • Increased risk of leukemia in children whose mothers exposed during pregnancy (OR=8.3; 95% C.I.=0.7-94.7, p(trend)<.05) Number of Cases of Childhood Leukemia Diagnosed by Year of Diagnosis in Woburn, MA Jan. 1, 1969 - Aug. 1, 1999 4 Contaminated Wells Closed 3 2 1 99 97 95 93 91 89 87 85 83 81 79 77 75 73 71 69 0 Groundwater Treatment Process Statistical methods • Standardized incidence ratios for population of interest – Compare observed to expected cases, calculate p-value and 95% confidence interval • Utilize cluster statistics – CDC software “Cluster version 3.1” – Knox space-time statistic – Scan statistic, cusum statistic, etc. • Kulldorff methods “SaTScan v8.0.1, June, 2009” Breast cancer in Mass. • Silent Spring Institute/BUSPH studies – Mass. Breast Cancer Coalition’s critical role – Initial descriptive epidemiology • SIR significantly elevated from 1982 to 1990 – Upper Cape study • Breast cancer in relation to PCE water contamination, Mass. Military Reservation exposures Breast Cancer SIRs • source: Silent Spring Institute, www.silentspring.org Upper Cape Cod Sandwich Bourne MMR * Barnstable Falmouth Mashpee * Massachusetts Military Reservation Adjusted breast cancer ORs Smoothed (Paulu, et al., 2002) OR OR 0.75 1.00 1.25 a) k=50 controls 1.50 OR 0.50 1.00 1.50 b) k=30 controls 2.00 0.00 0.50 1.00 1.50 2.00 2.50 c) k=10 controls Adjusted ORs in 3-D a) k=50 controls 2.5 2.5 2.5 2.0 2.0 2.0 1.5 1.5 1.5 1.0 1.0 1.0 0.5 0.5 0.5 0.0 0.0 0.0 b) k=30 controls c) k=10 controls Breast cancer on Cape Cod Breast cancer in Mass. (cont.) • On-going studies of household, consumer product and environmental exposures – U. Mass.- Lowell/TURI/Silent Spring collaboration at http://gis.uml.edu/mediawiki/index.php/Breast_Cancer_ Risk_Project – BUSPH expanded case-control and cohort studies, further GIS methods (Vieira, et al.) Interpolation of town-level breast cancer incidence data (Brown, et al., 2009) Inverse root distance weighting was used on town-level aggregated SIR data on town geographic centroids, with a radius of influence of 30km. (Data: SSI; map: TURI) How to tell the difference? • No “magic wand” can tell whether a cluster has a real cause or not • Basis for reasoned judgment – Toxicologic and epidemiologic literature – Assessment of local disease and exposure patterns – Interpretation of detailed epidemiologic studies, if available The obligation to act • “From the right to know and the duty to inquire flows the obligation to act.” (Sandra Steingraber, Living Downstream, 1997) • Cluster investigations do not take precedence over reduction of likely harmful exposures; no proof of harm is not proof of no harm Exercise • Sandwich, MA is adjacent to the Massachusetts Military Reservation (MMR) and has been part of an on-going series of investigations of cancer and adverse birth outcomes over the past two decades. Recently, parents have raised a concern about a possible cluster of Ewing’s Sarcoma (a rare bone cancer) in Sandwich children. They have documented two cases in Sandwich and five additional cases in other Cape Cod communities. Exercise, continued • As an employee of the State Health Department, what would you recommend as a way of evaluating the community's concerns? What types of data would you look at in order to get an initial assessment of the problem? Consider the exposures that have already been identified in previous studies (see the MMR website, publications by Aschengrau, et al., and other sources you may find). Look at the Mass. Cancer Registry on-line data and consider what additional data you would want to request.