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18        <TITLE>New Mexico Small Areas</TITLE>
19        <CONTENT>
20        <a name="TOP"></a>
21        <ibis:include href="../../text/SmallArea.xml"/><br/><br/>
22<!--            New Mexico Small Areas are 108 geographic areas across the state with population sizes that are just
23                large enough to calculate rates for selected health events (e.g., diabetes deaths, asthma hospitalization,
24                etc.). New Mexico small areas were based on population size, not land area. Most (95%) of the New Mexico
25                small areas range in population size from 9,000 to 30,000 persons. Some counties have multiple small areas
26                (Bernalillo County has 34 small areas within its boundaries). In other cases, whole counties (e.g.,
27                Harding, Quay and De Baca Counties) were combined to create a single small area.
30                Reporting of health data for New Mexico sub-state geographies has formerly consisted of
31                presentation of data at the county level. County-level presentation is problematic
32                in New Mexico because of the large differences in county population sizes. Smaller counties
33                such as Harding and DeBaca (with 2010 U.S. Census estimated population sizes of 695 and 2,022,
34                respectively)<a href="#Bib-1">1</a>, have unstable rates on most health measures, while health measures
35                calculated for Bernalillo County (2010 Census population estimate=662,564) lack meaning because the
36                population is large and diverse.
37                <br/><br/>
39                The New Mexico Department of Health (NMDOH) decision to embark on the small area project was based on
40                the intense demand for health status information at the community level,<a href="#Bib-2">2</a> the
41                desire to study the associations between health inequity and place, and the belief that a standard
42                set of small areas would improve efficiency in production of community data reports and accumulation
43                of comparable community-level data across various public health indicators and datasets.
44                <br/><br/>     
46                <table class="Contents">
47                        <tr><td class="ContentsHeader">Contents</td></tr>
48                        <tr><td>
49                        <a href="#part1">Methodology</a><br/>
50                        <span class="Indent"><a href="#part2">Small Area Reference Materials</a></span><br/>
51                        <span class="Indent"><a href="#part3">Geocoding and Classification of Data to Small Areas</a></span><br/>
52                        <span class="Indent"><a href="#part4">Population Estimates</a></span><br/>
53                        <a href="#part5">Small Area Workgroup</a>
54                        <br/><a href="#REF">References</a><br/>
55                        </td></tr>
56                </table><br/>
58                        <a id="part1"/>
59                        <br/>
60                        <h1>Methodology</h1><br/>
62                        From May of 2009 through November 2011, a workgroup consisting of staff from NMDOH, UNM,
63                        and others has met to design a set of New Mexico "Small Areas" for data reporting.
64                        The following design criteria were developed and used by the group.<br/><br/>
66                        <h3>Table 1. Criteria for Design of New Mexico Small Areas</h3>
67                        <div><ol>
68                        <li>    Areas should allow calculation of stable rates. To achieve stability in the
69                                rates, a target minimum population of 10,000 was set (yielding a denominator
70                                of at least 50,000 person-years across five years).</li>
71                        <li>    NM small area geographies should be meaningful to communities. Small area
72                                boundaries should follow community boundaries whenever possible, and small
73                                areas should be as small as possible. A target maximum population size was
74                                set at 30,000.</li>
75                        <li>    NM small areas will have within-area homogeneity and between-area heterogeneity
76                                on health-relevant demographic characteristics (given that criterion #2 is met).
77                                The demographic characteristics considered were(<a href="#Bib-3">3</a>):
78                                <div><ul>
79                                <li>Percentage of persons of Hispanic origin</li>
80                                <li>Percentage of persons age 65+</li>
81                                <li>Percentage of persons with a 4-year college degree</li>
82                                <li>Percentage of children under age 17 in poverty</li>
83                                <li>Percentage of owner-occupied housing units</li>
84                                </ul></div>
85                                </li>
86                        <li>    Numerators and denominators must be available at the census tract level to
87                                support the calculation of mortality and other rates. Small areas will be
88                                designed by combining census tracts.</li>
89                        <li>    Absent other relevant considerations, a single area will not cross health
90                                region or county boundaries.</li>
92                        <br/><h4>Considerations for Presentation of Data by Small Areas:</h4>
94                        <li>    Adhere to the New Mexico DOH small numbers rules (to protect privacy).</li>
95                        <li>    Combine up to five years of data to improve reliability of the estimates.</li>
96                        <li>    Consider and communicate the likely impact of geocoding of numerator events
97                                to geographic features other than a complete, correct address.</li>
98                        </ol></div><br/>
100                <p align="right"><a href="#TOP">Back to Top</a></p>
102                        The New Mexico "Small Areas" Workgroup reviewed research and considered methods for
103                        defining small areas. All methods have advantages and disadvantages. For instance, ZIP
104                        code boundaries are relatively easy to communicate, but the boundaries shift over time
105                        and commercial marketing firms must be relied on to provide estimates of population size
106                        and other demographic characteristics.<br/><br/>
108                        The group decided to develop the New Mexico Small Areas by aggregating census tracts using
109                        above criteria as a guide. In the 2010 decennial census, New Mexico has 499 reporting
110                        census tracts with an average population size of 4,127. All but two NM Small Areas
111                        (<a href="#Bib-4">4</a>) were defined by combining adjacent census tracts. Demographic
112                        characteristics from the 2000 U.S. Decennial Census were examined to meet criterion #3.
113                        <br/><br/>
115                        The process yielded 108 New Mexico small areas with population sizes ranging from 929 
116                        (Area 99, Santa Fe County, State Penitentiary)(<a href="#Bib-5">5</a>) to 31,925 (Area
117                        35, Chaves County, Roswell, N.E.). The area average population size is 18,892, and the
118                        median is 17,982. Many of New Mexico's more urban counties had sufficient population to
119                        support multiple sub-county small areas. In rural areas of the state, all or parts of
120                        two or more counties were often combined to reach the minimum population target of 10,000.
121                        Five New Mexico counties, Cibola, Torrance, Socorro, Lincoln, and Luna counties, were
122                        designated as single-county small areas.
123                        <br/><br/>
125                <a id="part2"/>
126                        <br/>
127                        <h2>Small Area Reference Materials</h2>
129                        <h3>New Mexico Small Area Boundaries and Locations Map</h3>
130                        <br/>
131                        <img src="contentfile/image/resource/NMSmallArea/Statewide2.PNG" 
132                        title="New Mexico Small Areas, Version 1.3.3" alt="New Mexico Small Area Map"/> 
133                        <br/><br/>
135        <!--            Please visit the <a href="contentfile/html/SareaMapArcGIS.html" alt="Small Area Reference Map" target="blank">Small Area Reference Map</a>.
136                        This is an interactive map of small areas showing where each area is located in New Mexico.
137        -->             
138                        <br/><br/>
139                        <h3>Small Area Population Files</h3>
140                        <ibis:SelectionsList class="ExtraWhiteSpace">
141                                <SELECTIONS>
142                                        <SELECTION>
143                                                <TITLE>Small Area Population Data Query on NM-IBIS</TITLE>
144                                                <DESCRIPTION>Custom queries of population data by small area, year, age, sex and race/ethnicity.</DESCRIPTION>
145                                                <URL>query/selection/pop/_PopSelection.html</URL>
146                                        </SELECTION>
147                                        <SELECTION>
148                                                <TITLE>Small Area Population Data Files</TITLE>
149                                                <DESCRIPTION>Data files and codebook for Small Areas.</DESCRIPTION>
150                                                <URL>resource/PopData.html</URL>
151                                        </SELECTION>
152                                </SELECTIONS>
153                        </ibis:SelectionsList>
154                        <br/>
155                        <h3>Small Area Mapping Resources</h3>
156                        <ibis:SelectionsList class="ExtraWhiteSpace">
157                                <SELECTIONS>
158        <!--                            <SELECTION>
159                                                <TITLE>Small Area esri Files (.MPK file)</TITLE>
160                                                <DESCRIPTION>Shape files used with ESRI ArcGIS.</DESCRIPTION>
161                                                <URL>/contentfile/docs/PopData/SmallAreaV133.mpk</URL>
162                                        </SELECTION>
163        -->
164                                        <SELECTION>
165                                                <TITLE>NM Small-Area-to-Census-Tract Crosswalk and SAS Code (Excel file)</TITLE>
166                                                <DESCRIPTION>Excel file matches up 2000 and 2010 U.S. Census Tracts with NM Small Areas.
167                                                                 SAS code creates and labels areas from 2000 and/or 2010 U.S. census tracts.</DESCRIPTION>
168                                                <URL>/contentfile/docs/PopData/SArea134.xlsx</URL>
169                                        </SELECTION>
170                                </SELECTIONS>
171                        </ibis:SelectionsList>
173                <p align="right"><a href="#TOP">Back to Top</a></p>
174                        <br/><br/>     
175                        A decision was made to avoid using tribal geographies as a design factor in the 108
176                        small areas. That decision was based on the following considerations, 1) it is NMDOH
177                        policy to release tribal health data and results of analysis identified by tribe to
178                        only the tribe, and not release them publicly, 2) New Mexico census tracts did not always
179                        follow tribal area boundaries, and 3) the NMDOH tribal epidemiologist is able to provide
180                        tribes with tribe-specific data and analysis of results.
181                        <br/><br/><br/>
183                <a id="part3"/>
184                        <br/>
185                        <h2>Classification of Data Records to Small Areas</h2><br/>
187                        Health event counts for a given New Mexico Small Area were derived by attempting to geocode
188                        the residential address of each decedent. Geocoding assigned each address an x and y
189                        coordinate that corresponded to the Earth's latitude and longitude. The accuracy and
190                        precision of the geocoding process depended on having a complete and correct address
191                        on every death certificate that could be matched uniquely to a standardized address
192                        in a geodatabase that provided the needed geographic coordinates. Death records such
193                        as P.O boxes or rural routes that could not be matched to a standardized address were
194                        geocoded with the most precise alternate geocode available. Often this was the geocode
195                        of a nearby intersection, or the geographic centroid of the ZIP code, populated place,
196                        or county referenced in the address. Certain conditions make it difficult to precisely
197                        geocode every death record, including:
198                        <div><ul>
199                        <li>Missing or incorrect street numbers</li>
200                        <li>Missing, misspelled, or nonstandard street names</li>
201                        <li>Use of a post office box only</li>
202                        <li>Use of a rural route, highway contract route or general delivery address</li>
203                        </ul></div>
204                        <br/>
205                        <br/>
207                        <div class="Note">
208                                <img src="contentfile/image/resource/important_icon.gif" alt="important! icon" width="16" height="15" title="IMPORTANT!"/>
209                                It is important to recognize that small areas with misclassified data records
210                                will yield calculated health event rates that are higher or lower than the actual 
211                                rate in that area. The New Mexico Department of Health is currently evaluating
212                                the small area rates published on NM-IBIS for misclassification errors. Until that
213                                evaluation is complete, please use those rates with caution and include the following
214                                caveat along with any report of your results:
215                                <br/><br/>
217                                <div class="Note">
218                                        <ibis:include href="../../text/SmallAreaCaveat.xml"/>
219                                        <!--    *****Important! Small Area Analysis Caveat:*****
220                                                Birth and death counts for a given New Mexico Small Area were derived by geocoding the
221                                                residential address of each decedent. Geocoding assigned each address an x and y
222                                                coordinate corresponding to the Earth's latitude and longitude. Geocoding accuracy
223                                                depends on having complete and correct addresses. Birth and death certificates with
224                                                addresses such as P.O boxes or rural routes were geocoded with the closest coordinates
225                                                available, often the center of a town or zip code area. Assignment of data records to
226                                                an incorrect small area has likely resulted in small area counts and rates that are
227                                                higher or lower than they should be. Misclassification errors are more likely to occur
228                                                in rural areas of the state (where P.O. boxes and rural routes are more common), but may
229                                                have occurred in any of the 108 small areas.
230                                                For more information on the New Mexico Small Area Methodology,
231                                                please visit: -->
232                                </div>
233                        </div><br/>
235                <p align="right"><a href="#TOP">Back to Top</a></p>
236                <a id="part4"/>
237                        <br/>
238                        <h2>Population Estimates</h2><br/>
240                        Computation of death rates for a small area requires a count of deaths (numerator)
241                        and a population estimate (denominator) for each area and time period. The use of U.S.
242                        Census tract boundaries to define our small areas was based in part on the need for
243                        consistent geographies in the numerator and denominator. Census tract population estimates
244                        by year, age, sex and race for 2010 U.S. Census geographies for the years 1990 to 2010 were
245                        calculated by the Geospatial and Population Studies program at the University of New Mexico.
246                        (For more information on calculation of health event rates, please see the NM-IBIS page
247                        on <a href="resource/Rate.html">Health Event Rates</a>.)
248                        <br/><br/>
250                <a id="part5"/>
251                        <br/>
252                        <h1>New Mexico Department of Health Small Area Workgroup</h1><br/>
253                        The New Mexico Small Area Workgroup met from May of 2009 through November 2011 to design the New
254                        Mexico Small Areas and Small Area Methodology. <br/><br/>
256                        <div class="Indent">
257                                Will Athas - UNM, Family &amp; Community Medicine<br/>
258                                Alexis  Avery - DOH, PHD, Family Health Services Bureau<br/>
259                                Jack Baker - UNM, Bureau of Business and Economic Research<br/>
260                                Paige Best - DOH, ERD, Community Health Assessment Program<br/>
261                                David Broudy - DOH, Metro/Northwest Health Region<br/>
262                                Camille Clifford - DOH, Bureau of Vital Records and Health Statistics<br/>
263                                Kate Daniel - DOH, Northeast Health Region<br/>
264                                Janet Flores - DOH, Southwest Health Region<br/>
265                                Lois Haggard - DOH, ERD, Community Health Assessment Program<br/>
266                                Corazon Halasan - DOH, PHD, Diabetes Program<br/>
267                                Wayne Honey - DOH, ERD, Injury and Behavioral Epi Bureau, Survey Unit<br/>
268                                Heidi Krapfl - DOH, ERD, Environmental Epi Bureau<br/>
269                                Michael Landen - DOH, ERD<br/>
270                                Tracey Luna - DOH, Southeast Health Region<br/>
271                                Jerry Montoya - DOH, Metro/Northwest Health Region<br/>
272                                Larry Nielsen - DOH, Bureau of Vital Records and Health Statistics<br/>
273                                Srikanth Paladugu - Bernalillo County<br/>
274                                Jim Roeber - DOH, Injury and Behavioral Epi Bureau, Substance Use Epidemiology Section<br/>
275                                Tom Scharmen - DOH, Metro/Northwest Health Region<br/>
276                                Karen Scherzinger - UNM, Institute for Public Health<br/>
277                                Barbara Toth - DOH, ERD, Environmental Epi Bureau, EPHT Program<br/>
278                        </div>
280                <br/><br/>
281                <div>
282                <a id="REF"/>
283                <br/><p class="HRLeft"/>
284                <h2>References</h2>
285                <br/>   
287                <a name="Bib-1"></a>1. U.S. Census Population estimates downloaded from <a href="">
288      </a> on 10/27/2011.<br/><br/>
290                <a name="Bib-2"></a>2. Bernalillo County Community Health Council: Health Data.
291                Downloaded from <a href=""></a> 
292                on 11/1/2011.<br/><br/>
294                <a name="Bib-3"></a>3. The five demographic characteristics were selected based on analysis
295                performed by the Utah Department of Health suggesting that these characteristics were representative
296                of a larger set of demographic characteristics that were strongly associated with a variety of health
297                outcomes.<br/><br/>
299                <a name="Bib-4"></a>4. Area 9, Military bases, is spread across Bernalillo, Curry, Dona Ana, and Otero
300                Counties. Area 93 is a bow-tie-shaped area in Santa Fe County that has two almost contiguous parts.<br/><br/>
302                <a name="Bib-5"></a>5. Area 100, Santa Fe County, State Penitentiary, is more of a "carve-out" to improve
303                the representativeness of data for the surrounding area, 99 - Santa Fe County, South.<br/><br/>
305                <a name="Bib-6"></a>6. Scharmen, Thomas (2011) An Inventory of Address Variables in 18 Years of Birth
306                and Death Records. Presented at the October 5, 2011 meeting of the New Mexico Department of Health
307                Small Area Workgroup.<br/><br/>
308                </div>
310                <br/><br/><br/> 
311                <p align="right"><a href="#TOP">Back to Top</a></p>
312                <p align="center"><a href="resource/Glossary.html">--Back to Glossary/Index Page--</a></p>
315                <br/>   
316                <br/>
317                <ibis:include href="../../text/Suggestions.xml"/><br/><br/>
319                </CONTENT>
323Will Athas - UNM, Family & Community Medicine
324Alexis  Avery - DOH, PHD, Family Health Services Bureau
325Jack Baker - UNM, Bureau of Business and Economic Research
326Paige Best - DOH, ERD, Community Health Assessment Program
327David Broudy - DOH, Region 1,3
328Camille Clifford - DOH, Bureau of Vital Records and Health Statistics
329Kate Daniel - DOH, Region 2
330Janet Flores - DOH, Region 5
331Corazon Halasan - DOH, PHD, Diabetes Program
332Wayne Honey - DOH, ERD, Injury and Behavioral Epi Bureau, Survey Unit
333Heidi Krapfl - DOH, ERD, Environmental Epi Bureau
334Michael Landen - DOH, ERD
335Tracey Luna - DOH, Region 4
336Jerry Montoya - DOH, Region 1,3
337Larry Nielsen - DOH, Bureau of Vital Records and Health Statistics
338Srikanth Paladugu - Bernalillo County
339Jim Roeber - DOH, Injury and Behavioral Epi Bureau, Substance Use Epidemiology Section
340Tom Scharmen - DOH, Region 1,3
341Karen Scherzinger - UNM, Institute for Public Health
342Barbara Toth - DOH, ERD, Environmental Epi Bureau, EPHT Program
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