| Course | DPH 810 Advanced Epidemiology in Public Health |
|---|---|
| Module | Module 2 |
| Paper type | Documented literature search |
| Length | About 1,055 words, 6 pages |
| Format | APA 7 student paper |
| School | Aspen University |
| Program | Doctor of Public Health |
| Updated | September 2026 |
Free sample paper for DPH 810 Module 2
Mapping What Is Known: A Documented Literature Search on Food Environments and Diabetes Incidence
Student Name
Doctor of Public Health Program, Aspen University
DPH 810: Advanced Epidemiology in Public Health
Instructor Name
Month Day, Year
Mapping What Is Known: A Documented Literature Search on Food Environments and Diabetes Incidence
A doctoral study must build on what is already known and show where knowledge is thin. A documented literature search records every step so others can judge its completeness and repeat it. What follows is the record of the search behind a study asking if food swamp residence adds to new type 2 diabetes cases.
Search Question
The search question followed the PECO structure: in adults, is residence in neighborhoods with high concentrations of fast-food and convenience outlets, compared with healthier food environments, associated with incident type 2 diabetes? Structured frameworks such as PICO and its variants help translate questions into search concepts, and comparison studies suggest they retrieve relevant studies more completely than some alternatives (Methley et al., 2014).
Concepts and Terms
The search combined three concepts. Food environment: food swamp, food desert, fast food, convenience store, retail food environment, food outlet density, neighborhood food. Outcome: type 2 diabetes, incident diabetes, diabetes incidence, glycemic control. Design: cohort, longitudinal, prospective. Subject headings included Residence Characteristics, Fast Foods and Diabetes Mellitus, Type 2.
Sources
PubMed and a second bibliographic database were searched from 2000 to the present, supplemented by reference lists of key studies and reviews, government reports on food environments and dissertations. Gray literature was included because food environment research is often published by public health agencies and policy institutes. A health sciences librarian reviewed the strategy before the final search.
Inclusion and Exclusion Criteria
Included studies measured a neighborhood food environment exposure, assessed type 2 diabetes incidence or prevalence in adults and used cohort, case-control or cross-sectional designs with comparison groups. Excluded were studies of children only, studies measuring only individual diet and commentaries without data.
Flow of Records
The table summarizes the flow, following reporting conventions for systematic searches (Page et al., 2021).
| Stage | Records |
|---|---|
| Identified through databases | 580 |
| Identified through other sources | 32 |
| After duplicates removed | 498 |
| Screened by title and abstract | 498 |
| Excluded at screening | 421 |
| Full texts assessed | 77 |
| Excluded at full text | 53 |
| Included in evidence table | 24 |
Key Studies
Several studies anchor the evidence. Among participants in the Multi-Ethnic Study of Atherosclerosis, living with stronger local supports for healthy eating and exercise was tied to 38% lower diabetes incidence over a median five years (Auchincloss et al., 2009). In a nationwide Swedish cohort, people whose neighborhoods gained unhealthy food outlets, or who moved into such areas, were more likely to develop diabetes (Mezuk et al., 2016). A county-level analysis found food swamps predicted obesity rates more strongly than food deserts (Cooksey-Stowers et al., 2017).
Appraisal Notes
Most included studies were cross-sectional, limiting causal inference. Cohort studies were fewer, and measures of the food environment varied, from counts within buffers to ratios and store audits. Few studies addressed residential self-selection, the tendency for people with certain health behaviors to choose certain neighborhoods.
Gaps
Gaps include few US cohort studies using food swamp ratios rather than grocery access alone, limited data from mixed urban and rural counties, inconsistent handling of confounding by individual income and scarce evidence on changes in food environments over time. The proposed study addresses the first two directly. These gaps also suggest questions for future studies beyond the doctoral project.
Managing Records
Citations were managed in reference software, duplicates removed automatically and checked manually, and screening decisions logged with reasons for exclusion. The search log records dates, databases, strings and result counts, and will be updated before the dissertation proposal.
Search Strings
The PubMed string combined the food environment terms joined by OR, the diabetes terms joined by OR and the design terms joined by OR, with the three groups joined by AND and limited to humans and adults. The second database used equivalent terms adapted to its vocabulary.
Limitations of the Search
Limiting the search to English and two databases may have missed some studies. Food environment terminology varies widely, and some relevant studies may use unexpected terms. Checking reference lists of reviews reduced this risk.
Search Strategy Refinement
The first search returned many studies of food deserts alone. Adding terms for fast food and convenience stores, and testing whether known key studies were retrieved, improved relevance. The final strategy found all four studies the author already knew, a simple check of sensitivity.
Themes in the Evidence
Three themes emerged: unhealthy food outlet density appears to matter more than distance to supermarkets; associations are stronger in lower-income areas; and study designs and exposure definitions vary so widely that comparing results is difficult. These themes shape the proposed study's focus on food swamp ratios and effect modification by income.
Evidence Table Structure
The evidence table records for each study the setting, design, sample size, exposure measure, outcome, confounders adjusted and main result. Organizing studies this way makes differences in methods visible and supports appraisal.
Using the Search in Later Modules
The search informs the choice of exposure definition, the list of confounders, the study design and the discussion of limitations. It will be updated before the proposal defense to capture new studies.
Quality Appraisal Approach
Each included study was appraised for design, exposure measurement, outcome definition, confounder adjustment and handling of residential mobility. A simple rating of strong, moderate or weak for each domain helped weigh evidence and identify recurring weaknesses the proposed study can avoid.
Reporting the Search in the Proposal
The dissertation proposal will include a flow diagram of records, the full PubMed string in an appendix and an evidence table summarizing included studies. Reviewers can then judge whether the search was thorough and whether the proposed study truly fills a gap.
Keeping the Search Current
Alerts in both databases will flag new studies matching the search terms each month, so the literature review remains current through the proposal defense and final dissertation.
Implications for Design
The dominance of cross-sectional studies argues for a longitudinal design. Variation in exposure measures argues for testing more than one definition. Weak handling of self-selection argues for sensitivity analyses among long-term residents.
Conclusion
The documented search identified 24 studies, most showing that less healthy food environments are associated with more diabetes or obesity, but with few US cohort studies using food swamp measures and inconsistent control of confounding. These gaps justify a cohort study in the composite county and inform the design choices ahead.
References
Auchincloss, A. H., Diez Roux, A. V., Mujahid, M. S., Shen, M., Bertoni, A. G., & Carnethon, M. R. (2009). Neighborhood resources for physical activity and healthy foods and incidence of type 2 diabetes mellitus: The Multi-Ethnic Study of Atherosclerosis. Archives of Internal Medicine, 169(18), 1698-1704. https://doi.org/10.1001/archinternmed.2009.302
Cooksey-Stowers, K., Schwartz, M. B., & Brownell, K. D. (2017). Food swamps predict obesity rates better than food deserts in the United States. International Journal of Environmental Research and Public Health, 14(11), Article 1366. https://doi.org/10.3390/ijerph14111366
Methley, A. M., Campbell, S., Chew-Graham, C., McNally, R., & Cheraghi-Sohi, S. (2014). PICO, PICOS and SPIDER: A comparison study of specificity and sensitivity in three search tools for qualitative systematic reviews. BMC Health Services Research, 14, Article 579. https://doi.org/10.1186/s12913-014-0579-0
Mezuk, B., Li, X., Cederin, K., Rice, K., Sundquist, J., & Sundquist, K. (2016). Beyond access: Characteristics of the food environment and risk of diabetes. American Journal of Epidemiology, 183(12), 1129-1137. https://doi.org/10.1093/aje/kwv318
Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., Brennan, S. E., Chou, R., Glanville, J., Grimshaw, J. M., Hróbjartsson, A., Lalu, M. M., Li, T., Loder, E. W., Mayo-Wilson, E., McDonald, S., ... Moher, D. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, Article n71. https://doi.org/10.1136/bmj.n71
Reading the DPH 810 Module 2 assignment instructions
The catalog entry for DPH 810 names the literature search among the steps toward the doctoral project, and because Aspen reserves the second module's wording for enrolled students, this example documents one in full. Documented search assignments generally ask for the question, concepts, terms, databases, criteria, results at each stage and an evidence summary. Record everything as you go. Test your strategy by checking that known key studies appear. Include gray literature where relevant. Report numbers at each screening stage. Summarize included studies in a table. Close by naming the gaps your study will fill. Keep a log of every change to your strings with the date, since instructors often ask why the final search differs from the first. Explain how you handled duplicates between databases.
How the DPH 810 Module 2 example is put together
About 1,050 words appear under eighteen headings, with a two-column table showing the flow of records through each stage. The paper states the search question and concepts, sources and criteria, then presents the flow table, key studies, appraisal notes, gaps, record management, search strings and limitations. Strategy refinement, themes, evidence table structure, use in later modules, quality appraisal, reporting in the proposal, keeping current and design implications follow. A side comment explains that framing the question first shows where each search concept comes from. The conclusion links gaps to the proposed study. The search strings appear in a compact block so a reader can paste them straight into a database. A later heading explains how the evidence table columns were chosen to feed the design and measures papers in the modules that follow, and the paper states the date the search was last run.
Where the marks sit in the DPH 810 Module 2 rubric
Literature search papers are assessed on a reproducible strategy, appropriate sources, clear criteria, transparent reporting of numbers and a thoughtful synthesis of gaps. This paper cites a comparison of question frameworks, the PRISMA 2020 statement and the key food environment studies in APA format. The flow table follows reporting conventions. Appraisal notes show critical reading. Design implications show how the search shapes the study. Doctoral graders reward searches that others could repeat exactly. Instructors check that the numbers in the flow table add up from one stage to the next, so every excluded record is counted with a reason. The appraisal section weighs design strength rather than simply listing findings, and the gray literature sources are named rather than described vaguely.
DPH 810 Module 2 help: mistakes that cost marks
Students often describe searches in general terms without strings, dates or counts, which makes them impossible to repeat. Others include only studies that support their hypothesis. Save your exact strings. Report counts at each stage. Include contrary findings. Explain exclusions. If you need help with database syntax, a tutor can build and test a search with you. End with the three gaps that most justify your study. If your search returns thousands of records, the concept groups are probably too loose; add a subject heading or narrow the outcome term. If it returns very few, drop the least essential concept. A useful test is whether the three studies you already know appear in the results. Plan to rerun the search before your proposal defense.
Write yours, or have the desk draft it
This paper is an original model document written by our desk, not a submitted student paper and not an official Aspen University document. Read it for the moves, then write your own to the instructions in your classroom. If you want one built to your exact prompt and rubric, the first custom sample is free and arrives in 24 to 48 hours.
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DPH 810 Module 2 questions, answered
What does DPH 810 Module 2 usually ask for?
Aspen's DPH 810 includes a literature search toward the doctoral project, so a documented search is a typical assignment. Check your classroom prompt.
What makes a literature search documented?
Recording databases, dates, full search strings, criteria, counts at each stage and reasons for exclusion so others can repeat it.
Why include gray literature?
Government reports, dissertations and agency evaluations often contain relevant evidence not published in journals.
Where can I find a free DPH 810 Module 2 sample paper?
This page holds the documented literature search, including a table tracing records from identification to inclusion.
What goes into a documented literature search in DPH 810 Module 2?
The question and concepts, search terms and strings, sources, inclusion criteria, counts at each stage, an evidence table and the gaps identified.