| Course | HLTH 4200 Principles of Epidemiology |
|---|---|
| Week | Week 6 |
| Paper type | Study design comparison |
| Length | About 1,120 words, 7 pages |
| Format | APA 7 student paper |
| School | Walden University |
| Program | BS in Public Health |
| Updated | October 2026 |
Free sample paper for HLTH 4200 Week 6
Night Shifts and Injury at the Eastgate Regional Distribution Warehouse: The Same Question Sketched as a Cohort, a Case-Control and a One-Day Cross-Sectional Study, Each Judged on Claim, Cost and Fit
Student Name
Walden University
HLTH 4200: Principles of Epidemiology
Instructor Name
Month Day, Year
Night Shifts and Injury at the Eastgate Regional Distribution Warehouse: The Same Question Sketched as a Cohort, a Case-Control and a One-Day Cross-Sectional Study, Each Judged on Claim, Cost and Fit
The Question and the Site
The question is whether working night shifts increases the risk of workplace injury among employees at the Eastgate Regional Distribution Warehouse, a composite facility with about 1,400 workers across three shifts: day (6 a.m. to 2 p.m.), evening (2 p.m. to 10 p.m.) and night (10 p.m. to 6 a.m.). Workers pick, pack and load goods, using forklifts, conveyors and ladders. The warehouse's safety office records every injury reported to supervisors, with date, time, shift and type, and its human resources system records each worker's shift assignment by week. Those two records, and the fact that about one-fifth of workers change shifts each quarter, decide which designs are practical.
Research on working hours gives reason to ask. In a national U.S. cohort, jobs with overtime schedules were associated with a 61% higher injury hazard rate than jobs without overtime, and working at least 12 hours a day was associated with a 37% higher hazard rate (Dembe et al., 2005). Night work was not the exposure in that study, but fatigue is a shared pathway.
Design 1: A Cohort Study
Sketch
All 1,400 workers would be followed for 12 months using the shift and injury records. Each worker's time would be classified week by week as day, evening or night shift, and injuries would be counted in each. The outcome would be the injury rate per 100 full-time worker-years on night shifts compared with day shifts.
What It Could Claim
A cohort study measures exposure before the outcome and can estimate incidence and relative risk directly (Grimes & Schulz, 2002b). Because the warehouse already records shift by week, exposure can be assigned to the time when each injury occurred, so the study could say whether injuries were more frequent per hour worked at night. With adjustment for job type, age and experience, it could support a claim that night work is associated with a higher injury rate at this warehouse.
What It Would Cost
Because the records already exist, the main cost is analysis time: linking the shift file to the injury file and checking both. A prospective version with new data collection would cost more, but it is not needed here.
What Makes It Practical
The existing weekly shift records are the deciding fact. Workers who change shifts contribute time to more than one exposure group, which is handled naturally by counting person-time. The main limit is the number of injuries: if the warehouse records 60 injuries in a year, estimates by shift will have wide uncertainty.
Design 2: A Case-Control Study
Sketch
Cases would be workers injured during the past two years; controls would be workers who were not injured, sampled from those on the roster during the same weeks. Investigators would compare the proportion of cases and controls who were working a night shift at the time of injury, or, for controls, in the matched week.
What It Could Claim
A case-control study estimates an odds ratio for exposure among cases versus controls (Schulz & Grimes, 2002). If injuries are uncommon, the odds ratio approximates the relative risk. It could support a claim of association similar to the cohort study's, and it could collect more detail on each case, such as hours slept before the shift, through interviews.
What It Would Cost
It would cost less than a new prospective cohort if interviews were needed, because only cases and a sample of controls would be interviewed. But at Eastgate the cohort study already costs little, because the records exist.
What Makes It Practical or Not
The case-control design is most useful when an outcome is rare and full follow-up is expensive. Neither is true here: injuries are not rare enough to require it, and the full cohort is already recorded. Its added value would be interviews on fatigue and sleep, which records do not hold, but those interviews would be subject to recall bias, since injured workers might remember tiredness differently from uninjured ones.
Design 3: A One-Day Cross-Sectional Study
Sketch
On one day, every worker present would complete a short survey asking their current shift and whether they had been injured at work in the past 12 months.
What It Could Claim
In a cross-sectional study, exposure and outcome are captured in one snapshot, which suits estimates of prevalence (Grimes & Schulz, 2002a). It could report the share of current night workers and day workers who recall an injury in the past year. It could not establish whether the injury happened while the worker was on nights, because the current shift may differ from the shift at the time of injury.
What It Would Cost
It would be the cheapest design: one day, one questionnaire.
What Makes It Impractical
The fact that one-fifth of workers change shifts each quarter undermines this design. A worker injured on a night shift six months ago and now on days would be counted as a day worker with an injury. Workers seriously injured may have left the warehouse and would not be surveyed at all. The survey would also miss workers absent that day, who may include night workers sleeping after a shift.
Comparison
Table 1
Three Designs for the Same Question at Eastgate
| Design | Can claim | Cost at Eastgate | Fit with the warehouse's facts | |
|---|---|---|---|
| Cohort (from records) | Injury rate by shift; relative risk | Low, using existing records | Strong: weekly shift records allow exposure at the time of injury | |
| Case-control | Odds ratio; interview detail on fatigue | Moderate if interviews are added | Weak: outcome not rare enough to need it; recall bias in interviews | |
| One-day cross-sectional | Prevalence of recalled injury by current shift | Lowest | Poor: shift changes and departures misclassify exposure | |
The warehouse's existing weekly shift and injury records make the cohort design both the strongest and among the cheapest.
Recommendation
The cohort design, built from existing records, should be used. It can assign shift at the time of each injury, estimate rates and relative risk and adjust for job type and experience. If the safety office wants to understand why night injuries occur, a small case-control study with interviews could follow, with its recall bias acknowledged.
Conclusion
The same question about night shifts and injury yields three different studies. At Eastgate, the deciding facts are that shift assignment is already recorded weekly and that many workers change shifts. Those facts make a cohort study from records strong and inexpensive, make a case-control study unnecessary except for added detail and make a one-day survey unable to link injury to the shift on which it happened.
References
Dembe, A. E., Erickson, J. B., Delbos, R. G., & Banks, S. M. (2005). The impact of overtime and long work hours on occupational injuries and illnesses: New evidence from the United States. Occupational and Environmental Medicine, 62(9), 588-597. https://doi.org/10.1136/oem.2004.016667
Grimes, D. A., & Schulz, K. F. (2002a). An overview of clinical research: The lay of the land. The Lancet, 359(9300), 57-61. https://doi.org/10.1016/S0140-6736(02)07283-5
Grimes, D. A., & Schulz, K. F. (2002b). Cohort studies: Marching towards outcomes. The Lancet, 359(9303), 341-345. https://doi.org/10.1016/S0140-6736(02)07500-1
Schulz, K. F., & Grimes, D. A. (2002). Case-control studies: Research in reverse. The Lancet, 359(9304), 431-434. https://doi.org/10.1016/S0140-6736(02)07605-5
The Walden HLTH 4200 Week 6 instructions
Study design comparisons ask you to apply several designs to one question and judge them against each other. State the question and describe the setting in enough detail to show which designs are feasible, including what records exist. For each design, sketch how the study would run, what it could claim, what it would cost and which feature of the setting helps or hinders it. Use a methods reading to support claims about what each design can establish. A comparison table helps. Conclude with a recommendation tied to the setting's specific facts, not to a general ranking of designs. Make sure the same question runs through every sketch, so differences in your judgments come from the designs rather than from a shifting question.
How the HLTH 4200 Week 6 example is put together
The sample opens with the question, the warehouse and the records it keeps, with Dembe and colleagues' findings as background. Three sections each sketch a design: a records-based cohort, citing Grimes and Schulz on what cohorts can estimate; a case-control version, drawing on Schulz and Grimes for odds ratios and recall; and a one-day cross-sectional survey, citing the Grimes and Schulz overview on what cross-sectional data show. Each section covers claim, cost and fit. Table 1 compares the designs, a recommendation favors the records-based cohort with an optional interview study and a conclusion links the choice to the warehouse's facts.
HLTH 4200 Week 6 rubric: what earns full marks
Faculty evaluate a design comparison on whether each design is applied concretely to the same question. Accurate statements about what each design can establish earn credit. Discussing cost and feasibility in terms of the specific setting is expected. Faculty value comparisons that identify the single fact that makes a design strong or weak in this setting, such as existing records or workers who change shifts. A clear comparison table and a recommendation tied to those facts are rewarded. Comparisons that rank designs in general terms, without reference to the setting, or that misstate what a design can show, earn less. Accurate citation of methods sources is checked.
HLTH 4200 Week 6 help from the desk
Start with your setting, not with the designs. List what records already exist, how people move between exposure groups and how common the outcome is. Then sketch each design briefly and ask three questions of it: what could it claim, what would it cost here and what about this setting helps or hurts it? Write your answers in a table before writing paragraphs. Find a methods reading that explains each design's strengths. Our writers can draft a sample comparison for a question and setting you have been given. When you finish, cover your recommendation and see whether a reader could predict it from your table alone; if not, the table needs sharper entries.
Get a HLTH 4200 Week 6 example written to your instructions
Share the research question from your Week 6 prompt, and the rubric; if a setting or dataset comes with it, include that too. Each design is sketched for your question, rated on the same criteria and weighed against the records actually available. The first sample is on the house, delivered in 24-48 hours.
More HLTH 4200 papers and BS in Public Health samples
- HLTH 4200 Week 1: Case Definition
- HLTH 4200 Week 2: Surveillance Note
- HLTH 4200 Week 3: Rate Calculation
- HLTH 4200 Week 4: Denominator Audit
- HLTH 4200 Week 5: Two-by-Two Table
- HLTH 4200 Week 7: Confounding Write-Up
- HLTH 4200 Week 8: Screening Accuracy Write-Up
- HLTH 4200 Week 9: Outbreak Narrative
- HLTH 4200 Week 10: Causal Criteria Essay
- HLTH 4200 Week 11: Applied Epidemiology Paper
- HLTH 3115 Week 6: Midterm Discussion Post
- HLTH 2500 Week 6: Midterm Discussion Post
- HLTH 2110 Week 6: Midterm Discussion Post
- HLTH 1000 Week 6: Midterm Discussion Post
HLTH 4200 Week 6 questions, answered
Where can I find a free HLTH 4200 Week 6 sample paper?
The comparison of three study designs for night shifts and warehouse injury, with its table and references, is free to read here.
Which designs does the HLTH 4200 Week 6 example compare?
A cohort from existing records, a case-control study and a one-day cross-sectional survey.
Why is the records-based cohort recommended?
The warehouse already records shift by week and every injury, so rates by shift can be estimated cheaply with exposure assigned at the time of injury.
What weakens the case-control design here?
Injuries are not rare enough to require it, and interviews about fatigue would be subject to recall bias.
Why does the cross-sectional survey fail?
Workers change shifts often and injured workers may have left, so current shift does not reflect the shift at the time of injury.