PU525 Unit 10 Rabies Vaccine Completion Report Example

Four Shots Over Two Weeks, and Who Finishes Them: A Biostatistics Report on How Many People Starting Rabies Post-Exposure Vaccination in a Composite County Completed the Series, Whether Distance From the Clinic Made a Difference and How Confident the County Can Be

[Student Name]

Purdue University Global

PU525: Biostatistics for Public Health

Unit 10 Biostatistics Report

[Instructor Name]

[Date]

The county, its records and every figure are composite and bracketed for the writer's own data; the guidance and research cited are real.

Plain-Language Summary

About [8] in [10] people who started rabies shots after a bite finished all four. People living within [10] miles of the health department clinic finished about [87] times in [100]; people living farther away finished about [73] times in [100]. A gap that large would rarely appear by chance alone. Offering the later shots closer to home, and reminding people of their appointments, could close most of the gap.

The Question

Once rabies causes symptoms, survival is extremely rare, while vaccination after exposure works very well if every dose is given. In the United States, about [55,000] people a year seek post-exposure prophylaxis (Pieracci et al., 2019). For people with normal immune systems, national guidance recommends rabies immune globulin and a first vaccine dose on day [0], followed by vaccine on days [3], [7] and [14] (Rupprecht et al., 2010). The county asked how often people finish the series and whether distance from the clinic matters.

Data

Source: the health department's post-exposure prophylaxis log for [three] years, linked to the state immunization registry to find doses given elsewhere. Included: [612] people who received a day-0 dose. Excluded: [19] people for whom the animal was later found not to have rabies and the series was stopped on medical advice, since stopping was correct. Completion: receipt of the day-[14] dose within [7] days of its due date. Distance: road distance from home address to the clinic, grouped as within [10] miles or farther. Candor about the data: some doses given out of state may be missing from the registry, which would understate completion.

Findings

Overall completion: [496] of [612], [81.0] percent. Within [10] miles: [300] of [345], [87.0] percent. Farther than [10] miles: [196] of [267], [73.4] percent. Difference: [13.5] percentage points, 95 percent confidence interval [7.2] to [19.9]. A chi-square test of completion by distance group gives about [18.0] with one degree of freedom, P below [0.001]. Distance cost about one in seven people living far from the clinic their full series. Most missed doses were the day-[7] or day-[14] dose; [61] of [116] people who did not complete received three of the four.

Who Started the Series

Of the [612] people, [58] percent were bitten by dogs or cats whose owners could not be found or whose animals could not be observed, [27] percent had contact with bats, often a bat found in a bedroom, and [15] percent were bitten by wild animals such as raccoons or foxes. Ages ranged from [2] to [88]; [22] percent were children. Exposure type mattered less than expected: completion was similar for dog, cat and bat exposures, which suggests that the barrier lies in reaching the clinic rather than in how seriously people took the exposure.

What People Said About Missed Doses

Nurses called [64] of the [116] people who did not complete the series. The most common reasons were no transportation, inability to take time off work, a belief that the first dose was enough, and confusion about appointment dates. Several people living far away said a second trip in four days was impossible without a car. These reasons point to practical solutions rather than education alone.

Why Incomplete Series Matter

A person who receives rabies immune globulin and fewer than four vaccine doses may have incomplete protection, and the county cannot know who is protected. Each course also costs several thousand dollars, much of it in the immune globulin given on day [0]; an incomplete course spends most of that money without assuring the benefit.

Equity

The farther group includes most of the county's rural residents and a higher share of uninsured people. A gap in completion by distance is therefore also a gap by place and income, which the recommended changes would narrow.

Is Distance the Explanation?

People living farther away might differ in other ways, such as age or insurance. A logistic regression adjusting for age group, insurance type and exposure type gave an odds ratio for completion among those living within [10] miles of [2.2], 95 percent confidence interval [1.4] to [3.4]. The association persisted after adjustment, supporting distance as a real barrier, though unmeasured factors, such as access to a car, may also play a part (Rosner, 2016).

How Confident Can the County Be?

The confidence interval for the difference is well away from zero, and the adjusted analysis points in the same direction. The main uncertainty is not chance but measurement: doses given outside the state are not captured, and they are more likely among people who travel. If anything, completion is slightly higher than reported in both groups.

How the Analysis Was Done

Completion was calculated as a simple proportion with its confidence interval. The difference between distance groups was tested with a chi-square test, and the gap between the two completion percentages was given its own interval. The adjusted analysis used logistic regression with completion as the outcome and distance group, age group, insurance type and exposure type as predictors, chosen before the analysis began. Software output and the code are kept with the report so another analyst can reproduce every figure.

Questions Residents Asked at the Board Meeting

Residents asked whether a pharmacy could give the later shots, whether the county would pay for travel and whether missing one shot meant starting over. The answers, given by the medical director, were that pharmacies can give the later doses under a standing order, that vouchers are proposed in this report, and that a late dose should be given as soon as possible without restarting the series, following clinical guidance.

What the County Could Do

Offer day-[3], [7] and [14] doses at the county's two satellite clinics and at participating pharmacies; send text reminders the day before each dose; provide transportation vouchers for people without a car; and schedule all four appointments at the first visit, handing a card with the dates.

Monitoring

Track completion monthly by distance group, with a target of [90] percent in both groups within a year.

Limits

The analysis covers one county and three years. Completion was defined by the timing window in the guidance; a stricter or looser window would change the figures slightly.

Conclusion

Most people finish their rabies shots, but distance from the clinic makes a measurable difference. Bringing the later doses closer to home is the clearest step.

References

Pieracci, E. G., Pearson, C. M., Wallace, R. M., Blanton, J. D., Whitehouse, E. R., Ma, X., Stauffer, K., Chipman, R. B., & Olson, V. (2019). Vital signs: Trends in human rabies deaths and exposures, United States, 1938-2018. MMWR Morbidity and Mortality Weekly Report, 68(23), 524-528. https://doi.org/10.15585/mmwr.mm6823e1

Rosner, B. (2016). Fundamentals of biostatistics (8th ed.). Cengage Learning.

Rupprecht, C. E., Briggs, D., Brown, C. M., Franka, R., Katz, S. L., Kerr, H. D., Lett, S. M., Levis, R., Meltzer, M. I., Schaffner, W., & Cieslak, P. R. (2010). Use of a reduced (4-dose) vaccine schedule for postexposure prophylaxis to prevent human rabies: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recommendations and Reports, 59(RR-2), 1-9.