Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Subject allocation and study curtailment for fixed event comparative Poisson trials.

Donald R Hoover1

  • 1Department of Statistics, Rutgers University, 473 Hill Center, 110 Frelinghuysen Road, Piscataway, NJ 08854-8019, U.S.A. drhoover@stat.rutgers.edu

Statistics in Medicine
|April 15, 2004
PubMed
Summary

Comparative Poisson trials for vaccines can be shortened. Altering treatment allocation (k) and early stopping (curtailed stopping) can reduce disease cases and follow-up time (N(u+t)). Equal allocation (k=0.5) with curtailed stopping is often optimal.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Genital Inflammatory Responses in Women Living with HIV Randomized to Copper or Levonorgestrel Intrauterine Contraceptives: A secondary analysis of a randomized trial.

medRxiv : the preprint server for health sciences·2026
Same author

Serum Biomarkers of Macrophage Activation and Incident CKD in People With and Without HIV: Findings From the MACS-WIHS Combined Cohort Study.

Open forum infectious diseases·2026
Same author

HIV disease progression following WHO treat all guideline adoption among people enrolled in HIV care in Central Africa: A multistate analysis.

Annals of epidemiology·2026
Same author

Feasibility, acceptability, and preliminary efficacy protocol of an intervention for caregivers of hospice patients living with dementia: A pilot randomized control trial.

PloS one·2025
Same author

Antiretroviral-specific associations between bone hormonal changes and treatment induced weight gain.

AIDS (London, England)·2025
Same author

Poor Sleep Quality is Associated With Frailty Among Women With and Without HIV.

Journal of acquired immune deficiency syndromes (1999)·2025

Area of Science:

  • Biostatistics
  • Clinical Trial Design
  • Epidemiology

Background:

  • Comparative Poisson trials, often used for prophylactic interventions like vaccines, are typically lengthy and expensive.
  • Reducing the number of disease cases and person-years of follow-up (N(u+t)) is crucial for efficiency.
  • Existing methods for optimizing trial design need further evaluation for practical implementation.

Purpose of the Study:

  • To evaluate two easily implemented approaches for reducing N(u+t) in comparative Poisson trials with a fixed number of cases (T).
  • To assess the impact of altering the allocation proportion (k) of person-years to treatment.
  • To examine the benefits of curtailed stopping before reaching T cases.

Main Methods:

  • Evaluated normal and arcsine approximations, alongside discrete exact tests.

Related Experiment Videos

  • Assessed strategies including altering the allocation proportion (k) and implementing curtailed stopping rules.
  • Analyzed scenarios with one-sided alpha (0.005–0.025), beta (0.1–0.2), and alternative hypothesized relative incidence (r(a) = 0.2–0.5).

    • Main Results:

    • For studies not stopped early, allocating approximately 1/(1+sqrt(r_a)) person-years to treatment minimizes T, moderately reducing cases compared to equal allocation (k=0.5).
    • However, k=0.5 may be optimal for minimizing N(u+t) without early stopping.
    • Curtailed stopping reduced disease cases and N(u+t) by 6-40% for exact tests, with k=0.5 or k=0.6 performing well.

    Conclusions:

    • Curtailed stopping is an effective strategy to reduce trial duration and case numbers in comparative Poisson trials.
    • Equal allocation (k=0.5) with curtailed stopping generally minimizes person-years of follow-up and cases.
    • Careful selection of k is important, as deviations can lead to underpowered studies, especially with exact tests.