Abstract:
:We simulated multinomial AIDS incidence counts from 27 'representative' AIDS epidemics that spanned a period corresponding to previous applications of backcalculation (1 January 1977 to 1 July 1987) and assessed mean square error for several back-calculated estimators of HIV prevalence and short-term AIDS projections. Estimators were based on flexible model selection procedures that chose the best-fitting non-negatively constrained model of the infection curve from a family of possible step-function models. Selection of the best-fitting model from a family of four-step models each with a long last step of width of 4 or 4.5 years offered a favourable tradeoff between bias and variance when compared with selection from families of models with three steps or from families with a short last step. Five-step models performed as well as four-step models. Three-step models had substantially larger mean square error in some epidemic situations. Percentage root mean square error (PRMSE) for estimates of cumulative HIV prevalence as of 1 January 1985 was less than 14 per cent over a range of hypothetical epidemics of N = 50,000 infected individuals. PRMSE for short-term projections was less than 18 per cent. Estimates of cumulative HIV prevalence as of 1 July 1987 were substantially more uncertain and had a PRMSE of 33 per cent in the unfavourable case of a rapidly rising HIV epidemic. Estimates of cumulative HIV prevalence as of 1 July 1987 were positively biased in HIV epidemics with a rapidly decreasing recent HIV incidence rate and negatively biased in rapidly increasing HIV epidemics. Despite these uncertainties, we obtained useful estimates even for HIV epidemics with as few as 5000 infected individuals.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Rosenberg PS,Gail MH,Pee Ddoi
10.1002/sim.4780100802subject
Has Abstractpub_date
1991-08-01 00:00:00pages
1167-80issue
8eissn
0277-6715issn
1097-0258journal_volume
10pub_type
杂志文章abstract::The intraclass correlation coefficient rho plays a key role in the design of cluster randomized trials. Estimates of rho obtained from previous cluster trials and used to inform sample size calculation in planned trials may be imprecise due to the typically small numbers of clusters in such studies. It may be useful t...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1643
更新日期:2003-12-30 00:00:00
abstract::In clinical research, we are often interested in assessing how a biomarker changes with time, and whether it could be used as a surrogate marker when evaluating the efficacy of a new drug. However, when the longitudinal marker is correlated with survival, linear mixed models for longitudinal data may be inappropriate....
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3142
更新日期:2007-12-30 00:00:00
abstract::Age-period-cohort (APC) analysis is widely used in cancer epidemiology to model trends in cancer rates. We develop methods for comparative APC analysis of two independent cause-specific hazard rates assuming that an APC model holds for each one. We construct linear hypothesis tests to determine whether the two hazards...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3865
更新日期:2010-05-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4497
更新日期:2012-07-20 00:00:00
abstract::Two important qualities of controlled clinical trials are that they reduce dependence on historical standards for evaluating therapy and separate the effect of treatment from the confounding influence of time. Whatever the theory of the clinical trial, however, time has not easily been banished from the analysis of me...
journal_title:Statistics in medicine
pub_type: 杂志文章,评审
doi:10.1002/sim.4780081106
更新日期:1989-11-01 00:00:00
abstract::The sample size required for a cluster randomised trial is inflated compared with an individually randomised trial because outcomes of participants from the same cluster are correlated. Sample size calculations for longitudinal cluster randomised trials (including stepped wedge trials) need to take account of at least...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7028
更新日期:2016-11-20 00:00:00
abstract::A problem occurring in chronic disease modeling is the estimation of transition probabilities of moving from one state of a categorical risk factor to another. Transitions could be obtained from a cohort study, but often such data may not be available. However, under the assumption that transitions remain stable over ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4423
更新日期:2012-03-15 00:00:00
abstract::To compare the survival functions based on right-truncated data, Lagakos et al. proposed a weighted logrank test based on a reverse time scale. This is in contrast to Bilker and Wang, who suggested a semi-parametric version of the Mann-Whitney test by assuming that the distribution of truncation times is known or can ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2556
更新日期:2007-02-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7993
更新日期:2019-03-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2555
更新日期:2007-02-10 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780050610
更新日期:1986-11-01 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5647
更新日期:2013-06-30 00:00:00
abstract::We consider counting process methods for analysing time-to-event data with multiple or recurrent outcomes, using the models developed by Anderson and Gill, Wei, Lin and Weissfeld and Prentice, Williams and Peterson. We compare the methods, and show how to implement them using popular statistical software programs. By ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19970930)16:18<2029::aid-s
更新日期:1997-09-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5359
更新日期:2012-12-10 00:00:00
abstract::Piecewise constant incidence models were developed to estimate the force of infection in women from age- and time-specific antenatal or neonatal seroprevalence data. Differential inclusion of infected women in sero-surveys compared to uninfected women was taken into account, with respect to both changes in inclusion r...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780131809
更新日期:1994-09-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3510
更新日期:2009-03-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5317
更新日期:2012-08-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2607
更新日期:2007-03-30 00:00:00
abstract::We examine the properties of several tests for goodness-of-fit for multinomial logistic regression. One test is based on a strategy of sorting the observations according to the complement of the estimated probability for the reference outcome category and then grouping the subjects into g equal-sized groups. A g x c c...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3202
更新日期:2008-09-20 00:00:00
abstract::I derive the locally most powerful rank tests for acceleration against semi-parametric alternatives when some patients are cured of the disease. I consider some particular classes of alternatives and present simulation results to verify the validity of the proposed tests. Real data from clinical trials for childhood l...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141905
更新日期:1995-10-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/(sici)1097-0258(19981030)17:20<2313::aid-s
更新日期:1998-10-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6478
更新日期:2015-07-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/1097-0258(20000830)19:16<2195::aid-sim522>
更新日期:2000-08-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1135
更新日期:2001-12-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8804
更新日期:2021-02-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7970
更新日期:2019-02-10 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4204
更新日期:2011-06-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3474
更新日期:2009-01-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4297
更新日期:2011-09-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780091216
更新日期:1990-12-01 00:00:00