|Dec 3rd||9:30-10:15 in room 4.39||| Simon Bang Kristensen |
| PhD Fellow, Section of Biostatistics, Aarhus University |
Bivariate logistic mixed effect regression models based on latent variables
|ABSTRACT: Bivariate observations of binary and ordinal data arise frequently in clinical trials and the cognitive sciences. Consider for example an efficacy-toxicity study for some drug, in which efficacy is binary and toxicity is measured as side-effects on an ordinal scale. While robust methods offer the possibility to evaluate drug effects taking into account the correlation between efficacy and toxicity, a bivariate modelling approach is required in scenarios where one is interested in aspects of the marginal distributions in themselves along with the association between the two. For example, we may be interested in efficacy and toxicity as separate outcomes but also wish to estimate the probability of benefiting from a positive treatment outcome while not experiencing a high degree of side-effects as a function of dosage.
We consider methods for constructing such bivariate models with logistic marginals and propose a model based on the Ali-Mikhail-Haq bivariate logistic distribution. We motivate the model as an extension of that based on the Gumbel type 2 distribution as considered by other authors and as a bivariate extension of the logistic distribution which preserves certain natural characteristics.
Basic properties of the obtained model are studied and the proposed method is exemplified by analysis of a cognitive experiment of visual recognition and awareness.
|Oct 11th||11:00-12:00 in room 4.39||| Dr Mauro Laudicella |
| DaCHE, SDU |
20 Years of Falling Hospital Rates: What Impacts Can We Expect?
|ABSTRACT: In the past twenty years, hospital mortality rates have fallen dramatically in many high-income countries due to constant improvements in hospital quality of care and investments in new technologies. I will present two key studies investigating the impact of the decline in hospital mortality rates on the demand for unplanned acute care in England; I will then discuss their implications for the Danish Health System and the scope for further investigations. In the first study, I examined the impact of reducing hospital mortality rates on hospital readmissions occurring after 30 days from first admission.
The study found evidence of a negative relationship between hospital performance in mortality and readmissions: hospital that were more successful in reducing their mortality rates experienced greater readmissions rates due to a larger share of frail patients surviving the first admission and thus at risk of being readmitted as compared to other hospitals. In the second study, I examined the impact of reducing hospital mortality rates nation wide and over a ten-years time period on the number of emergency admissions experienced by patients one year after the first admission.
The study found evidence that one third of the growth in the demand for emergency admissions can be explained by the increasing number of patients surviving their first admission overtime, but increasingly frail and at risk of being readmitted to the hospital within one year.
1. Laudicella, M., P. Li Donni, and P.C. Smith, Hospital readmission rates: signal of failure or success? J Health Econ, 2013. 32(5): p. 909-21.
2. Laudicella, M., et al., Do Reduced Hospital Mortality Rates Lead to Increased Utilization of Inpatient Emergency Care? A Population-Based Cohort Study. Health Serv Res, 2018. 53(4): p. 2324-2345.
|June 6th||10:00-12:00 in room 4.39||
Research on tattoos and risk of cancer| Dr Milena Foerster |
| The International Agency for Research on Cancer, Lyon, France |
| Dr Jørgen Serup |
| Bispebjerg Hospital, Copenhagen University, the Tattoo Clinic |
| Karina Friis |
| DEFACTUM Research, Aarhus University |
| Signe B. Clemmensen | | EBB, SDU |
|ABSTRACT: Studies regarding the health risks of tattoos are limited. Epidemiological studies of tattoos and association with cancer risk are basically non-existent as exposure data are hard to get. Several researchers are concerned about the lack of knowledge because the trend of tattooing is rapidly increasing: 15-20% of adult Danes are estimated to be tattooed.
This seminar has been arranged as part of the first meeting in a discussion group comprised of researchers who are working on or are initiating studies about the exposure to tattoo ink and possible association with risk of cancer. The 4 groups (see above) will present themselves and their upcoming studies and there will be time for debate between each presentation.
|May 2nd||10:00-11:00 in room 4.48||| Dr Noreen Goldman |
| Professor at Princeton University |
Predicting Survival of Older Adults
|April 9-10||9 Apr 13:00 - 10 Apr 13:00 in room 15-0.55||
2-Day Meeting in the Danish Society of Theoretical Statistics - DSTSSpeaker, titles, and abstracts for the presentations
|Jan 15th||9.00-13.00||| Claire Steves |
| Professor at Department of Twin Research and Genetic Epidemiology |
| King's College London |
Multi-morbidity and frailty: Insights from Twins UK