The Inuence of Misspecified Covariance on False Discovery Control when Using Posterior Probabilities

This paper focuses on the influence of a misspecified covariance structure on false discovery rate for the large scale multiple testing problem. Specifically, we evaluate the influence on the marginal distribution of local fdr statistics, which are used in many multiple testing procedures and related to Bayesian posterior probabilities. Explicit forms of the marginal distributions under both correctly specified and incorrectly specified models are derived. The Kullback-Leibler divergence is used to quantify the influence caused by a misspecification. Several numerical examples are provided to illustrate the influence. A real spatio-temporal data on soil humidity is discussed.Comment: 22 pages, 5 figure

Power-enhanced multiple decision functions controlling family-wise error and false discovery rates

Improved procedures, in terms of smaller missed discovery rates (MDR), for performing multiple hypotheses testing with weak and strong control of the family-wise error rate (FWER) or the false discovery rate (FDR) are developed and studied. The improvement over existing procedures such as the \v{S}id\'ak procedure for FWER control and the Benjamini--Hochberg (BH) procedure for FDR control is achieved by exploiting possible differences in the powers of the individual tests. Results signal the need to take into account the powers of the individual tests and to have multiple hypotheses decision functions which are not limited to simply using the individual $p$-values, as is the case, for example, with the \v{S}id\'ak, Bonferroni, or BH procedures. They also enhance understanding of the role of the powers of individual tests, or more precisely the receiver operating characteristic (ROC) functions of decision processes, in the search for better multiple hypotheses testing procedures. A decision-theoretic framework is utilized, and through auxiliary randomizers the procedures could be used with discrete or mixed-type data or with rank-based nonparametric tests. This is in contrast to existing $p$-value based procedures whose theoretical validity is contingent on each of these $p$-value statistics being stochastically equal to or greater than a standard uniform variable under the null hypothesis. Proposed procedures are relevant in the analysis of high-dimensional "large $M$, small $n$" data sets arising in the natural, physical, medical, economic and social sciences, whose generation and creation is accelerated by advances in high-throughput technology, notably, but not limited to, microarray technology.Comment: Published in at http://dx.doi.org/10.1214/10-AOS844 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

The relationship between psychosis symptoms and pain in nursing home residents

Abstract Background: In nursing homes (NH) >80% have dementia, and 30-60% experience pain daily. Psychosis symptoms (delusions and hallucinations) are common. These can lead to reduced quality of life (QoL) and are often treated with antipsychotic medication, which can cause harmful side-effects. Previous studies have suggested an association between pain and psychosis symptoms, but none have investigated the longitudinal association as well as the effect of pain treatment on psychosis. Aim: To investigate the relationship between pain and psychosis symptoms, and the characteristics of NH patients with psychosis symptoms. The thesis also aims to investigate the effect of pain treatment on psychosis symptoms and the effect of a multicomponent intervention on psychosis symptoms and pain. Methods: Paper 1 investigates the effect of pain treatment on psychosis symptoms and uses data from a cluster-randomized controlled trial (cRCT), the Pain-BPSD study. Papers 2 and 3 use data from a cRCT, the COSMOS-trial, and investigate the characteristics of NH residents with psychosis symptoms, as well as the association between pain and psychosis symptoms over time and the effect of a multicomponent intervention on pain and psychosis. Pain was measured using the MOBID-2 pain scale, while psychosis symptoms are measured using the NPI-NH. Results: Paper 1 included 352 residents from 60 NH units, while the COSMOS-trial included 723 residents from 67 NH units. Pain treatment reduced psychosis symptoms (p = 0.034). Residents with psychosis had lower QoL (p <0.001) and more depressive symptoms (p <0.001). Pain was longitudinally associated with psychosis symptoms as a group (p = 0.009) and delusion individually (p = 0.007). The COSMOS-intervention had no effect on total pain or psychosis symptoms. Conclusion: Pain in NH residents was associated with psychosis symptoms as a group and delusion individually. Psychosis symptoms were associated with depression and lower QoL. The effect of non-pharmacological interventions on psychosis symptoms needs further research. Implications: Pain assessment should be a prerequisite when making treatment decisions on psychosis symptoms in NH residents. Thorough guidelines for treating psychosis symptoms in NHs need to be developed to reduce their negative impact.Bakgrunn: På sykehjem (SH) har over 80% demens, og 30-60% opplever daglig smerte. Psykosesymptomer er vanlig, kan føre til redusert livskvalitet, og behandles ofte med antipsykotika som kan gi skadelige bivirkninger. Tidligere studier indikerer en sammenheng mellom smerte og psykosesymptomer, men ingen har undersøkt den longitudinelle sammenhengen, eller effekten av smertebehandling på psykose. Formål: Undersøke sammenhengen mellom smerte og psykosesymptomer, samt karakteristika til SH-pasienter med psykosesymptomer. Avhandlingen undersøker også effekten av smertebehandling på psykosesymptomer, samt effekten av en multikomponent-intervensjon på psykosesymptomer og smerte. Metode: Artikkel 1 undersøker effekten av smertebehandling på psykosesymptomer, og analyser data fra den klynge-randomiserte kontrollerte, Pain-BPSD studien. Artikkel 2 og 3 bruker data fra den klyngerandomiserte kontrollerte KOSMOSstudien, og undersøker karakteristika til SH pasienter med psykosesymptomer, i tillegg til sammenhengen mellom smerte og psykose over tid, samt effekten av en multikomponent intervensjon på smerte og psykose. Smerte måles med MOBID-2 smerteskala. Nevropsykiatrisk intervjuguide – SH-versjon brukes for å måle psykose. Resultat: Artikkel 1 inkluderte 352 pasienter fra 60 SH avdelinger, mens KOSMOSstudien inkluderte 545 pasienter fra 67 SH avdelinger. Smertebehandling reduserte psykosesymptomer (p = 0.034). Pasienter med psykosesymptomer hadde lavere livskvalitet (p <0.001) og mer depresjonssymptomer (p <0.001). Smerte var longitudinelt assosiert til psykosesymptomer som gruppe (p = 0.009), og vrangforestillinger individuelt (p = 0.007). KOSMOS-intervensjonen hadde ingen effekt på total smerte eller psykosesymptomer. Konklusjon: Smerte er assosiert med psykosesymptomer som gruppe, og vrangforestillinger individuelt. Psykosesymptomer er assosiert med lavere livskvalitet, og har negativ påvirkning på SH pasienter. Effekten av ikkefarmakologiske intervensjoner på psykosesymptomer trenger videre undersøkelse. Implikasjoner: Smertevurdering bør være standard når en skal vurdere behandlingsvalg for psykosesymptomer. Klare retningslinjer trengs for behandling av psykosesymptomer for å redusere de negative konsekvensene de har.Doktorgradsavhandlin

Zinc Gluconate in the Treatment of Dysgeusia—a Randomized Clinical Trial

In the treatment of dysgeusia, the use of zinc has been frequently tried, with equivocal results. The aim of the present randomized clinical trial, which involved a sufficiently large sample, was therefore to determine the efficacy of zinc treatment. Fifty patients with idiopathic dysgeusia were carefully selected. Zinc gluconate (140 mg/day; n = 26) or placebo (lactose; n = 24) was randomly assigned to the patients. The patients on zinc improved in terms of gustatory function (p < 0.001) and rated the dysgeusia as being less severe (p < 0.05). Similarly, signs of depression in the zinc group were less severe (Beck Depression Inventory, p < 0.05; mood scale, p < 0.05). With the exception of the salivary calcium level, which was higher in the zinc patients (p < 0.05), no other significant group differences were found. In conclusion, zinc appears to improve general gustatory function and, consequently, general mood scores in dysgeusia patients

Das Hold-Up Problem in Supply Chains bei verhandelten Verrechnungspreisen

Diese Magisterarbeit beschäftigt sich mit dem Hold-Up Problem in Supply Chains bei verhandelten Verrechnungspreisen. Dazu wird untersucht, ob Lösungsansätze für das Unterinvestitionsproblem zwischen zwei Bereichen auch uneingeschränkt für Supply Chains mit mehr als zwei Mitgliedern gültig sind oder ob beziehungsweise inwieweit diese Ansätze modifiziert werden müssen. Als erstes werden die Grundlagen von Verrechnungspreisen vermittelt und das Hold-Up Problem erklärt. Danach werden die zwei Möglichkeiten – der Festmengenvertrag nach Böckem und Schiller (2004) und der Optionsvertrag nach Böckem und Schiller (2008) – zur Erreichung des optimalen Investitionsgrades in Supply Chains vorgestellt. Es wird gezeigt, dass im Rahmen des Festmengenvertrages eine zusätzliche Annahme, welche die Koordination von Verhandlungen betrifft, getätigt werden muss, damit das Modell von Edlin und Reichelstein (1995), welches das Hold-Up Problem zwischen zwei Beteiligten behandelt, auch für Supply Chains mit mindestens drei Mitgliedern gilt. Auch der Optionsvertrag muss hinsichtlich des Verhandlungsablaufes modifiziert werden um den Ansatz von Nöldeke und Schmidt (1995) bei Supply Chains anwenden zu können.There is lot of literature which is dealing with the hold-up problem in a traditional two-party case. This diploma thesis deals with the hold-up problem in supply chains under negotiated transfer pricing. I investigate, whether approaches for a solution to the hold-up problem between two parties are also valid absolutely for supply chains with more than two members or if respectively to which extent those approaches must be modified. At first I explain the basics of transfer pricing and the hold-up problem. After that I analyse two possibilities to achieve efficient investment levels in supply chains – the fixed quantity contract according to Böckem and Schiller (2004) and the option contract according to Böckem and Schiller (2008). I show that within the scope of a fixed quantity contract an additional assumption regarding the coordination of the negotiations must be made to make sure that the model of Edlin and Reichelstein (1995), which is dealing with the hold-up problem between two parties, is also applicable for supply chains with at least three members. Also the option contract must be modified regarding the sequence of the renegotiations to make the approach of Nöldeke and Schmidt (1995) useable for supply chains