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Reporting Bias (reporting + bias)
Selected AbstractsREPORTING BIAS AND SELF-REPORTED DRUG USEADDICTION, Issue 4 2005JOHN MACLEOD DR No abstract is available for this article. [source] Reporting Bias and Information Discrepancy, and Consequences for Volatility in Financial Markets,ASIA-PACIFIC JOURNAL OF FINANCIAL STUDIES, Issue 5 2010Jae Joon Han D8; D53; G14 Abstract This paper presents an analytical explanation of price volatility and mispricing in a rational financial market. In the proposed model, specialists might have private interest in manipulating their reports, which can affect the security price. Additionally, traders differ in terms of both rationality and available information. The present study shows that mispricing and price volatility occurs in a rational financial market when specialist reports are incorporated under different trader types. Also analyzed are comparative statics of the magnitude of misreports, the informativeness of the price, and price volatility when the ratio of superior traders to ordinary traders changes. Both price volatility and the potential for extra profit gain by superior traders might increase when they are dominant. [source] Changing Graph Use in Corporate Annual Reports: A Time-Series AnalysisCONTEMPORARY ACCOUNTING RESEARCH, Issue 2 2000VIVIEN A. BEATTIE Abstract Graphs in corporate annual reports form part of a powerfully designed annual report package that offers considerable potential for "impression management." The primary purpose of this paper is to determine whether graph use depends on corporate performance. Time-series analysis, not previously used in the financial graphs literature, allows discretionary changes in graph use by companies to be identified and related to changes in individual companies' corporate performance over time. Based on the prior financial graphs and accounting choice literature, we develop two hypotheses that relate changes in graph use to changes in corporate performance. These hypotheses focus on the aggregate and individual company levels. We base our analysis on the corporate annual reports of 137 top UK companies that were in continued existence during the five-year period from 1988 to 1992. At both the aggregate and individual company levels, we find the decision to use key financial variable (KFV) graphs, the primary graphical choice, to be associated positively with corporate performance measures. This finding is consistent with the manipulation hypothesis - that is, that financial graphs in corporate annual reports are used to "manage" favorably the reader's impression of company performance, and hence that there is a reporting bias. [source] Randomized controlled trial of the effects of completing the Alcohol Use Disorders Identification Test questionnaire on self-reported hazardous drinkingADDICTION, Issue 2 2008Jim McCambridge ABSTRACT Aims The direct effects of screening on drinking behaviour have not previously been evaluated experimentally. We tested whether screening reduces self-reported hazardous drinking in comparison with a non-screened control group. Design Two-arm randomized controlled trial (RCT), with both groups blinded to the true nature of the study. Setting and participants A total of 421 university students aged 18,24 years, recruited in five London student unions. Interventions Both groups completed a brief pen-and-paper general health and socio-demographic questionnaire, which for the experimental group also included the 10-item Alcohol Use Disorders Identification Test (AUDIT) screening questionnaire. Measurements The primary outcome was the between-group difference in AUDIT score at 2,3-month follow-up. Eight secondary outcomes comprised other aspects of hazardous drinking, including dedicated measures of alcohol consumption, problems and dependence. Findings A statistically significant effect size of 0.23 (0.01,0.45) was detected on the designated primary outcome. The marginal nature of the statistical significance of this effect was apparent in additional analyses with covariates. Statistically significant differences were also obtained in three of eight secondary outcomes, and the observed effect sizes were not dissimilar to the known effects of brief interventions. Conclusions It is unclear to what extent these findings represent the effects of screening alone, a Hawthorne effect in which drinking behaviour has changed in response to monitoring, or whether they indicate reporting bias. These possibilities have important implications both for the dissemination of screening as an intervention in its own right and for behavioural intervention trials methodology. [source] Successful use of recombinant factor VIIa in a patient with inhibitor secondary to severe factor XI deficiencyHAEMOPHILIA, Issue 2 2002P. LAWLER Factor XI (FXI) inhibitors are a rare complication of inherited FXI deficiency. We report the successful use of recombinant factor VIIa (FVIIa) in a patient with a high-responding inhibitor undergoing cataract extraction. At the time of surgery there were limited available data on the optimal management of patients with FXI deficiency. A 62-year-old Ashkenazi Jewish woman had a lifelong history of excessive bleeding secondary to severe FXI deficiency (2 U dL,1), and received FXI concentrate (FXI:C) when she underwent a colposuspension procedure. She was subsequently diagnosed with a FXI inhibitor of 16 Bethesda units (BU) when she developed a poor response to FXI:C at the time of total hip replacement. Two months later she was admitted for cataract extraction. The FXI level was < 1 U dL,1 with an inhibitor titre of 48 BU. She received 90 ,g kg,1 of FVIIa immediately preoperatively followed by continuous infusion at a rate of 20 ,g kg,1 h,1 for 24 h. The cataract extraction was successful and there was no excess bleeding during surgery or in the postoperative period. Mutation analysis of the FXI gene showed that the patient was homozygous for the type II genotype [exon 5, Glu117,Ter]. The reason for the low prevalence of inhibitor formation in patients with FXI deficiency is unclear but may reflect a number of factors including reporting bias, the rarity of absent circulating FXI:C activity, and the infrequent use of FXI replacement therapy. [source] Does reporting heterogeneity bias the measurement of health disparities?HEALTH ECONOMICS, Issue 3 2008Teresa Bago d'Uva Abstract Heterogeneity in reporting of health by socio-economic and demographic characteristics potentially biases the measurement of health disparities. We use anchoring vignettes to identify socio-demographic differences in the reporting of health in Indonesia, India and China. Homogeneous reporting by socio-demographic group is rejected and correcting for reporting heterogeneity tends to reduce slightly estimated disparities in health by education (not China) and to increase those by income. But the method does not reveal substantial reporting bias in measures of health disparities. Copyright © 2007 John Wiley & Sons, Ltd. [source] Outcome of intensive care of homozygous alpha-thalassaemia without prior intra-uterine therapyJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 7-8 2007Shing YR Lee Aim: To review the outcome of homozygous alpha-thalassaemia without prior intra-uterine therapy treated in neonatal intensive care unit and identify the factors associated with survival. Methods: The hospital records of all patients with homozygous alpha-thalassaemia treated in our neonatal intensive care unit in the last 15 years were reviewed. A literature search beginning in the year 1980 was done to identify homozygous alpha-thalassaemia actively treated in neonatal intensive care units. Those receiving prior intra-uterine therapy were excluded. The following information was collected: the severity of hydrops, sizes of liver and spleen, haemoglobin level, Apgar score at 5 min, ventilator settings, timing and forms of red blood cell transfusion and presence of persistent hypoxaemia. The survivors and the non-survivors were compared. Results: In our centre, in the last 15 years there were six infants born with homozygous alpha-thalassaemia who did not receive intra-uterine therapy; one survived and five succumbed despite aggressive respiratory therapy. In our literature search there were more reports of survivors (10) than non-survivors (six) for these infants, suggesting a reporting bias towards selection of rare cases of survival. Apgar score of four or above occurred in seven of the eight survivors with data available in the reports, whereas this occurred in four of the 11 non-survivors (P = 0.035, Fisher Exact test). Five of the 11 survivors had abnormal neurological outcome including developmental delay and spastic quadriplegia. Conclusion: Without prior intra-uterine therapy, homozygous alpha-thalassaemia has grave outlook in terms of mortality and morbidity despite aggressive respiratory therapy. [source] Establishment of a pharmacoepidemiological database in Germany: methodological potential, scientific value and practical limitationsPHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 3 2008Dipl., Iris Pigeot Dr rer.nat. Abstract Purpose We present a new population-based pharmacoepidemiological (PE) database obtained from statutory health insurances (SHIs) that is able to generate signals, to monitor prescribed drugs and to describe drug utilisation. We discuss methodological features of the database and we assess to which degree this database reflects basic demographic characteristics and hospitalisation rates of the general population. Methods Files of three SHIs were linked with drug dispensation data from a pharmacies' electronic data processing centre on an individual basis using the unique subject identification number (ID) at a trusted third party centre. Plausibility checks and descriptive analyses were carried out. Results The database covers 3.6 million SHI-members, provides drug utilisation data and data on hospitalisations. SHI membership is fairly stable over time. Our data indicate marked differences in socio-demographic characteristics between SHIs. Hospital admission rates standardised for age vary between 0.164 and 0.229 per person year, which is in good agreement with official statistics (0.20). The age distribution shows good agreement for men and some underrepresentation for women above the age of 60 as compared to the general population. Conclusions Confounder information on medical conditions, concomitant medications and socio-demographic variables can be obtained from the database, while the assessment of confounders related to lifestyle requires supplementary data collection. The database allows for a population-based approach and reflects daily practice including off-label use of drugs. Independent recording of exposure and outcome data prevents reporting bias on medication or outcome. Legal conditions that allow continuous updating of the database need to be settled. Copyright © 2008 John Wiley & Sons, Ltd. [source] | |||||||||||||