Research Topics
| Asbjørn HróbjartssonSummaryAffiliation: Det Nordiske Cochrane Center Country: Denmark Publications
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Detail Information
Publications
Is the placebo powerless? An analysis of clinical trials comparing placebo with no treatmentA Hrobjartsson
Department of Medical Philosophy and Clinical Theory, University of Copenhagen, Panum Institute, and the Nordic Cochrane Centre, Rigshospitalet, Denmark
N Engl J Med 344:1594-602. 2001..Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this finding has not been rigorously evaluated...- [What is the effect of placebo interventions? A systematic review of randomized clinical trials with placebo treated and untreated patients]Asbjørn Hróbjartsson
Afdeling for Medicinsk Videskabsteori, Københavns Universitet, Panum Instituttet, DK 2200 København N
Ugeskr Laeger 164:329-33. 2002..Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this belief has not been rigorously evaluated... - What are the main methodological problems in the estimation of placebo effects?Asbjørn Hróbjartsson
Department of Medical Philosophy and Clinical Theory, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK 220 Ø Copenhagen N, Denmark
J Clin Epidemiol 55:430-5. 2002..The effect of patient-provider interaction can similarly be assessed by comparing manipulation of the patient-provider interaction with no manipulation. In both cases bias due to lack of double-blinding is a potential problem... - Is the placebo powerless? Update of a systematic review with 52 new randomized trials comparing placebo with no treatmentA Hrobjartsson
Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
J Intern Med 256:91-100. 2004..It is widely believed that placebo interventions induce powerful effects. We could not confirm this in a systematic review of 114 randomized trials that compared placebo-treated with untreated patients... - [Selective reporting of positive outcomes in randomised trials--secondary publication.. A comparison of protocols with published reports]Asbjørn Hróbjartsson
H S Rigshopitalet, Det Nordiske Cochrane Center, University Health Network Toronto, Department of Medicine
Ugeskr Laeger 167:3189-91. 2005..Selective reporting of positive outcomes is associated with bias... 
Reporting on blinding in trial protocols and corresponding publications was often inadequate but rarely contradictoryAsbjørn Hróbjartsson
The Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
J Clin Epidemiol 62:967-73. 2009..To compare the reporting on blinding in protocols and articles describing randomized controlled trials...- Observer bias in randomized clinical trials with measurement scale outcomes: a systematic review of trials with both blinded and nonblinded assessorsAsbjørn Hróbjartsson
Nordic Cochrane Centre, Rigshospitalet Department 7811, Copenhagen, Denmark
CMAJ 185:E201-11. 2013..We wanted to evaluate the effect of nonblinded outcome assessment on estimated effects in randomized clinical trials with outcomes that involved subjective measurement scales... - The use of placebo interventions in medical practice--a national questionnaire survey of Danish cliniciansAsbjørn Hróbjartsson
Nordic Cochrane Centre, University of Copenhagen
Eval Health Prof 26:153-65. 2003..Approximately 30% (28-36) of the clinicians believed in an effect of placebo interventions on objective outcomes, and 46% (42-50) found clinical placebo interventions generally ethically acceptable... 
Ghost authorship in industry-initiated randomised trialsPeter C Gøtzsche
Nordic Cochrane Centre, Copenhagen, Denmark
PLoS Med 4:e19. 2007..The prevalence and nature of ghost authorship in industry-initiated randomised trials is not known...- Unsubstantiated claims of large effects of placebo on pain: serious errors in meta-analysis of placebo analgesia mechanism studiesAsbjørn Hróbjartsson
The Nordic Cochrane Centre, Rigshospitalet, Denmark
J Clin Epidemiol 59:336-8; discussion 339-41. 2006 - Comparison of descriptions of allocation concealment in trial protocols and the published reports: cohort studyJulie Pildal
Nordic Cochrane Centre, H S Rigshospitalet, DK 2100 Copenhagen, Denmark
BMJ 330:1049. 2005.... - Placebo effect studies are susceptible to response bias and to other types of biasesAsbjørn Hróbjartsson
The Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
J Clin Epidemiol 64:1223-9. 2011..The history of placebo shows that assessment of its clinical significance has a real potential to be biased. We analyze and discuss typical types of bias in studies on placebo... - Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort studyAndreas Lundh
The Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
PLoS Med 7:e1000354. 2010..We investigated industry-supported trials' influence on journal impact factors and revenue... - Powerful spin in the conclusion of Wampold et al.'s re-analysis of placebo versus no-treatment trials despite similar results as in original reviewAsbjørn Hróbjartsson
Hróbjartsson, The Nordic CochraneCentre, Rigshospitalet, Department 7112, Blegdamsvej 9, DK 2100 Copenhagen Ø
J Clin Psychol 63:373-7. 2007..95 (95% confidence interval = 0.88-1.02) versus odds ratio 0.99 (95% confidence interval = 0.81-1.23). Thus, B. E. Wampold et al.'s conclusion was not substantiated by their data, and is best characterized as powerful spin. ... - [Constraints on publication rights in industry-initiated clinical trials--secondary publication]Peter C Gøtzsche
H S Rigshospitalet, Det Nordiske Cochrane Center, DK 2100 København Ø
Ugeskr Laeger 168:2467-9. 2006..These facts were not noted in any of the trial reports. We found similar constraints on publication rights in 44 protocols from 2004. This tight sponsor control over industry-initiated trials should be changed... - [A new scientific source of bias: SILLY bias. Analysis of citations of BMJ's Christmas articles]Ulrik A Felding
Det Nordiske Cochrane Center, Rigshospitalet, København Ø
Ugeskr Laeger 171:3784-9. 2009..Thus, we document a new type of bias in medical research: Serious Idiopathic Loss of Ludic ironY (SILLY) bias, both in citation practices and in metaanalyses... - Clinical placebo interventions are unethical, unnecessary, and unprofessionalAsbjørn Hróbjartsson
Nordic Cochrane Centre, Rigshospitalet, Copenhagen
J Clin Ethics 19:66-9. 2008 - Acupuncture treatment for pain: systematic review of randomised clinical trials with acupuncture, placebo acupuncture, and no acupuncture groupsMatias Vested Madsen
Nordic Cochrane Centre, Rigshospitalet, Department 3343, Blegdamsvej 9, DK 2100 Copenhagen, Denmark
BMJ 338:a3115. 2009..To study the analgesic effect of acupuncture and placebo acupuncture and to explore whether the type of the placebo acupuncture is associated with the estimated effect of acupuncture... - Observer bias in randomised clinical trials with binary outcomes: systematic review of trials with both blinded and non-blinded outcome assessorsAsbjørn Hróbjartsson
Nordic Cochrane Centre, Rigshospitalet Department 3343, Blegdamsvej 9, 2100 Copenhagen Ø, Denmark
BMJ 344:e1119. 2012..To evaluate the impact of non-blinded outcome assessment on estimated treatment effects in randomised clinical trials with binary outcomes... - Spontaneous improvement in randomised clinical trials: meta-analysis of three-armed trials comparing no treatment, placebo and active interventionLasse Theis Krogsbøll
The Nordic Cochrane Centre, Rigshospitalet, Dept, 3343, Blegdamsvej 9, DK 2100 Copenhagen, Denmark
BMC Med Res Methodol 9:1. 2009..It is not known to which extent spontaneous improvement, effect of placebo and effect of active interventions contribute to the observed change from baseline, and we aimed at quantifying these contributions... - Data extraction errors in meta-analyses that use standardized mean differencesPeter C Gøtzsche
Nordic Cochrane Centre, Rigshospitalet, Copenhagen Ø, Denmark
JAMA 298:430-7. 2007..It is not known how reliable such meta-analyses are... - [Johannes Fibiger and the controlled clinical trial]Asbjørn Hróbjartsson
Det Nordiske Cochrane Center, Rigshospitalet, DK 2100 København Ø
Ugeskr Laeger 169:2876. 2007 - Divine intervention? A Cochrane review on intercessory prayer gone beyond science and reasonKarsten Juhl Jørgensen
Dept 3343, The Nordic Cochrane Centre, Rigshospitalet, DK 2100 Copenhagen, Denmark
J Negat Results Biomed 8:7. 2009..The review fails to live up to the high standards required for Cochrane reviews... - Disagreements in meta-analyses using outcomes measured on continuous or rating scales: observer agreement studyBritta Tendal
Nordic Cochrane Centre, Rigshospitalet, Dept 3343, Blegdamsvej 9, DK 2100 Copenhagen, Denmark
BMJ 339:b3128. 2009..To study the inter-observer variation related to extraction of continuous and numerical rating scale data from trial reports for use in meta-analyses... - Who is blinded in randomized clinical trials? A study of 200 trials and a survey of authorsMette Thorlund Haahr
The Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
Clin Trials 3:360-5. 2006..Insufficient blinding of persons involved in randomized clinical trials is associated with bias. The appraisal of the risk of bias is difficult without adequate information in trial reports...