%0 Journal Article %1 Simpson2008 %A Simpson, Helen Blair %A Petkova, Eva %A Cheng, Jianfeng %A Huppert, Jonathan %A Foa, Edna %A Liebowitz, Michael R %D 2008 %J Journal of psychiatric research %K Adolescent Adult Aged ChoiceBehavior Clomipramine Clomipramine:therapeuticuse CognitiveTherapy CognitiveTherapy:methods CombinedModalityTherapy Humans LongitudinalStudies MiddleAged Obsessive-CompulsiveDisorder Obsessive-CompulsiveDisorder:drugtherapy Obsessive-CompulsiveDisorder:psychology Obsessive-CompulsiveDisorder:therapy OutcomeAssessment(HealthCare) OutcomeAssessment(HealthCare):statistics&num Placebos RandomizedControlledTrialsasTopic:statistics ResearchDesign SerotoninUptakeInhibitors SerotoninUptakeInhibitors:therapeuticuse StatisticsasTopic StatisticsasTopic:methods TreatmentOutcome RCT %N 8 %P 631-8 %R 10.1016/j.jpsychires.2007.07.012 %T Statistical choices can affect inferences about treatment efficacy: a case study from obsessive-compulsive disorder research. %U http://www.ncbi.nlm.nih.gov/pubmed/17892885 %V 42 %X Longitudinal clinical trials in psychiatry have used various statistical methods to examine treatment effects. The validity of the inferences depends upon the different method's assumptions and whether a given study violates those assumptions. The objective of this paper was to elucidate these complex issues by comparing various methods for handling missing data (e.g., last observation carried forward LOCF, completer analysis, propensity-adjusted multiple imputation) and for analyzing outcome (e.g., end-point analysis, repeated-measures analysis of variance RM-ANOVA, mixed-effects models MEMs) using data from a multi-site randomized controlled trial in obsessive-compulsive disorder (OCD). The trial compared the effects of 12 weeks of exposure and ritual prevention (EX/RP), clomipramine (CMI), their combination (EX/RP&CMI) or pill placebo in 122 adults with OCD. The primary outcome measure was the Yale-Brown Obsessive Compulsive Scale. For most comparisons, inferences about the relative efficacy of the different treatments were impervious to different methods for handling missing data and analyzing outcome. However, when EX/RP was compared to CMI and when CMI was compared to placebo, traditional methods (e.g., LOCF, RM-ANOVA) led to different inferences than currently recommended alternatives (e.g., multiple imputation based on estimation-maximization algorithm, MEMs). Thus, inferences about treatment efficacy can be affected by statistical choices. This is most likely when there are small but potentially clinically meaningful treatment differences and when sample sizes are modest. The use of appropriate statistical methods in psychiatric trials can advance public health by ensuring that valid inferences are made about treatment efficacy. %@ 0022-3956

@article{Simpson2008, abstract = {Longitudinal clinical trials in psychiatry have used various statistical methods to examine treatment effects. The validity of the inferences depends upon the different method's assumptions and whether a given study violates those assumptions. The objective of this paper was to elucidate these complex issues by comparing various methods for handling missing data (e.g., last observation carried forward [LOCF], completer analysis, propensity-adjusted multiple imputation) and for analyzing outcome (e.g., end-point analysis, repeated-measures analysis of variance [RM-ANOVA], mixed-effects models [MEMs]) using data from a multi-site randomized controlled trial in obsessive-compulsive disorder (OCD). The trial compared the effects of 12 weeks of exposure and ritual prevention (EX/RP), clomipramine (CMI), their combination (EX/RP&CMI) or pill placebo in 122 adults with OCD. The primary outcome measure was the Yale-Brown Obsessive Compulsive Scale. For most comparisons, inferences about the relative efficacy of the different treatments were impervious to different methods for handling missing data and analyzing outcome. However, when EX/RP was compared to CMI and when CMI was compared to placebo, traditional methods (e.g., LOCF, RM-ANOVA) led to different inferences than currently recommended alternatives (e.g., multiple imputation based on estimation-maximization algorithm, MEMs). Thus, inferences about treatment efficacy can be affected by statistical choices. This is most likely when there are small but potentially clinically meaningful treatment differences and when sample sizes are modest. The use of appropriate statistical methods in psychiatric trials can advance public health by ensuring that valid inferences are made about treatment efficacy.}, added-at = {2023-02-03T11:44:35.000+0100}, author = {Simpson, Helen Blair and Petkova, Eva and Cheng, Jianfeng and Huppert, Jonathan and Foa, Edna and Liebowitz, Michael R}, biburl = {https://www.bibsonomy.org/bibtex/28a1b8ee8dba842ca69da768e9c5c2699/jepcastel}, city = {Department of Psychiatry, Columbia University, USA. simpson@nyspi.cpmc.columbia.edu}, doi = {10.1016/j.jpsychires.2007.07.012}, interhash = {4d62896b7c133ec64b3d1576ed2c2673}, intrahash = {8a1b8ee8dba842ca69da768e9c5c2699}, isbn = {0022-3956}, issn = {0022-3956}, journal = {Journal of psychiatric research}, keywords = {Adolescent Adult Aged ChoiceBehavior Clomipramine Clomipramine:therapeuticuse CognitiveTherapy CognitiveTherapy:methods CombinedModalityTherapy Humans LongitudinalStudies MiddleAged Obsessive-CompulsiveDisorder Obsessive-CompulsiveDisorder:drugtherapy Obsessive-CompulsiveDisorder:psychology Obsessive-CompulsiveDisorder:therapy OutcomeAssessment(HealthCare) OutcomeAssessment(HealthCare):statistics&num Placebos RandomizedControlledTrialsasTopic:statistics ResearchDesign SerotoninUptakeInhibitors SerotoninUptakeInhibitors:therapeuticuse StatisticsasTopic StatisticsasTopic:methods TreatmentOutcome RCT}, month = {7}, note = {4609<m:linebreak></m:linebreak>GR: K23 MH01907/MH/NIMH NIH HHS/United States; GR: R01 MH45404/MH/NIMH NIH HHS/United States; GR: R01 MH45436/MH/NIMH NIH HHS/United States; JID: 0376331; 0 (Placebos); 0 (Serotonin Uptake Inhibitors); 303-49-1 (Clomipramine); 2006/11/30 [received]; 2007/07/20 [accepted]; 2007/09/24 [aheadofprint]; ppublish;<m:linebreak></m:linebreak>Anàlisi de dades}, number = 8, pages = {631-8}, pmid = {17892885}, timestamp = {2023-05-04T09:00:45.000+0200}, title = {Statistical choices can affect inferences about treatment efficacy: a case study from obsessive-compulsive disorder research.}, url = {http://www.ncbi.nlm.nih.gov/pubmed/17892885}, volume = 42, year = 2008 }