The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach.
Background: Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbi...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2012-10-01
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| Series: | Frontiers in Psychiatry |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpsyt.2012.00092/full |
| _version_ | 1828229374703304704 |
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| author | Charles eGreen Joy eSchmitz Jan eLindsay Jan eLindsay Claudia ePedroza Scott D. Lane Rob eAgnelli Kimberly eKjome F Gerard Moeller |
| author_facet | Charles eGreen Joy eSchmitz Jan eLindsay Jan eLindsay Claudia ePedroza Scott D. Lane Rob eAgnelli Kimberly eKjome F Gerard Moeller |
| author_sort | Charles eGreen |
| collection | DOAJ |
| description | Background: Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbidopa for cocaine dependence; and (2) apply an informative-priors, Bayesian approach for estimating the probability of a subgroup-by-treatment interaction effect.Method: A secondary data analysis of two previously published, double-blind, randomized controlled trials provided samples for the historical dataset (Study 1: N = 64 complete observations) and current dataset (Study 2: N = 113 complete observations). Negative binomial regression evaluated Treatment Effectiveness Scores (TES) as a function of medication condition (levodopa/carbidopa, placebo), baseline marijuana use (days in past 30), and their interaction. Results: Bayesian analysis indicated that there was a 96% chance that baseline marijuana use predicts differential response to treatment with levodopa/carbidopa. Simple effects indicated that among participants receiving levodopa/carbidopa the probability that baseline marijuana confers harm in terms of reducing TES was 0.981; whereas the probability that marijuana confers harm within the placebo condition was 0.163. For every additional day of marijuana use reported at baseline, participants in the levodopa/carbidopa condition demonstrated a 5.4% decrease in TES; while participants in the placebo condition demonstrated a 4.9% increase in TES.Conclusion: The potential moderating effect of marijuana on cocaine treatment response should be considered in future trial designs. Applying Bayesian subgroup analysis proved informative in characterizing this patient-treatment interaction effect. |
| first_indexed | 2024-04-12T18:33:07Z |
| format | Article |
| id | doaj.art-804fe00247624c45856e8db812d264d7 |
| institution | Directory Open Access Journal |
| issn | 1664-0640 |
| language | English |
| last_indexed | 2024-04-12T18:33:07Z |
| publishDate | 2012-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Psychiatry |
| spelling | doaj.art-804fe00247624c45856e8db812d264d72022-12-22T03:21:01ZengFrontiers Media S.A.Frontiers in Psychiatry1664-06402012-10-01310.3389/fpsyt.2012.0009233505The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach.Charles eGreen0Joy eSchmitz1Jan eLindsay2Jan eLindsay3Claudia ePedroza4Scott D. Lane5Rob eAgnelli6Kimberly eKjome7F Gerard Moeller8University of Texas Medical School at HoustonUniversity of Texas Medical School at HoustonMichael E. DeBakey VA Medical CenterBaylor College of MedicineUniversity of Texas Medical School at HoustonUniversity of Texas Medical School at HoustonSAS Inc.University of Texas Medical School at HoustonUniversity of Texas Medical School at HoustonBackground: Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbidopa for cocaine dependence; and (2) apply an informative-priors, Bayesian approach for estimating the probability of a subgroup-by-treatment interaction effect.Method: A secondary data analysis of two previously published, double-blind, randomized controlled trials provided samples for the historical dataset (Study 1: N = 64 complete observations) and current dataset (Study 2: N = 113 complete observations). Negative binomial regression evaluated Treatment Effectiveness Scores (TES) as a function of medication condition (levodopa/carbidopa, placebo), baseline marijuana use (days in past 30), and their interaction. Results: Bayesian analysis indicated that there was a 96% chance that baseline marijuana use predicts differential response to treatment with levodopa/carbidopa. Simple effects indicated that among participants receiving levodopa/carbidopa the probability that baseline marijuana confers harm in terms of reducing TES was 0.981; whereas the probability that marijuana confers harm within the placebo condition was 0.163. For every additional day of marijuana use reported at baseline, participants in the levodopa/carbidopa condition demonstrated a 5.4% decrease in TES; while participants in the placebo condition demonstrated a 4.9% increase in TES.Conclusion: The potential moderating effect of marijuana on cocaine treatment response should be considered in future trial designs. Applying Bayesian subgroup analysis proved informative in characterizing this patient-treatment interaction effect.http://journal.frontiersin.org/Journal/10.3389/fpsyt.2012.00092/fullBayesianmarijuana: cocainetreatment responsesubgroup analysis |
| spellingShingle | Charles eGreen Joy eSchmitz Jan eLindsay Jan eLindsay Claudia ePedroza Scott D. Lane Rob eAgnelli Kimberly eKjome F Gerard Moeller The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. Frontiers in Psychiatry Bayesian marijuana : cocaine treatment response subgroup analysis |
| title | The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. |
| title_full | The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. |
| title_fullStr | The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. |
| title_full_unstemmed | The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. |
| title_short | The influence of baseline marijuana use on treatment of cocaine dependence: application of an informative-priors Bayesian approach. |
| title_sort | influence of baseline marijuana use on treatment of cocaine dependence application of an informative priors bayesian approach |
| topic | Bayesian marijuana : cocaine treatment response subgroup analysis |
| url | http://journal.frontiersin.org/Journal/10.3389/fpsyt.2012.00092/full |
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