Powell 1995.
Study characteristics | ||
Methods | Design: placebo‐controlled parallel trial | |
Participants |
Participants: men with alcohol dependence and comorbid psychiatric disorders (subgroup with AsPD) Sex: male only Age: not reported for AsPD subgroup; for the whole sample, mean 41.3 (SD = 9.2) years Unit of allocation: individual participant Number randomised: 65 with AsPD (out of 216; see note 1) Number completing: 29 with AsPD (out of 99; see note 1) Setting: initially inpatient, then outpatient; two sites; USA (Kansas and Topeka) Inclusion criteria: alcohol dependence (DSM‐III‐R; measured using the PDI‐R) Exclusion criteria: medical condition contraindicating use of tricyclic antidepressants or bromocriptine; receiving psychotropic medication (see note 2), living more than 150 miles from treatment site Ethnicity: for the whole sample: white (63%); black (32%); native American (2%); other (3%) Baseline characteristics: for the whole sample: all veterans; college degree (4%); some college or vocational training (39%); high school education or equivalent (47%); less than high school education (10%); married (21%); separated (15%); divorced/widowed (43%); never married (20%); employed full or part time in the month before admission (50%); retired (4%); student (1%); unemployed (45%) |
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Interventions | Three conditions:
In analysis, the 2 placebo groups were combined such that total completed = 9 (see note 3) Duration of intervention: 6 months Duration of trial: 6 months Length of follow‐up: participants were not followed up beyond the end of the intervention period Dose adjustment: nortriptyline dose adjusted to therapeutic levels (50 to 150 ng/ml plasma) with corresponding increase in capsules made for placebo patients; bromocriptine initially 2.5 mg 3 times daily, but increased to 5 mg 3 times daily from month 4 to month 6; placebo as matching capsules with number adjusted to match a participant in the active treatment group Other notes: participants reimbursed 15 US Dollars for each clinic visit; payment was not made until the participant either dropped out or completed the study |
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Outcomes |
Primary outcomes Global state/functioning: Global Assessment Scale (GAS); global severity index sub scale of the Symptom Check List‐90 (SCL‐90) Adverse effects: medication side effects via participant self‐report Secondary outcomes Substance misuse: severity of alcoholism (Alcohol Severity Scale (ASS), self report); alcohol craving (visual analogue scale); alcohol dependence (Severity of Alcohol Dependence Questionnaire (SADQ)) Other outcomes depression (Beck Depression Inventory; SCL‐90 depression sub scale); anxiety (Beck Anxiety Inventory (BAI); SCL‐90 anxiety sub scale); problem behaviours (Problem Behavior Checklist) Timing of outcome assessments Monthly blood levels; GAS, SCL‐90, ASS, SADQ, BDI at baseline and 6‐month follow‐up |
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Notes |
Study funding: National Institute of Alcohol Abuse and Alcoholism (USA) Declaration of interests: The study authors state "We thank Sandoz Pharmaceuticals Corp. for supplying us with Parlodel (bromocriptine mesylate) and Pamelor (nortriptyline HCI*)." (quote, p 468) *HCl = hydrochloride |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Unclear risk | Comment: A two‐stage randomization process was used; patients within each of the subgroups (alcoholism alone, alcoholism + mood/anxiety disorders, alcoholism + AsPD) "were first randomly assigned to the bromocriptine or nortriptyline arm of the study. Patients within each drug arm were then randomised to receive either active drug or placebo" (p.463, col 1). No further information given. Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared. |
Allocation concealment (selection bias) | Unclear risk | Comment: A two‐stage randomization process was used (see above). "Patients within each drug arm were then randomised to receive either active drug or placebo" (p.463, col 1). No further information given. Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared. |
Blinding (performance bias and detection bias) of participants | Low risk | Comment: Investigators reported that "both active medications and placebo were prepared as identical‐appearing capsules. . . . when the number of pills was increased for a given patient, a corresponding increase in pills was made for a placebo patient" (p.463, col 1). Review authors judged that appropriate care was taken to ensure blinding of participants, and that it was unlikely that this blinding could have been broken. |
Blinding (performance bias and detection bias) of personnel | Low risk | Comment: Investigators reported that "at each visit, a physician blinded to the patients' treatment assignment obtained blood samples and systematically recorded pill counts, medication side effects and other medical information" (p.463, col 2). Review authors judged that appropriate care was taken to ensure blinding of trial personnel, and that it was unlikely that this blinding could have been broken. |
Blinding (performance bias and detection bias) of outcome assessors | Unclear risk | Comment: Investigators reported that "a research assistant then recorded number of drinking days and patient rating of alcohol craving since the last follow‐up visit" (p.463, col 2), but there was no indication that this research assistant was blinded, other than the statement that the study was "double‐blind". Clarification has been requested from the trial investigators, but no further information was available at the time this review was prepared. |
Incomplete outcome data (attrition bias) All outcomes | High risk |
Comment: Incomplete outcome data arise from participants not completing the study and applies to all measured outcomes. The investigators reported significant dropout rates for the comorbidity and medication subgroups which ranged from 52.1% to 55.4%, and note that there were 99 participants (overall) who completed the study and 117 (overall) who did not (p.464, col 1). No details on missing data were provided for the AsPD subgroup. Clarification has been requested from the trial investigators but no further information was available at the time this review was prepared. In this review, data from the 29 participants with AsPD who completed the study were included in the analysis (bromocriptine condition, n = 9; nortriptyline condition, n = 11; control condition, n = 9). |
Selective reporting (reporting bias) | Unclear risk | Comment: Study protocol is not available but it seems clear that the published report includes all expected outcomes, including those that were pre‐specified. |
Other bias | Low risk | Comment: The study appeared to be free of other sources of bias. |