Carnwath 1998.
| Methods | Randomised, controlled, double‐blind trial | |
| Participants | Setting: home‐based, Manchester, UK. Participants: 50, opioid dependent by DSM‐IV, using methadone or other opiates. Group sizes: (1) n = 26, (2) n = 24. (1) 43%, (2) 71% used iv, otherwise groups similar. Mean age: 28 years. 70% men. Mean 6.9 years opiate use. 66% had previous detoxification experience; 17% employed, 63% supported by relative. |
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| Interventions | All stabilised on methadone (40 mg/day or less) prior to study. (1) n = 26: lofexidine, 0.2 mg/capsule, or (2) n = 24: clonidine 0.1 mg/capsule. Both increased over 3 days to max 8 capsules/day, and tapered over last 3 days. Various adjunct medications available. Total duration of medication unclear. Home‐based treatment with participants visited at least 4 times in week 1, 3 times in week 2, and once in each of weeks 3 and 4. Treatment considered successful if participants opiate‐free by urine test at 4 weeks. Scheduled duration 12 days | |
| Outcomes | Number completing treatment; number with extra home visits; mean withdrawal scores; mean side effects score | |
| Notes | Participants completed Short Opiate Withdrawal Scale (10 items, 0 to 3 severity) during each visit by trial personnel. Financial support provided by Britannia Pharmaceuticals and the "North West Region Medical Innovation Scheme" | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "Patients were assigned randomly ..." Comment: Although the method of sequence generation was not reported, the similarity of the groups and allocation by the separate pharmacy suggests the method was adequate |
| Allocation concealment (selection bias) | Low risk | Quote: "Treatment courses were sent out to patients by Trafford pharmacy, which also conducted the treatment group assignment without knowledge of patient or drug team staff." |
| Blinding (performance bias and detection bias) Subjective outcomes ‐ intensity of withdrawal, adverse effects | Low risk | Participants and treating staff blind to treatment. Drugs prepared in identical capsules |
| Blinding (performance bias and detection bias) Objective outcomes ‐ duration of treatment, completion of treatment | Low risk | Participants and treating staff blind to treatment. Drugs prepared in identical capsules |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quote: "Those [participants] stopping early experienced higher maximum SOWS scores." Comment: Differential drop‐out may have reduced mean daily SOWS score in clonidine group to a greater extent than the lofexidine group, but this outcome was not used in this review |
| Selective reporting (reporting bias) | Low risk | None apparent |
| Other bias | Low risk | None apparent |