Table 5 Summary of included non-randomised controlled trials
Author/Year, Country | Study Design | Participants (n, age, gender, ethnicity, level of intellectual disabilities) | Setting | Intervention (including medication that was targeted, Duration of deprescribing intervention and length of follow up) | Outcome Measures | Summary of Findings |
|---|---|---|---|---|---|---|
Aman et al. 1985 New Zealand [35] | Prospective non randomised controlled design | n: 24 mean age: Not reported gender: 71% male ethnicity: not reported ID = severe / profound 100% | Inpatient | Intervention: Participants received their full antipsychotic dosage during the first week, a half dosage during the second week, and no medication thereafter for 4 weeks. The control group were not taking psychotropic medicines prior to the study Medication: trifluoperazine, thioridazine, periciazine, haloperidol Duration: Over one week Length of follow up: 8 weeks after discontinuation | DISCO | The antipsychotic medication group was rated as having higher total dyskinesia scores. However, examination of three Group by Time interactions indicated that the symptom scores rose more rapidly for the control group. |
Carpenter et al. 1990 USA [36] | Prospective non randomised controlled design | n: 10 mean age: 30 (18 to 53) gender: 90% male ethnicity: 70% black 30% white ID = borderline 10% mild 50% moderate 10% severe 30% | Inpatient | Intervention: Reduction of antipsychotic medication by 25–100%,; no medication changes in control group Medication: chlorpromazine, Thioridazine, haloperidol Duration: Not reported Length of follow up: Not reported | Performance on a discrimination task requiring matching of colours presented sequentially on a computer screen | Group that had their medicines deprescribed achieved better scores than control group. |
Gerrard et al. 2019 U.K. [37] | Prospective non randomised controlled design | n: 54 (may include participants also reported in Gerrard 2020 [38]) mean age: Not reported gender: 50% male ethnicity: not reported ID = mild 16 (30%) moderate 16 (30%) severe 20 (37%) profound 2 (3%) | Community | Intervention: The experimental group were considered for deprescribing with input from specialist PBS team, while the control group underwent unsupported medication challenge. Medication: amisulpride 5%, aripiprazole 29%, olanzapine 5%, quetiapine 9%, risperidone 52% Duration: Variable Length of follow up: Variable | Number of patients who: agreed to initiation of a reduction schedule agreed to subsequent reductions had medication reviews discontinued medication Number of patients restarted on medication Number of patients achieving 25, 50% or 75% reduction Number of patients who had medication increased | There was a significantly higher success rate for medication reduction and discontinuation when PBS assessment and intervention was provided. At each stage of the process, initiating a reduction schedule, there is a difference between the two groups, pointing to greater success with the support of PBS. Complete discontinuation: 60% in PBS group 15% in non PBS group At least 50% reduction: 20% in PBS group, 7% in non PBS group Represcribing or dose increases: 1 person in PBS group 66% In non PBS group |
Swanson et al. 1996 USA [39] | Prospective non randomised controlled design | n:80 mean age: 38 gender: 61% male ethnicity: not reported ID = Moderate: 1% Severe: 16% Profound: 80% Unknown: 3% | Inpatient | Intervention: antipsychotic dose reduced by 10% every 3 months until discontinued Medication: risperidone Duration: Variable Length of follow up:6 months post discontinuation | DISCUS ABC | Transient increase in average DISCUS score in antipsychotic only group after withdrawal with return to baseline 6 months after discontinuation. In group antipsychotic plus anticonvulsant no change in scores reported. Transient increase in average ABC during antipsychotic withdrawal in those also prescribed anticonvulsants. |
Wigal et al. 1993 USA [40] | Prospective non randomised controlled design | n: 56 (may include participants also reported in Wigal et al., 1994 [41]) mean age: 33 gender: 64% male ethnicity: not reported ID = severe/profound 96% | Inpatient | Intervention: Medication review and dose reduction programme Four groups compared increase in antipsychotic dose (IN; n = 5), no change in antipsychotic dose (NC; n = 14), reduction in antipsychotic dose of < 25% (SD; n = 21), and reduction in antipsychotic dose of ≥25% (25D, n = 16) Medication: antipsychotic Duration: Variable Length of follow up:10 months | DISCUS Proportion of participants with dyskinesia Number of participants discontinuing and decreasing dosage | No difference in DISCUS score between groups at baseline; DISCUS score at follow-up was increased in NC, SD, and 25D groups—greatest increase observed in 25D group; DISCUS score at follow- up decreased in the IN group; significant correlation observed between degree of dose reduction and DISCUS score (r = 0·51; p < 0·001); proportion with dyskinesia increased from 30% at baseline to 60% at follow-up in the 25D group, did not change in the SD or NC groups, and fell from 60 to 20% in the IN group. |
Wigal et al. 1994 USA [41] | Prospective non randomised controlled design | n:43 (may include participants also reported in Wigal et al., 1993 [40]) mean age: 24 gender:67% male ethnicity: not reported ID = Severe/ Profound: 86% | Inpatient | Intervention: Medication review and dose reduction programme Medication: antipsychotics Duration: Variable Length of follow up:10 months | Rates of dyskinesia | 63% of discontinuation group and 29% of dose reduction group developed dyskinesia. No dyskinesia reported in participants in no change, increase or unmedicated group. |
Zuddas et al. 2000 Italy [42] | Prospective non randomised controlled design | n:10 mean age: 12.3 (7 to 17) gender: 70% male ethnicity: not reported ID = mild 2 Moderate 5 Severe 3 | Community | Intervention: Following open label treatment with risperidone, three patients discontinued Medication: risperidone Duration: Medication tapered over 3 to 4 weeks Length of follow up: 5 months | CARS CPRS CGI C-GAS Kiddie SAD-PL Intellectual functioning was measured using the Raven progressive matrices. Physical and neurological examinations, vital signs and measurement of body weight were carried out for all patients at baseline, weekly for the first month and monthly thereafter. | 3 participants discontinued risperidone, 6 months after withdrawal, atypical antipsychotic was represcribed. (risperidone ×  2, olanzapine ×  1) Patients who discontinued risperidone showed progressive behaviour deterioration. |