Minett TS, C., Thomas A, Wilkinson L, M., et al. What happens when donepezil is suddenly withdrawn? An open label trial in dementia with Lewy bodies and Parkinson’s disease with dementia. International Journal of Geriatric Psychiatry 2003;18:988-93
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/14618549
Full text article: https://onlinelibrary.wiley.com/doi/abs/10.1002/gps.995
| Methods | Study design: Comparative study with two-singlearms
Number of groups: Two groups |
| Participants | Number of participants: 24 enrolled, 19 started deprescribing phase, 9 completed
· Dementia with Lewy Bodies group: 9 enrolled, 8 started deprescribing phase, 4 completed · Parkinson’s Disease Dementia group: 15 enrolled, 11 started deprescribing phase, 5 completed Age: 81 years, median age 73.2 years Sex: Not stated Participants with dementia: All · Dementia with Lewy Bodies, n=9 · Parkinson’s Disease Dementia n=15 Mean MMSE score before administering donepezil · 15.8 for Dementia with Lewy Bodies group · 17.5 for Parkinson’s Disease Dementia group Mean MMSE score after administering donepezil for 20 weeks: · 19.9 for Dementia with Lewy Bodies group · 21.3 for Parkinson’s Disease Dementia group Inclusion criteria: · Primary diagnosis of probable Dementia with Lewy Bodies or Parkinson’s Disease Dementia Exclusion criteria: · Severe gastrointestinal, renal or liver disease · History of cardiac bradyarrhythmias · Asthma · Bladder outflow obstruction, · Recent history of cerebrovascular disease · Taking cholinergic, anti-cholinergic, non-steroidal anti-inflammatory medication or neuroleptic Country: England Setting: Community – single center from Newcastle and Gateshead Old Age Psychiatry and Neurology Out-patient Departments over 12 months |
| Interventions | Medicine: Donepezil 10mg at night or donepezil 5mg at night (highest tolerated dose) for 20 weeks
Withdrawal Schedule: Stopped abruptly after 20 weeks of treatment Comparator: Parkinson’s Disease Dementia and Dementia with Lewy Bodies group to Dementia with Lewy Bodies group |
| Outcomes | MMSE score
Neuropsychiatric Index score Unified Parkinson’s Disease Rating Scale III scores |
| Dates | Dates: Not described
Follow-up duration: 12 months total (20 weeks drug treatment, 6 weeks deprescribing, 26 weeks drug treatment) |
| Funding sources | Contract/grant sponsor: FAPESP; contract/grant number: 99/04928-9 Contract/grant sponsor: CAPES; contract/grant number: BEX 0096/01-6. |
| Notes | Additional information sought, and received. Emailed author to ask age groups for screening:
The mean age for the Dementia with Lewy Bodies group was 81. None of them were younger than 65. |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | High risk | Comparative study with single arms |
| Allocation concealment (selection bias) | High risk | No blinding |
| Blinding of participants and personnel (performance bias) | 5 out of 5 | No blinding |
| Blinding of outcome assessment (detection bias) | 5 out of 5 | No blinding |
| Incomplete outcome data (attrition bias) | 3 out of 5 | Some outcomes are given as the change in outcomes rather than the raw numbers, and in other cases without any absolute values.
No mention of whom and how many participants withdrew. |
| Selective reporting (reporting bias) | 3 out of 5 | All pre-specified measures were reported.
There was no prior published protocol though the stated outcomes are reported with varying levels of detail. “The mean Unified Parkinson’s Disease Rating III scores for both groups of patients did not alter significantly from baseline.” |
| Confounding (non-randomized) | 5 out of 5 | There was no concurrent control group. |
| Other bias | High risk | TSC Minett was supported by grants from FAPESP (99/04928-9) and CAPES (BEX 0096/01-6). |
| Newcastle-Ottawa scale | ||
| Selection bias | Representativeness of the exposed cohort | Selected group of users. |
| Selection of the non-exposed cohort | There was no concurrent control group. | |
| Ascertainment of exposure | Ascertainment of exposure: secure record. | |
| Demonstration that outcome of interest was not present at start of study | Demonstrated that outcome of interest was not present at start of study. | |
| Comparability bias | Comparability of cohorts on the basis of the design or analysis | The study controlled for the cessation of donepezil. |
| Outcome bias | Assessment of outcome | Assessment of outcomes by record linkage. |
| Was follow-up long enough for outcomes to occur | Follow-up was long enough for outcomes to occur – One year would be ideal, but the study ran for half a year, which is sufficient to see change. | |
| Adequacy of follow-up of cohorts | No statement on follow-up. | |
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