Tsunoda K, Uchida H, Suzuki T, et al. Effects of discontinuing benzodiazepine-derivative hypnotics on postural sway and cognitive functions in the elderly. International Journal of Geriatric Psychiatry 2010;25:1259-65
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/20054834
Full text article: https://onlinelibrary.wiley.com/doi/full/10.1002/gps.2465
| Methods | Study design: Before-and-after study
Number of groups: One group |
| Participants | Number of participants: 30 enrolled, 24 completed
Age*: 79.1 ± 8.9 years (range 50 – 77 years) Sex: 13 females, 17 males Participants with dementia: Yes · 7 participants diagnosed with dementia · 23 not diagnosed with dementia Baseline MMSE: 21.6 ± 4.8, range: (8–29) Inclusion criteria: · None stated Exclusion criteria: · History of substance abuse within 6 months of the study · Significant medical condition that required immediate referral to specialists · Individuals whose physician judged their participation inappropriate Country: Japan Setting: Residential aged care facility – Kusonoki-en, a nursing home affiliated with Minamihannou Hospital, in Saitama, Japan between August 2007 and August 2009. It has 98 beds for people aged 60 and older. Approximately half the residents have dementia. |
| Interventions | Medicine:
Benzodiazepines: · Brotizolam n=8 · Flunitrazepam n=7 · Etizolam n=6 · Quazepam n=4 · Estazolam n=4 · Nitrazepam n=2 · Flurazepam n=2 · Diazepam n=1 Withdrawal schedule: Weekly reduction of 25% from baseline each week for three weeks |
| Outcomes | Stability of body
Neuropsychological status Critical Flicker Fusion Test Leeds Sleep Evaluation Questionnaire |
| Dates | Dates: August 2007 and August 2009
Follow-up duration: Eight weeks |
| Funding sources | The authors do not state the funding source for the current study. However, they disclose, “Dr. Uchida has received speaker’s honoraria, manuscript fees, or grants from the Japanese Society of Clinical Neuropsychopharmacology, Pfizer Health Research Foundation, Mochida Memorial Foundation, GlaxoSmithKline, Otsuka, Dainippon Sumitomo Pharma, Janssen Pharmaceutical, and Pfizer within the past 5 years. Dr.Suzuki has received fellowship awards from the Japanese Society of Clinical Neuropsychopharmacology, Government of Canada Post- Doctoral Research Fellowship, and Kanae Foundation. Dr. Watanabe has received speaker’s honoraria, advisory fees, or grants from Pfizer, GlaxoSmithKline, Meiji, Dainippon Sumitomo Pharma, Janssen Pharmaceutical, Eli Lilly, Otsuka, Kyowa Hakko Kirin, and Astellas within the past 5 years.” |
| Notes | *age range given as 50 – 77. However, facility has beds for people 60 years and over, and the mean age is 79.1 years.
The authors state: “Conflict of interest None known.” |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | High risk | Not a randomized study design. |
| Allocation concealment (selection bias) | High risk | No concurrent control group. |
| Blinding of participants and personnel (performance bias) | 5 out of 5 | Open group. |
| Blinding of outcome assessment (detection bias) | 5 out of 5 | Open group. |
| Incomplete outcome data (attrition bias) | 5 out of 5 | As-treated analysis.
Four subjects withdrew prematurely due to insomnia and thus failed to do the end-point assessment. The baseline medicine was reintroduced,and they recovered. Two subjects reduced their dose to 50 and 67% and then refused further tapering. They were excluded from end-point assessment. All 30 patients were accounted for, but non-completers were excluded from the analysis. The reason that these patients dropped out could have been directly related to the outcome of the intervention. |
| Selective reporting (reporting bias) | 5 out of 5 | The outcome criteria were vague. In the intro, only sleep was mentioned. In the procedure, trunk movements and cognitive measures were mentioned. The aim of the paper is unclear.
An a priori published protocol was not available, and the study reports on outcomes that were not specified. |
| Confounding (non-randomized) | 5 out of 5 | No concurrent control group.
Before-and-after measurements to assess change – no control group, so no measurement to assess if the change was affected by factors other than deprescribing benzodiazepine. No list of confounding factors considered before the study but mentioned in discussion. The use of non-benzodiazepine sedatives e.g. chlorpromazine should be considered. |
| Other bias | High risk | At least one outcome was only measured at end-point, so subjective when the authors state that it indicated better sleep than before intervention. This outcome is retrospectively assessed, and, therefore,subject to recall bias. |
| Newcastle-Ottawa scale | ||
| Selection bias | Representativeness of the exposed cohort | Truly representative of the average older adult in residential aged care with dementia who uses a benzodiazepine medicine for sleep. |
| Selection of the non-exposed cohort | No concurrent control group. | |
| Ascertainment of exposure | Ascertainment of exposure was by 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 benzodiazepine withdrawal. |
| Outcome bias | Assessment of outcome | Assessment of outcome: record linkage. |
| Was follow-up long enough for outcomes to occur
|
Follow-up was long enough for outcomes to occur.
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| Adequacy of follow-up of cohorts | Follow-up probably long enough. Four subjects withdrew prematurely due to insomnia and thus failed to do the end-point assessment. The baseline medicine was reintroduced,and they recovered. two subjects reduced their dose to 50 and 67% and then refused further tapering. They were excluded from end-point assessment. | |
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