Fair JF. Supervised withdrawal of long-term digoxin therapy. Family Practice 1990;7(1):56-59
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/2318375
| Methods | Study design: Before-and-after study
Number of groups: One group |
| Participants | Number of participants: 32 enrolled, 32 completed
Age men: 74.2 years Age women: 83.1 years Sex: 23 females, 9 males Participants with dementia: No Inclusion criteria: · Patient at one practice population · Taking digoxin therapy for longer than three months at the start of the study Exclusion criteria: · Not described Country: Scotland Setting: Community – one general practice population (n=1750), which was predominantlymiddle-class |
| Interventions | Medicine: Digoxin
Withdrawal schedule: Not described |
| Outcomes | Successful deprescribing
Adverse drug withdrawal events Digoxin dose when reinstated |
| Dates | Dates: Not described
Follow-up duration: Four to 11 months |
| Funding sources | Not described |
| Notes | Unclear if patients were aware they were included in the research.
“routine consultation, during routine visits to sheltered accommodation, or by telephone. Those requesting repeat prescriptions were initially asked to make an appointment for reassessmentof their regular medication in order not to provoke unnecessary anxiety.” “The patient’s informed consent to withdrawal from digoxin was obtained.” |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | High risk | Not a randomized study |
| Allocation concealment (selection bias) | High risk | Open single-arm study |
| Blinding of participants and personnel (performance bias) | 5 out of 5 | The study was not blinded. |
| Blinding of outcome assessment (detection bias) | 5 out of 5 | As above. |
| Incomplete outcome data (attrition bias) | 1 out of 5 | It appears that there is 100% follow-up. There has been no statistical analysis undertaken. |
| Selective reporting (reporting bias) | 5 out of 5 | There is no evidence of a pre-specified protocol and analysis plan. No pre-specified outcome and that measurethat were mentionedwere subjective. |
| Confounding (non-randomized) | 5 out of 5 | There is no control group.
No measurement of digoxin levels. No measurement of digoxin levels is a critical miss in the method as these are notorious for being low in the community. The method described is vague and relies on the judgment of individual general practitioners for timing and assessment. |
| Other bias | High risk | The methods section is not sufficiently developed to ascertain other potential sources of bias.
It is not clear if the participants were aware that they were participating in a clinical trial. The researchers appear to have been the participants regular general practitioners, and while “patient’s informed consent to withdrawal from digoxin was obtained” it is not clear that they gave informed consent to participate in a clinical trial. |
| Newcastle-Ottawa scale | ||
| Selection bias | Representativeness of the exposed cohort | The intervention cohort was a selected group of users. |
| Selection of the non-exposed cohort | There was no concurrent control group.
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| Ascertainment of exposure | Ascertainment of exposure was through secure records. | |
| Demonstration that outcome of interest was not present at start of study | Yes. | |
| Comparability bias | Comparability of cohorts on the basis of the design or analysis | The study controls for digoxin exposure. |
| Outcome bias | Assessment of outcome | Outcome assessment through self-report. |
| Was follow-up long enough for outcomes to occur | Follow-upduration appeared to be long enough for outcomes to occur.
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| Adequacy of follow-up of cohorts | Complete follow-up – all subjects accounted for | |
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