Ekbom T, Lindholm LH, Oden A, et al. A 5-year prospective, observational study of the withdrawal of antihypertensive treatment in elderly people. Journal of Internal Medicine 1994;235:581-88.
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/8207364
| Methods | Study design: Before-and-after study
Number of groups: One group |
| Participants | Number of participants: 333 enrolled
Age baseline: 75.2 ± 3.8 years (range: 70 to 84 years) Age end study: 80.4 ± 4.8 years Sex: 226 female, 107 male Participants with dementia: No Inclusion criteria: · Aged 70 to 84 years · Untreated or treated essential hypertension · Three separate occasions during a 1-month placebo run-in phase in previously untreated patients (run-in phase was preceded by a 1-6-month wash-out period in previously treated patients): o Systolic pressure was 180 mm Hg or above, and diastolic pressure of at least 90 mm Hg, or o Diastolic pressure was above 105 mm Hg irrespective of the systolic pressure · Previously treated people who started a wash-out period to ensure that the inclusion criteria of the mainSTOP-Hypertension study were met Exclusion criteria for the STOP-Hypertension trial: · Supine blood pressure above 230 mm Hg systolic and/or120 mm Hg diastolic · Isolated systolic hypertension (180 mm Hg or higher with diastolic below 90 mm Hg) · Orthostatic hypotension (more than 30 mm Hg fall in systolic blood pressure on standing) · Contraindications to any of the drugs · Myocardial infarction or a stroke during the previous 12 months · Angina pectoris requiring treatment with drugs other than glyceryl trinitrate · Other severe or incapacitating illnesses · Unwillingness to take part · Not fully withdrawn their blood pressure-lowering drugs Participants included in the STOP-Hypertension trial but excluded from this study: o Not fully withdrawn their blood pressure-lowering drugs o Received blood pressure-lowering drugs for reasons other than hypertension o Under 70 years Country: Sweden Setting: Community – multicentre study was carried out at 116 health centers(out of 846) throughout Sweden |
| Interventions | Medicine: Antihypertensive
· Single-drug diuretics including potassium supplementation or potassium-sparing agents · Single-drug beta-blockers · Other single-drug therapies (alpha-methyldopa, ACE-inhibitor, clonidine) · Combinations of diuretics and beta-blockers · Other combinations Withdrawal schedule: beta-blockers were recommended to be reduced step-wise over a few days, to minimize sympatheticrebound effects. |
| Outcomes | Probability of restarting antihypertensive therapy
Total mortality Cardiovascular events Comparison of death hazard between the three states and that of the normal Swedish population, matched for age and sex Major reasons for restarting treatment |
| Dates | Dates: Ended January 1991 to June 1992
Follow-up durations: 60 months |
| Funding sources | Astra/Hassle. ICI Pharma, Merck Sharpe & Dohme (Sweden), Sandoz, and the Swedish County Councils, and by a travelinggrant from the Swedish Society of Medicine |
| Notes | This paper describes the preliminary “wash-out” phase of the main study. |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | High risk | This was not a randomized study design. |
| Allocation concealment (selection bias) | High risk | At this stage, they were not yet allocated for the main (STOP-Hypertension) study. There was no concealment.
“Elderly hypertensives aged 70-84 started either a wash-out period (if previously treated) or a run-in period (if previously untreated), to ensure that the inclusion criteria of the main STOP-Hypertension study were met. The present study comprises only the former ‘ wash-out’ group.” |
| Blinding of participants and personnel (performance bias) | 5 out of 5 | 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 the outcomedata is complete. |
| Selective reporting (reporting bias) | 1 out of 5 | There was a pre-specified protocol and analysis for the main study (published)though this did not include the present study. However, the outcomes reported seem to match the stated objectives and are logical for the study.
The apparently additional analysis to compare the observed death rate to the age and sex-matchedexpected death rate seems logical given that 22% of the participants died during the observation period. |
| Confounding (non-randomized) | 5 out of 5 | Open single-arm study.
However, most confounders seem to have been considered. |
| Other bias | Low risk | |
| Newcastle-Ottawa scale | ||
| Selection bias | Representativeness of the exposed cohort | Somewhat representative of a relatively healthy cohort of older community-dwelling adults. |
| Selection of the non-exposed cohort | There is no concurrent control group.
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| Ascertainment of exposure | Ascertainment of exposure was by securerecord. | |
| Demonstration that outcome of interest was not present at start of study | Demonstration that outcome of interest was not present at the start of the study. | |
| Comparability bias | Comparability of cohorts on the basis of the design or analysis | The studycontrols for the cessationof medication. |
| Outcome bias | Assessment of outcome | Assessment of outcome was by record linkage. |
| Was follow-up long enough for outcomes to occur | The follow-up duration was not 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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