Kuramoto 1981.
| Methods | Randomised double‐blind placebo‐controlled single‐site study conducted in ambulatory patients in a home for the aged in Tokyo, Japan | |
| Participants | 91 patients 60 years or older; 45% female; mean age 76.1 years; race not stated. Pre‐existing factors not reported. Blood pressure (BP) entry criteria not clearly stated. Mean blood pressure at entry: 169/86 mmHg (isolated systolic hypertension in 44% of participants). Pulse pressure 83 mmHg Inclusion criteria were SBP/DBP 160/90 mmHg to < 200/110 mmHg Exclusion criteria were not mentioned Follow up: 2.7 years |
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| Interventions | Treatment: trichlormethiazide 1 to 4 mg (80% monotherapy) Reserpine (0.3 mg), methyldopa (125 to 500 mg), and hydralazine (50 to 100 mg) added Control: placebo |
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| Outcomes | Mortality, stroke, CHD, CHF Cardiovascular mortality and morbidity includes fatal and non‐fatal stroke, and cerebral haemorrhage fatal and non‐fatal MI, plus CHF with arrhythmia Systolic BP and diastolic BP Dropout due to side effects: not reported Quality of life or functional status outcomes: not reported |
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| Notes | Difference in blood pressure at study end (Treatment ‐ Control) systolic/diastolic: 20/7 mmHg (Mulrow 1994) Data on mortality, cardiovascular mortality and morbidity (does not include TIA), cerebrovascular mortality and morbidity, and CHD mortality and morbidity are available for 60 or older patients and not for 60 to 79 years and 80 years or older subgroups |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: "described as randomised double blind placebo controlled study" "The matched pair group was selected by the age, sex, and blood pressure levels during the drug‐off control period of about 1 year" Comment: method of randomisation was not described |
| Allocation concealment (selection bias) | Unclear risk | Allocation of individuals within matched pairs to treatment and control groups made by a blinded statistical co‐ordinator; thought to be randomised but not entirely clear (unpublished information as per personal conversation with author from Mulrow 1998) |
| Blinding of participant and personnel (performance and detection bias) | Low risk | Quote: "a double‐blind study utilizing 87 out‐patients has been conducted in the Baltimore City Hospitals hypertension clinic to examine the feasibility and value of maintaining patients with essential hypertension on effective long‐term hypotensive therapy" Comment: although study does not state whether patients and physicians were blinded, patients and providers were blinded (unpublished information as per personal conversation with author from Mulrow 1998) |
| Blinding of outcome assessment | High risk | Outcome assessors were not blinded |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Quote: "patients were excluded from the trial when the blood pressure exceeded 200/110, and appearance of cerebrovascular or cardiac complications, other diseases which needed hospital admission, death, or moving out from home were considered to be drop out" "As a whole 9 out of 41 cases or 22.0% in the placebo group, and 4 out of 38 cases or 10.5% in the drug group, dropped out by cerebrovascular or cardiac complications. In addition to the cerebrovascular and cardiac complications, dropouts due to blood pressure elevation were observed in 8 cases in the placebo group, and total dropouts in the placebo group were 17 cases or 41.5%. This incidence was significantly higher than that in the drug treated group (Table IV)" "Six cases of dropout due to moving out from the home were observed in both groups, and follow‐up cases were 38 in the drug group and 41 in the placebo group" For blood pressure measurements, the number of follow‐up cases in the placebo group decreased markedly from 47 to 32, 24, 13, and 7 at the end of each year. The number of follow‐up cases at the end of each year in the drug group declined from 44 to 32, 26, 25, and 22 due to dropouts Comment: follow‐up of participants was incomplete |
| Selective reporting (reporting bias) | Unclear risk | Protocol is not available Comment: insufficient information to judge selective reporting bias |
| Industry sponsorship bias | Unclear risk | Comment: no mention about source of funding and conflict of interest |