Cohen 1991.
| Study characteristics | ||
| Methods | Design: parallel, cluster‐randomised Date: not stated Duration: 12 months Number of study centres: 1 Setting: model family practice unit (Pittsburgh), USA | |
| Participants |
Who participated: 30 hypertensive and obese people stratified by residents (residents, not participants, were randomised to intervention or control group) Main inclusion criteria: age 20 to 75 years; BMI ≥ 28 kg/m2 (men); ≥ 27 kg/m2 (women); SBP ≥ 140 mm Hg, DBP ≥ 90 mm Hg in 2 or more readings Main exclusion criteria: not described in detail Subgroup analyses: weight losers vs weight gainer |
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| Interventions |
Dietary intervention: physicians (n = 10) were taught by a behavioural psychologist; the goal of the dietary advice was to reduce the caloric content of the diet without radically changing the participant's lifestyle; monthly participant consultations and reviewing diet history sheet; the suggested diets were not specifically intended to be salt‐reducing (N = 15)
No dietary intervention: physicians (n = 8) received no special instructions or materials; the participants continued to be treated with their usual care (N = 15) Additional treatment: ‐ |
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| Outcomes |
Primary outcomes: 1. Mortality: ‐ 2. Cardiovascular morbidity: ‐ 3. Adverse events: ‐ Secondary outcomes: 1. Changes in systolic blood pressure [mm Hg]: ‐ 2. Changes in diastolic blood pressure [mm Hg]: ‐ 3. Changes in body weight [kg]: Definition: body weight change from baseline to 6 months, from baseline to 12 months, and from 6 months to 12 months Additional outcome measured in the trial: 1. Mean arterial blood pressure change in mm Hg 2. Change in number of antihypertensive medications 3. Number of visits |
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| Study details |
Length of follow‐up: 12 months Trial terminated before regular end (for benefit / because of adverse events): No Trial ID: ‐ |
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| Publication details |
Language of publication: English Funding: ‐ Publication status: Full‐text journal publication |
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| Study aim | Quote from publication: "...to determine whether this was an effective milieu for the treatment of hypertension by weight reduction using a low‐technology low‐cost approach and involving only the physician as the therapeutic medium." | |
| Notes | ‐ | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Comment: No details on sequence generation are provided; stratified randomisation of investigators instead of participants with very small cluster size Quote: "The residents were stratified by residency year and randomly assigned to either control or experimental groups. ... The experimental or control status of a patient was determined by the status of the physician, and great care was taken to avoid contamination." |
| Allocation concealment (selection bias) | Unclear risk | Comment: Method of concealment is not described |
| Blinding (performance bias and detection bias) Total mortality | Unclear risk | Comment: Outcome not reported |
| Blinding (performance bias and detection bias) Cardiovascular morbidity | Unclear risk | Comment: Outcome not reported |
| Blinding (performance bias and detection bias) Adverse events | Unclear risk | Comment: Outcome not reported |
| Blinding (performance bias and detection bias) Change in blood pressure | High risk | Comment: Since the physicians assigned to the experimental group were taught about the weight‐reducing programme, knowledge of the allocation intervention was not prevented during study |
| Blinding (performance bias and detection bias) Change in body weight | High risk | Comment: Since the physicians assigned to the experimental group were taught about the weight‐reducing programme, knowledge of the allocation intervention was not prevented during study |
| Incomplete outcome data (attrition bias) Total mortality | Unclear risk | Comment: Outcome not reported |
| Incomplete outcome data (attrition bias) Cardiovascular morbidity | Unclear risk | Comment: Outcome not reported |
| Incomplete outcome data (attrition bias) Adverse events | Unclear risk | Comment: Outcome not reported |
| Incomplete outcome data (attrition bias) Change in blood pressure | Low risk | Comment: no withdrawals; all participants were analysed |
| Incomplete outcome data (attrition bias) Change in body weight | Low risk | Comment: No withdrawals; all participants were analysed |
| Selective reporting (reporting bias) | Unclear risk | Comment: No study protocol available; no primary and secondary outcomes were defined in the publication |
| Other bias | Low risk | Comment: Non detected |