Cohen 1991.
| Methods | DESIGN: parallel, cluster randomised, no information on blinding DURATION: 12 months NUMBER OF STUDY CENTRES: 1 COUNTRY OF PUBLICATION: USA SPONSOR: ‐ | |
| Participants | WHO PARTICIPATED: hypertensive and obese patients stratified by residents (residents not patients were randomised to intervention or control group)
SETTING: model family practice unit (Pittsburgh) 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 NUMBER (educationally oriented intervention vs standard consultation): 15 vs 15 patients were randomised (10 vs 8 physicians); 15 vs 15 were analysed GENERAL BASELINE CHARACTERISTICS (dietary intervention vs no dietary intervention): MEAN AGE [YEARS]: 59 vs 60 GENDER [% MALE]: 27 vs 27 NATIONALITY: ‐ ETHNICITY: ‐ WEIGHT [kg]: 92 vs 92 BODY MASS INDEX [kg/m2]: 34 vs 34 SITTING SYSTOLIC BLOOD PRESSURE [mm Hg]: ‐ SITTING DIASTOLIC BLOOD PRESSURE [mm Hg]: ‐ MEAN ARTERIAL BLOOD PRESSURE [mm Hg]: 106 vs 106 COMORBID CONDITIONS: obesity ANTIHYPERTENSIVE TREATMENT: (number of medications 1.6 vs 1.2) DURATION OF HYPERTENSION: ‐ SUBGROUP ANALYSES: weight losers vs weight gainer |
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| Interventions | LENGTH OF FOLLOW‐UP: 12 months 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 patient's lifestyle; monthly patient consultations and reviewing diet history sheet; the suggested diets were not specifically intended to be salt reducing NO DIETARY INTERVENTION: physicians (n = 8) received no special instructions or materials; the patients continued to be treated with their usual care |
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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. 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 OUTCOMES MEASURED IN THE STUDY: 1. Mean arterial blood pressure change in mm Hg 2. Change in number of antihypertensive medications 3. Number of visits |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: No details on generation sequence are provided 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) All outcomes | High risk | Comments: No description of randomisation; 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) All outcomes | Unclear risk | WITHDRAWALS: none REASONS/DESCRIPTIONS: ‐ |
| Selective reporting (reporting bias) | Unclear risk | Comment: No primary and secondary outcomes were defined |
| Other bias | High risk | Comments: 1. Lack of information of randomisation 2. Stratified randomisation of investigators instead of patients with very small cluster size |