DISH 1985.

Study characteristics
Methods	Design: parallel, randomised, open Date: not stated Duration: 13 months (56 weeks) Number of study centres: 4 Setting: outpatient clinic, USA
Participants	Who participated: 584 people who were previously enrolled in the HDFP treated with antihypertensive drugs and who had sufficiently controlled hypertension. The dietary change on the return of hypertension after withdrawal of prolonged antihypertensive therapy (dish) included 7 treatment arms; the results of 2 of those arms met the inclusion criteria for this review (hypertensive and obese patients with either dietary intervention or not) Main inclusion criteria: HDFP participants; DBP ≥ 95 mm hg on first screening, confirmed by second screening with DBP ≥ 90 mm hg; patients had received antihypertensive medication for at least 5 years; eligible participants had to be "controlled"; hypertensive persons defined by: no SBP > 180 mm Hg during previous year average DBP < 95 mm Hg during previous year average of last 2 DBP ≤ 90 mm Hg and neither > 95 mm Hg Main exclusion criteria: history of congestive heart failure; myocardial infarction; stroke or transient ischaemic attacks; creatinine level ≥ 2.5 mg/dl; ß‐blocker therapy for angina; glucocorticoid therapy for indefinite period Subgroup analyses: results from participants with mild and severe hypertension (not clear whether subgroups were predefined or post hoc)
Interventions	Dietary intervention: according to revised "metropolitan life insurance" standards; intervention consisted of 8 initial weekly group sessions followed by monthly sessions plus individual consultation as needed (weight loss component of the trial: N = 87) No dietary intervention: no recommendations (weight loss component of the trial: N = 89) Additional treatment: discontinuation of antihypertensive treatment using a step‐down withdrawal programme; bi‐weekly consultations for BP measurement for 16 weeks followed by monthly consultations; no change in salt uptake
Outcomes	Primary outcomes: 1. Mortality: ‐ 2. Cardiovascular morbidity: ‐ 3. Adverse events: Definition: withdrawal due to the need to restart antihypertensive medication 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 endpoint visit Additional outcomes measured in the study: 1. Number of participants without antihypertensive medication 2. Change in sodium excretion
Study details	Length of follow‐up: 13 months (56 weeks ) Trial terminated before regular end (for benefit / because of adverse events): No Trial ID: ‐
Publication details	Language of publication: English Funding: grant from National Heart, Lung and Blood Institute; drugs were supplied by the following companies: Ayerst Laboratories, New York; Merck Sharp & Dohme, West Point, PA; Ciba‐Geigy Corp, Summit, NJ; Boehringer Ingelheim Ltd., Ridgefield, CT; USV Pharmaceutical Corp, Tuckahoe, NY; G.D. Searle & Co, Chicago Publication status: Full‐text journal publication
Study aim	Quote from publication: "... to determine whether long‐term aggressive antihypertensive therapy can be withdrawn in selected patients without relapse and if the substitution of dietary modification will reduce the recidivism rate."
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: No details on sequence generation are provided
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: Open design; participants and investigators not blinded; no information on blinding for outcome assessors
Blinding (performance bias and detection bias) Change in blood pressure	Unclear risk	Comment: Outcome not reported
Blinding (performance bias and detection bias) Change in body weight	Unclear risk	Comment: Open design; participants and investigators not blinded; no information on blinding for outcome assessors
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	High risk	Comment: Only withdrawals due to the need to resume antihypertensive medication were reported; no other adverse events were reported
Incomplete outcome data (attrition bias) Change in blood pressure	Unclear risk	Comment: Outcome not reported
Incomplete outcome data (attrition bias) Change in body weight	High risk	Comment: Withdrawals: and reasons/descriptions (dietary intervention vs no dietary intervention): concerning the endpoint success of withdrawal from antihypertensive medication: 0 vs 0; concerning body weight at week 56: 20 vs 12; although there were no losses to follow‐up in the relevant subgroups for success of discontinuing antihypertensive treatment, for 13% respectively 23% participants weight at week 56 is not reported
Selective reporting (reporting bias)	Unclear risk	Comment: No study protocol available; no primary and secondary outcomes were defined in the publications
Other bias	High risk	Comment: 1. Randomisation before consent of participants (possible selection bias) 2. Different body weight at baseline 3. Participants were in previous trial for 5 years (selected population may not be representative)