Effectiveness of brief structured interventions on risk factor modification for patients with coronary heart disease: a systematic review

Abstract

Background: The physical and psychosocial benefits of participation in cardiac rehabilitation following a coronary event have well been established. Despite these benefits there is strong evidence that participation in traditional cardiac rehabilitation programs remains low. Various models of cardiac rehabilitation have been implemented including the use of brief structured interventions to enable modification of coronary risk factors. Objectives: The objective of this review was to determine the effect of brief structured interventions on risk factor modification in patients with coronary heart disease. Search strategy : A literature search was performed using the following databases MEDLINE (1966-2006) CINAHL (1982-2006), EMBASE (1980-current) and up to the Cochrane Controlled Trials Register (Issue 2, 2006 of Cochrane Library). In addition, the reference lists of relevant trials and conference proceedings were also scrutinised. Company representatives, experts and investigators were contacted to elicit further information. Selection criteria : All randomised and quasi-randomised controlled trials that compared the effects of brief structured interventions on risk factor modification in patients with coronary heart disease were considered for inclusion in the review. Data collection and analysis : Eligibility of the trials for inclusion in the review, details of eligible trials and the methodological quality of the trials were assessed independently by two reviewers. Relative risks for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals. Where synthesis was inappropriate, trials were considered separately. Main results : Seventeen trials involving a total of 4725 participants were included in the final review: three trials compared the effects of brief structured interventions on diet modification; seven on smoking cessation; and seven on multiple risk factors. Two trials involving 76 patients compared brief structured intervention versus usual care for dietary modification. Although there was a tendency for more participants in the intervention arm to lose weight at the 12-week follow up and achieve target cholesterol levels at the 6-month follow up, these results were not statistically significant. Only one small trial involving 36 patients compared brief structured intervention and extensive intervention for dietary modification and demonstrated a significant reduction in the percentage of energy obtained from fat and saturated fat intake among participants receiving extensive intervention. However, no difference in fish, fruit and vegetable intake between the groups was evident. Six trials involving 2020 patients compared brief structured intervention versus usual care for smoking cessation. There was no difference in the smoking cessation rates at the 3- and 6-week follow up, however, there was evidence of a benefit of brief structured interventions for smoking cessation at the 3-, 6- and 12-month follow up. In the only trial that and compared brief structured intervention and extensive intervention for smoking cessation in 254 participants there was no clear difference of a likelihood of smoking cessation between the two groups. In the seven trials that compared brief structured intervention and usual care for multiple risk factor modification there was evidence of a benefit of the intervention on behavioural changes such as fat intake, weight loss and consequently on reduction in the body mass index, smoking cessation and physical activity among the participants. The findings concerning the effect on blood pressure, blood glucose levels and the lipid profile, however, remain inconclusive. Conclusions : There is suggestive but inconclusive evidence from the trials of a benefit in the use of brief interventions for risk factor modification in patients with coronary heart disease. This review, however, supports the concept that brief interventions for patients with coronary heart disease can have beneficial effects on risk factor modification and consequently on progression of coronary heart disease. Further trials using larger sample sizes need to be undertaken to demonstrate the benefits of brief structured intervention targeted at the modification of single or multiple risk factors.