Characteristics associated with informed consent for genetic studies in the ACCORD trial

BACKGROUND

Prior studies found that some groups have lower genetic consent rates than others. Participant consent for genetic studies enables randomized trials to examine effects of interventions compared to control in participants with different genotypes.

METHODS

Unadjusted and multivariate associations between genetic consent rates and participant, study, and consent characteristics in 9573 participants approached for genetics consent in the multicenter Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, which used a layered genetics consent.

RESULTS

Eighty-nine percent of eligible participants consented to genetic studies ("Any Consent") and 64.7% consented to studies of any genes by any investigator ("Full Consent"), with similar rates in randomized groups. Controlling for multiple characteristics, African-Americans had lower consent rates than others (Any Consent Odds Ratio, OR = 0.62, p = 0.0004; Full Consent OR = 0.67, p < 0.0001). Those with high school or higher education level had higher rates than less than high school graduates (Full Consent ORs 1.41-1.69, p-values < 0.0001). Consent rates were lower when genetics consent was separate from the main trial consent on the same day (Any Consent OR 0.30; Full Consent OR 0.52, p values < 0.0001) or on a subsequent day (Any Consent OR 0.70, p = 0.0022; Full Consent OR 0.76, p = 0.0002).

CONCLUSION

High rates of consent for genetic studies can be obtained in complex randomized trials, with lower consent rates in African-Americans, in participants with less than high-school education, and for sharing samples with other investigators. A genetics consent separated from the main trial consent was associated with lower consent rates.

Effects of combination lipid therapy in type 2 diabetes mellitus

BACKGROUND

We investigated whether combination therapy with a statin plus a fibrate, as compared with statin monotherapy, would reduce the risk of cardiovascular disease in patients with type 2 diabetes mellitus who were at high risk for cardiovascular disease.

METHODS

We randomly assigned 5518 patients with type 2 diabetes who were being treated with open-label simvastatin to receive either masked fenofibrate or placebo. The primary outcome was the first occurrence of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The mean follow-up was 4.7 years.

RESULTS

The annual rate of the primary outcome was 2.2% in the fenofibrate group and 2.4% in the placebo group (hazard ratio in the fenofibrate group, 0.92; 95% confidence interval [CI], 0.79 to 1.08; P=0.32). There were also no significant differences between the two study groups with respect to any secondary outcome. Annual rates of death were 1.5% in the fenofibrate group and 1.6% in the placebo group (hazard ratio, 0.91; 95% CI, 0.75 to 1.10; P=0.33). Prespecified subgroup analyses suggested heterogeneity in treatment effect according to sex, with a benefit for men and possible harm for women (P=0.01 for interaction), and a possible interaction according to lipid subgroup, with a possible benefit for patients with both a high baseline triglyceride level and a low baseline level of high-density lipoprotein cholesterol (P=0.057 for interaction).

CONCLUSIONS

The combination of fenofibrate and simvastatin did not reduce the rate of fatal cardiovascular events, nonfatal myocardial infarction, or nonfatal stroke, as compared with simvastatin alone. These results do not support the routine use of combination therapy with fenofibrate and simvastatin to reduce cardiovascular risk in the majority of high-risk patients with type 2 diabetes. (ClinicalTrials.gov number, NCT00000620.)

Effects of intensive blood-pressure control in type 2 diabetes mellitus

BACKGROUND

There is no evidence from randomized trials to support a strategy of lowering systolic blood pressure below 135 to 140 mm Hg in persons with type 2 diabetes mellitus. We investigated whether therapy targeting normal systolic pressure (i.e., <120 mm Hg) reduces major cardiovascular events in participants with type 2 diabetes at high risk for cardiovascular events.

METHODS

A total of 4733 participants with type 2 diabetes were randomly assigned to intensive therapy, targeting a systolic pressure of less than 120 mm Hg, or standard therapy, targeting a systolic pressure of less than 140 mm Hg. The primary composite outcome was nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The mean follow-up was 4.7 years.

RESULTS

After 1 year, the mean systolic blood pressure was 119.3 mm Hg in the intensive-therapy group and 133.5 mm Hg in the standard-therapy group. The annual rate of the primary outcome was 1.87% in the intensive-therapy group and 2.09% in the standard-therapy group (hazard ratio with intensive therapy, 0.88; 95% confidence interval [CI], 0.73 to 1.06; P=0.20). The annual rates of death from any cause were 1.28% and 1.19% in the two groups, respectively (hazard ratio, 1.07; 95% CI, 0.85 to 1.35; P=0.55). The annual rates of stroke, a prespecified secondary outcome, were 0.32% and 0.53% in the two groups, respectively (hazard ratio, 0.59; 95% CI, 0.39 to 0.89; P=0.01). Serious adverse events attributed to antihypertensive treatment occurred in 77 of the 2362 participants in the intensive-therapy group (3.3%) and 30 of the 2371 participants in the standard-therapy group (1.3%) (P<0.001).

CONCLUSIONS

In patients with type 2 diabetes at high risk for cardiovascular events, targeting a systolic blood pressure of less than 120 mm Hg, as compared with less than 140 mm Hg, did not reduce the rate of a composite outcome of fatal and nonfatal major cardiovascular events. (ClinicalTrials.gov number, NCT00000620.)

Effect of intensive compared with standard glycemia treatment strategies on mortality by baseline subgroup characteristics: the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial

OBJECTIVE

To determine if baseline subgroups in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial can be identified for whom intensive compared with standard glycemia treatment had different effects on all-cause mortality.

RESEARCH DESIGN AND METHODS

Exploratory post hoc intention-to-treat comparisons were made between intensive and standard glycemia groups on all-cause mortality by subgroups defined by baseline characteristics.

RESULTS

There were few significant interactions between baseline characteristics and effects of intensive versus standard glycemia treatment on mortality: self-reported history of neuropathy (hazard ratio [HR] 1.95, 95% CI 1.41-2.69) versus no history of neuropathy (0.99, 0.79-1.26; P value for interaction 0.0008), higher A1C (A1C >8.5%: HR 1.64, 95% CI 1.22-2.22; A1C 7.5-8.4%: 1.00, 0.75-1.34; A1C <7.5%: 1.00, 0.67-1.50; P value for interaction 0.04), and aspirin use (HR 1.45, 95% CI 1.13-1.85, compared with 0.96, 0.72-1.27, in nonusers; P value for interaction 0.03).

CONCLUSIONS

We found a remarkable similarity of effect from intensive compared with standard glycemia treatment on mortality across most baseline subgroups. No differential effect was found in subgroups defined by variables anticipated to have an interaction: age, duration of diabetes, and previous history of cardiovascular disease. The three baseline characteristics that defined subgroups for which there was a differential effect on mortality may help identify patients with type 2 diabetes at higher risk of mortality from intensive regimens for glycemic control. Further research is warranted.

Effects of combination lipid therapy in type 2 diabetes mellitus

BACKGROUND

We investigated whether combination therapy with a statin plus a fibrate, as compared with statin monotherapy, would reduce the risk of cardiovascular disease in patients with type 2 diabetes mellitus who were at high risk for cardiovascular disease.

METHODS

We randomly assigned 5518 patients with type 2 diabetes who were being treated with open-label simvastatin to receive either masked fenofibrate or placebo. The primary outcome was the first occurrence of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The mean follow-up was 4.7 years.

RESULTS

The annual rate of the primary outcome was 2.2% in the fenofibrate group and 2.4% in the placebo group (hazard ratio in the fenofibrate group, 0.92; 95% confidence interval [CI], 0.79 to 1.08; P=0.32). There were also no significant differences between the two study groups with respect to any secondary outcome. Annual rates of death were 1.5% in the fenofibrate group and 1.6% in the placebo group (hazard ratio, 0.91; 95% CI, 0.75 to 1.10; P=0.33). Prespecified subgroup analyses suggested heterogeneity in treatment effect according to sex, with a benefit for men and possible harm for women (P=0.01 for interaction), and a possible interaction according to lipid subgroup, with a possible benefit for patients with both a high baseline triglyceride level and a low baseline level of high-density lipoprotein cholesterol (P=0.057 for interaction).

CONCLUSIONS

The combination of fenofibrate and simvastatin did not reduce the rate of fatal cardiovascular events, nonfatal myocardial infarction, or nonfatal stroke, as compared with simvastatin alone. These results do not support the routine use of combination therapy with fenofibrate and simvastatin to reduce cardiovascular risk in the majority of high-risk patients with type 2 diabetes. (ClinicalTrials.gov number, NCT00000620.)

The Scientific Foundation for personal genomics: recommendations from a National Institutes of Health-Centers for Disease Control and Prevention multidisciplinary workshop

The increasing availability of personal genomic tests has led to discussions about the validity and utility of such tests and the balance of benefits and harms. A multidisciplinary workshop was convened by the National Institutes of Health and the Centers for Disease Control and Prevention to review the scientific foundation for using personal genomics in risk assessment and disease prevention and to develop recommendations for targeted research. The clinical validity and utility of personal genomics is a moving target with rapidly developing discoveries but little translation research to close the gap between discoveries and health impact. Workshop participants made recommendations in five domains: (1) developing and applying scientific standards for assessing personal genomic tests; (2) developing and applying a multidisciplinary research agenda, including observational studies and clinical trials to fill knowledge gaps in clinical validity and utility; (3) enhancing credible knowledge synthesis and information dissemination to clinicians and consumers; (4) linking scientific findings to evidence-based recommendations for use of personal genomics; and (5) assessing how the concept of personal utility can affect health benefits, costs, and risks by developing appropriate metrics for evaluation. To fulfill the promise of personal genomics, a rigorous multidisciplinary research agenda is needed.

Effects of intensive glucose lowering in type 2 diabetes

BACKGROUND

Epidemiologic studies have shown a relationship between glycated hemoglobin levels and cardiovascular events in patients with type 2 diabetes. We investigated whether intensive therapy to target normal glycated hemoglobin levels would reduce cardiovascular events in patients with type 2 diabetes who had either established cardiovascular disease or additional cardiovascular risk factors.

METHODS

In this randomized study, 10,251 patients (mean age, 62.2 years) with a median glycated hemoglobin level of 8.1% were assigned to receive intensive therapy (targeting a glycated hemoglobin level below 6.0%) or standard therapy (targeting a level from 7.0 to 7.9%). Of these patients, 38% were women, and 35% had had a previous cardiovascular event. The primary outcome was a composite of nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes. The finding of higher mortality in the intensive-therapy group led to a discontinuation of intensive therapy after a mean of 3.5 years of follow-up.

RESULTS

At 1 year, stable median glycated hemoglobin levels of 6.4% and 7.5% were achieved in the intensive-therapy group and the standard-therapy group, respectively. During follow-up, the primary outcome occurred in 352 patients in the intensive-therapy group, as compared with 371 in the standard-therapy group (hazard ratio, 0.90; 95% confidence interval [CI], 0.78 to 1.04; P=0.16). At the same time, 257 patients in the intensive-therapy group died, as compared with 203 patients in the standard-therapy group (hazard ratio, 1.22; 95% CI, 1.01 to 1.46; P=0.04). Hypoglycemia requiring assistance and weight gain of more than 10 kg were more frequent in the intensive-therapy group (P<0.001).

CONCLUSIONS

As compared with standard therapy, the use of intensive therapy to target normal glycated hemoglobin levels for 3.5 years increased mortality and did not significantly reduce major cardiovascular events. These findings identify a previously unrecognized harm of intensive glucose lowering in high-risk patients with type 2 diabetes. (ClinicalTrials.gov number, NCT00000620.)

Effects of individual components of multiple behavior changes: the PREMIER trial

OBJECTIVES

To assess contributions of individual lifestyle changes on systolic blood pressure (SBP) changes.

METHODS

We examined associations between lifestyle behavior changes and SBP after 6 and 18 months in 782 PREMIER trial participants.

RESULTS

In multivariate models omitting weight, predicted SBP reductions ranged from (1)/2 to 1(1)/2 mm Hg for reduced urinary sodium, improved fitness, and adherence to the DASH diet (except sodium at 18 months). With weight included, only fitness change additionally predicted SBP at 18 months.

CONCLUSIONS

Several lifestyle behavior changes are important for BP lowering, but are difficult to detect when weight is included in multivariate models.

Severe hypoglycemia monitoring and risk management procedures in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial

Hypoglycemia is a potentially serious side effect of blood glucose lowering in diabetes mellitus. The intensive glycemia treatment arm of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is designed to treat patients with type 2 diabetes with target glycemia within the normal range (ie, glycosylated hemoglobin <6%). Because it is known that treating glycemia to such a low level in patients with diabetes will result in episodes of hypoglycemia, it is necessary to address prevention and treatment of such episodes to ensure patient safety. Thus, several approaches are being taken in the ACCORD trial to prevent initial episodes of severe hypoglycemia, to monitor the frequency of episodes that do occur, and to prevent recurrence. This report describes the processes used in the ACCORD trial, including the definition of severe hypoglycemia, the type of education provided to participants and staff members to prevent initial and subsequent episodes of severe hypoglycemia, and the monitoring systems implemented to identify severe hypoglycemia and prevent its recurrence. The ACCORD trial conducts review and oversight of individual cases of severe hypoglycemia and monitors rates of severe hypoglycemia by clinical site and treatment arm. If the ACCORD intensive glycemia treatment is found to be efficacious in preventing cardiovascular disease events, assessment of the risk and benefit will be essential. In addition, translation of the principles behind the monitoring of severe hypoglycemia in ACCORD into feasible strategies for use in clinical practice will be needed.

Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial: design and methods

Most patients with type 2 diabetes mellitus develop cardiovascular disease (CVD), with substantial loss of life expectancy. Nonfatal CVD contributes greatly to excess healthcare costs and decreased quality of life in patients with diabetes. The current epidemic of obesity has raised expectations that CVD associated with type 2 diabetes will become an even greater public health challenge. Despite the importance of this health problem, there is a lack of definitive data on the effects of the intensive control of glycemia and other CVD risk factors on CVD event rates in patients with type 2 diabetes. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial is a randomized, multicenter, double 2 x 2 factorial design study involving 10,251 middle-aged and older participants with type 2 diabetes who are at high risk for CVD events because of existing CVD or additional risk factors. ACCORD is testing the effects of 3 medical treatment strategies to reduce CVD morbidity and mortality. All participants are in the glycemia trial, which is testing the hypothesis that a therapeutic strategy that targets a glycosylated hemoglobin (HbA1c) level of <6.0% will reduce the rate of CVD events more than a strategy that targets an HbA1c level of 7.0%-7.9%. The lipid trial includes 5,518 of the participants, who receive either fenofibrate or placebo in a double-masked fashion to test the hypothesis of whether, in the context of good glycemic control, a therapeutic strategy that uses a fibrate to increase high-density lipoprotein cholesterol and lower triglyceride levels together with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) to lower low-density lipoprotein cholesterol will reduce the rate of CVD events compared with a strategy that uses a statin plus a placebo. The blood pressure trial includes the remaining 4,733 participants and tests the hypothesis that a therapeutic strategy that targets a systolic blood pressure of <120 mm Hg in the context of good glycemic control will reduce the rate of CVD events compared with a strategy that targets a systolic blood pressure of <140 mm Hg. The primary outcome measure for all 3 research questions is the first occurrence of a major CVD event, specifically nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Upon the expected completion of participant follow-up in 2009, the ACCORD trial should document for the first time the benefits and risks of intensive glucose control, intensive blood pressure control, and the combination of fibrate and statin drugs in managing blood lipids in high-risk patients with type 2 diabetes.

Prevention of cardiovascular disease in persons with type 2 diabetes mellitus: current knowledge and rationale for the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial

Patients with type 2 diabetes mellitus die of cardiovascular disease (CVD) at rates 2-4 times higher than patients without diabetes but with similar demographic characteristics. The prevalence of diabetes is increasing in the United States and, thus, the prevention of CVD in patients with diabetes poses an urgent public health challenge. The objective of this report is to review the current knowledge base for the prevention of CVD in patients with diabetes, with particular emphasis on the control of glycemia, lipids, and blood pressure. Epidemiologic analyses suggest that each 1% increase in glycosylated hemoglobin increases the risk for CVD by approximately 18%; however, evidence from the randomized trials that have examined whether glucose lowering reduces this risk is conflicting. Randomized trials have shown that lowering low-density lipoprotein cholesterol reduces CVD event rates by 17%-43% in patients with diabetes. Limited data support a role for lowering triglycerides and increasing high-density lipoprotein cholesterol in the prevention of CVD. Evidence from clinical trials shows that reducing systolic blood pressure to <140 mm Hg results in 30%-60% reductions in CVD events; however, epidemiologic evidence suggests that lowering to optimal systolic blood pressure levels (<120 mm Hg) may be additionally beneficial. Important questions regarding prevention of CVD in patients with diabetes remain unresolved, including the benefits of near-normal glycemic control, comprehensive therapy for diabetes-related dyslipidemia, and optimal blood pressure control. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial will test hypotheses to address these unanswered questions.

Higher self-reported physical activity is associated with lower systolic blood pressure: the Dietary Intervention Study in Childhood (DISC)

OBJECTIVE

Children participating in a dietary clinical trial were studied to (1) assess physical activity patterns in boys and girls longitudinally from late childhood through puberty and (2) determine the association of level of physical activity on systolic blood pressure, low-density lipoprotein cholesterol, and BMI.

PATIENTS AND METHODS

In the Dietary Intervention Study in Childhood, a randomized clinical trial of a reduced saturated fat and cholesterol diet in 8- to 10-year-olds with elevated low-density lipoprotein, a questionnaire that determined time spent in 5 intensity levels of physical activity was completed at baseline and at 1 and 3 years. An estimated-metabolic-equivalent score was calculated for weekly activity; hours per week were calculated for intense activities. We hypothesized that weekly self-reported physical activity would be associated with lower systolic blood pressure, low-density lipoprotein, and BMI over 3 years. Longitudinal data analyses were performed for each outcome (systolic blood pressure, low-density lipoprotein, and BMI) by using generalized estimating equations with estimated-metabolic-equivalent score per week as the independent variable adjusted for visit, gender, and Tanner stage (BMI was included in models for systolic blood pressure and low-density lipoprotein).

RESULTS

The initial study cohort comprised 663 youths (362 boys [mean age: 9.7 years] and 301 girls [mean age: 9.0 years], of whom 623 (94%) completed the 3-year visit. For every 100 estimated-metabolic-equivalent hours of physical activity, there was a decrease of 1.15 mmHg of systolic blood pressure. There was a 1.28 mg/dL decline in low-density lipoprotein for a similar energy expenditure. For BMI, an analysis of intense physical activity showed that for every 10 hours of intense activity, there was a trend toward significance with a 0.2 kg/m2 decrease.

CONCLUSIONS

Children with elevated cholesterol levels who lead a more physically active lifestyle have lower systolic blood pressure and a trend toward lower low-density lipoprotein over a 3-year interval. Long-term participation in intense physical activity may reduce BMI as well.

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension.

Design of the Trial of Activity in Adolescent Girls (TAAG)

The primary aim of the Trial of Activity in Adolescent Girls (TAAG) is to test an intervention to reduce by half the age-related decline in moderate to vigorous physical activity (MVPA) in middle school girls. The intervention will be evaluated using a group-randomized trial involving 36 middle schools. The primary endpoint is the mean difference in intensity-weighted minutes (i.e., MET-minutes) of MVPA between intervention and comparison schools assessed using accelerometry. The TAAG study design calls for two cross-sectional samples, one drawn from 6th graders at the beginning of the study and the second drawn from 8th graders at the end of the study following the 2-year implementation of the intervention. An important strength of this design over a cohort design is the consistency with the goals of TAAG, which focus on environmental-level rather than individual-level interventions to produce change. The study design specifies a recruitment rate of 80% and a smaller sample of girls at baseline (n=48 per school) than at follow-up (n=96 per school). A two-stage model will be used to test the primary hypothesis. In the first stage, MET-weighted minutes of MVPA will be regressed on school, time (baseline or follow-up), their interaction, ethnicity and week of data collection. The second stage analysis will be conducted on the 72 adjusted means from the first stage. In the main-effects model, we will regress the follow-up school mean MET-weighted minutes of MVPA on study condition, adjusting for the baseline school mean. The TAAG study addresses an important health behavior, and also advances the field of group-randomized trials through the use of a study design and analysis plan tailored to serve the main study hypothesis.

Effect of the Dietary Approaches to Stop Hypertension Diet and Reduced Sodium Intake on Blood Pressure Control

The authors hypothesized that the Dietary Approaches to Stop Hypertension (DASH) diet and reduced sodium intake would control stage 1 hypertension and reduce high-normal blood pressure (BP) to optimal levels. Adults with systolic BP 120-159 mm Hg and diastolic BP 80-95 mm Hg were randomly assigned to receive the DASH diet or a typical American (control) diet, consuming three different sodium intakes (higher=142 mmol/d, intermediate=107 mmol/d, and lower=65 mmol/d) for 30 days each. BP control was defined as systolic BP <140 mm Hg and diastolic BP <90 mm Hg. Among subjects with hypertension at baseline, at higher sodium intake the DASH diet increased BP control two-fold over control (63% vs. 32%; 95% confidence interval, 1.4-2.9). Reducing sodium intake in the control diet group increased BP control 2.3-fold (74% vs. 32%; 95% confidence interval, 1.7-3.2). The maximum BP control rate (84%) was achieved with the DASH/lower sodium diet. BP became normal or optimal in 71% of persons consuming the control/lower sodium diet and 77% of persons consuming the DASH/lower sodium diet. Both the DASH diet and reduced sodium intake improved BP control.

Premier: a clinical trial of comprehensive lifestyle modification for blood pressure control: rationale, design and baseline characteristics

PURPOSE

To describe PREMIER, a randomized trial to determine the effects of multi-component lifestyle interventions on blood pressure (BP).

METHODS

Participants with above optimal BP through stage 1 hypertension were randomized to: 1) a behavioral lifestyle (BLS) intervention that implements established recommendations, 2) a BLS intervention that implements established recommendations plus the DASH diet, or 3) an advice only standard of care group. The two BLS interventions consist of group and individual counseling sessions for 18 months. The primary outcome is systolic BP at 6 months. Additional outcomes include diastolic BP and homocysteine at 6 months; systolic and diastolic BP at 18 months; fasting lipids, glucose and insulin at 6 and 18 months; and effects in subgroup.

CONCLUSION

Results from the PREMIER trial will provide scientific rationale for implementing multi-component behavioral lifestyle intervention programs to control BP and prevent CVD.

Effects of diet and sodium intake on blood pressure: subgroup analysis of the DASH-sodium trial

BACKGROUND

Initial findings from the Dietary Approaches to Stop Hypertension (DASH)-Sodium Trial demonstrated that reduction of sodium intake in two different diets decreased blood pressure in participants with and without hypertension.

OBJECTIVE

To determine effects on blood pressure of reduced sodium intake and the DASH diet in additional subgroups.

DESIGN

Randomized feeding study.

SETTING

Four clinical centers and a coordinating center.

PARTICIPANTS

412 adults with untreated systolic blood pressure of 120 to 160 mm Hg and diastolic blood pressure of 80 to 95 mm Hg.

INTERVENTION

Participants followed the DASH diet or a control (typical U.S.) diet for three consecutive 30-day feeding periods, during which sodium intake (50, 100, and 150 mmol/d at 2100 kcal) varied according to a randomly assigned sequence. Body weight was maintained.

MEASUREMENTS

Systolic and diastolic blood pressure.

RESULTS

In all subgroups, the DASH diet and reduced sodium intake were each associated with significant decreases in blood pressure; these two factors combined produced the greatest reductions. Among nonhypertensive participants who received the control diet, lower (vs. higher) sodium intake decreased blood pressure by 7.0/3.8 mm Hg in those older than 45 years of age (P < 0.001) and by 3.7/1.5 mm Hg in those 45 years of age or younger (P < 0.05).

CONCLUSION

The DASH diet plus reduced sodium intake is recommended to control blood pressure in diverse subgroups.

Angiotensinogen genotype and blood pressure response in the Dietary Approaches to Stop Hypertension (DASH) study

OBJECTIVE

To determine the relationship between angiotensinogen (ANG) genotype and blood pressure response to the dietary patterns of the Dietary Approaches to Stop Hypertension (DASH) trial. The angiotensin converting enzyme (ACE) gene was also tested.

DESIGN

The DASH trial was a randomized outpatient feeding study comparing the effects on blood pressure (BP) of three dietary patterns: a control diet, similar to typical American intake; a 'fruits and vegetables' diet (F/V) that is rich in fruits and vegetables but otherwise resembles the control diet; and the DASH diet that is reduced in fats and that emphasizes fruits, vegetables and low-fat dairy products. Participants' genotype was also determined.

SETTING

Four clinical sites.

PARTICIPANTS

Adults with above-optimal BP or stage 1 hypertension.

INTERVENTION

Participants ate one of the three dietary patterns for 8 weeks. Sodium intake and weight were held constant. In 355 of 459 DASH participants, DNA was extracted from leukocytes and genotyped for the G-6A ANG polymorphism and the D/I ACE polymorphism, by the polymerase chain reaction.

MAIN OUTCOMES

Genotype at ANG and ACE loci; BP after 8 weeks of intervention diet.

RESULTS

There was no association between ACE genotype and BP response. Associations with ANG polymorphism were significant: net systolic and diastolic BP response to the DASH diet was greatest in individuals with the AA genotype (-6.93/-3.68 mmHg) and least in those with the GG genotype (-2.80/0.20 mmHg). A similar relationship existed for the F/V diet.

CONCLUSIONS

ANG genotype is associated with BP response to the DASH diet. The AA genotype confers excess risk of hypertension and is associated with increased responsiveness to diet.

Long-term safety and efficacy of a cholesterol-lowering diet in children with elevated low-density lipoprotein cholesterol: seven-year results of the Dietary Intervention Study in Children (DISC)

OBJECTIVE

Diets reduced in fat and cholesterol are recommended for children over 2 years of age, yet long-term safety and efficacy are unknown. This study tests the long-term efficacy and safety of a cholesterol-lowering dietary intervention in children.

METHODS

Six hundred sixty-three children 8 to 10 years of age with elevated low-density lipoprotein cholesterol (LDL-C) were randomized to a dietary intervention or usual care group, with a mean of 7.4 years' follow-up. The dietary behavioral intervention promoted adherence to a diet with 28% of energy from total fat, <8% from saturated fat, up to 9% from polyunsaturated fat, and <75 mg/1000 kcal cholesterol per day. Serum LDL-C, height, and serum ferritin were primary efficacy and safety outcomes.

RESULTS

Reductions in dietary total fat, saturated fat, and cholesterol were greater in the intervention than in the usual care group throughout the intervention period. At 1 year, 3 years, and at the last visit, the intervention compared with the usual care group had 4.8 mg/dL (.13 mmol/L), 3.3 mg/dL (.09 mmol/L), and 2.0 mg/dL (.05 mmol/L) lower LDL-C, respectively. There were no differences at any data collection point in height or serum ferritin or any differences in an adverse direction in red blood cell folate, serum retinol and zinc, sexual maturation, or body mass index.

CONCLUSION

Dietary fat modification can be achieved and safely sustained in actively growing children with elevated LDL-C, and elevated LDL-C levels can be improved significantly up to 3 years. Changes in the usual care group's diet suggest that pediatric practices and societal and environmental forces are having positive public health effects on dietary behavior during adolescence.

Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. DASH-Sodium Collaborative Research Group

BACKGROUND

The effect of dietary composition on blood pressure is a subject of public health importance. We studied the effect of different levels of dietary sodium, in conjunction with the Dietary Approaches to Stop Hypertension (DASH) diet, which is rich in vegetables, fruits, and low-fat dairy products, in persons with and in those without hypertension.

METHODS

A total of 412 participants were randomly assigned to eat either a control diet typical of intake in the United States or the DASH diet. Within the assigned diet, participants ate foods with high, intermediate, and low levels of sodium for 30 consecutive days each, in random order.

RESULTS

Reducing the sodium intake from the high to the intermediate level reduced the systolic blood pressure by 2.1 mm Hg (P<0.001) during the control diet and by 1.3 mm Hg (P=0.03) during the DASH diet. Reducing the sodium intake from the intermediate to the low level caused additional reductions of 4.6 mm Hg during the control diet (P<0.001) and 1.7 mm Hg during the DASH diet (P<0.01). The effects of sodium were observed in participants with and in those without hypertension, blacks and those of other races, and women and men. The DASH diet was associated with a significantly lower systolic blood pressure at each sodium level; and the difference was greater with high sodium levels than with low ones. As compared with the control diet with a high sodium level, the DASH diet with a low sodium level led to a mean systolic blood pressure that was 7.1 mm Hg lower in participants without hypertension, and 11.5 mm Hg lower in participants with hypertension.

CONCLUSIONS

The reduction of sodium intake to levels below the current recommendation of 100 mmol per day and the DASH diet both lower blood pressure substantially, with greater effects in combination than singly. Long-term health benefits will depend on the ability of people to make long-lasting dietary changes and the increased availability of lower-sodium foods.

Characteristics of inactive primary care patients: baseline data from the activity counseling trial. For the Activity Counseling Trial Research Group

BACKGROUND

Although many primary care patients are inactive, being able to classify even small amounts and intensities of activity and factors associated with these activity levels could be helpful for physicians who are trying to motivate their patients to become more physically active.

METHODS

Sociodemographics, physical activity, fitness, other cardiovascular risk factors, and psychosocial measures were measured at baseline in the 874 patients in the Activity Counseling Trial. Patients were categorized into three groups: (1) no moderate-to-vigorous physical activity (MVPA), (2) some moderate but no vigorous activity, and (3) some vigorous activity. Multiple logistic regression was used to determine factors cross-sectionally associated with activity intensity.

RESULTS

One or more cardiovascular risk factors in addition to physical inactivity were present in 84% of participants. Maximal oxygen uptake averaged 25.2 ml/kg/min; 85% had poor to fair aerobic fitness. Physical activity averaged 32.7 kcal/kg/day, with 13.5 min of MVPA/day; 26% engaged in some vigorous activity, 11% engaged in no MVPA. In unadjusted analyses, gender, age, race, education, income, employment, smoking, alcohol use, and exercise self-efficacy were associated with activity intensity (P = 0.05-0.001). A greater percentage engaged in moderate than in vigorous activity in all subgroups. In multiple logistic regression analyses, odds ratios (95% confidence intervals) for engaging in vigorous activity were 0. 39 (0.28, 0.56) for women, 0.38 (0.19, 0.75) for 65+ compared with 35- to 44-year-olds, and 1.14 (1.06, 1.22) for 10-unit increases in performance self-efficacy score.

CONCLUSIONS

Most primary care patients who are physically inactive have additional cardiovascular risk factors, particularly overweight and obesity. All subgroups pursue moderate-intensity activity more often than vigorous activity. Women, older persons, and those with lower exercise self-efficacy are less likely to engage in vigorous activity.

Efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol in children with elevated LDL cholesterol: the Dietary Intervention Study in Children

BACKGROUND

Few studies have shown the efficacy and safety of lower-fat diets in children.

OBJECTIVE

Our objective was to assess the efficacy and safety of lowering dietary intake of total fat, saturated fat, and cholesterol to decrease LDL-cholesterol concentrations in children.

DESIGN

A 6-center, randomized controlled clinical trial was carried out in 663 children aged 8-10 y with LDL-cholesterol concentrations greater than the 80th and less than the 98th percentiles for age and sex. The children were randomly assigned to either an intervention group or a usual care group. Behavioral intervention promoted adherence to a diet providing 28% of energy from total fat, <8% from saturated fat, </=9% from polyunsaturated fat, and <0.018 mg cholesterol*kJ(-)(1)*d(-)(1) (not to exceed 150 mg/d). The primary efficacy measure was mean LDL cholesterol and the safety measures were mean height and serum ferritin concentration at 3 y.

RESULTS

At 3 y, dietary total fat, saturated fat, and cholesterol were lower in the intervention group than in the usual care group (all P: < 0. 001). LDL cholesterol decreased in the intervention and usual care groups by 0.40 mmol/L (15.4 mg/dL) and 0.31 mmol/L (11.9 mg/dL), respectively. With adjustment for baseline concentration, sex, and missing data, the mean difference between groups was -0.08 mmol/L (95% CI: -0.15, -0.01), or -3.23 mg/dL (95% CI: -5.6, -0.5) (P: = 0. 016). There were no significant differences between groups in adjusted mean height or serum ferritin.

CONCLUSION

Dietary changes are effective in achieving modest lowering of LDL cholesterol over 3 y while maintaining adequate growth, iron stores, nutritional adequacy, and psychological well-being during the critical growth period of adolescence.

Impact of community intervention to reduce patient delay time on use of reperfusion therapy for acute myocardial infarction: rapid early action for coronary treatment (REACT) trial. REACT Study Group

BACKGROUND

Reperfusion therapy for acute myocardial infarction (AMI) is a time-dependent intervention that can reduce infarct-related morbidity and mortality. Out-of-hospital patient delay from symptom onset until emergency department (ED) presentation may reduce the expected benefit of reperfusion therapy.

OBJECTIVE

To determine the impact of a community educational intervention to reduce patient delay time on the use of reperfusion therapy for AMI.

METHODS

This was a randomized, controlled community-based trial to enhance patient recognition of AMI symptoms and encourage early ED presentation with resultant increased reperfusion therapy rates for AMI. The study took place in 44 hospitals in 20 pair-matched communities in five U.S. geographic regions. Eligible study subjects were non-institutionalized patients without chest injury (aged > or =30 years) who were admitted to participating hospitals and who received a hospital discharge diagnosis of AMI (ICD 410); n = 4,885. For outcome assessment, patients were excluded if they were without survival data (n = 402), enrolled in thrombolytic trials (n = 61), receiving reperfusion therapy >12 hours after ED arrival (n = 628), or missing symptom onset or reperfusion times (n = 781). The applied intervention was an educational program targeting community organizations and the general public, high-risk patients, and health professionals in target communities. The primary outcome was a change in the proportion of AMI patients receiving early reperfusion therapy (i.e., within one hour of ED arrival or within six hours of symptom onset). Trends in reperfusion therapy rates were determined after adjustment for patient demographics, presenting blood pressure, cardiac history, and insurance status. Four-month baseline was compared with the 18-month intervention period.

RESULTS

Of 3,013 selected AMI patients, 40% received reperfusion therapy. Eighteen percent received therapy within one hour of ED arrival (46% of treated patients), and 32% within six hours of symptom onset (80% of treated patients). No significant difference in the trends in reperfusion therapy rates was attributable to the intervention, although increases in early reperfusion therapy rates were noted during the first six months of the intervention. A significant association of early reperfusion therapy use with ambulance use was identified.

CONCLUSIONS

Community-wide educational efforts to enhance patient response to AMI symptoms may not translate into sustained changes in reperfusion practices. However, an increased odds for early reperfusion therapy use during the initiation of the intervention and the association of early therapy with ambulance use suggest that reperfusion therapy rates can be enhanced.

Effect of a community intervention on patient delay and emergency medical service use in acute coronary heart disease: The Rapid Early Action for Coronary Treatment (REACT) Trial

CONTEXT

Delayed access to medical care in patients with acute myocardial infarction (AMI) is common and increases myocardial damage and mortality.

OBJECTIVE

To evaluate a community intervention to reduce patient delay from symptom onset to hospital presentation and increase emergency medical service (EMS) use.

DESIGN AND SETTING

The Rapid Early Action for Coronary Treatment Trial, a randomized trial conducted from 1995 to 1997 in 20 US cities (10 matched pairs; population range, 55,777-238,912) in 10 states.

PARTICIPANTS

A total of 59,944 adults aged 30 years or older presenting to hospital emergency departments (EDs) with chest pain, of whom 20,364 met the primary population criteria of suspected acute coronary heart disease on admission and were discharged with a coronary heart disease-related diagnosis.

INTERVENTION

One city in each pair was randomly assigned to an 18-month intervention that targeted mass media, community organizations, and professional, public, and patient education to increase appropriate patient actions for AMI symptoms (primary population, n=10,563). The other city in each pair was randomly assigned to reference status (primary population, n=9801).

MAIN OUTCOME MEASURES

Time from symptom onset to ED arrival and EMS use, compared between intervention and reference city pairs.

RESULTS

General population surveys provided evidence of increased public awareness and knowledge of program messages. Patient delay from symptom onset to hospital arrival at baseline (median, 140 minutes) was identical in the intervention and reference communities. Delay time decreased in intervention communities by -4.7% per year (95% confidence interval [CI], -8.6% to -0.6%), but the change did not differ significantly from that observed in reference communities (-6. 8% per year; 95% CI, -14.5% to 1.6%; P=.54). EMS use by the primary study population increased significantly in intervention communities compared with reference communities, with a net effect of 20% (95% CI, 7%-34%; P<.005). Total numbers of ED presentations for chest pain and patients with chest pain discharged from the ED, as well as EMS use among patients with chest pain released from the ED, did not change significantly.

CONCLUSIONS

In this study, despite an 18-month intervention, time from symptom onset to hospital arrival for patients with chest pain did not change differentially between groups, although increased appropriate EMS use occurred in intervention communities. New strategies are needed if delay time from symptom onset to hospital presentation is to be decreased further in patients with suspected AMI. JAMA. 2000;284:60-67

Missed opportunities to impact fast response to AMI symptoms

The potential for reducing cardiovascular disease mortality rates lies both in prevention and treatment. The earlier treatment is administered, the greater the benefit. Thus, duration of time from onset of symptoms of acute myocardial infarction to administration of treatment is important. One major factor contributing to failure to receive efficacious therapy is the delay time from acute myocardial infarction (AMI) symptom onset to hospital arrival. This paper examines the relationship of several factors with regard to intentions to seek care promptly for symptoms of AMI. A random-digit dialed telephone survey (n = 1294) was conducted in 20 communities located in 10 states. People who said they would wait until they were very sure that symptoms were a heart attack were older, reported their insurance did not pay for ambulance services, and reported less confidence in knowing signs and symptoms in themselves. When acknowledging symptoms of a heart attack, African-Americans and people with more than a high school education reported intention to act quickly. No measures of personal health history, nor interaction with primary care physicians or cardiologists were significantly related to intention to act fast. The study confirms the importance of attribution and perceived self-confidence in symptom recognition in care seeking. The lack of significant role of health history (i.e. those with chronic conditions or risk factors) and clinician contact highlights missed opportunities for health care providers to educate and encourage patients about their risk and appropriate action.

Incorporating physical activity advice into primary care: physician-delivered advice within the activity counseling trial

INTRODUCTION

The Activity Counseling Trial (ACT) was designed to compare the effectiveness of physician advice alone with physician advice plus behavioral counseling, provided by ACT-trained health educators, to increase levels of physical activity in healthy, sedentary patients. The objective was to determine health care providers' adherence to the ACT protocol for delivering initial "physician" advice on physical activity and to determine providers' satisfaction with the protocol.

METHODS

Fifty-four physicians or physician assistants from 11 primary care practices located in California, Texas, and Tennessee volunteered to participate as ACT-trained physicians. Providers were trained to integrate 3 to 4 minutes of initial physical activity advice into the routine office visits of sedentary patients, aged 35 to 75 years, with no acute or serious chronic conditions. This advice included assessment of current physical activities, advising the patient about an appropriate physical activity goal, and referring the patient to the health educator. Providers initialed forms to document delivery of advice, and ACT health educators recorded their advice on a computerized tracking system. A provider survey measured length of time spent advising patients about physical activity and provider satisfaction with the program.

RESULTS

Ninety-nine percent of patients received the initial physician advice about physical activity. Eighty-three percent of the providers spent less than 5 to 6 minutes, and 46% spent the recommended 3 to 4 minutes providing advice. Sixty-three percent said the advice resulted in little or no increase in the length of an office visit, and 83% said participation was an asset to their clinics.

CONCLUSIONS

Providers incorporated brief physical activity advice into routine primary care visits with little disruption. Their response to the ACT advice protocol was positive and participation in the study was viewed as beneficial.

Prehospital delay in patients hospitalized with heart attack symptoms in the United States: the REACT trial. Rapid Early Action for Coronary Treatment (REACT) Study Group

BACKGROUND

The use of thrombolytic therapy for patients with myocardial infarction has been limited by patient delay in seeking care. We sought to characterize prehospital delay in patients hospitalized for evaluation of heart attack symptoms.

METHODS AND RESULTS

The Rapid Early Action for Coronary Treatment (REACT) is a multicenter, randomized community trial designed to reduce patient delay. At baseline, data were abstracted from the medical records of 3783 patients hospitalized for evaluation of heart attack symptoms in 20 communities. The median prehospital delay was 2.0 hours; 25% of patients delayed longer than 5.2 hours. In a multivariable analysis, delay time was longer among non-Hispanic blacks than among non-Hispanic whites, longer at older ages, longer among Medicaid-only recipients and shorter among Medicare recipients than among privately insured patients, and shorter among patients who used an ambulance.

CONCLUSIONS

The observed pattern of differences is consistent with the contention that demographic, cultural, and/or socioeconomic barriers exist that impede rapid care seeking.

Effect of dietary patterns on ambulatory blood pressure : results from the Dietary Approaches to Stop Hypertension (DASH) Trial. DASH Collaborative Research Group

We measured ambulatory blood pressure (ABP) in 354 participants in the Dietary Approaches to Stop Hypertension (DASH) Trial to determine the effect of dietary treatment on ABP (24-hour, day and night) and to assess participants' acceptance of and compliance with the ABP monitoring (ABPM) technique. After a 3-week run-in period on a control "typical" American diet, subjects (diastolic blood pressure [BP], 80 to 95 mm Hg; systolic BP, <160 mm Hg; mean age, 45 years) were randomly assigned to 1 of 3 diets for an 8-week intervention period: a continuation of the control diet; a diet rich in fruits and vegetables; and a "combination" diet that emphasized fruits, vegetables, and low-fat dairy products. We measured ABP at the end of the run-in and intervention periods. Both the fruit/vegetable and combination diets lowered 24-hour ABP significantly compared with the control diet (P<0. 0001 for systolic and diastolic pressures on both diets: control diet, -0.2/+0.1 mm Hg; fruit/vegetable diet, -3.2/-1.9 mm Hg; combination diet, -4.6/-2. 6 mm Hg). The combination diet lowered pressure during both day and night. Hypertensive subjects had a significantly greater response than normotensives to the combination diet (24-hour ABP, -10.1/-5.5 versus -2.3/-1.6 mm Hg, respectively). After correction for the control diet responses, the magnitude of BP lowering was not significantly different whether measured by ABPM or random-zero sphygmomanometry. Participant acceptance of ABPM was excellent: only 1 participant refused to wear the ABP monitor, and 7 subjects (2%) provided incomplete recordings. These results demonstrate that the DASH combination diet provides significant round-the-clock reduction in BP, especially in hypertensive participants.

Effects of interventions in health care settings on physical activity or cardiorespiratory fitness

INTRODUCTION

This paper reviews studies of physical activity interventions in health care settings to determine effects on physical activity and/or fitness and characteristics of successful interventions.

METHODS

Studies testing interventions to promote physical activity in health care settings for primary prevention (patients without disease) and secondary prevention (patients with cardiovascular disease [CVD]) were identified by computerized search methods and reference lists of reviews and articles. Inclusion criteria included assignment to intervention and control groups, physical activity or cardiorespiratory fitness outcome measures, and, for the secondary prevention studies, measurement 12 or more months after randomization. The number of studies with statistically significant effects was determined overall as well as for studies testing interventions with various characteristics.

RESULTS

Twelve studies of primary prevention were identified, seven of which were randomized. Three of four randomized studies with short-term measurement (4 weeks to 3 months after randomization), and two of five randomized studies with long-term measurement (6 months after randomization) achieved significant effect on physical activity. Twenty-four randomized studies of CVD secondary prevention were identified; 13 achieved significant effects on activity and/or fitness at twelve or more months. Studies with measurement at two time points showed decaying effects over time, particularly if the intervention were discontinued. Successful interventions contained multiple contacts, behavioral approaches, supervised exercise, provision of equipment, and/or continuing intervention. Many studies had methodologic problems such as low follow-up rates.

CONCLUSION

Interventions in health care settings can increase physical activity for both primary and secondary prevention. Long-term effects are more likely with continuing intervention and multiple intervention components such as supervised exercise, provision of equipment, and behavioral approaches. Recommendations for additional research are given.

Rapid early action for coronary treatment: rationale, design, and baseline characteristics. REACT Research Group

OBJECTIVE

Early reperfusion for acute myocardial infarction (AMI) can reduce morbidity and mortality, yet there is often delay in accessing medical care after symptom onset. This report describes the design and baseline characteristics of the Rapid Early Action for Coronary Treatment (REACT) community trial, which is testing community intervention to reduce delay.

METHODS

Twenty U.S. communities were pair-matched and randomly assigned within pairs to intervention or comparison. Four months of baseline data collection was followed by an 18-month intervention of community organization and public, patient, and health professional education. Primary cases were community residents seen in the ED with chest pain, admitted with suspected acute cardiac ischemia, and discharged with a diagnosis related to coronary heart disease. The primary outcome was delay time from symptom onset to ED arrival. Secondary outcomes included delay time in patients with MI/unstable angina, hospital case-fatality rate and length of stay, receipt of reperfusion, and ED/emergency medical services utilization. Impact on public and patient knowledge, attitudes, and intentions was measured by telephone interviews. Characteristics of communities and cases and comparability of paired communities at baseline were assessed.

RESULTS

Baseline cases are 46% female, 14% minorities, and 73% aged > or =55 years, and paired communities have similar demographics characteristics. Median delay time (available for 72% of cases) is 2.3 hours and does not vary between treatment conditions (p > 0.86).

CONCLUSIONS

REACT communities approximate the demographic distribution of the United States and there is baseline comparability between the intervention and comparison groups. The REACT trial will provide valuable information for community educational programs to reduce patient delay for AMI symptoms.

Activity Counseling Trial (ACT): rationale, design, and methods. Activity Counseling Trial Research Group

The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal.kg-1.day-1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effect, and cost-effectiveness, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical setting, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.

Overview of the Activity Counseling Trial (ACT) intervention for promoting physical activity in primary health care settings. Activity Counseling Trial Research Group

Counseling by health care providers has the potential to increase physical activity in sedentary patients, yet few studies have tested interventions for physical activity counseling delivered in health care settings. The Activity Counseling Trial (ACT) is a 5-yr randomized clinical trial to evaluate the efficacy of two primary care, practice-based physical activity behavioral interventions relative to a standard care control condition. A total of 874 sedentary men and women, 35-75 yr of age, have been recruited from primary care physician offices at three clinical centers for 2 yr of participation. They were randomly assigned to one of three experimental conditions that vary, in a hierarchical fashion, by level of counseling intensity and resource requirements. The interventions, which are based on social cognitive theory and the transtheoretical model, are designed to alter empirically based psychosocial mediators that are known to be associated with physical activity. The present paper describes the theoretical background of the intervention, the intervention methods, and intervention training and quality control procedures.

A meta-analysis of trials evaluating patient education and counseling for three groups of preventive health behaviors

OBJECTIVES

To examine the overall effectiveness of patient education and counseling on preventive health behaviors and to examine the effects of various approaches for modifying specific types of behaviors.

DATA SOURCES

Computerized databases (Medline, Healthline, Dissertation Abstracts, and Psychological Abstracts), bibliographies 1971-1994. Search terms (patient education, patient compliance, and self care) with modifiers (evaluation and specific preventive behaviors).

STUDY SELECTION

Randomized and non-randomized controlled trials measuring behavior in clinical settings with patients without diagnosed disease. Abstracts and retrieved studies screened by multiple reviewers; 13% of retrieved studies met screening criteria.

DATA EXTRACTION

Replicated coding by multiple observers.

DATA SYNTHESIS

Behaviors were grouped based on whether the behavior is addictive and whether the desired change required subtraction of existing behaviors or adding new behaviors. The weighted average effect size from a random effects model for smoking/alcohol studies was 0.61 (CI = 0.45, 0.77), for nutrition/weight, 0.51 (CI = 0.20, 0.82) and for other behaviors, 0.56 (CI = 0.34, 0.77) indicating that the behavioral outcomes for these subgroups were significantly different from zero. Multiple regression models for the three groups indicated that using behavioral techniques, particularly self-monitoring, and using several communication channels, e.g., media plus personal communication, produces larger effects for the smoking/alcohol and nutrition/weight groups.

CONCLUSIONS

Patient education and counseling contribute to behavior change for primary prevention of disease. Some techniques are more effective than others in changing specific behaviors.

Safety of a fat-reduced diet: the Dietary Intervention Study in Children (DISC)

OBJECTIVE

To assess the relationship between energy intake from fat and anthropometric, biochemical, and dietary measures of nutritional adequacy and safety.

DESIGN

Three-year longitudinal study of children participating in a randomized controlled trial; intervention and usual care group data pooled to assess effects of self-reported fat intake; longitudinal regression analyses of measurements at baseline, year 1, and year 3.

PARTICIPANTS

Six hundred sixty-three children (362 boys and 301 girls), 8 to 10 years of age at baseline, with elevated low-density lipoprotein cholesterol, who are participants of the Dietary Intervention Study in Children.

MEASURES

Energy intake from fat assessed from three 24-hour recalls at each time point was the independent variable. Outcomes were anthropometric measures (height, weight, body mass index, and sum of skinfolds), nutritional biochemical determinations (serum ferritin, zinc, retinol, albumin, beta-carotene, and vitamin E, red blood cell folate, and hemoglobin), and dietary micronutrients (vitamins A, C, E, thiamin, riboflavin, niacin, vitamins B-6, B-12, folate, calcium, iron, zinc, magnesium, and phosphorus).

RESULTS

Lower fat intake was not related to anthropometric measures or serum zinc, retinol, albumin, beta-carotene, or vitamin E. Lower fat intake was related to: 1) higher levels of red blood cell folate and hemoglobin, with a trend toward higher serum ferritin; 2) higher intakes of folate, vitamin C, and vitamin A, with a trend toward higher iron intake; 3) lower intakes of calcium, zinc, magnesium, phosphorus, vitamin B-12, thiamin, niacin, and riboflavin; 4) increased risk of consuming less than two-thirds of the Recommended Dietary Allowances for calcium in girls at baseline, and zinc and vitamin E in boys and girls at all visits.

CONCLUSIONS

Lower fat intakes during puberty are nutritionally adequate for growth and for maintenance of normal levels of nutritional biochemical measures, and are associated with beneficial effects on blood folate and hemoglobin. Although lower fat diets were related to lower self-reported intakes of several nutrients, no adverse effects were observed on blood biochemical measures of nutritional status. Current public health recommendations for moderately lower fat intakes in children during puberty may be followed safely.

Diet and blood pressure in children and adolescents

Identifying dietary factors associated with blood pressure (BP) in children and adolescents would help guide recommendations for prevention of elevated BP, which is a major public health problem. This paper reviews 46 reports of studies examining relationships between dietary nutrients and BP in children and adolescents, many of which studied more than one nutrient. Sodium is the most extensively studied nutrient, with 25 observational and 12 intervention studies identified. Although many studies suffer from methodological problems, the results suggest that higher sodium intake is related to higher BP in children and adolescents. The results of 13 observational and 2 intervention studies of potassium and BP do not provide a clear picture of a relationship. The results of 8 observational and 1 intervention study of calcium and BP are inconclusive. Five observational studies of magnesium and BP provide evidence of an inverse relationship, but no intervention studies were identified. Nine studies of macronutrients and food groups or dietary patterns are inconclusive. Additional research is needed to provide more information about the relationships between dietary nutrients and BP in children and adolescents. Recommendations are provided for methodological features of additional research on diet and BP in children and adolescents.

Nutrient intake and blood pressure in the Dietary Intervention Study in Children

Delineating the role that diet plays in blood pressure levels in children is important for guiding dietary recommendations for the prevention of hypertension. The purpose of this study was to investigate relationships between dietary nutrients and blood pressure in children. Data were analyzed from 662 participants in the Dietary Intervention Study in Children who had elevated low-density lipoprotein cholesterol and were aged 8 to 11 years at baseline. Three 24-hour dietary recalls, systolic pressure, diastolic pressure, height, and weight were obtained at baseline, 1 year, and 3 years. Nutrients analyzed were the micronutrients calcium, magnesium, and potassium; the macronutrients protein, carbohydrates, total fat, saturated fat, polyunsaturated fat, and monounsaturated fat; dietary cholesterol; and total dietary fiber. Baseline and 3-year longitudinal relationships were examined through multivariate models on diastolic and systolic pressures separately, controlling for height, weight, sex, and total caloric intake. The following associations were found in longitudinal analyses: analyzing each nutrient separately, for systolic pressure, inverse associations with calcium (P < .05); magnesium, potassium, and protein (all P < .01); and fiber (P < .05), and direct associations with total fat and monounsaturated fat (both P < .05); for diastolic pressure, inverse associations with calcium (P < .01); magnesium and potassium (both P < .05), protein (P < .01); and carbohydrates and fiber (both P < .05), and direct associations with polyunsaturated fat (P < .01) and monounsaturated fat (P < .05). Analyzing all nutrients simultaneously, for systolic pressure, direct association with total fat (P < .01); for diastolic pressure, inverse associations with calcium (P < .01) and fiber (P < .05), and direct association with total and monounsaturated fats (both P < .05). Results from this sample of children with elevated low-density lipoprotein cholesterol indicate that dietary calcium, fiber, and fat may be important determinants of blood pressure level in children.

Smoking, smoking cessation, and understanding of the role of multiple cardiac risk factors among the urban poor

OBJECTIVE

To determine in a population of low socioeconomic status (SES) patients: (a) rates of current smoking and smoking cessation, (b) persons' understanding of the adverse health impact of multiple cardiovascular disease (CVD) risk factors, and (c) if the diagnosis of other CVD risk factors, specifically hypertension or hypercholesterolemia, was related to smoking cessation.

DESIGN

Cross-sectional interview survey.

SETTING

Community clinics and eligibility centers of the Harris County Hospital District (HD), which provides primary care to over 166,000 indigent persons in Houston, Texas.

SUBJECTS

Randomly selected adults attending an HD setting for eligibility screening or primary care.

RESULTS

Over 93% of subjects approached participated (n = 547). Their mean age was 40.7 years, 55% were female, and 39% had > 9 years of education. The ethnic distribution was 54% Hispanic, 28% black, and 14% non-Hispanic white. Current smoking ranged from 10% among Hispanic females to 56% among black males. The percentage of ever smokers who had quit was 24% among black males, 44% among black females, 43% among Hispanic males, and 70% among Hispanic females. The majority recognized the increase in danger from smoking in the presence of hypertension or hypercholesterolemia. Among patients who were smokers when they found out they had hypertension (n = 70), 65% reported it increased their desire to quit. After adjustment for other variables including age and known CVD, predictors of being an ex-smoker were being female (OR 2.1, 95% CI 1.3-3.5), being Hispanic (OR 2.8 95% CI 1.5-5.7), and having hypertension (OR 2.3, 95% CI 1.3-4.2).

CONCLUSION

In this low SES population, there was substantial smoking cessation, widespread acknowledgment of the cumulative effect of smoking and other CVD risk factors, and some evidence that smoking cessation increased after the diagnosis of hypertension.

Funding avenues for research in emergency medicine at the National Institutes of Health and the National Heart, Lung, and Blood Institute

There are opportunities for research in EM at the NIH, which may be appropriate for a variety of Institutes, depending on the topic area. Most NIH-funded research is through investigator-initiated grant applications, and the PHS 398 application packet is a source of more information. RFAs and RFPs, which have set-aside funding, are released for specific topic areas when an Institute identifies an area requiring multiple studies or multicenter research. PAs, which do not have set-aside funding, announce areas of interest for an Institute. The NIH Guide to Grants and Contracts announces RFAs, RFPs, and PAs. It is important to become expert in a field of research to be successful in achieving research funding, whether investigator- or institute-initiated.

Hypertension treatment trials and stroke occurrence revisited. A quantitative overview

To provide further understanding of the decline in stroke mortality in the United States, data from 16 randomized controlled trials of hypertension treatment and stroke published to date are pooled. The overall weighted average blood pressure reduction was 13/6 mm Hg. The pooled odds ratio was 0.61 (95% confidence interval: 0.55, 0.68), indicating approximately a 39% (32 to 45%) reduction in stroke occurrence. Percent reduction was somewhat higher in studies of mild-moderate hypertension (47%) and somewhat lower in studies of the elderly (35%). There was no differential effect by gender (reductions of 37% for women, 34% for men) or by race (32% for blacks, 37% for whites). The magnitudes of reductions for fatal (41%) and nonfatal (37%) strokes, and for diuretics and beta-blockers (odds ratio diuretic versus beta-blocker, 0.86; 95% CI: 0.69, 1.08) were similar. Implications for the decline in stroke mortality in the United States are discussed.

Cholesterol-related knowledge, attitudes, and behaviors in a low-income, urban patient population

To determine knowledge, attitudes, behaviors, and self-reported cholesterol measurement in a low-income, urban patient population, we conducted an interview survey of users and potential users of primary care services in a public health care system for low-income Harris County, Texas, residents. The response rate was 93%, with a final sample of 547 randomly selected subjects 18 years of age and older, who were Hispanic (54%), black (28%), non-Hispanic white (14%), and Asian, Native American, or other (4%). Results indicated that 76% had heard of serum or blood cholesterol, and 30% reported past cholesterol measurement. Knowledge that dietary saturated fat can raise blood cholesterol ranged from 11% in Hispanic men to 51% in non-Hispanic white men and women. A lower percentage of Hispanics correctly answered all knowledge questions, and Hispanics reported higher-fat food choices than blacks and non-Hispanic whites. More than 90% of the respondents expressed interest in more information on diet, 60% reported that they read nutrition labels, and 15% said they have been trying to reduce blood cholesterol levels. A lower percentage of Hispanics reported previous cholesterol measurement than blacks or non-Hispanic whites, a difference that persisted after adjusting for multiple factors associated with cholesterol measurement. Older age (older than 50) and more physician visits in the past year also were associated with past cholesterol measurement. Comparisons with national surveys show that cholesterol knowledge and actual measurement in this low-income sample lag behind those of the national population. Yet, despite gaps in knowledge and cholesterol measurement, respondents showed positive attitudes about and interest in cholesterol-lowering interventions.