Behavioral mediators of treatment effects in the weight loss maintenance trial.

BACKGROUND: The Weight Loss Maintenance Trial tested strategies for maintenance of weight loss. Personal contact was superior to interactive technology and self-directed conditions. PURPOSE: We aimed to identify behavioral mediators of the superior effect of personal contact vs. interactive technology and of personal contact vs. self-directed arms. METHODS: Overweight/obese adults at risk for cardiovascular disease (n = 1,032) who lost at least 4 kg were randomized to personal contact, interactive technology, or self-directed. After 30 months, 880 participants had data on weight and behavioral strategies. RESULTS: Reported increase of intake of fruits and vegetables and physical activity and more frequent self-weighing met criteria as mediators of the better outcome of personal contact vs. interactive technology. Increased intake of fruits and vegetables, more frequent self-weighing, and decreased dessert consumption were mediators of the difference between personal contact vs. self-directed. CONCLUSION: Inducing changes in the identified behaviors might yield better outcomes in future weight loss maintenance trials.

Branched-chain amino acid levels are associated with improvement in insulin resistance with weight loss.

AIMS/HYPOTHESIS: Insulin resistance (IR) improves with weight loss, but this response is heterogeneous. We hypothesised that metabolomic profiling would identify biomarkers predicting changes in IR with weight loss. METHODS: Targeted mass spectrometry-based profiling of 60 metabolites, plus biochemical assays of NEFA, ß-hydroxybutyrate, ketones, insulin and glucose were performed in baseline and 6 month plasma samples from 500 participants who had lost ≥4 kg during Phase I of the Weight Loss Maintenance (WLM) trial. Homeostatic model assessment of insulin resistance (HOMA-IR) and change in HOMA-IR with weight loss (∆HOMA-IR) were calculated. Principal components analysis (PCA) and mixed models adjusted for race, sex, baseline weight, and amount of weight loss were used; findings were validated in an independent cohort of patients (n = 22). RESULTS: Mean weight loss was 8.67 ± 4.28 kg; mean ∆HOMA-IR was -0.80 ± 1.73, range -28.9 to 4.82). Baseline PCA-derived factor 3 (branched chain amino acids [BCAAs] and associated catabolites) correlated with baseline HOMA-IR (r = 0.50, p < 0.0001) and independently associated with ∆HOMA-IR (p < 0.0001). ∆HOMA-IR increased in a linear fashion with increasing baseline factor 3 quartiles. Amount of weight loss was only modestly correlated with ∆HOMA-IR (r = 0.24). These findings were validated in the independent cohort, with a factor composed of BCAAs and related metabolites predicting ∆HOMA-IR (p = 0.007). CONCLUSIONS/INTERPRETATION: A cluster of metabolites comprising BCAAs and related analytes predicts improvement in HOMA-IR independent of the amount of weight lost. These results may help identify individuals most likely to benefit from moderate weight loss and elucidate novel mechanisms of IR in obesity.

Efficacy of chlorhexidine varnish for the prevention of adult caries: a randomized trial.

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D(1-2)FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877).

Screening and brief intervention for hazardous drinking in an HMO: effects on medical care utilization.

This study examined whether a brief intervention to reduce hazardous alcohol consumption among primary care patients reduced use of medical care. In a parent, randomized controlled trial, at-risk drinkers identified in HMO outpatient waiting rooms were randomly assigned to receive usual care or brief clinician advice plus a 15-minute motivational counseling session. The current study (n = 514) examined the groups' use of outpatient and inpatient medical services during two years after intervention. Although the intervention reduced alcohol consumption at six-month follow-up, intervention and control groups made similar numbers of outpatient visits (M = 17.7 vs. 18.3, respectively; p = .47), were equally likely to be hospitalized (21.2% vs. 22.0%; p = .81), and among those hospitalized, had similar lengths of stay (4.7 vs. 6.6 days; p = .37). Although brief interventions to reduce hazardous drinking may potentially reduce medical care utilization, more evidence is needed to substantiate their practicality and cost-effectiveness.

Implementation and effectiveness of a brief smoking-cessation intervention for hospital patients.

OBJECTIVES: Previous research has documented that hospital-based smoking-cessation counseling is efficacious and cost-effective when delivered by research staff. This study evaluated the implementation and effectiveness of this intervention program when delivered by respiratory therapists chosen from the regular hospital staff. METHODS: A total of 1,173 hospitalized smokers were randomly assigned to either usual care or a stage-based bedside counseling program supplemented with a videotape, self-help materials, and a follow-up telephone call. RESULTS: Using an intent-to-treat analysis and counting those lost to follow-up as smokers, we did not find a significant difference in outcome between intervention (14.2% reported being abstinent for > or =6 months at the 1-year follow-up) and usual care conditions (13.6% abstinence). Process analyses revealed that these results were due to a combination of failure to reach many patients and reduced effectiveness of respiratory therapist interventionists compared with experienced professional counselors in a previous study conducted in the same hospitals. CONCLUSIONS: We recommend implementation of hospital-based smoking-cessation counseling by professional counselors whose primary responsibility is to deliver the intervention. Recommendations for future research and for innovative ways to reach hospitalized smokers who are not receiving intervention are discussed.

Relapse and maintenance issues for smoking cessation.

This article reviews short-term (6 months) and longer term (12-24 months) maintenance of cessation and relapse in adult smokers and the factors and treatments that affect these outcomes. MedLine and PsycLIT searches were done for research published in English between 1988 and 1998 meeting a defined set of criteria. Intensive intervention, telephone counseling, and use of pharmacotherapy were found to improve outcomes; however, compared with public health approaches, they reach relatively few smokers. Brief interventions during medical visits are cost-effective and could potentially reach most smokers but are not consistently delivered. Predictors of relapse include slips, younger age, nicotine dependence, low self-efficacy, weight concerns, and previous quit attempts. Potential areas for research, recommendations for longer follow-up assessments, and standard definitions for slip, relapse, and long-term maintenance are discussed.

Stress management intervention for primary prevention of hypertension: detailed results from Phase I of Trials of Hypertension Prevention (TOHP-I).

PURPOSE: Stress Management Intervention (SMI) was one of seven nonpharmacologic approaches evaluated in Phase I Trials of Hypertension Prevention (TOHP-I) for efficacy in lowering diastolic blood pressure (BP) in healthy men and women aged 30 to 54 years with diastolic BP 80-89 mm Hg. METHODS: A total of 242 and 320 participants were randomized to SMI or an "assessment only" SMI Control, respectively, at four clinical centers. The SMI consisted of 37 contact hours in 21 group and two individual meetings over 18 months and included: training in four relaxation methods, techniques to reduce stress reactions, cognitive approaches, communication skills, time management, and anger management within a general problem-solving format. Standardized protocols detailed methods and timing for collecting BP, psychosocial measures, and urinary samples from both SMI and SMI Control participants. RESULTS: In intention-to-treat analyses, although significant baseline to termination BP reductions were observed in both groups, net differences between the SMI and SMI Control groups' BP changes (mean (95% CI)) were not significant: -0.82 (-1.86, 0.22) for diastolic BP, and -0.47 (-1.96, 1.01) for systolic BP. Extensive adherence sub-group analyses found one effect: a significant 1.36 mm Hg (p = 0.01) reduction in diastolic BP relative to SMI Controls at the end of the trial for SMI participants who completed 61% or more of intervention sessions. CONCLUSIONS: While the TOHP-I SMI was acceptable to participants as evident from high levels of session completion, the absence of demonstrated BP lowering efficacy in intention-to-treat analyses suggests that the TOHP-I SMI is an unlikely candidate for primary prevention of hypertension in a general population sample similar to study participants. The isolated finding of significant diastolic BP lowering in SMI participants with higher adherence provides very weak evidence of SMI BP lowering efficacy and may be a chance finding. Whether similar or other stress management interventions can produce significant BP lowering in populations selected for higher levels of BP, stress, or intervention adherence remains to be demonstrated.

Adolescent health care visits: opportunities for brief prevention messages.

CONTEXT: It has been suggested that clinicians should increase efforts to modify and prevent risky behavior in adolescents. Professional organizations have proposed recommendations about access to care and preventive services, but it is difficult to know where and how to most effectively deliver such services. PRACTICE PATTERN EXAMINED: Clinic visits among adolescent HMO members (14 to 17 years of age). SETTING: Kaiser Permanente Northwest Division, a medium-sized, nonprofit, group-model HMO in the Pacific Northwest. DATA SOURCES: Two administrative databases (one for membership and one for outpatient utilization). RESULTS: A total of 22,626 adolescents who met the inclusion criteria were identified. Of these, 62% (more than 14,000 adolescents) were seen in a primary care clinic within 1 year; almost 83% (more than 18,000 adolescents) were seen within 2 years. There were several opportunities for follow-up for adolescents who had at least one visit in 1995: 60% had more than one visit during 1995, and 80% had more than one visit over the 2-year span of 1995 and 1996. The largest number of adolescent visits occurred in August through November, and most visits took place in the afternoon. CONCLUSIONS: Primary care visits in an HMO present an excellent opportunity to reach many teenagers outside of a school setting. Short-term educational or prevention programs would be optimal during late summer and fall; additional staff members may be able to present these programs after school once school begins.

Cost-effectiveness of a hospital-based smoking cessation intervention.

OBJECTIVES: This study evaluated the cost-effectiveness of a smoking cessation and relapse-prevention program for hospitalized adult smokers from the perspective of an implementing hospital. It is an economic analysis of a two-group, controlled clinical trial in two acute care hospitals owned by a large group-model health maintenance organization. The intervention included a 20-minute bedside counseling session with an experienced health counselor, a 12-minute video, self-help materials, and one or two follow-up calls. METHODS: Outcome measures were incremental cost (above usual care) per quit attributable to the intervention and incremental cost per discounted life-year saved attributable to the intervention. RESULTS: Cost of the research intervention was $159 per smoker, and incremental cost per incremental quit was $3,697. Incremental cost per incremental discounted life-year saved ranged between $1,691 and $7,444, much less than most other routine medical procedures. Replication scenarios suggest that, with realistic implementation assumptions, total intervention costs would decline significantly and incremental cost per incremental discounted life-year saved would be reduced by more than 90%, to approximately $380. CONCLUSIONS: Providing brief smoking cessation advice to hospitalized smokers is relatively inexpensive, cost-effective, and should become a part of the standard of inpatient care.

The medical care system and prevention: the need for a new paradigm.

The American medical care system falls to provide effective prevention services even though some prevention services are among the most cost-effective medical procedures available. Many prevention services are routinely delivered in inefficient or ineffective ways, and new technologies may be widely and aggressively implemented despite serious doubts about their efficacy and cost-effectiveness. The barriers to effective prevention services result from conceptual limitations in our model of medical care systems, particularly the lack of a population-based perspective. A change in paradigm is needed before reforms in our health care system can improve health without bankrupting the nation.

Does gender affect response to a brief clinic-based smoking intervention?

INTRODUCTION: Although recent reviews suggest few gender differences in smoking-cessation outcomes, it is important to establish whether gender differences exist in response to the brief interventions increasingly recommended as part of routine medical care. METHODS: We used data from an efficacious primary care-based smoking intervention to examine gender differences in smoking characteristics, use of intervention components, self-reported quitting activities, and cessation outcomes among all smokers randomized to receive clinician advice and nurse-assisted intervention (n = 1,978, 58% female). RESULTS: Although female and male smokers differed on a number of sociodemographic and smoking-related characteristics, they were equally likely to participate in each step of the recommended intervention. Female and male smokers were also equally likely to report quit attempts and cessation at 3, 12, and 3 and 12 months (combined long-term cessation endpoint). Similarly, no gender difference in relapse at 12 months was seen. Women attempting to quit used a greater number and variety of smoking-cessation strategies, suggesting that, although outcomes were similar, the processes of cessation may vary by gender. CONCLUSIONS: Since this brief intervention in primary care was equally efficacious and acceptable to female and male smokers, broader implementation in medical settings of this population-based approach to reducing tobacco use is warranted. Indeed, widespread implementation of smoking-cessation programs in medical settings may particularly benefit women, who are more likely than men to have contacts with the medical care system.

Take Heart II: replication of a worksite health promotion trial.

The purpose of this study was to evaluate the effects of a revised worksite health promotion program that featured an employee steering committee/menu approach to intervention. The "Take Heart II" program was evaluated using a quasi-experimental matched-pair design with worksite as the unit of analysis. Experimental and control worksites did not differ on baseline organizational or employee demographic variables or on baseline levels of dependent variables. Outcome and process results revealed consistent, but modest effects favoring intervention worksites on most measures. Cross-sectional analyses generally failed to produce statistically significant intervention effects, but cohort analyses revealed significant beneficial effects of the Take Heart II intervention on eating patterns, behavior change attempts, and perceived social support. Neither analysis detected a beneficial effect of intervention on cholesterol levels.

Effective group behavioral intervention for older periodontal patients.

A randomized clinical trial assessed the effect of a group-based behavior modification intervention on oral hygiene skills, adherence and clinical outcomes for older periodontal patients. Subjects (n = 107) were aged 50-70 yr with moderate periodontal disease. They were randomly assigned to usual care or intervention. Intervention consisted of 5 weekly, 90-min sessions that included skill training, self-monitoring, weekly feedback about bleeding points and group support focused on long-term habit change. Four-month follow-up indicated significant improvements in the intervention versus the usual periodontal maintenance group for oral hygiene skills and self-reported flossing (p < 0.001), plaque, gingival bleeding, bleeding upon probing throughout the mouth, and pocket depth for sulcus depths that measured between 3 and 6 mm at baseline (p < 0.009). Group oral health intervention provides an effective and relatively inexpensive means of helping patients improve their self-care skills and achieve high levels of adherence to an effective self-care regimen.

Brief intervention in a primary care setting for hazardous drinkers.

INTRODUCTION: The study was designed to test a brief intervention for reducing alcohol consumption among moderate to heavy (hazardous) drinkers in a busy HMO primary care setting. METHODS: In a randomized controlled trial, hazardous drinkers (n = 516) were identified by the AUDIT screening questionnaire. Intervention included brief clinician advice (30 seconds), a 15-minute motivational session by counselors, and printed materials. RESULTS: At six-month follow-up, intervention subjects reported fewer total standard drinks in the past three months (176 versus 216, P = .04, one-tailed) and fewer drinking days per week (2.8 versus 3.3, P = .02) than controls, but similar drinks per drinking day (3.3 versus 3.5; P = .13). At 12 months, intervention subjects again reported fewer drinking days per week (2.7 versus 3.1; P = .04) than controls, but similar numbers of standard drinks (157 versus 179; P = .13) and drinks per drinking day (3.6 versus 3.3; P = .20). Intervention subjects were somewhat more likely than controls to report drinking within daily recommended limits (< or = 3 for men, < or = 2 for women) at both six months (79% versus 71%; P = .06) and 12 months (80% versus 73%; P = .07), but did not differ significantly from controls on other drinking outcomes (percent abstinent, frequency of drinking > or = 6 drinks per drinking occasion, estimated peak blood alcohol concentration), or use of medical care in the year following intervention. CONCLUSIONS: A one-time, brief motivational intervention using minimal clinician time supplemented by trained counselors resulted in a modest reduction in frequency of alcohol consumption in a busy primary care population. Future research should focus on strengthening and maintaining intervention effects.

Tobacco cessation interventions in health care settings: rationale, model, outcomes.

Health care settings provide opportunities to reach populations of tobacco users with personalized cessation assistance. We describe a model for doing so which emphasizes a team approach, minimizes the burden on clinicians, and uses brief counseling by allied professionals, videos, written materials, and telephone calls to augment clinician advice. The model has been implemented in several diverse settings including outpatient, inpatient, and dental clinic managed care; fee-for-service dentistry and pediatric practices; and planned parenthood clinics. Data from several randomized trials support the effectiveness of the approach. The brief, low-intensity interventions derived from the model appear to be sustainable on a routine basis in many settings.

Brief assessments of dietary behavior in field settings.

Our research team is involved in ongoing research in both worksites and medical office settings. These settings offer great potential for reaching individuals who would not otherwise participate in health promotion, but they also place considerable constraints on assessment time and efforts, especially if one's goal is to attract a high and representative proportion of employees or patients. This paper reports on our experience with measures of dietary behavior in these two settings. We found it problematic to collect detailed assessments such as 4-day food records or comprehensive food frequency/history checklists in worksites or medical office settings using population-based samples. Instead, we recommend and provide data on the utility of a dietary-fat screening instrument, and on the Food Habits Questionnaire (FHQ-Kristal, Shattuck, & Henry, 1990), a brief measure of dietary behaviors associated with high-fat eating patterns. The FHQ, in particular, was found to correlate well with other more costly and time-consuming methods of assessment, to be reliable and responsive to intervention effects, and to provide behavioral targets for intervention. The strengths and limitations of these measures for tailoring intervention and assessing outcomes are discussed.

Design of a multicenter trial to evaluate long-term life-style intervention in adults with high-normal blood pressure levels. Trials of Hypertension Prevention (phase II). Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

Phase II of the Trials of Hypertension Prevention (TOHP) is a multicenter, randomized trial sponsored by the National Heart, Lung, and Blood Institute designed to test whether weight loss alone, sodium reduction alone, or the combination of weight loss and sodium reduction will decrease diastolic (DBP) and systolic blood pressure (SBP) as well as the incidence of hypertension (DBP > or = 90 mm Hg, SBP > or = 140 mm Hg, and/or use of antihypertensive medications) in subjects with high-normal DBP (83 to 89 mm Hg) and SBP less than 140 mm Hg at entry. These interventions were chosen for longer-term testing with end points including hypertension prevention as well as blood pressure (BP) change based on their demonstrated short-term efficacy in reducing BP in phase I of TOHP. The phase II study population is comprised of 2382 participants (1566 men and 816 women) who are 110 to 165% of desirable body weight, allocated at random to the four treatment arms using a 2 x 2 factorial design. The trial has 80% power to detect an overall treatment effect on DBP of 1.2 mm Hg for weight loss or sodium reduction and a difference of 1.6 mm Hg between the combined intervention and placebo groups. BP observers are blinded to participant treatment assignments. Participants will be followed for 3 to 4 years. This trial may have important public policy implications concerning the ability of life-style modifications to reduce BP and prevent the development of hypertension over the long term, thereby avoiding the need for drug therapy which while effective is costly and may have side effects.

Recruitment for phase II of the Trials of Hypertension Prevention. Effective strategies and predictors of randomization. Trials of Hypertension Prevention (TOHP) Collaborative Research Group.

Phase II of the Trials of Hypertension Prevention is a multicenter, randomized, controlled trial designed to determine the efficacy of weight loss and reduction of sodium intake for lowering blood pressure and incidence of hypertension among persons with high-normal levels of blood pressure. The 2 x 2 factorial study design includes weight loss alone, restricted sodium intake alone, the combination of weight loss and sodium restriction, and a control group. Nine clinical centers used a variety of recruitment strategies to enroll 2382 participants over 17 months, which exceeded the sample size goal of 2250. Among randomized participants, 21% were minorities and 34% were women. Overall, direct mail generated the most randomized participants (73%), followed by community screening (12%) and media advertisement (11%). Referrals from community health care providers yielded few participants. Prescreening improved overall efficiency and reduced costs. Participants who were more likely to drop out voluntarily during the three-visit screening regimen tended to be younger, single, male, smokers, and less educated.

Take heart: results from the initial phase of a work-site wellness program.

OBJECTIVES: The purpose of this study was to evaluate the short-term effects of a low-intensity work-site heart disease risk reduction program using a matched pair design with work site as the unit of analysis. METHODS: Twenty-six heterogeneous work sites with between 125 and 750 employees were matched on key organization characteristics and then randomly assigned to early or delayed intervention conditions. Early intervention consisted of an 18-month multifaceted program that featured an employee steering committee and a menu approach to conducting key intervention activities tailored to each site. RESULTS: Cross-sectional and cohort analyses produced consistent results. At the conclusion of the intervention, early and delayed intervention conditions did not differ on changes in smoking rates, dietary intake, or cholesterol levels. There was considerable variability in outcomes among work sites within each condition. CONCLUSIONS: Despite documented implementation of key intervention activities and organization-level changes in terms of perceived support for health promotion, this intervention did not produce short-term improvements beyond secular trends observed in control work sites. Research is needed to understand determinants of variability between work sites.