Impact of obesity in asthma: evidence from a large prospective disease management study.

BACKGROUND: asthma and obesity continue to have a significant effect on public health. It is widely accepted that obesity may be an independent risk factor for asthma and affect asthma severity and quality of life (QOL). OBJECTIVE: to examine the relationship between body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and asthma severity, spirometry findings, health care utilization (HCU), and QOL. METHODS: this 12-month prospective randomized controlled trial comparing disease management with traditional care enrolled 902 patients (473 pediatric and 429 adults) representing an underserved population. Data collected at baseline and at 6-month intervals included demographics, asthma severity, medication use, spirometry findings, and HCU. The QOL was assessed using the pediatric and adult versions of the Asthma Quality of Life Questionnaire and the 36-Item Short Form Health Survey. All HCU was determined by means of patient interview and extensive medical record review. Data were analyzed using negative binomial regression and analysis of variance. RESULTS: in children, 45% were overweight/obese (17% with BMIs >85th percentile; 28% with BMIs ≥ 95th percentile). In adults, 58% were obese (BMIs ≥ 30). There was no relationship in children between BMI and severity of asthma, spirometry findings, QOL, or HCU. In adults, there was no relationship between BMI and asthma severity or HCU. Higher BMI was associated with a significant reduction in QOL (P < .001). The BMI had an inverse relationship with forced vital capacity but with no other spirometric values. CONCLUSIONS: obesity was not associated with worse asthma severity, spirometry findings, QOL, or HCU in children. In adults with asthma, obesity was associated with lower forced vital capacity and QOL but not with severity or HCU.

Long-term cost-effectiveness of disease management in systolic heart failure.

BACKGROUND: Although congestive heart failure (CHF) is a primary target for disease management programs, previous studies have generated mixed results regarding the effectiveness and cost savings of disease management when applied to CHF. OBJECTIVE: We estimated the long-term impact of systolic heart failure disease management from the results of an 18-month clinical trial. METHODS: We used data generated from the trial (starting population distributions, resource utilization, mortality rates, and transition probabilities) in a Markov model to project results of continuing the disease management program for the patients' lifetimes. Outputs included distribution of illness severity, mortality, resource consumption, and the cost of resources consumed. Both cost and effectiveness were discounted at a rate of 3% per year. Cost-effectiveness was computed as cost per quality-adjusted life year (QALY) gained. RESULTS: Model results were validated against trial data and indicated that, over their lifetimes, patients experienced a lifespan extension of 51 days. Combined discounted lifetime program and medical costs were $4850 higher in the disease management group than the control group, but the program had a favorable long-term discounted cost-effectiveness of $43,650/QALY. These results are robust to assumptions regarding mortality rates, the impact of aging on the cost of care, the discount rate, utility values, and the targeted population. CONCLUSIONS: Estimation of the clinical benefits and financial burden of disease management can be enhanced by model-based analyses to project costs and effectiveness. Our results suggest that disease management of heart failure patients can be cost-effective over the long term.

Cost-effectiveness of telephonic disease management in heart failure.

OBJECTIVE: To evaluate the cost-effectiveness of a telephonic disease management (DM) intervention in heart failure (HF). STUDY DESIGN: Randomized controlled trial of telephonic DM among 1069 community-dwelling patients with systolic HF (SHF) and diastolic HF performed between 1999 and 2003. The enrollment period was 18 months per subject. METHODS: Bootstrap-resampled incremental cost-effectiveness ratios (ICERs) were computed and compared across groups. Direct medical costs were obtained from a medical record review that collected records from 92% of patients; 66% of records requested were obtained. RESULTS: Disease management produced statistically significant survival advantages among all patients (17.4 days, P = .04), among patients with New York Heart Association (NYHA) class III/IV symptoms (47.7 days, P = .02), and among patients with SHF (24.2 days, P = .01). Analyses of direct medical and intervention costs showed no cost savings associated with the intervention. For all patients and considering all-cause medical care, the ICER was $146 870 per quality-adjusted life-year (QALY) gained, while for patients with NYHA class III/IV symptoms and patients with SHF, the ICERs were $67 784 and $95 721 per QALY gained, respectively. Costs per QALY gained were $101 120 for all patients, $72 501 for patients with SHF, and $41 348 for patients with NYHA class III/IV symptoms. CONCLUSIONS: The intervention was effective but costly to implement and did not reduce utilization. It may not be cost-effective in other broadly representative samples of patients. However, with program cost reductions and proper targeting, this program may produce life-span increases at costs that are less than $100 000 per QALY gained.

Assessing the value of disease management: impact of 2 disease management strategies in an underserved asthma population.

BACKGROUND: The goal of disease management (DM) is to improve health outcomes and reduce cost through decreasing health care utilization. Although some studies have shown that DM improves asthma outcomes, these interventions have not been examined in a large randomized controlled trial. OBJECTIVE: To compare the effectiveness of 2 previously successful DM programs with that of traditional care. METHODS: Nine hundred two individuals with asthma (429 adults; 473 children) were randomly assigned to telephonic DM, augmented DM (ADM; DM plus in-home visits by a respiratory therapist), or traditional care. Data were collected at enrollment and at 6 and 12 months. Primary outcomes were time to first asthma-related event, quality of life (QOL), and rates of asthma-related health care utilization. Secondary outcomes included rate of controller medication initiation, number of oral corticosteroid bursts, asthma symptom scores, and number of school days missed. RESULTS: There were no significant differences between groups in time to first asthma-related event or health care utilization. Adult participants in the ADM group had greater improvement in QOL (P = .04) and a decrease in asthma symptoms (P = .001) compared with other groups. Of children not receiving controller medications at enrollment (13%), those in the intervention groups were more likely to have controller medications initiated than the control group (P = .01). Otherwise, there were no differences in outcomes. CONCLUSIONS: Overall, participation in asthma DM did not result in significant differences in utilization or clinical outcomes. The only significant impact was a higher rate of controllermedication initiation in children and improvement in asthma symptoms and QOL in adults who received ADM.

Cumulative recruitment experience in two large single-center randomized, controlled clinical trials.

BACKGROUND: Trial recruitment is challenging for researchers, who frequently overestimate the pool of qualified, willing participants. Little has been written about recruitment and the comparative success of recruitment strategies. We describe one center's experience with recruitment in two regional single-center clinical trials with a combined total of 1971 participants. METHODS: The heart failure trial was conducted between 1999 and 2003. The asthma trial was performed between 2003 and 2006. Trial databases were queried for referral source of each individual. Data were analyzed for effectiveness of referral source using three measures: percentage of enrollment due to that source, subject commitment to the trial (retention rate), and economics (cost per enrollee). RESULTS: 47.8% of CHF enrollees came from computer-generated lists or from healthcare provider referrals. Average marketing cost for enrollees and completers was $29.20 and $41.96 respectively. The most economical marketing strategy was self-referral in response to flyers. Most asthma participants (53.5%) were referred from healthcare providers, mailings to lists from local healthcare institutions, or self-referred in response to flyers. Average marketing cost for enrollees and completers was $20.44 and $38.10 respectively. The most economical marketing strategy was patient mailings. Retention rates were not markedly different among referral sources in either trial. CONCLUSION: In order to be considered effective, a recruitment strategy must demonstrate a balance between response to recruitment, retention rates, and economics. Despite the differences between these two clinical trials, the most effective recruitment strategies in both trials were mailings to locally-generated, targeted lists, and referrals from healthcare providers.

Quantifying asthma symptoms in adults: the Lara Asthma Symptom Scale.

BACKGROUND: Accurate assessment of asthma symptoms is critical in research and clinical settings. A multidimensional asthma control questionnaire could provide more accurate information about asthma symptoms than global assessments, which often overestimate asthma control. OBJECTIVE: We sought to evaluate the efficacy of the Lara Asthma Symptom Scale (LASS) in adults with persistent asthma. METHODS: Participants were 18 to 64 years of age with persistent asthma. Data were collected at baseline, 6 months, and 12 months. We described the construct and predictive validity of the LASS by comparing it with measures of pulmonary function (FEV(1)), asthma-specific quality of life (Juniper's Asthma Quality of Life Questionnaire [AQLQ]), and health care use (emergency department [ED] visits and hospitalizations). RESULTS: Three hundred eighty-three participants provided baseline data. The LASS had high internal consistency reliability (Cronbach alpha = .84). LASS scores correlated significantly with baseline measures of FEV(1) (-0.20, P = .0002), AQLQ (-0.68, P < .0001), ED visits (0.17, P = .002), and hospitalizations (0.15, P = .008). Baseline LASS scores were associated significantly with ED visits (P = .03) and hospitalizations (P = .04) over the subsequent 12 months. Change in LASS scores over time correlated significantly with changes in FEV(1) (-0.22, P = .001) and AQLQ (-0.70, P < .001). CONCLUSIONS: The LASS demonstrated good internal consistency, excellent validity based on concurrent criterion validity and longitudinal predictive validity, and good discriminatory properties in a heterogeneous sample of adults with persistent asthma. CLINICAL IMPLICATIONS: This study validates a simple multidimensional asthma questionnaire as a clinical tool in the assessment of asthma control in adults.

Impact of home environment characteristics on asthma quality of life and symptom scores.

We explore the relationship between home-based triggers, asthma symptoms, and quality of life (QOL) with data from 177 adult and pediatric participants who received a home environmental assessment. Outcomes included the Asthma Quality of life Questionnaire, the Prediatric Asthma Quality of Life Questionnaire, the Paediatric Asthma Caregiver's Quality of Questionnaires and the Lara Asthma Symptom Scale. The absence of roaches and the use of dust mite covers were positively associated with QOL in pediatric and adult participants. Frequent bed sheet washing was associated with increased symptoms and decreased quality of life in adults and caregivers of pediatric participants. These findings confirm existing wisdom on roaches and dust mite covers and raise important questions about bed sheet washing recommendations.

Educational attainment has a limited impact on disease management outcomes in heart failure.

The objective of this study was to assess whether educational attainment moderates outcomes in the intervention group in a trial of disease management in heart failure (HF). Data were collected from a sample of 654 patients enrolled in the disease management arm of a community- based study of HF patients. The full sample was used to analyze two primary outcomes- all-cause mortality and cardiac event-free survival. Two other primary outcomes- rates of HF-related emergency department (ED) visits and inpatient admissions-and secondary outcomes (patient self-confidence in managing HF symptoms and daily dietary sodium intake in milligrams) were analyzed in a smaller sample of 602 patients who completed at least 6 months of disease management. One-way analysis of variance and chi (2) tests were used to assess differences in baseline demographic and clinical characteristics. Survival analyses were conducted with proportional hazards regression, while negative binomial regression was used to assess educational differences in ED usage and inpatient admissions. Repeated measures analysis of variance models were used to assess whether secondary outcomes differed across educational strata and/or over time. All outcome analyses were adjusted for confounders. Patients with the least education fared the poorest for all-cause mortality, but education- related differences failed to achieve statistical significance. No education-related differences were observed for cardiac event-free survival, or for the rates of inpatient admission and ED usage. For secondary outcomes, sodium intake differed significantly by education (p = 0.04), with the largest drop (-838 mg/day) observed in the least well-educated group. Confidence increased an approximately equal amount (2.1-3.0 points on a 100-point scale) across all educational strata (p = ns). Low educational attainment may not be a barrier to effective disease management.

Disease management produces limited quality-of-life improvements in patients with congestive heart failure: evidence from a randomized trial in community-dwelling patients.

BACKGROUND: Disease management programs are reported to improve clinical and quality-of-life outcomes while simultaneously lowering healthcare costs. OBJECTIVE: To examine the effectiveness of disease management in improving health-related quality of life (HRQL) among patients with heart failure beyond 12 months. METHODS: A total of 1069 community-dwelling patients 18 years and older in South Texas with echocardiographic evidence of congestive heart failure were randomly assigned to disease management, augmented disease management, and control groups. They were followed up 18 months. Patients in the control group received usual care. Patients in the intervention groups were assigned a registered nurse as a disease manager who performed telephonic patient education and medication management. Health-related quality-of-life data (based on the Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]) were collected 4 times, at 6-month intervals. RESULTS: Disease management has a limited effect on HRQL. Analysis of the SF-36 health transition measure showed a positive effect of the intervention on self-reported improvement in health at 6 months and at 12 months (P = .04 and P = .004, respectively). However, no effect of disease management was observed across any of the SF-36 components. Women and patients with diastolic heart failure had poorer HRQL scores. CONCLUSIONS: Participation in disease management has little effect on HRQL outcomes in congestive heart failure. Beneficial effects on the SF-36 scale scores seen at 6 and 12 months were not sustained. Therefore, it is unclear whether disease management can provide long-term improvement in HRQL for patients with congestive heart failure.