The relationship between health perception and utility in heart failure patients in a clinical trial: results from an OVERTURE substudy

BACKGROUND

Cost-effectiveness analyses should be based on incremental years of life gained adjusted with a health status measure known as a utility. Measuring utilities for all subjects in a large-scale randomized trial, however, would be prohibitively cumbersome. We therefore sought to estimate utilities for all subjects from results obtained in a subset of patients.

METHODS AND RESULTS

We studied a subset of patients enrolled in a randomized trial of omapatrilat for the treatment of heart failure. Survey instruments (a time trade-off questionnaire, a visual analog scale [VAS] score of overall health perception, and the Duke Activity Status Index [DASI]) were administered to patients by mail and by telephone interviews. There was a significant (P <.0001) relationship between VAS score and utility described by the power function u=1-(1-v)q, where q=2.17 (95% CI 1.76 to 2.58). There was a significant positive correlation (r=.17, P <.04) between the DASI and utility, and a significant negative correlation (r=-.26, P <.001) between utility and New York Heart Association functional class.

CONCLUSION

There is a significant relationship between the relatively easily obtainable health perception score by VAS with the more complex utility by time tradeoff for a subset of patients in a multicenter randomized clinical trial. This relationship may be helpful in examining the cost-effectiveness of new treatments for heart failure.

The cost-effectiveness of irbesartan in the treatment of hypertensive patients with type 2 diabetic nephropathy

BACKGROUND

End-stage renal disease (ESRD)-related health care costs are substantial. Improving clinical outcomes in patients at risk of progression to ESRD could lead to considerable health care savings.

OBJECTIVE

We estimated the cost-effectiveness of irbesartan compared with placebo or amlodipine in the treatment of patients with type 2 diabetes mellitus, hypertension, and overt nephropathy.

METHODS

Three treatments for hypertension patients with type 2 diabetes mellitus and nephropathy were assessed: (1) irbesartan, (2) amlodipine, and (3) placebo. A Markov model was developed based on primary data from the Irbesartan in Diabetic Nephropathy Trial and the United States Renal Data System. Projected survival and costs were compared for each treatment at 3-, 10-, and 25-year time horizons. Different assumptions of treatment benefits and costs were tested with use of sensitivity analyses.

RESULTS

At 10 and 25 years, the model projected irbesartan to be both the least costly and most effective (ie, demonstrating a survival advantage) strategy. At 25

Assessment of the association between blood pressure control and health care resource use

BACKGROUND

Several studies have reported increased health care resource use among hypertensive patients with uncontrolled blood pressure (BP).

OBJECTIVE

The purpose of this study was to investigate the relationship between BP control and health care resource use.

METHODS

Data were obtained from the Caring for Hypertension on Initiation: Costs and Effectiveness (CHOICE) study, a multicenter feasibility study of actual physician and patient behavior and clinical outcomes in a naturalistic setting. Adult patients with newly diagnosed hypertension were randomized to either Group 1 (treatment with diuretics or beta-blockers) or Group 2 (treatment with calcium channel blockers or angiotensin-converting enzyme inhibitors) and followed for 5 +/- 1 months. Physicians practiced standard care while documenting medications, BP measurements, and health care resource use for their patients. A subsequent analysis evaluating the relationship between BP and physician visits was performed for the whole population and for a subpopulation of patients with at least 4 months of follow-up data. Cox regression was used to model time to next visit.

RESULTS

A total of 512 patients with newly diagnosed hypertension were followed: 399 had follow-up data for at least 4 months. Baseline demographic characteristics were similar in the 2 groups. Kaplan-Meier curves and a log-rank test showed that the time to next visit for patients with uncontrolled BP was significantly shorter than for patients whose BP was controlled (P < 0.05). On average, patients with uncontrolled BP (> or = 140/90 mm Hg) had follow-up office visits approximately 13 days earlier than patients with controlled BP (< 140/90 mm Hg). This association remained significant after adjustment for repeated measures, and after exclusion of the first return visit. Cox regression analysis showed that higher systolic and diastolic BP measurements were significantly associated with a shorter time to next visit, after adjustment for age and sex. Total estimated costs during the study period were $170 per patient for medications and $283 per patient for office visits.

CONCLUSIONS

In the CHOICE study, higher BP was associated with a shorter time to next visit. Office visits were the main cost driver in the short-term management of hypertension.

Temporal patterns of circulating leptin levels in lean and obese adolescents: relationships to insulin, growth hormone, and free fatty acids rhythmicity

Alterations in nutritional status, such as obesity, markedly influence insulin, leptin, GH secretion, and free fatty acid (FFA) levels. We measured every hour for 24 h circulating leptin, insulin, GH, and FFA levels in lean and obese adolescents to determine: 1) the impact of adolescent obesity on the diurnal changes in leptin concentrations; and 2) the temporal relationships between the diurnal patterns of circulating leptin levels and insulin, GH, and FFA levels. During puberty, we found that the 24-h profile of circulating plasma leptin levels follows a bimodal pattern with minimal concentrations occurring early in the afternoon and a nocturnal elevation starting after midnight and culminating early morning. The time course of the diurnal variation in leptin levels in the obese adolescents was not different from that in lean controls. Of note, however, in obese girls leptin 24-h excursion and leptin night to day ratio were lower than those found in lean girls. In obese adolescents, mean GH levels varied significantly less during the day and night than lean controls. During the day, there were distinct preprandial increases and postprandial decreases in FFA levels, whereas after midnight FFA levels rose in both lean and obese adolescents. A significant positive correlation was found between mean plasma insulin levels between 0800 h and 2000 h and peak in leptin in lean and obese girls and boys (r = 0.63, P: < 0.001). Peak leptin was inversely correlated with the area under the nocturnal GH levels in all groups (r = -0.31, P: < 0.0003), whereas it was positively correlated with the nocturnal peak in FFA levels (r = 0.45, P: < 0.004). In summary, we report in obese adolescent girls a blunted relative diurnal excursion in leptin levels. This abnormal rhythmicity may, in part, explain their leptin resistance state. The nocturnal rise in leptin was paralleled by a nocturnal rise in GH and FFA levels. Additional studies are needed to test the potential link between the adipose-derived peptide and GH axis in humans.