Biomedical subjects

A David Paltiel

Publications and source records attributed to A David Paltiel.

At least 19 recordsLinked to original sources

PubMed2006

Expanded HIV screening in the United States: effect on clinical outcomes, HIV transmission, and costs.

BACKGROUND: An extensive literature supports expanded HIV screening in the United States. However, the question of whom to test and how frequently remains controversial. OBJECTIVE: To inform the design of HIV screening programs by identifying combinations of screening frequency and HIV prevalence and incidence at which screening is cost-effective. DESIGN: Cost-effectiveness analysis linking simulation models of HIV screening to published reports of HIV transmission risk, with and without antiretroviral therapy. DATA SOURCES: Published randomized trials, observational cohorts, national cost and service utilization surveys, the Red Book, and previous modeling results. TARGET POPULATION: U.S. communities with low to moderate HIV prevalence (0.05% to 1.0%) and annual incidence (0.0084% to 0.12%). TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTIONS: One-time and increasingly frequent voluntary HIV screening of all adults using a same-day rapid test. OUTCOME MEASURES: HIV infections detected, secondary transmissions averted, quality-adjusted survival, lifetime medical costs, and societal cost-effectiveness, reported in discounted 2004 dollars per quality-adjusted life-year (QALY) gained. RESULTS OF BASE-CASE ANALYSIS: Under moderately favorable assumptions regarding the effect of HIV patient care on secondary transmission, routine HIV screening in a population with HIV prevalence of 1.0% and annual incidence of 0.12% had incremental cost-effectiveness ratios of 30,800 dollars/QALY (one-time screening), 32,300 dollars/QALY (screening every 5 years), and 55,500 dollars/QALY (screening every 3 years). In settings with HIV prevalence of 0.10% and annual incidence of 0.014%, one-time screening produced cost-effectiveness ratios of 60,700 dollars/QALY. RESULTS OF SENSITIVITY ANALYSIS: The cost-effectiveness of screening policies varied within a narrow range as assumptions about the effect of screening on secondary transmission varied from favorable to unfavorable. Assuming moderately favorable effects of antiretroviral therapy on transmission, cost-effectiveness ratios remained below 50,000 dollars/QALY in settings with HIV prevalence as low as 0.20% for routine HIV screening on a one-time basis and at prevalences as low as 0.45% and annual incidences as low as 0.0075% for screening every 5 years. LIMITATIONS: This analysis does not address the difficulty of determining the prevalence and incidence of undetected HIV infection in a given patient population. CONCLUSIONS: Routine, rapid HIV testing is recommended for all adults except in settings where there is evidence that the prevalence of undiagnosed HIV infection is below 0.2%.

Adult↗

PubMed2006

Cost-effectiveness of an intervention to improve adherence to antiretroviral therapy in HIV-infected patients.

Adherence to antiretroviral medications has been shown to be an important factor in predicting viral suppression and clinical outcomes. The objective of this analysis was to assess the cost-effectiveness of a nursing intervention on antiretroviral adherence using data from a randomized controlled clinical trial as input to a computer-based simulation model of HIV disease. For a cohort of HIV-infected patients similar to those in the clinical trial (mean initial CD4 count of 319 cells/mm), implementing the nursing intervention in addition to standard care yielded a 63% increase in virologic suppression at 48 weeks. This produced increases in expected survival (from 94.5 to 100.9 quality-adjusted life months) and estimated discounted direct lifetime medical costs ($253,800 to $261,300). The incremental cost-effectiveness ratio for the intervention was $14,100 per quality-adjusted life year gained compared with standard care. Adherence interventions with modest effectiveness are likely to provide long-term survival benefit to patients and to be cost-effective compared with other uses of HIV care funds.

Adult↗

PubMed2006

The effect of age and chronic illness on life expectancy after a diagnosis of colorectal cancer: implications for screening.

BACKGROUND: Older adults with shorter life expectancies may receive less benefit from colorectal cancer screening than younger, healthier patients. OBJECTIVE: To determine the degree to which life expectancy after diagnosis of an early-stage cancer varies according to age or coexisting chronic illness. DESIGN: Retrospective cohort study. SETTING: Population-based cancer registry with linked administrative claims data. PATIENTS: Patients 67 years of age or older who received a diagnosis of colorectal cancer from 1993 through 1999. MEASUREMENTS: Chronic conditions were identified by searching Medicare claims. Using a life-table approach, the authors quantified the degree to which life expectancy associated with each cancer stage at diagnosis varied with patient age, sex, and burden of chronic conditions. RESULTS: The final study sample consisted of 35 755 patients. After accounting for cancer stage at diagnosis, the authors found that life expectancy was strongly related to both age and the burden of chronic illness. Among men who received a diagnosis of stage I cancer at 67 years of age, life expectancy decreased from 19.1 years (95% CI, 17.8 to 20.5 years) for patients with no chronic conditions to 12.4 years (CI, 11.4 to 13.5 years) for those with 1 or 2 conditions and 7.6 years (CI, 6.1 to 9.4 years) for those with 3 or more conditions. A similar trend was noted among female counterparts, with life expectancy decreasing from approximately 23 years to 16 years and 7 years for the 3 chronic condition groups, respectively. For men and women 81 years of age with no chronic illnesses, life expectancy after stage I cancer diagnosis was 10.3 years (CI, 9.2 to 11.9 years) and 13.8 years (CI, 12.3 to 15.3 years), respectively. LIMITATIONS: Administrative claims may not identify all chronic conditions. Life expectancy estimates at the population level are averages and, therefore, may not accurately predict the life expectancy of individual patients. CONCLUSIONS: Coexisting chronic illness is associated with a substantial reduction in life expectancy after diagnosis of early-stage colorectal cancer. Physicians should consider this when deciding whether to screen older persons.

Age Factors↗

PubMed2006

Rapid HIV testing at home: does it solve a problem or create one?

The U.S. Food and Drug Administration (FDA) is considering approval of an over-the-counter, rapid HIV test for home use. To date, testimony presented before the FDA has been overwhelmingly supportive. Advocates have argued enthusiastically that there is value in empowering individuals to manage their HIV risks and have suggested that the availability of a rapid home HIV test will dramatically increase rates of disease detection in communities that have proven difficult to reach and to link to appropriate care. The authors offer a more cautious perspective. According to what is already known about the market demand for over-the-counter HIV testing kits, their costs, and the performance of rapid HIV tests in that market, the authors do not anticipate that the rapid home test will have a profound impact either on the HIV public health crisis or on the populations in greatest need. Home HIV testing will attract a predominantly affluent clientele, composed disproportionately of HIV-uninfected new couples and "worried well" persons, as well as very recently infected persons with undetectable disease. The authors illustrate how testing in these populations may have the perverse effect of increasing both false-positive and false-negative results. A poorly functioning home HIV test may thereby undermine confidence in the reliability of HIV testing more generally and weaken critical efforts to expand HIV detection and linkage to lifesaving care for the estimated 300,000 U.S. citizens with unidentified HIV infection.

Costs and Cost Analysis↗

PubMed2006

Forced expiratory volume in 1 second percentage improves the classification of severity among children with asthma.

OBJECTIVE: Spirometry is an important component of the National Asthma Education and Prevention Program guidelines for asthma, yet published data show variable associations between forced expiratory volume in 1 second percentage (FEV1%) predicted, symptoms and health care utilization. The objective of this analysis was to examine the association between FEV1% and future risk of exacerbations among a well-characterized population of children with asthma. METHODS: Using data that are available from the Childhood Asthma Management Program, we examined the relationship between prebronchodilator FEV1% and important clinical outcomes. Multiple observations of FEV1 were available for each patient; multivariate regression analysis, using a general estimating equation approach, was used to control for the correlation between repeated measurements among individuals and potential confounders. FEV1% was categorized into 4 levels and as a continuous variable. Outcomes of interest included mean symptom score (0-3), episode-free days, and asthma-related events (oral steroid use, emergency department visits, and hospitalizations) during the ensuing 4-month period. Our analysis was limited to the placebo group (N = 417). RESULTS: We observed a clear relationship between prebronchodilator FEV1% and important clinical outcomes. In multivariable models that simultaneously controlled for covariates of interest, age at baseline, time, previous event history, and nocturnal awakenings, a significant relationship between FEV1% and asthma symptoms and serious asthma exacerbations (oral steroids, emergency department visits, and hospitalizations) was observed. Compared with children with an FEV1% > or = 100%, children with FEV1% 80% to 99%, 60% to 79%, and < 60% were 1.3, 1.8, and 4.8, respectively, more likely to have a serious asthma exacerbation during the ensuing 4 months. CONCLUSIONS. In children with mild to moderate asthma, FEV1% predicted is independently associated with future asthma symptoms and health care utilization. Previous asthma-related hospitalizations and nocturnal symptoms also were independently associated with risk for future adverse events. FEV1 is an important component of asthma health status and asthma severity classification.

Albuterol↗

PubMed2006

The survival benefits of AIDS treatment in the United States.

BACKGROUND: As widespread adoption of potent combination antiretroviral therapy (ART) reaches its tenth year, our objective was to quantify the cumulative survival benefits of acquired immunodeficiency syndrome (AIDS) care in the United States. METHODS: We defined eras corresponding to advances in standards of human immunodeficiency virus (HIV) disease care, including opportunistic infection prophylaxis, treatment with ART, and the prevention of mother-to-child transmission (pMTCT) of HIV. Per-person survival benefits for each era were determined using a mathematical simulation model. Published estimates provided the number of adult patients with new diagnoses of AIDS who were receiving care in the United States from 1989 to 2003. RESULTS: Compared with survival associated with untreated HIV disease, per-person survival increased 0.26 years with Pneumocystis jiroveci pneumonia prophylaxis alone. Four eras of increasingly effective ART in addition to prophylaxis resulted in per-person survival increases of 7.81, 11.05, 11.57, and 13.33 years, compared with the absence of treatment. Treatment for patients with AIDS in care in the United States since 1989 yielded a total survival benefit of 2.8 million years. pMTCT averted nearly 2900 infant infections, equivalent to 137,000 additional years of survival benefit. CONCLUSIONS: At least 3.0 million years of life have been saved in the United States as a direct result of care of patients with AIDS, highlighting the significant advances made in HIV disease treatment.

Acquired Immunodeficiency Syndrome↗

PubMed2006

Cost-effectiveness of inhaled steroids in asthma: impact of effect on bone mineral density.

BACKGROUND: The effects of inhaled corticosteroid (ICS) preparations on bone health have been debated. Multiple analyses have been published examining the question, with mixed results. OBJECTIVES: We examined how assumptions about the effect of ICS on bone mineral density (BMD) influence the cost-effectiveness of ICS in asthma. METHODS: We developed a mathematical simulation model to estimate clinical outcomes and costs for a cohort with mild/moderate asthma. The analysis conformed to reference case recommendations of the US Panel on Cost-Effectiveness in Health and Medicine. Sensitivity analysis evaluated the stability of our results to uncertainty in treatment duration, age at treatment, and ICS dose. RESULTS: Assuming a dose of 200 microg twice per day of ICS, a literature-based average effect of ICS on BMD and a 10-year time horizon, we observed a minimal increase in the costs attributed to hip fracture and incremental cost effectiveness ratio of $26,000 per quality-adjusted life-year and $14.00 per symptom-free day gained. Over an extended the time horizon (lifetime), the incremental cost effectiveness ratio increased to $42,000/quality-adjusted life-year. Only under a scenario of high-dose ICS, a lifetime horizon, and a large effect of ICS on BMD did the potential impact of ICS on BMD dramatically affect the economic attractiveness of therapy. CONCLUSION: To minimize any potential impact, use of the lowest effective dose of ICS and measures to target and intervene in high-risk individuals are warranted. However, ICS therapy in mild/moderate asthma compares favorably with commonly accepted interventions over a wide range of assumptions regarding this treatment and its effects on BMD.

Administration, Inhalation↗

PubMed2005

Cost advantage of dual-chamber versus single-chamber cardioverter-defibrillator implantation.

OBJECTIVES: The purpose of this study was to determine the least expensive strategy for device selection in patients receiving implantable cardioverter-defibrillators (ICDs). BACKGROUND: Device cost for a single-chamber ICD is less than an atrioventricular (dual-chamber) ICD (AV-ICD); however, some patients without clinical need for AV-ICD at implantation might require a later upgrade, potentially offsetting the initial cost advantage of the single-chamber device. METHODS: Decision analysis was used to estimate expected resource utilization costs of three alternative implantation strategies: 1) single-chamber device in all, with later upgrade to AV-ICD if needed; 2) initial implantation of an AV-ICD in all; and 3) targeted device selection on the basis of results of electrophysiologic testing (presence or absence of induced bradyarrhythmias or atrial arrhythmias). Clinical base estimates were obtained from retrospective review of all patients receiving ICDs between June 1997 and July 2001 at a single university hospital. Economic inputs were collected from national and single-center sources. RESULTS: In patients without other indications for electrophysiologic study (EPS), the expected per-person cost was least with the strategy of universal initial AV-ICD implantation (36,232 dollars) compared with initial single-chamber ICD/upgrade as needed (39,230 dollars) or EPS-guided selection (41,130 dollars). Sensitivity analyses demonstrated that universal AV-ICD implantation remained least expensive with upgrade rates as low as 10%. At a 5% upgrade rate, AV-ICD remained cheapest if the device cost-differential narrowed to 1,568 dollars. For patients undergoing EPS for risk assessment, EP-guided selection was least expensive. CONCLUSIONS: The strategy of universal AV-ICD implantation, which provides the benefits of dual-chamber capability while obviating any potential need for future upgrade, is the least costly strategy for most patient populations receiving ICDs.

Atrial Fibrillation↗

PubMed2005

Cost-effectiveness of enfuvirtide in treatment-experienced patients with advanced HIV disease.

OBJECTIVE: Enfuvirtide (ENF) has been shown to improve short-term virologic responses when given to highly treatment-experienced patients with advanced HIV disease. Because of the high cost of ENF compared with other antiretroviral agents, our objectives were to determine the potential long-term clinical impact and cost-effectiveness of ENF in these patients. METHODS: We used a computer simulation model of HIV disease to project life expectancy, quality-adjusted life expectancy, cost, and cost-effectiveness of ENF in treatment-experienced patients. Input data were from the T-20 versus Optimized Regimen Only (TORO) 1 and 2 trials, 2 studies comparing ENF plus an optimized background regimen (OBR) with an OBR alone. RESULTS: ENF plus an OBR increased projected discounted quality-adjusted life expectancy from 45.4 months with an OBR alone to 54.9 months, a difference of 9.5 quality-adjusted life-months. At the current annual ENF cost of US 18,500 dollars per year (in 2001 US dollars), the incremental cost-effectiveness ratio for ENF plus an OBR was US 69,500 dollars per quality-adjusted life-year (QALY) compared with an OBR alone. When 48-week virologic suppression rates for ENF plus an OBR were varied from a 50% reduction to a 250% increase in the suppression rate attributable to ENF, gains in quality-adjusted life expectancy ranged from 4.5 to 25.9 quality-adjusted life-months compared with an OBR alone, with cost-effectiveness ratios ranging from US 97,900 dollars per QALY to US 52,300 dollars per QALY gained. If ENF is continued after the HIV RNA level returns to the pretreatment baseline, the cost-effectiveness ratio increases to US 168,200 dollars per QALY. CONCLUSIONS: In highly treatment-experienced patients, ENF plus an OBR provides substantial gains in quality-adjusted life expectancy compared with an OBR alone. Although ENF plus an OBR is less cost-effective than other commonly used interventions in HIV disease, its use may be justified, given the poor prognosis of these patients and their otherwise limited options for antiretroviral therapy.

Adult↗

PubMed2005

Expanded screening for HIV in the United States--an analysis of cost-effectiveness.

BACKGROUND: Although the Centers for Disease Control and Prevention (CDC) recommend routine HIV counseling, testing, and referral (HIVCTR) in settings with at least a 1 percent prevalence of HIV, roughly 280,000 Americans are unaware of their human immunodeficiency virus (HIV) infection. The effect of expanded screening for HIV is unknown in the era of effective antiretroviral therapy. METHODS: We developed a computer simulation model of HIV screening and treatment to compare routine, voluntary HIVCTR with current practice in three target populations: "high-risk" (3.0 percent prevalence of undiagnosed HIV infection; 1.2 percent annual incidence); "CDC threshold" (1.0 percent and 0.12 percent, respectively); and "U.S. general" (0.1 percent and 0.01 percent). Input data were derived from clinical trials and observational cohorts. Outcomes included quality-adjusted survival, cost, and cost-effectiveness. RESULTS: In the high-risk population, the addition of one-time screening for HIV antibodies with an enzyme-linked immunosorbent assay (ELISA) to current practice was associated with earlier diagnosis of HIV (mean CD4 cell count at diagnosis, 210 vs. 154 per cubic millimeter). One-time screening also improved average survival time among HIV-infected patients (quality-adjusted survival, 220.7 months vs. 219.8 months). The incremental cost-effectiveness was 36,000 dollars per quality-adjusted life-year gained. Testing every five years cost 50,000 dollars per quality-adjusted life-year gained, and testing every three years cost 63,000 dollars per quality-adjusted life-year gained. In the CDC threshold population, the cost-effectiveness ratio for one-time screening with ELISA was 38,000 dollars per quality-adjusted life-year gained, whereas testing every five years cost 71,000 dollars per quality-adjusted life-year gained, and testing every three years cost 85,000 dollars per quality-adjusted life-year gained. In the U.S. general population, one-time screening cost 113,000 dollars per quality-adjusted life-year gained. CONCLUSIONS: In all but the lowest-risk populations, routine, voluntary screening for HIV once every three to five years is justified on both clinical and cost-effectiveness grounds. One-time screening in the general population may also be cost-effective.

Anti-Retroviral Agents↗

PubMed2005

Cost-effectiveness of HIV screening for incarcerated pregnant women.

Antiretroviral therapy (ART) initiated on a prenatal basis in HIV-infected pregnant women is a highly effective method for preventing mother-to-child HIV transmission. We developed a decision analytic model to project the clinical and economic outcomes of alternative HIV screening strategies (voluntary prenatal screening [VPS], routine prenatal screening [RPS], and mandatory newborn screening [MNS]) for a high-risk population of incarcerated pregnant women. Data for the decision model came from the HIV voluntary counseling and testing program at Connecticut's sole correctional facility for women and a comprehensive anonymously linked serosurvey of all inmates who entered the facility during the 2-year period beginning in October 1994. Based on serosurvey results, in the absence of any HIV screening program, 2.5 cases of pediatric HIV infection would be expected per 1000 pregnancies. Multiplied by the discounted lifetime cost per case of $247,000, this translates to a cost of $624 per testing-eligible prison entrant. Entrants were considered eligible if they were pregnant and their HIV status was unknown. MNS would save money, cost $364 per eligible entrant, and simultaneously reduce the rate of infections to 1.1 per 1000 pregnancies. Doing both MNS and RPS is most effective in reducing the rate of new infections (down to 0.2 per 1000 pregnancies). It would, however, increase costs to $430 per eligible entrant. This would result in an incremental cost of $73,603 per additional pediatric HIV case averted when compared with MNS alone. If mandatory newborn testing was not considered a feasible option, RPS would dominate VPS and would be cost-saving compared with no screening. RPS compares favorably with alternative uses of HIV prevention and treatment resources. In correctional facilities where voluntary newborn screening is already in place, our findings show that there remains a small marginal benefit to be realized from switching to RPS. In settings where HIV screening policies are not in place, however, the implementation of RPS can be expected to significantly reduce pediatric HIV cases and net health care expenditures.

Adult↗

PubMed2005

Routine human immunodeficiency virus testing: an economic evaluation of current guidelines.

BACKGROUND: The Centers for Disease Control and Prevention guidelines recommend human immunodeficiency virus (HIV) counseling, testing, and referral for all patients in hospitals with an HIV prevalence of >or=1%. The 1% screening threshold has not been critically examined since HIV became effectively treatable in 1995. Our objective was to evaluate the clinical effect and cost-effectiveness of current guidelines and of alternate HIV prevalence thresholds. METHODS: We performed a cost-effectiveness analysis using a computer simulation model of HIV screening and disease as applied to inpatients in U.S. hospitals. RESULTS: At an undiagnosed inpatient HIV prevalence of 1% and an overall participation rate of 33%, HIV screening increased mean quality-adjusted life expectancy by 6.13 years per 1000 inpatients, with a cost-effectiveness ratio of 35,400 dollars per quality-adjusted life-year (QALY) gained. Expansion of screening to settings with a prevalence as low as 0.1% increased the ratio to 64,500 dollars per QALY gained. Increasing counseling and testing costs from 53 dollars to 103 dollars per person still yielded a cost-effectiveness ratio below 100,000 dollars per QALY gained at a prevalence of undiagnosed infection of 0.1%. CONCLUSION: Routine inpatient HIV screening programs are not only cost-effective but would likely remain so at a prevalence of undiagnosed HIV infection 10 times lower than recommended thresholds. The current HIV counseling, testing, and referral guidelines should now be implemented nationwide as a way of linking infected patients to life-sustaining care.

Centers for Disease Control and Prevention, U.S.↗

PubMed2005

Optimal frequency of CD4 cell count and HIV RNA monitoring prior to initiation of antiretroviral therapy in HIV-infected patients.

CONTEXT: Guidelines regarding the frequency of CD4 cell count and HIV RNA monitoring in HIV-infected patients vary, with recommended strategies ranging from every 2 to every 6 months. OBJECTIVE: To determine optimal CD4 cell count and HIV RNA monitoring frequency in HIV-infected patients prior to antiretroviral therapy initiation. DESIGN: Cost-effectiveness (CE) analysis using an HIV simulation model incorporating CD4 cell count and HIV RNA as immunological and virological predictors of clinical outcomes. SETTING: Hypothetical clinical setting. PATIENTS: Simulated cohort based on initial clinical presentation of HIV-infected patients in the US. INTERVENTION: CD4 cell count and HIV RNA monitoring at frequencies ranging from every 2 to 24 months prior to antiretroviral initiation, as well as accelerated monitoring frequencies as CD4 cell counts approach a specified treatment threshold. OUTCOME MEASURES: Life expectancy, quality-adjusted life expectancy and costs. RESULTS: For patients presenting with median CD4 cell count 546/mm3 and median HIV RNA 4.8 log10 copies/ml, incremental CE ratios ranged from US$37800/quality-adjusted life year (QALY) gained for a constant testing frequency of every 18 months compared with every 24 months, to US$303300/QALY gained for a constant testing frequency of every 2 months compared with every 4 months when starting treatment at a CD4 cell count of 350/mm3. Monitoring every 12 months until a warning CD4 cell count threshold of 450/mm3 followed by every 3 months until 350/mm3 had an incremental CE ratio of US$74700/QALY gained. When starting antiretroviral therapy at CD4 cell count 200/mm3, monitoring every 12 months until 300/mm3 followed by every 2 months until treatment initiation yielded an incremental CE ratio of US$52200/QALY gained compared with the next best strategy. Increasing monitoring frequency as CD4 cell counts approached a treatment threshold yielded greater incremental clinical benefit for less cost than strategies using a constant frequency. CONCLUSIONS: Monitoring HIV-infected patients every 12 months until 100 CD4 cells/mm3 prior to a specified treatment threshold followed by more frequent monitoring every 2 or 3 months until antiretroviral therapy initiation is both more effective and cost-effective than the current standard of care.

Anti-HIV Agents↗

PubMed2004

A therapeutic HIV vaccine: how good is good enough?

The goal of a therapeutic HIV vaccine is to attenuate HIV disease progression in those already infected. Our objective was to establish comparative efficacy and cost-effectiveness thresholds at which a therapeutic vaccine would make a valuable contribution to HIV care. Using an HIV computer simulation model, we compared therapeutic vaccination with HIV standard of care without vaccination. Input data were obtained from the literature. Base case and sensitivity analyses related to vaccine magnitude, penetrance, durability, and cost. In the base case (0.5 log magnitude, 25% penetrance, 3-year durability, and US$ 4000 per series), vaccination increased quality-adjusted life expectancy (QALE) by 0.50 months compared to no vaccination (cost-effectiveness ratio US$ 89,900 per quality-adjusted life year (QALY)). Increasing vaccine penetrance to 50% increased the projected QALE benefit to 0.91 months (cost-effectiveness ratio US$ 45,500/QALY). Even modestly effective therapeutic HIV vaccines may produce small but meaningful increases in life expectancy and compare favorably to alternative uses of scarce HIV care resources.

AIDS Vaccines↗

PubMed2004

Quality of life after aortic valve replacement with tissue and mechanical implants.

OBJECTIVES: We sought to determine whether changes in quality of life at 18 months following aortic valve replacement differ depending on the use of tissue valves or mechanical valves. METHODS: We prospectively studied 73 patients with tissue valve replacements and 53 patients with mechanical valve replacements performed from April 1998 through March 1999 at Yale-New Haven Hospital. Quality of life was measured at baseline and at 18 months using the Medical Outcomes Trust Short Form 36-Item Health Survey. RESULTS: Baseline unadjusted mean quality-of-life scores were lower in tissue valve recipients than in mechanical valve recipients and, for both groups, were generally lower than US population norms. At 18 months postoperatively, quality-of-life scores were greatly improved in both groups and were comparable to population norms (ie, within one-half a standard deviation). After adjusting for baseline quality of life, age, and other prognostic factors in an analysis of covariance, improvements in quality-of-life scores for tissue valve recipients versus mechanical valve recipients were similar. Of 10 (8 domains and 2 summary) scales examined, the only significant difference between the 2 groups was for the improvement in role limitations due to physical problems (Role Physical), which was more favorable in patients with mechanical valve implants (P =.04). CONCLUSIONS: The use of tissue valve implants versus mechanical valve implants has little influence on improvement in quality of life at 18 months following aortic valve replacement. Thus, decisions about whether to choose a tissue valve or mechanical valve implant should depend upon other factors such as rates of complications and differences in the life span of the implants.

Aged↗

PubMed2004

Association between preference-based health-related quality of life and asthma severity.

BACKGROUND: Preference-based measures of health-related quality of life (HRQL) focus on choice and strength of preference for health outcomes. If the value people attach to the health improvement they receive from medical treatments for asthma is known, preference-based measures can be used in cost-effectiveness analyses to aid resource allocation decisions. International guidelines have been developed to guide medical management according to asthma severity defined by lung function and symptom frequency. OBJECTIVE: To test the hypothesis that preferences correlate with asthma severity and that the relationships vary among the preference instruments used and the components of asthma severity studied. METHODS: Preferences for subjects' health states were measured using (1) a rating scale (RS), (2) standard gamble (SG), (3) time tradeoff (TTO), (4) Health Utilities Index 3 (HUI3), and (5) Asthma Symptom Utility Index (ASUI). We measured level of airways obstruction by forced expiratory volume in 1 second (FEV1) and symptom frequency of cough, wheeze, dyspnea, and nighttime awakening. Asthma severity was defined by either percentage of predicted FEV1 or symptom frequency. RESULTS: One hundred adults with asthma were studied. Preference scores were lowest for the HUI3 (mean, 0.57) and highest for the SG (mean, 0.91). Spearman correlations showed that the strength of the relationship between preference scores and percentage of predicted FEV1 was weak to moderate (r = 0.14-0.36). One-way analysis of variance showed that RS, TTO, and ASUI scores were significantly associated with the percentage of predicted FEV1 (P < or = .01). Both RS and HUI3 scores were significantly associated with frequency of all symptoms (P < .05). CONCLUSIONS: Preference-based measures of HRQL are correlated with asthma severity defined by lung function or symptoms. The RS was significantly associated with level of airways obstruction and all 4 symptoms evaluated, whereas the SG was not correlated with either marker of asthma severity.

Adult↗

PubMed2004

A single measure of FEV1 is associated with risk of asthma attacks in long-term follow-up.

BACKGROUND: Clinical practice guidelines for asthma care emphasize the use of objective measures of asthma severity, and yet little data exist on the relationship between FEV(1) and asthma outcomes over long-term follow-up. METHODS: We explored the association between measures of FEV(1) percentage of predicted (FEV(1)% predicted) and subsequent asthma attacks over 3-year intervals. Subjects were identified from two longitudinal cohort studies conducted in the United States and the Netherlands. Persons were included in the analysis if they reported ever having an attack of wheezing with associated shortness of breath prior to or during the follow-up period. RESULTS: Over the course of longitudinal follow-up at 3-year intervals, 195 subjects in the Netherlands cohort contributed 510 observations, and 698 subjects in the US cohort contributed 1,268 observations (for each observation, the report of an attack since their last visit was paired with the subject's FEV(1) recorded 3 years prior). Overall, subjects in the Netherlands cohort experienced 114 attacks (22% of the observations) and subjects in the US cohort had 517 attacks (40.6% of the observations). FEV(1)% predicted was significantly associated with risk of an asthma attack over the 3 years following its measurement. After adjusting for current smoking and gender, FEV1% predicted remained an independent predictor of subsequent asthma attacks. CONCLUSIONS: These findings support the use of spirometry as an objective measure of asthma severity and risk of adverse outcomes.

Adolescent↗

PubMed2003

Projecting the cost-effectiveness of adherence interventions in persons with human immunodeficiency virus infection.

PURPOSE: To explore the cost-effectiveness of interventions to improve adherence to combination antiretroviral therapy in patients with human immunodeficiency virus (HIV) infection. METHODS: A simulation model of HIV infection, incorporating CD4 cell count and HIV ribonucleic acid levels as predictors of disease progression, was used to estimate the lifetime costs and quality-adjusted life expectancy associated with clinical interventions to improve adherence to antiretroviral therapy (e.g., directly observed therapy, automatic medication dispensers, beepers, portable alarms) in a clinical trial cohort with early disease (mean CD4 count, 350 cells/microL), a clinical trial cohort with advanced disease (mean CD4 count, 87 cells/microL), and an urban cohort (mean CD4 count, 217 cells/microL). Data were from clinical trials, national databases, and published literature. RESULTS: For relatively healthy patients with early disease, interventions that reduced virologic failure rates by 10% increased quality-adjusted life expectancy by 3.2 months, whereas those that reduced failure by 80% increased quality-adjusted life expectancy by 34.8 months, as compared with standard care. The cost-effectiveness ratio was below 50000 US dollars per quality-adjusted life-year (QALY) for interventions costing 100 US dollars per month provided that failure rates were reduced by at least 10%, and for those costing 500 US dollars per month provided that failure rates were reduced by more than 50%. For both patients with advanced disease and those from an urban cohort, adherence interventions costing about 500 US dollars per month (e.g., directly observed therapy) had to reduce failure by about 25% to have cost-effectiveness ratios below 50000 US dollars per QALY. CONCLUSION: In patients with lower baseline levels of adherence or advanced disease, even very expensive, moderately effective adherence interventions are likely to confer cost-effectiveness benefits that compare favorably with other interventions.

Antiretroviral Therapy, Highly Active↗