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Biomedical subjects

A K Biddle

Publications and source records attributed to A K Biddle.

At least 19 recordsLinked to original sources

Measuring the effect of clinical guidelines on patient outcomes.

OBJECTIVES: To identify and examine the methodologic issues related to evaluating the effectiveness of treatment adherence to clinical guidelines. The example of antiretroviral therapy guidelines for human immunodeficiency virus (HIV) disease is used to illustrate the points. METHODS: Regression analysis was applied to observational HIV clinic data for patients with CD4+ cell counts less than 500 per microL and greater than 50 per microL at baseline (n = 704), using Cox proportional hazards time-varying covariates models controlling for baseline risk. The results are compared with simpler models (Cox model [without time-varying covariates] and logistic regression). In addition, the effect of including a measure of exposure to antiretroviral guidelines in the model is explored. RESULTS: This study has three implications for modeling clinical guideline effectiveness. To capture events that are time-sensitive, a duration model should be used, and covariates that are time-varying should be modeled as time-varying. Thirdly, incorporating a threshold measure of exposure to reflect the minimum period of time for guideline adherence required for a measurable effect on patient outcome should be considered. CONCLUSIONS: The methods proposed in this paper are important to consider if guidelines are to evolve from being a tool for summarizing and transferring the results of research from the literature to clinicians into a practical tool that influences clinical practice patterns. However, the methodology tested in this study needs to be validated using additional data on similar patients and using data on patients with other diseases.

Anti-HIV Agents↗

Effectiveness and economic impact of screening for colorectal cancer by mass fecal occult blood testing.

OBJECTIVES: Fecal occult blood testing has been shown to reduce mortality from colorectal cancer in large randomized, controlled trials conducted in the United States, Denmark, and the United Kingdom, and mathematical simulation modeling found it to be cost-effective relative to other health care services. Before making a concerted effort to implement mass fecal occult blood testing based on this evidence alone, however, we considered it prudent to critically re-evaluate the effectiveness and economic impact of screening in the US population as a whole. METHODS: To assess the effectiveness of screening, we projected published outcomes from each of the three large randomized controlled trials of fecal occult blood testing to the US population, as if each clinical trial had been done in the population as a whole. We then determined the resource costs of detection and treatment that would be associated with the outcomes predicted from each trial. RESULTS: More than 1 million colorectal cancers could be expected to arise over 10 yr in the cohort of US residents eligible to enter a screening program in 1997, and trial outcomes indicate that > or = 60% of these cancers would be fatal. If the 60-67% compliance rate of the population-based randomized controlled trials were achieved, a fecal occult blood testing program would detect 30% of known colorectal cancers and save 100,000 lives over 10 yr. Screening would incur total costs of $3-4 billion over 10 yr, or $2,500 per life-year saved. CONCLUSIONS: Mass fecal occult blood testing is cost-effective, and, although not inexpensive, many would consider the total cost acceptable. Even with a concerted effort to achieve compliance, however, the effectiveness of fecal occult blood testing would be limited to saving the lives of < or = 15% of those who otherwise would die from their cancer in the first 10 yr after beginning mass screening. The limitations of fecal occult blood testing suggest the need to further evaluate the role of endoscopy in screening, and to develop more effective, noninvasive screening tools.

Aged↗

Cost-benefit analysis of sumatriptan tablets versus usual therapy for treatment of migraine.

We performed a systematic assessment of the costs and benefits of sumatriptan and usual therapy for migraine from society's perspective. A decision tree was constructed with probability estimates based on data from an open-label clinical trial assessing the economic and human impacts of sumatriptan and usual therapy on nursing personnel. Direct medical care costs including costs for drug, physician, and emergency room visits were considered. Benefits were estimated using the human capital approach based on the national average of weekly earnings and productivity loss estimated from a migraine clinical trial. The net benefits of sumatriptan and usual therapy for the treatment of a single migraine attack were estimated to be $50 and $20, respectively. The annual incremental net benefit of sumatriptan over usual therapy was estimated to be $114-540/patient. The price difference was offset by benefits of sumatriptan in reducing use of health care resources and productivity loss.

Absenteeism↗

Developing clinical practice guidelines for spinal cord medicine. Lessons learned.

This article describes the process used by the Consortium for Spinal Cord Medicine to develop evidence-based clinical practice guidelines for managing and treating individuals with spinal cord injury and provides important information on lessons learned and the potential problems to avoid. Issues to consider during the guideline development process include topic selection and explication, methods for selecting the panel chair and panel members, the writing of recommendations and supporting scientific rationales, peer-reviewing guidelines, and the process for disseminating, implementing, and evaluating guidelines. The applicability, advantages, and disadvantages of available evidence and guideline recommendation grading systems and issues arising from the lack of scientific evidence supporting particular recommendations are also discussed.

Humans↗

Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia.

BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia. DESIGN: Cost-effectiveness analysis. DATA SOURCES: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees. TARGET POPULATION: Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy. OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective. RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY. CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.

Anti-Bacterial Agents↗

Decision-analysis of transjugular intrahepatic portosystemic shunt versus distal splenorenal shunt for portal hypertension.

Transjugular intrahepatic portosystemic shunt (TIPS) and surgical distal splenorenal shunt (DSRS) are treatments for complications of portal hypertension. TIPS is widely used because it is relatively easy to place. Because TIPS may malfunction over time, it is unclear whether TIPS is superior to DSRS in patients with Child's class A cirrhosis who enjoy a longer survival. This study compared the cost-effectiveness of TIPS to DSRS for portal hypertension in Child's class A cirrhosis. A decision analysis model was used to evaluate the number of procedures, life expectancy, and costs over the first 2 years in patients with Child's class A cirrhosis who underwent a TIPS or DSRS. Patients who received TIPS survived 1.96 years, required 1.7 procedures, and incurred $41,685 in costs. Patients who underwent a DSRS survived 1.86 years, required 1.0 procedure, and incurred $26,951 in costs. The cost-effectiveness of TIPS compared with DSRS was $147,340 per life-year saved. Adjusting the rate of TIPS dysfunction, 1-year survival, or the number of ultrasounds to detect TIPS dysfunction did not change the results. In patients with Child's class A cirrhosis, DSRS is a more cost-effective treatment than TIPS. Until the results of a randomized controlled trial comparing TIPS with DSRS are available, TIPS should be regarded as experimental and prohibitively expensive in Child's class A cirrhosis.

Decision Support Techniques↗

Costs of developing childhood immunization registries: case studies from four All Kids Count projects.

We conducted case studies using structured interviews at four sites to understand the financial resources needed to implement childhood immunization registries. The total cost of planning and implementing a central registry ranged from $2.4 million to almost $7 million over the first five years. In addition, substantial investment by individual or group providers often was required. Registries are large information systems that require considerable investment of developmental resources, regardless of the number of children eventually entered into the system. Given the substantial investment that a registry represents, the realistic anticipation of such resource needs is important to successful planning and implementation.

Child Welfare↗

The health insurance puzzle: a new approach to assessing patient coverage preferences.

Previous studies of preferences for health insurance benefits have required individuals to make a series of complex and repetitive decisions, and have assumed that all insured benefits are desirable. This study reports the development and testing of a simple, innovative instrument to measure preferences for health insurance benefits. The newly developed instrument (Puzzle) is designed to allow subjects to select health benefits in a way that underscores the trade-offs dictated by budgets and costs. A "puzzle-like" frame representing budget constraints and "puzzle piece" benefit cards proportionately sized to represent the premium price of a single year's coverage comprise the instrument. In a comparison procedure (Money Game), participants "purchase" individual benefits by exchanging "play" money for benefit tokens. The Puzzle's utility was assessed by examining the convergence of results from both instruments and the subject's ratings of and preference for the instruments. One hundred five elderly Medicare enrollees seen in the general Internal Medicine outpatient clinic of a major southeastern teaching hospital were interviewed. Subjects answered interviewer-administered questionnaires and completed both the Puzzle and the Money Game. Both McNemar's test and Kendall's tau-b indicated a high degree of concordance between benefit choices made using the two instruments. Descriptive statistics demonstrated that the Puzzle was clear, easy to use, understandable, and preferred to the Money Game. The results suggest that the Puzzle is a promising tool for assessing health insurance coverage preferences under circumstances of limited expenditures, which can be modified for use with various populations who face limited insurance benefits.

Aged↗

Impact of a new universal purchase vaccine program in North Carolina.

OBJECTIVE: To explore the effects of state universal purchase (UP) of vaccines for all children, regardless of income or insurance status, on North Carolina physicians and families. DESIGN: Cross-sectional survey. PARTICIPANTS: Pediatricians and family physicians (N = 2163) were surveyed in 1995 to compare immunization charges in North Carolina (new UP) with those of Massachusetts (UP) and Texas (free market). MAIN OUTCOME MEASURES: Patient charges for immunizations and well-child visits and physician perceptions of the effects of state immunization programs. Models were devised to simulate the net effect of the North Carolina UP program on immunization revenue for physicians and on families' out-of-pocket costs for well-child care. RESULTS: Physician participation rates in the 2 UP programs were very high. North Carolina physicians reported substantial decreases in immunization charges and reduced referrals to public clinics, but thought that UP increased their administrative burden. Sixty percent of North Carolina physicians increased charges for well-child visits, nearly twice that in the 2 control states. Families who previously had received immunizations from public clinics but chose to remain in the private-sector "medical home" for immunizations after implementation of UP had increased out-of-pocket expenses that varied by their insurance status. CONCLUSIONS: The North Carolina UP program is effective in decreasing patient immunization charges and reducing referrals to public clinics. However, UP does not eliminate cost as a barrier to immunization, nor does it enable all children to remain in their medical homes. Underinsured children still may face considerable financial barriers to immunization in a UP system.

Cross-Sectional Studies↗

Older Medicare enrolees' choices for insured services.

OBJECTIVES: The Medicare Trust Fund is expected to be bankrupt in the next decade, thus threatening the viability of the Medicare Program. We have ascertained what Medicare enrollees' priorities for insured services would be, and why, if it were fiscally necessary to limit Medicare benefits to maintain the viability of the Program. DESIGN: A cross-sectional survey using anonymous, inperson interviews and an innovative instrument to elicit choices. SETTING: General Internal Medicine outpatient clinic at a university teaching hospital. PARTICIPANTS: One hundred five adults, 65 years of age and older, who had primary care physician visits between July and September 1995. MEASUREMENTS: Desire to personally select insurance benefits, insurance benefit choices, and the reasons for selection or rejection of benefits. RESULTS: Subjects of various educational and economic backgrounds were able to carry out the selection process with relative case, and four-fifths of respondents preferred to make their own choices about insured services. The most frequently selected services were hospitalization, outpatient care, prescription drugs, eye care, and home care, in descending order. Subjects selected 52 different combinations of services. Only 2% of respondents picked the current Medicare service package. The reasons given for selection varied by service; cost and current or anticipated need for a service were the most frequently cited forces driving the choices made. CONCLUSION: These data suggest that Medicare enrollees prefer some element of choice about their health insurance coverage. Their choices vary widely and differ from the current Medicare package.

Aged↗

The effects of having a regular doctor on access to primary care.

The authors assessed the relationship between having a regular doctor and access to care, as measured by a set of preventive and primary care utilization indicators recommended by the Institute of Medicine. The 1987 National Medical Expenditure Survey was used in the analyses (n = 30,012). The results of the regression analyses suggest that individuals with any type of regular source of care had better access than those without a regular source of care. Persons with a regular doctor had better access to primary care than those with a regular site but no regular doctor. However, the apparent advantage of having a regular doctor over a regular site disappeared when only those individuals reporting a physician's office, clinic, or health maintenance organization as their regular source of care were compared. These results suggest that policies that promote the doctor-patient relationship will increase access, although the gains may be negligible for individuals who use mainstream primary care sites (physician's office, clinic, or health maintenance organization) versus sites such as walk-in clinics or emergency rooms.

Adolescent↗

Health insurance access to young adult survivors of childhood cancer in North Carolina.

Historically, there has been evidence to support the hypothesis that survivors of childhood cancer have been discriminated against in the private health insurance market in some areas of the United States. Results of previous studies have been inconsistent and have generally focused on a limited number of outcome variables. A retrospective cohort study of young adult survivors of childhood cancer and their siblings was performed to determine the risk of health insurance access problems of childhood cancer survivors in North Carolina. Mailed questionnaires were completed by 182 cancer survivors from three institutions who were diagnosed between 1976 and 1988, and by 101 of their siblings for a response of 62.1%. Using logistic regression in SAS, cancer survivors were found to be more likely to be denied health insurance than their siblings, with an adjusted odds ratio of 15.1. Childhood cancer survivors also had health insurance policies that excluded care for pre-existing medical conditions more often than their siblings (OR = 5.5). In addition, cancer survivors reported problems obtaining health insurance coverage more frequently than their siblings with an adjusted odds ratio of 22.8. In general, survivors of childhood cancer who were diagnosed in North Carolina have had decreased access to health insurance coverage when compared to their siblings of similar age. North Carolina health insurance regulations permit health insurance firms to discriminate against cancer survivors because of their history of illness, often decreasing their access to needed follow-up care.

Adult↗

A model for estimating the impact of changes in children's vaccines.

OBJECTIVES: To assist in strategic planning for the improvement of vaccines and vaccine programs, an economic model was developed and tested that estimates the potential impact of vaccine innovations on health outcomes and costs associated with vaccination and illness. METHODS: A multistep, iterative process of data extraction/integration was used to develop the model and the scenarios. Parameter replication, sensitivity analysis, and expert review were used to validate the model. RESULTS: The greatest impact on the improvement of health is expected to result from the production of less reactogenic vaccines that require fewer inoculations for immunity. The greatest economic impact is predicted from improvements that decrease the number of inoculations required. CONCLUSIONS: Scenario analysis may be useful for integrating health outcomes and economic data into decision making. For childhood infections, this analysis indicates that large cost savings can be achieved in the future if we can improve vaccine efficacy so that the number of required inoculations is reduced. Such an improvement represents a large potential "payback" for the United States and might benefit other countries.

Child, Preschool↗

Changes in follow-up care for Medicare surgical patients under the prospective payment system.

In this study, changes in the number, site, and source of follow-up visits and allowed charges were examined for follow-up visits provided to Medicare surgical patients between 1984 and 1986. Among the 21 surgical procedures studied, follow-up visits decreased by 5.2%, after adjusting for case mix. Despite the physician fee freeze during the most of the study period, total allowed charges increased by 8.1%, indicating that the average intensity of visits increased by 14.0%. Inpatient visits decreased 6.7%, while outpatient visits increased 3.9%. Thus, while some substitution of outpatient for inpatient visits occurred, prospective payment system-related reductions in inpatient length of stay were associated with reductions in both the total visits and total allowed charges. Holding other factors constant, the 9.5% overall reduction in length of stay produced a 6.4% reduction in total allowed charges. The authors concluded, then, that prospective payment system had a significant effect in reducing the growth of Medicare expenditures for physician visits. The reduction in submitted claims for inpatient follow-up visits and the absence of a strong substitution effect suggest that some inpatient visits may not have been necessary. These results also raise several issues concerning Medicare's global fee for surgical procedures, and provide additional evidence in support of a uniform global fee policy under the new Medicare fee schedule.

Aftercare↗

Predictors of safety belt initiative by primary care physicians. A social learning theory perspective.

Even with the passage of state safety belt laws, primary care physicians can contribute to their patients' safety by brief interventions. The present study explores the prevalence of such action with adult patients and tests the power of constructs taken from social learning theory to explain physicians' behavior. These constructs included self-efficacy, personal behavior (self-modeling) and three outcome expectations--expectation of patient follow-through, health impact, and impact of health promotion on the practice. Data were taken from a survey of Texas family physicians prior to enactment of the state law (n = 209). History-taking and advising were combined to form a single scale, "safety belt action." Prevalence of safety belt action was low. Overall, only 5% said they ask routinely about safety belts; 58.1% do not advise or discuss the risk even when they are aware of nonuse. Social learning theory variables accounted for 34% of the variance in safety-belt action after controlling for year of graduation in a hierarchical regression analysis. Self-efficacy was entered first, and it predicted 25% of the variance. The other social learning variables were entered together, and they predicted the additional 9% of the variance after controlling for year of graduation and self-efficacy. Of these other variables, only health impact was significant, however. These findings suggest several avenues for improving safety belt action and add evidence for the importance of outcome expectations over and above self-efficacy.

Adult↗

Efficacy of psychoeducational interventions on pain, depression, and disability in people with arthritis: a meta-analysis.

Meta-analysis is a technique which combines data from several properly and similarly designed controlled studies so as to increase the power of the relevant statistical analysis. Fifteen studies on the effects of psychoeducational interventions on disability, pain and depression in individuals with chronic rheumatoid arthritis or osteoarthritis were analyzed by this method. The results indicate that patient education can indeed contribute to improving the health status of such patients.

Adult↗

Modeling the use of triple combination therapy in five countries: nevirapine, Zidovudine, and Didanosine.

OBJECTIVE: In this study, we modify previously published models to estimate the short- and long-term consequences of nevirapine triple combination therapy use in five developed countries. Current pharmacoeconomic practice requires the de novo model development for each new therapy comparison. This approach is lengthy and costly, and it may yield models with very different structures. Standardized, detailed disclosure of model assumptions and parameters makes it possible to recycle published models with minor structural modifications to examine the efficiency of therapies based on new trial data. METHODS: Two well-publicized models of HIV therapy are modified to fit new trial data comparing double and triple combination therapy with nevirapine; model parameters are adjusted to represent clinical practice and cost structure in five countries. A short-term model uses trial data from advanced-stage patients to estimate first-year costs and consequences. A long-term model uses data from antiretroviral-naïve patients to estimate long-term cost-effectiveness. RESULTS: During the first year, for each 100 individuals treated with nevirapine triple combination therapy, 2.7 deaths and 30.8-31.4 opportunistic disease events would be averted compared to employing dual therapy. Additionally, 61% to 142% of the first-year costs of nevirapine therapy would be offset by other medical care costs savings [FF19,749, DM3,778, 3334 (x1000) lire, 293 (x1000) ptas, and US $3,569]. Compared to dual combination therapy, nevirapine triple combination therapy is predicted to yield incremental cost-effectiveness ratios (discounted at 3%) of FF101,057, DM30,709, 28,066 (x1000) lire, 1294 (x1000) ptas, and US $14,338. CONCLUSION: Published, well-constructed, and documented cost-effectiveness models can be reused to estimate the economic impact of therapies for HIV disease. Such models can also be used to provide insight into the factors that affect efficiency across countries. Our use of clinical trial data on nevirapine, together with published HIV economic models, provides support for the hypothesis that nevirapine is cost-effective under the cost structures of five developed countries.

AIDS-Related Opportunistic Infections↗