Causal inference in medical records and complementary systems pharmacology for metformin drug repurposing towards dementia

Metformin, a diabetes drug with anti-aging cellular responses, has complex actions that may alter dementia onset. Mixed results are emerging from prior observational studies. To address this complexity, we deploy a causal inference approach accounting for the competing risk of death in emulated clinical trials using two distinct electronic health record systems. In intention-to-treat analyses, metformin use associates with lower hazard of all-cause mortality and lower cause-specific hazard of dementia onset, after accounting for prolonged survival, relative to sulfonylureas. In parallel systems pharmacology studies, the expression of two AD-related proteins, APOE and SPP1, was suppressed by pharmacologic concentrations of metformin in differentiated human neural cells, relative to a sulfonylurea. Together, our findings suggest that metformin might reduce the risk of dementia in diabetes patients through mechanisms beyond glycemic control, and that SPP1 is a candidate biomarker for metformin's action in the brain.

Early analysis shows that endoscopic flexor hallucis longus transfer has a promising cost-effectiveness profile in the treatment of acute Achilles tendon ruptures

PURPOSE

Current options for treating an Achilles tendon rupture (ATR) include conservative and surgical approaches. Endoscopic flexor hallucis longus (FHL) transfer has been recently proposed to treat acute ruptures, but its cost-effectiveness potential remains to be evaluated. Therefore, the objective of this study was to perform an early cost-effectiveness analysis of endoscopic FHL transfer for acute ATRs, comparing the costs and benefits of current treatments from a societal perspective.

METHODS

A conceptual model was created, with a decision tree, to outline the main health events during the treatment of an acute ATR. The model was parameterized using secondary data. A systematic review of the literature was conducted to gather information on the outcomes of current treatments. Data related to outcomes of endoscopic FHL transfers in acute Achilles ruptures was obtained from a single prospective study. Analysis was limited to the two first years. The incremental cost-effectiveness ratio was the main outcome used to determine the preferred strategy. A willingness-to-pay threshold of $100,000 per quality-adjusted life-year was used. Sensitivity analyses were performed to determine whether changes in input parameters would cause significant deviation from the reference case results. Specifically, a probability sensitivity analysis was conducted using Monte Carlo simulations, and a one-way sensitivity analysis was conducted by sequentially varying each model parameter within a given range.

RESULTS

For the reference case, incremental cost-effectiveness ratios exceeded the willingness-to-pay threshold for all the surgical approaches. Overall, primary treatment was the main cost driver. Conservative treatment showed the highest direct costs related to the treatment of complications. In the probabilistic sensitivity analysis, at a willingness-to-pay threshold of $100,000, open surgery was cost-effective in 50.9%, minimally invasive surgery in 55.8%, and endoscopic FHL transfer in 72% of the iterations. The model was most sensitive to parameters related to treatment utilities, followed by the costs of primary treatments.

CONCLUSION

Surgical treatments have a moderate likelihood of being cost-effective at a willingness-to-pay threshold of $100,000, with endoscopic FHL transfer showing the highest likelihood. Following injury, interventions to improve health-related quality of life may be better suited for improved cost-effectiveness.

LEVEL OF EVIDENCE

Level III.

Economics of Beta-Cell Replacement Therapy

PURPOSE OF REVIEW

Type 1 diabetes impacts 1.3 million people in the USA with a total direct lifetime medical cost of $133.7 billion. Management requires a mix of daily exogenous insulin administration and frequent glucose monitoring. Decision-making by the individual can be burdensome.

RECENT FINDINGS

Beta-cell replacement, which involves devices protecting cells from autoimmunity and allo-rejection, aims at restoring physiological glucose regulation and improving clinical outcomes in patients. Given the significant burden of T1D in the healthcare systems, cost-effectiveness analyses can drive innovation and policymaking in the area. This review presents the health economics analyses performed for donor-derived islet transplantation and the possible outcomes of stem cell-derived beta cells. Long-term cost-effectiveness of islet transplantation depends on the engraftment of these transplants, and the expenses and thresholds assumed by healthcare systems in different countries. Early health technology assessment analyses for stem cell-derived beta-cell replacement suggest manufacturing optimization is necessary to reduce upfront costs.

Modeling biological and economic uncertainty on cell therapy manufacturing: the choice of culture media supplementation

AIM

To evaluate the cost-effectiveness of autologous cell therapy manufacturing in xeno-free conditions.

MATERIALS & METHODS

Published data on the isolation and expansion of mesenchymal stem/stromal cells introduced donor, multipassage and culture media variability on cell yields and process times on adherent culture flasks to drive cost simulation of a scale-out campaign of 1000 doses of 75 million cells each in a 400 square meter Good Manufacturing Practices facility.

RESULTS & CONCLUSION

Passage numbers in the expansion step are strongly associated with isolation cell yield and drive cost increases per donor of $1970 and 2802 for fetal bovine serum and human platelet lysate. Human platelet lysate decreases passage numbers and process costs in 94.5 and 97% of donors through lower facility and labor costs. Cost savings are maintained with full equipment depreciation and higher numbers of cells per dose, highlighting the number of cells per passage step as the key cost driver.

Nosocomial amplification of MERS-coronavirus in South Korea, 2015

Background

Nosocomial amplification resulted in nearly 200 cases of Middle East respiratory syndrome (MERS) during the 2015 South Korean MERS-coronavirus outbreak. It remains unclear whether certain types of cases were more likely to cause secondary infections than others, and if so, why.

Methods

Publicly available demographic and transmission network data for all cases were collected from the Ministry of Health and Welfare. Statistical analyses were conducted to determine the relationship between demographic characteristics and the likelihood of human-to-human transmission. Findings from the statistical analyses were used to inform a hypothesis-directed literature review, through which mechanistic explanations for nosocomial amplification were developed.

Results

Cases that failed to recover from MERS were more likely to cause secondary infections than those that did. Increased probability of direct, human-to-human transmission due to clinical manifestations associated with death, as well as indirect transmission via environmental contamination (e.g., fomites and indoor ventilation systems), may serve as mechanistic explanations for nosocomial amplification of MERS-coronavirus in South Korea.

Conclusions

In addition to closely monitoring contacts of MERS cases that fail to recover during future nosocomial outbreaks, potential fomites with which they may have had contact should be sanitized. Furthermore, indoor ventilation systems that minimize recirculation of pathogen-bearing droplets should be implemented whenever possible.

Medical Students Who Pursue a Joint MD/MBA Degree: Who Are They and Where Are They Heading?

Increasingly, health care is being delivered in large, complex organizations, and physicians must learn to function effectively in them. As a result, several medical and business schools have developed joint programs to train physician leaders who receive both medical degree (MD) and master of business administration (MBA) degrees. We examined several themes in relation to these programs, revolving around concerns about who is attracted to them and whether exposure to the differing cultures of medicine and business have an impact on the professional identities of their graduates as manifested in their motivations, aspirations, and careers. We addressed these issues by studying students in the joint MD/MBA program at Harvard Medical School (HMS) and Harvard Business School (HBS). Our data came from several internal sources and a survey of all students enrolled in the joint program in spring 2013. We found relatively few differences between joint program students and equivalent cohorts of HMS students in terms of personal characteristics, preadmission performance, and performance at HMS and HBS. Contrary to the concerns that such programs may draw students away from medicine, the vast majority embraced careers involving extensive postgraduate medical training, with long-term plans that leveraged their new perspectives and skills to improve health care delivery.

Disease-based modeling to predict fluid response in intensive care units

OBJECTIVE

To compare general and disease-based modeling for fluid resuscitation and vasopressor use in intensive care units.

METHODS

Retrospective cohort study involving 2944 adult medical and surgical intensive care unit (ICU) patients receiving fluid resuscitation. Within this cohort there were two disease-based groups, 802 patients with a diagnosis of pneumonia, and 143 patients with a diagnosis of pancreatitis. Fluid resuscitation either progressing to subsequent vasopressor administration or not was used as the primary outcome variable to compare general and disease-based modeling.

RESULTS

Patients with pancreatitis, pneumonia and the general group all shared three common predictive features as core variables, arterial base excess, lactic acid and platelets. Patients with pneumonia also had non-invasive systolic blood pressure and white blood cells added to the core model, and pancreatitis patients additionally had temperature. Disease-based models had significantly higher values of AUC (p < 0.05) than the general group (0.82 ± 0.02 for pneumonia and 0.83 ± 0.03 for pancreatitis vs. 0.79 ± 0.02 for general patients).

CONCLUSIONS

Disease-based predictive modeling reveals a different set of predictive variables compared to general modeling and improved performance. Our findings add support to the growing body of evidence advantaging disease specific predictive modeling.

Reducing unnecessary lab testing in the ICU with artificial intelligence

OBJECTIVES

To reduce unnecessary lab testing by predicting when a proposed future lab test is likely to contribute information gain and thereby influence clinical management in patients with gastrointestinal bleeding. Recent studies have demonstrated that frequent laboratory testing does not necessarily relate to better outcomes.

DESIGN

Data preprocessing, feature selection, and classification were performed and an artificial intelligence tool, fuzzy modeling, was used to identify lab tests that do not contribute an information gain. There were 11 input variables in total. Ten of these were derived from bedside monitor trends heart rate, oxygen saturation, respiratory rate, temperature, blood pressure, and urine collections, as well as infusion products and transfusions. The final input variable was a previous value from one of the eight lab tests being predicted: calcium, PTT, hematocrit, fibrinogen, lactate, platelets, INR and hemoglobin. The outcome for each test was a binary framework defining whether a test result contributed information gain or not.

PATIENTS

Predictive modeling was applied to recognize unnecessary lab tests in a real world ICU database extract comprising 746 patients with gastrointestinal bleeding.

MAIN RESULTS

Classification accuracy of necessary and unnecessary lab tests of greater than 80% was achieved for all eight lab tests. Sensitivity and specificity were satisfactory for all the outcomes. An average reduction of 50% of the lab tests was obtained. This is an improvement from previously reported similar studies with average performance 37% by [1-3].

CONCLUSIONS

Reducing frequent lab testing and the potential clinical and financial implications are an important issue in intensive care. In this work we present an artificial intelligence method to predict the benefit of proposed future laboratory tests. Using ICU data from 746 patients with gastrointestinal bleeding, and eleven measurements, we demonstrate high accuracy in predicting the likely information to be gained from proposed future lab testing for eight common GI related lab tests. Future work will explore applications of this approach to a range of underlying medical conditions and laboratory tests.

Vaccine availability in the United States during the 2009 H1N1 outbreak

OBJECTIVE

After initial flu cases are reported, months elapse before vaccine becomes available. The authors report the experience of US states during the fall of 2009 on H1N1 vaccine availability in relation to the occurrence of disease.

DESIGN

The authors used data from the Centers for Disease Control and prevention and state health departments to approximate second wave H1N1 epidemic curves. The authors compared these curves to two sources of vaccine distribution data-shipment and administration.

RESULTS

Ten states received their first shipments of vaccine after the epidemic peaked, four states during the week of the peak, and 10 states only 1 week prior to the peak. In nearly half of all states, the epidemic had already begun to decline before any individuals could have been protected.

CONCLUSIONS

A sensible approach would be to highlight the importance of diligent hygienic behavior and to reduce the rate of human-to-human contacts before vaccine is available.

Trends in the use and role of biomarkers in phase I oncology trials

PURPOSE

There has been interest in using biomarkers that aid the evaluation of new anticancer agents. We evaluated trends in the use of biomarkers and their contribution to the main goals of phase I trials.

EXPERIMENTAL DESIGN

We did a systematic review of abstracts submitted to the American Society of Clinical Oncology annual meeting from 1991 to 2002 and the publications related to these abstracts. We analyzed the use of biomarkers and their contribution to published phase I trials.

RESULTS

Twenty percent of American Society of Clinical Oncology phase I abstracts (503 of 2458) from 1991 to 2002 included biomarkers. This proportion increased over time (14% in 1991 compared with 26% in 2002; P < 0.02). Independent predictors of the use of biomarkers included National Cancer Institute sponsorship, submission in the time period of 1999 to 2002, adult population, and drug family (biological agents). Biomarkers supported dose selection for phase II studies in 11 of 87 of the trials (13%) emanating from these abstracts. However, the primary determinants of phase II dose and schedule were toxicity and/or efficacy in all but one of these 87 trials (1%). Biomarker studies provided evidence supporting the proposed mechanism of action in 34 of 87 of the published trials (39%).

CONCLUSIONS

The use of biomarkers in phase I trials has increased over the period from 1991 to 2002. To date, biomarker utilization has made a limited and primarily supportive contribution to dose selection, the primary end point of phase I studies. Additional studies are needed to determine what type of biomarker information is most valuable to evaluate in phase I trials.

A framework to evaluate the economic impact of pharmacogenomics

INTRODUCTION

Pharmacogenomics and personalized medicine promise to improve healthcare by increasing drug efficacy and minimizing side effects. There may also be substantial savings realized by eliminating costs associated with failed treatment. This paper describes a framework using health claims data for analyzing the potential value of pharmacogenomic testing in clinical practice.

METHODS

We evaluated a model of alternate clinical strategies using asthma patients' data from a retrospective health claims database to determine a potential cost offset. We estimated the likely cost impact of using a hypothetical pharmacogenomic test to determine a preferred initial therapy. We compared the annualized per patient costs distributions under two clinical strategies: testing all patients for a nonresponse genotype prior to treating and testing none.

RESULTS

In the Test All strategy, more patients fall into lower cost ranges of the distribution. In our base case (15% phenotype prevalence, 200 US dollars test, 74% overall first-line treatment efficacy and 60% second-line therapy efficacy) the cost savings per patient for a typical run of the testing strategy simulation ranged from 200 US dollars to 767 US dollars (5th and 95th percentile). Genetic variant prevalence, test cost and the cost of choosing the wrong treatment are key parameters in the economic viability of pharmacogenomics in clinical practice.

CONCLUSIONS

A general tool for predicting the impact of pharmacogenomic-based diagnostic tests on healthcare costs in asthma patients suggests that upfront testing costs are likely offset by avoided nonresponse costs. We suggest that similar analyses for decision making could be undertaken using claims data in which a population can be stratified by response to a drug.

Off-label prescribing among office-based physicians

BACKGROUND

Unlike medicines prescribed for Food and Drug Administration-approved indications, off-label uses may lack rigorous scientific scrutiny. Despite concerns about patient safety and costs to the health care system, little is known about the frequency of off-label drug use or the degree of scientific evidence supporting this practice.

METHODS

We used nationally representative data from the 2001 IMS Health National Disease and Therapeutic Index (NDTI) to define prescribing patterns by diagnosis for 160 commonly prescribed drugs. Each reported drug-diagnosis combination was identified as Food and Drug Administration-approved, off-label with strong scientific support, or off-label with limited or no scientific support. Outcome measures included (1) the proportion of uses that were off-label and (2) the proportion of off-label uses supported by strong scientific evidence. Multivariate analyses were used to identify drug-specific characteristics predictive of increased off-label use.

RESULTS

In 2001, there were an estimated 150 million (95% confidence interval, 127-173 million) off-label mentions (21% of overall use) among the sampled medications. Off-label use was most common among cardiac medications (46%, excluding antihyperlipidemic and antihypertensive agents) and anticonvulsants (46%), whereas gabapentin (83%) and amitriptyline hydrochloride (81%) had the greatest proportion of off-label use among specific medications. Most off-label drug mentions (73%; 95% confidence interval, 61%-84%) had little or no scientific support. Although several functional classes were associated with increased off-label use (P<.05), few other drug characteristics predicted off-label prescription.

CONCLUSIONS

Off-label medication use is common in outpatient care, and most occurs without scientific support. Efforts should be made to scrutinize underevaluated off-label prescribing that compromises patient safety or represents wasteful medication use.

The economic burden of anemia in cancer patients receiving chemotherapy

BACKGROUND

Anemia is one of the most common hematologic complications of cancer and cytotoxic treatment. The economic burden associated with anemia in patients with malignancy has not yet been extensively studied.

METHODS

Patients receiving chemotherapy within 6 months of initial cancer diagnosis were identified in a database of commercial health-care service claims and encounters. Patients with anemia were identified through a coded diagnosis of anemia, transfusion, or erythropoietin treatment. Exponential conditional mean models and a decomposition analysis were used to analyze mean 6-month health-care expenditures.

RESULTS

Twenty-six percent (26%) of 2760 cancer patients with recently diagnosed invasive cancer treated with chemotherapy had anemia. Mean (SD) 6-month unadjusted total expenditures were 62,499 dollars (78,016 dollars) for anemic patients and 36,871 dollars (52,308 dollars) for nonanemic patients (P < 0.0001), with inpatient services representing the largest cost differential between the groups. The adjusted mean 6-month expenditure for the average anemic patient receiving chemotherapy was 57,209 dollars. If anemic patients had the same average health status as nonanemic patients, their predicted 6-month expenditures would have been 19% lower (46,237 dollars). Alternatively, if anemic patients had the same expenditure structure or parameter estimates as nonanemic patients, their predicted expenditures would have been 51% lower (27,847 dollars). Thus, for any given health status, treating a patient who is anemic is associated with considerably higher expenditures.

CONCLUSIONS

Anemia among cancer patients receiving chemotherapy is associated with a substantial burden in terms of direct medical costs. Implications for the treatment of anemia are suggested by this research and should be confirmed in prospective studies.

Benefit plan design and prescription drug utilization among asthmatics: do patient copayments matter?

The ratio of controller-to-reliever medication use has been proposed as a measure of treatment quality for asthma patients. In this study we examine the effects of plan-level mean out-of-pocket asthma medication patient copayments and other features of benefit plan design on the use of controller medications alone, controller and reliever medications (combination therapy), and reliever medications alone. The 1995--2000 MarketScan claims data were used to construct plan-level out-of-pocket copayment and physician/practice prescriber preference variables for asthma medications. Separate multinomial logit models were estimated for patients in fee-for-service (FFS) and non-FFS plans relating benefit plan design features, physician/practice prescribing preferences, patient demographics, patient comorbidities, and county-level income variables to patient-level asthma treatment patterns. We find that the controller-to-reliever ratio rose steadily over 1995--2000, along with out-of-pocket payments for asthma medications, which rose more for controllers than for relievers. After controlling for other variables, however, plan-level mean out-of-pocket copayments were not found to have a statistically significant influence on patient-level asthma treatment patterns. On the other hand, physician/practice prescribing patterns strongly influenced patient-level treatment patterns. There is no strong statistical evidence that higher levels of out-of-pocket copayments for prescription drugs influence asthma treatment patterns. However, physician/practice prescribing preferences influence patient treatment.

Performance Decrements Resulting From Illness in the Workplace: The Effect of Headaches

OBJECTIVES

Studies on the impact of illness on work productivity are important to rationally allocate healthcare resources and to design programs to mitigate these effects. This investigation was conducted to develop and apply daily measures of illness episodes, and to collect subjective and objective data on work performance impacts. Medical bill reviewers completed daily responses to a questionnaire about headache manifestations, severity, and speed of work using interactive voice response (IVR). Of 134 eligible enrolled subjects, 117 (86%) provided at least 30 daily reports over 3 months. Their responses were matched to difficulty-adjusted objective measures: daily output, time on the system, and productivity. Respondents were clinically classified as migraineurs (n = 56), other headache disorders (n = 47), or having no headache disorder (n = 14). Each headache episode was classified as a migraine or nonmigraine headache based on reported manifestations.

RESULTS

The three groups were similar in a variety of demographic factors, and mean subject-specific measures of speed, output, and productivity. In a multivariate model using general estimating equations, only episode severity (not type of headache or person-specific diagnosis) was found to be associated with a significant decrement in speed or productivity. The self-reported decrement in speed (approximately 20%) was much greater than the actual measured effect on productivity (approximately 8%). Intensive daily diary collection by IVR on symptoms and work performance is feasible. However, analysis of detailed daily objective productivity data can be complex, with significant unmeasured sources of variance. Severity may be a more important determinant of headache effect on work performance than specific diagnosis. Future studies on illness episodes and work performance should measure informal accommodations that may enable employees to compensate for episodic illnesses.

Trends in the risks and benefits to patients with cancer participating in phase 1 clinical trials

CONTEXT

In the past, cancer patients entering phase 1 studies confronted the prospects of high risk and unlikely benefit. Over the last decade, cancer drugs under development have become more targeted, and the clinical research environment has become more scrutinized. The impact of these changes on the risks and benefits to patients who participate in phase 1 cancer trials is unknown.

OBJECTIVE

To determine trends in the rates of treatment-related (toxic) death, objective response, and serious toxicity and to identify factors associated with these outcomes.

DATA SOURCES

We searched abstracts and journal articles reporting the results of phase 1 cancer treatment trials originally submitted to annual meetings of the American Society of Clinical Oncology (ASCO) from 1991 through 2002.

STUDY SELECTION

We focused on published single-agent trials that enrolled patients with advanced solid tumors and excluded studies testing agents already approved by the US Food and Drug Administration at the time of the ASCO presentation.

DATA EXTRACTION

Multiple observers independently extracted information on trial design, location, sponsorship, types of tumors treated, drug class, route of administration, and clinical outcomes.

DATA SYNTHESIS

The overall toxic death rate for 213 studies (involving 6474 cancer patients) published in peer-reviewed journals was 0.54%, while the overall objective response rate was 3.8%. Toxic death rates decreased over the study period, from 1.1% over the first 4 years of the study (1991-1994) to 0.06% over the most recent 4-year period (1999-2002) (P<.01). Response rates also decreased but by proportionally much less. After adjusting for characteristics of the experimental trials and the investigational agents, the odds of a patient dying from an experimental treatment while participating in a trial submitted during the most recent 4-year period were less than one tenth those of a patient participating in a trial submitted during the first 4-year period (odds ratio, 0.09; 95% confidence interval, 0.01-0.67; P = .009). In comparison, the adjusted odds of a patient experiencing an objective response over the same time periods decreased by approximately half (odds ratio, 0.46; 95% confidence interval, 0.32-0.66; P<.001).

CONCLUSIONS

The level of risk experienced by cancer patients who participate in phase 1 treatment trials appears to have improved over the 12-year period from 1991 through 2002. Because toxic death rates have decreased more quickly than have objective response rates, the ratio of risk to benefit may have also improved. These changes relate in part to the targeted and less-toxic nature of newer cancer drugs and are coincident with the increased attention that has been paid to the safety of clinical research over the time period we analyzed.

The use of disease-modifying new drugs for multiple sclerosis treatment in private-sector health plans

OBJECTIVES

The aims of this study were to estimate the effects of demographics, location, severity of multiple sclerosis (MS), comorbidities, plan type, coinsurance levels, and time of entry into the sample on the use of disease-modifying agents.

METHODS

A retrospective analysis of medical claims data from 1996 through 2000 was conducted with a sample of MS patients covered by self-insured, employer-sponsored health plans. Proportional hazard analysis with the SAS procedure for proportional hazards regression was used to estimate the impact of the factors of interest on the use of disease-modifying agents. A simulation was conducted to assess the impact of changing drug copayments on the use of disease-modifying agents for MS.

RESULTS

The sample included 1807 patients. Patients were followed for as long as possible, but most were observed for <3 years; the mean (SD) follow-up time was 972.88 (440.59) days. Most factors associated with the use of disease-modifying agents were immutable. They included the following: high severity of illness (only marginally related; P = NS); history of seizures (P = 0.03), depression (P < 0.01), or heart disease (P = 0.01); census region of location (P < 0.01); union membership or association with a union member (P < 0.01); drug copayment requirements (P < 0.05); and year of entry into the sample (P < 0.01). In the simulation, a 50% reduction in drug copayments was associated with an increase of the proportion of patients treated with disease-modifying drugs from 41.2% to 54.7%. Patients' and physicians' preferences for treatment could not be measured directly. The true onset of MS may be unknown for many patients, but this would be the case even if medical records or other data were used for this study.

CONCLUSIONS

Our analyses showed an association between copayments and the use of disease-modifying drugs for MS. Insurance policies can be tailored to influence the use of disease-modifying drugs, enhancing the quality of care for MS patients and reducing price-related barriers to beneficial treatment. Future research should test whether reducing copayments for MS treatment would reduce the use of other health care services (via better MS treatment that modifies the course of illness), or whether the use of disease-modifying drugs would increase total costs to the plan, resulting in slightly higher premiums.

Costs of antidepressant medications associated with inadequate treatment

OBJECTIVE

To determine the costs of antidepressant medications used during inadequate treatment.

STUDY DESIGN

Retrospective database analysis of pharmacy claims made by patients who were treated under routine clinical conditions from July 1, 1999, through September 30, 2002.

PATIENTS AND METHODS

Our participants included 21,632 patients enrolled in a commercial HMO who had a primary care physician associated with our healthcare system. Patients never receiving at least a minimum likely effective antidepressant dose for at least 90 days were defined as having inadequate treatment. This study calculated the costs of antidepressants involved with inadequate treatment at the level of the patient and the medication trial.

RESULTS

A majority of patients (51%) received inadequate treatment. Of overall antidepressant costs, 16% were incurred during trials for patients never adequately treated. The majority of inadequate trials were short and unlikely to have been effective. Most patients (64%) had only a single trial of antidepressants. Venlafaxine, fluoxetine, and sertraline had significantly lower first-trial inadequacy rates compared with the most commonly prescribed agent, citalopram.

CONCLUSIONS

Improved patient care quality and lower antidepressant costs could result if clinicians and healthcare systems focus on reducing short trial rates. Initiating treatment with agents least likely to be discontinued prematurely may be helpful.

Prescriber intent, off-label usage, and early discontinuation of antidepressants: a retrospective physician survey and data analysis

BACKGROUND

Many patients discontinue antidepressant therapy long before the 6-month minimum duration recommended for the treatment of major depression and many other diagnoses. We explore various possibilities, including prescriber intent and patient diagnosis, to explain some of this early discontinuation.

METHOD

Patients from a single health maintenance organization who filled at least 1 prescription for an antidepressant during the first 4 months of 2001 and who did not fill an antidepressant prescription in the 6 months prior were identified retrospectively. Prescribers of those patients' antidepressants were surveyed for patient diagnosis and length of intended treatment with antidepressant medication. Actual length of treatment was then obtained from pharmacy data and correlated with survey data and other variables.

RESULTS

Prescriber surveys were returned for 51% (485/951) of the patients identified. Surveys indicated that for 34% of initial antidepressant prescriptions, < 6 months of treatment was intended. Important determinants of the length of antidepressant therapy included prescriber specialty area, number of prescribers, prescriber intent, diagnosis, specific antidepressant used, and concomitant benzodiazepine use.

CONCLUSIONS

Prescriber intention to treat many patients with short courses of antidepressants, often for off-label, non-mental health indications, was correlated with early discontinuation and needs further study of both its rationale and efficacy. Although less prevalent, short-term treatment of mental health disorders, including depression, was also intended by psychiatrists and other prescribers. The widespread practice of intended short-term treatment with antidepressants needs to be understood better, since it results in guideline-incompatible, early antidepressant discontinuation.

Impact of clinical trial results on national trends in alpha-blocker prescribing, 1996-2002

CONTEXT

Research on factors that influence prescribing patterns and the extent of change produced by clinical trial findings is limited.

OBJECTIVE

To examine the changes in prescribing of alpha-blockers for hypertension treatment before and after the April 2000 publication of the unfavorable Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) early termination involving the study's doxazosin mesylate arm. Changes in prescribing were considered in the context of other potential concurrent influences on medication use between 1996 and 2002, including changes in alpha-blocker drug prices, generic conversion, drug promotion, and competition.

DESIGN, SETTING, AND PATIENTS

Using 2 national pharmaceutical market research reports published by IMS HEALTH, alpha-blocker prescription orders reported in the National Prescription Audit-a random computerized sample of about 20 000 of 29 000 retail, independent, and mail order pharmacies and mass merchandise and discount houses--and office-based physician alpha-blocker prescribing patterns reported in the National Disease and Therapeutic Index--a random stratified sample of about 3500 physician offices--were tracked.

OUTCOME MEASURES

Trends in physician-reported use of alpha-blockers and alpha-blocker prescribing and dispensing by US pharmacies.

RESULTS

There were steady increases in alpha-blocker new prescriptions, dispensed prescriptions, and physician drug use from 1996 through 1999. There was a moderate reversal in these trends following ALLHAT early termination and subsequent publications in early 2000. Between 1999 and 2002, new annual alpha-blocker prescription orders declined by 26% (from 5.15 million to 3.79 million), dispensed prescriptions by 22% (from 17.2 million to 13.4 million), and physician-reported drug use by 54% (from 2.26 million to 1.03 million). Other potential influences did not appear to have contributed significantly to this decline although cessation of alpha-blocker marketing may have hastened the decline.

CONCLUSIONS

Modest yet statistically significant declines in the use of doxazosin and other alpha-blockers coincided with the early termination of the ALLHAT doxazosin arm. Although physicians responded to this new evidence, strategies to augment the impact of clinical trials on clinical practice are warranted.

A statistical analysis of the magnitude and composition of drug promotion in the United States in 1998

BACKGROUND

Although pharmaceutical industry marketing and other factors may influence physician decisions regarding medication prescribing in the United States, little information is available about the composition of promotional efforts by promotional mode and medication class.

OBJECTIVES

The aims of this study were to determine the magnitude of expenditures for common modes of promotion and to delineate patterns of promotional strategies for particular classes of medications.

METHODS

Nationally representative data on expenditures (in US $) for the 250 most promoted medications in the United States in 1998 were available from an independent pharmaceutical market research company for the 5 most commonly used modes of promotion. Key patterns of drug promotion were identified by descriptive statistics, a cluster analysis of expenditures by class, and an analysis of expenditure concentration.

RESULTS

In 1998, the pharmaceutical industry spent $12,724 million promoting its products in the United States, of which 85.9% was accounted for by the top 250 drugs and 51.6% by the top 50 drugs. Direct-to-consumer (DTC) advertising was more concentrated on a small subset of medications than was promotion to professionals. Overall, 1998 expenditures were dominated by free drug samples provided to physicians (equivalent retail cost of $6602 million) and office promotion ($3537 million), followed by DTC advertising ($1337 million), hospital promotion ($705 million), and advertising in medical journals ($540 million). Four distinct patterns of expenditures were observed: promotion to office physicians with little consumer promotion (14 drug classes); dual focus on office physicians and consumer advertising (4 drug classes); predominant DTC advertising (1 class: smoking-cessation products); and promotion to office- and hospital-based professionals without consumer advertising (1 class: narcotic analgesics).

CONCLUSIONS

The present findings reinforce the perception that the pharmaceutical industry invests heavily in promoting its products and demonstrates that promotional expenditures are concentrated on a small number of medications. Although promotion to professionals remains dominant, DTC advertising has become key for a subset of common medications

National trends in asthma visits and asthma pharmacotherapy, 1978-2002

BACKGROUND

Research is limited on physicians' compliance with recent clinical guidelines for asthma treatment.

OBJECTIVE

Our purpose was to investigate the relationships among clinical guidelines, asthma pharmacotherapy, and office-based visits through use of nationally representative data.

METHODS

Nationally representative data on prescribing patterns by office-based US physicians were extracted from the National Disease and Therapeutic Index. We tracked 1978-2002 trends in the frequency of asthma visits and patterns of asthma pharmacotherapy, focusing on the use of controller and reliever medications.

RESULTS

The estimated annual number of asthma visits in the United States increased continuously from 1978 through 1990 (18 million visits); since 1990, it has remained relatively stable. Controller medication use increased 8-fold between 1978 and 2002, inhaled corticosteroids manifesting the biggest increases. The use of reliever medications, particularly short-acting oral beta(2)-agonists, decreased modestly over this period. The aggregate use of controllers (83% of visits) superseded that of relievers (80%) for the first time in 2001. Improved appropriateness of asthma pharmacotherapy was also suggested by an increase in the controller-to-reliever ratio, which reached 92% in 2002. Xanthines, which once dominated asthma therapy (63% of visits in 1978), were used in only 2% of visits in 2002. More recent drug entrants have been adopted rapidly, single-entity long-acting inhaled beta(2)-agonists being used in 9% of visits and leukotriene modifiers in 24% of visits in 2002.

CONCLUSION

Asthma pharmacotherapy has changed extensively in the past 25 years. Practices over the last decade are increasingly consistent with evidence-based guidelines. These changes in medication use might have contributed to the lack of a recent increase in asthma visits.

Healthcare expenditure in patients treated with venlafaxine or selective serotonin reuptake inhibitors for depression and anxiety

We compared healthcare expenditure over a six-month period following initiation of therapy with either venlafaxine (immediate and extended-release) or a selective serotonin reuptake inhibitor (SSRI) in depressed patients with or without anxiety. Patients beginning treatment for a new depressive episode were identified retrospectively using the administrative data of the MEDSTAT MarketScan database for the period 1994-1999. Before beginning therapy, patients prescribed venlafaxine had more non-mental illnesses (0.85 vs 0.76; p<0.01) and hospitalisations for mental illness (0.53 vs 0.29; p<0.05) than patients prescribed SSRIs. In the six months after initiating treatment, venlafaxine was associated with lower hospitalisation expenditure for non-mental illness ($177 vs $526; p<0.01) than SSRIs, although total healthcare expenditure was not significantly different. Venlafaxine was associated with a 50% decrease in the odds of hospitalisation for non-mental illness compared with SSRIs, with significantly lower inpatient expenditure.

Treatment costs of venlafaxine and selective serotonin-reuptake inhibitors for depression and anxiety

In this article, health care expenditures are assessed for patients diagnosed with depression who are being treated with either venlafaxine (immediate or extended release) or a selective serotonin-reuptake inhibitor (SSRI). Patients beginning treatment for a new depressive episode were identified retrospectively from 1994 to 1998. Before beginning therapy, patients prescribed venlafaxine (N = 353) had more nonmental illnesses (0.84 vs. 0.75 clinical events/patient, respectively; P < .01) and hospitalizations for mental illness (0.56 vs. 0.30 hospitalizations/patient; P = .06) than patients prescribed SSRIs (N = 7,330). In the six months after initiating treatment, venlafaxine was associated with lower hospitalization expenditures for nonmental illness than were SSRIs ($206 vs. $472, respectively; P = .02), but total health care expenditures were not significantly different.

National Patterns of Medication Treatment for Depression, 1987 to 2001

BACKGROUND: We investigated trends in antidepressant use, as well as broader changes in depression treatment, following the availability of selective serotonin reuptake inhibitors (SSRIs). METHOD: Using data from the National Disease and Therapeutic Index, a nationally representative survey of U.S. office-based physicians conducted by IMS HEALTH, we analyzed trends in antidepressant prescribing patterns from 1987 through the third quarter of 2001. Annual sample sizes of physician visits by patients reported to have depression ranged from 3901 visits in 1987 to 6639 in 1998. Outcomes examined included the frequency of depression visits, the likelihood of antidepressant therapy, and the use of specific medications. RESULTS: The estimated national number of physician visits by patients with depression increased from 14.4 million visits in 1987 to 24.5 million in 2001 (annualized). The rate of antidepressant medication treatment in these patients also increased from 70% in 1987 to 89% in 2001. In 1987, tricyclic antidepressants were prescribed to 47% of patients with depression. The most common individual antidepressants were amitriptyline (14%), trazodone (12%), doxepin (8%), and desipramine (6%). In 1989, a year after its introduction, fluoxetine was prescribed to 21% of patients with depression. The introduction of other SSRIs led aggregate SSRI use to grow to 38% in 1992, 60% in 1996, and 69% in 2000. In 2001, sertraline (18%), paroxetine (16%), fluoxetine (14%), citalopram (13%), and bupropion (9%) were the leading antidepressants, while tricyclics were used in only 2% of patients. The use of benzodiazepines in depression declined from 21% of patients in 1987 to 8% in 2001. CONCLUSION: The increasing therapeutic dominance of SSRIs may have contributed to other changes in depression treatment, including declining benzodiazepine use, increased aggregate antidepressant treatment rates, and increased reporting of depression.

Health care use and at-work productivity among employees with mental disorders

This study examines the differential medical care use and work productivity of employees with and without anxiety and with other mental disorders at a large national firm. A unique aspect of this study is that we integrate medical claims and employer-provided, objective productivity data for the same employees. We find extensive mental health comorbidities among anxious employees. Although medical care use differs considerably among employees having no, one, or several treated mental disorders, in most cases their annual average absenteeism and average at-work productivity performance do not differ. Differences among subgroups are observed for job tenure and maternity claims. We discuss these long-term average productivity findings in relation to other literature encompassing shorter time periods.

Lost human capital from early-onset chronic depression

OBJECTIVE

Chronic depression starts at an early age for many individuals and could affect their accumulation of "human capital" (i.e., education, higher amounts of which can broaden occupational choice and increase earnings potential). The authors examined the impact, by gender, of early- (before age 22) versus late-onset major depressive disorder on educational attainment. They also determined whether the efficacy and sustainability of antidepressant treatments and psychosocial outcomes vary by age at onset and quantified the impact of early- versus late-onset, as well as never-occurring, major depressive disorder on expected lifetime earnings.

METHOD

The authors used logistic and multivariate regression methods to analyze data from a three-phase, multicenter, double-blind, randomized trial that compared sertraline and imipramine treatment of 531 patients with chronic depression aged 30 years and older. These data were integrated with U.S. Census Bureau data on 1995 earnings by age, educational attainment, and gender.

RESULTS

Early-onset major depressive disorder adversely affected the educational attainment of women but not of men. No significant difference in treatment responsiveness by age at onset was observed after 12 weeks of acute treatment or, for subjects rated as having responded, after 76 weeks of maintenance treatment. A randomly selected 21-year-old woman with early-onset major depressive disorder in 1995 could expect future annual earnings that were 12%-18% lower than those of a randomly selected 21-year-old woman whose onset of major depressive disorder occurred after age 21 or not at all.

CONCLUSIONS

Early-onset major depressive disorder causes substantial human capital loss, particularly for women. Detection and effective treatment of early-onset major depressive disorder may have substantial economic benefits.

Cost effectiveness, quality-adjusted life-years and supportive care. Recombinant human erythropoietin as a treatment of cancer-associated anaemia

OBJECTIVE

To measure the cost effectiveness of a supportive care intervention when the no-treatment option is unrealistic in an analysis of recombinant human erythropoietin (epoetin) treatment for anaemic patients with cancer undergoing chemotherapy. Further, to assess whether quality-adjusted life-years (QALYs) can provide the basis for an appropriate measure of the value of supportive care interventions.

DESIGN

A modelling study drawing cost and effectiveness assumptions from a literature review and from 3 US clinical trials involving more than 4500 patients with cancer who were treated with chemotherapy, radiotherapy, epoetin and blood transfusions as needed under standard care for patients with cancer.

MAIN OUTCOME MEASURES AND RESULTS

When compared with transfusions, epoetin is cost effective under varying assumptions, whether effectiveness is measured by haemoglobin level or quality of life. Specifically, under a base-case scenario, the effectiveness resulting from $US1 spent on standard care can be achieved with only $US0.81 of epoetin care. Due in part to the health-state dependence of the significance patients attach to incremental changes in their responses on the linear analogue scale, cost per QALY results are ambiguous in this supportive care context.

CONCLUSIONS

Under a broad range of plausible assumptions, epoetin can be used cost effectively in the treatment of anaemic patients with cancer. Further, QALYs have limited applicability here because, as a short term supportive treatment, epoetin enhances the quality but not the length of life. Future research would benefit from the establishment of consistent values for quality-of-life changes across patients and health status, and the extension of the QALY framework to supportive care.

Loss of work productivity due to illness and medical treatment

We examined the effects on work productivity of treatment with antihistamines in a retrospective study using linked health claims data and daily work output records for a sample of nearly 6000 claims processors at a large insurance company, between 1993 and 1995. We explained the variation in work output depending on the subjects' demographic characteristics, their jobs, and whether they were treated with "sedating" versus "nonsedating" antihistamines for nasal allergies. Differences of up to 13% in productivity were found after the subjects took sedating or nonsedating antihistamines. The observed effect suggests substantial indirect economic costs, which up to now have been largely overlooked because work productivity has proved difficult to measure objectively.

The economic burden of anxiety disorders in the 1990s

BACKGROUND

We assess the annual economic burden of anxiety disorders in the United States from a societal perspective.

METHOD

Using data from the National Comorbidity Study, we applied multivariate regression techniques to calculate the costs associated with anxiety disorders, after adjusting for demographic characteristics and the presence of comorbid psychiatric conditions. Based on additional data, in part from a large managed care organization, we estimated a human capital model of the societal cost of anxiety disorders.

RESULTS

We estimated the annual cost of anxiety disorders to be approximately $42.3 billion in 1990 in the United States, or $1542 per sufferer. This comprises $23.0 billion (or 54% of the total cost) in nonpsychiatric medical treatment costs, S13.3 billion (31%) in psychiatric treatment costs, $4.1 billion (10%) in indirect workplace costs, $1.2 billion (3%) in mortality costs, and $0.8 billion (2%) in prescription pharmaceutical costs. Of the $256 in workplace costs per anxious worker, 88% is attributable to lost productivity while at work as opposed to absenteeism. Posttraumatic stress disorder and panic disorder are the anxiety disorders found to have the highest rates of service use. Other than simple phobia, all anxiety disorders analyzed are associated with impairment in workplace performance.

CONCLUSION

Anxiety disorders impose a substantial cost on society, much of which may be avoidable with more widespread awareness, recognition, and appropriate early intervention.

Workplace performance effects from chronic depression and its treatment

Utilizing data from a clinical trial and an econometric model incorporating the impact of a medical intervention and regression to the mean, we present evidence supporting the hypotheses that for chronically depressed individuals: (i) the level of perceived at-work performance is negatively related to the severity of depressive status; and (ii) a reduction in depressive severity improves the patient's perceived work performance. Improvement in work performance is rapid, with about two-thirds of the change occurring already by week 4. Those patients having the greatest work improvement are those with both relatively low baseline work performance and the least severity of baseline depression.

The economic burden of depression in 1990

BACKGROUND

We estimate in dollar terms the economic burden of depression in the United States on an annual basis.

METHOD

Using a human capital approach, we develop prevalence-based estimates of three major cost-of-illness categories: (1) direct costs of medical, psychiatric, and pharmacologic care; (2) mortality costs arising from depression-related suicides; and (3) morbidity costs associated with depression in the workplace. With respect to the latter category, we extend traditional cost-of-illness research to include not only the costs arising from excess absenteeism of depressed workers, but also the reductions in their productive capacity while at work during episodes of the illness.

RESULTS

We estimate that the annual costs of depression in the United States total approximately $43.7 billion. Of this total, $12.4 billion-28%-is attributable to direct costs, $7.5 billion-17%-comprises mortality costs, and $23.8 billion-55%-is derived from the two morbidity cost categories.

CONCLUSION

Depression imposes significant annual costs on society. Because there are many important categories of cost that have yet to be estimated, the true burden of this illness may be even greater than is implied by our estimate. Future research on the total costs of depression may include attention to the comorbidity costs of this illness with a variety of other diseases, reductions in the quality of life experienced by sufferers, and added out-of-pocket costs resulting from the effects of this illness, including those related to household services. Finally, it may be useful to estimate the additional costs associated with expanding the definition of depression to include individuals who suffer from only some of the symptoms of this illness.

Depression: a neglected major illness

BACKGROUND

To illustrate the burden depression imposes on society, we present estimates of the annual costs of depression--$44 billion--as well as the number of individuals it affects per year--almost 11 million. Although these estimates point to depression as a major illness, this study examines why it is not generally considered as such by the medical and public health communities or by society at large.

METHOD

We develop a framework that compares depression with major illnesses such as coronary heart disease, cancer, and AIDS by highlighting salient characteristics of each illness. This comparative illness framework considers the costs, prevalence, distribution of sufferers, mortality, recognition, and treatability of each disease. This comparison underscores many of the similarities and differences among the illnesses examined.

RESULTS

Because depression often is not properly recognized and begins to affect many people at a relatively early age, it exacts costs over a longer period of time and in a more subtle manner than other major illnesses. It also imposes a particularly heavy burden on employers in the form of higher workplace costs.

CONCLUSION

We conclude that, because of the potential for successful treatment, increased attempts to reach untreated sufferers of depression appear to be warranted. Employers as a group have a particular incentive to invest in the recognition and treatment of this widespread problem, in order to reduce the substantial costs it imposes upon them each year.

Factors associated with clinical dental faculty research productivity

The purpose of this study was to determine factors that are associated with increased individual research productivity among clinical faculty in 67 United States and Canadian schools of dentistry. Individual faculty research productivity was defined as the total number of articles in refereed journals and book chapters published during an academic career. The 328 respondents represented a response rate of 62.8 percent from a 25 percent stratified random sample of faculty who (1) had full-time appointments and held at least the D.M.D./D.D.S. or foreign equivalent, (2) taught in a clinical department of the dental schools, and (3) were not department chairpersons and did not hold administrative positions (assistant dean, associate dean, or dean) within the dental school. Respondents reported a mean of 9.9 years in full-time dental education, a mean of 10.8 publications, and a mean of 7.5 hours spent in research per week. Forward addition multiple regression analysis demonstrated that five predictor variables, from a total of 20 variables evaluated, accounted for 59.9 percent of the variance in individual faculty research productivity. These predictor variables were total dollar amount of past research funding, career age, training status, colleague utilization in conducting research, and conducting research from planned goals.

Assessing technology for rehabilitation. Three cases and three countries

The rehabilitation field has not always been regarded as the most glamorous or commercially promising section of medical care. But changing attitudes and demographics in many industrial countries have led to increased recognition of opportunity to provide services for individuals with disabilities and those in need of chronic care. As hospitals are under increasing pressure to offer rehabilitation services, this article focuses on three different technologies developed in three different countries, Sweden, the United Kingdom, and the United States.

The process of evaluating medical technologies for third-party coverage

A detailed review of records and documentation considered more than 100 technology evaluations performed in conjunction with coverage decisions by the Medicare program and by a major Blue Cross/blue Shield plan. Medicare evaluations were highly structured, synthesizing thorough literature reviews, recommendations from the National Institutes of Health and other governmental agencies, and information solicited from medical specialty societies and independent practitioners; however, the material supplied by nongovernmental sources seldom influenced the coverage recommendations. In contrast, the Blue plan's evaluations were based largely on presentations and discussions at advisory committee meetings, after receiving informational inputs that were more limited than those used in Medicare evaluations. The fraction of technologies recommended for coverage was slightly over 50% for each carrier. If information was strongly positive about either a technology's safety, its effectiveness, or both, then coverage was nearly always recommended. Still, the carriers differed significantly in the stage of development of the practices evaluated and in their willingness to make a coverage decision in the face of both safety and effectiveness data that were regarded as tentative. Because coverage decisions, and the speed with which they are conducted, may be crucial to the rate of a technology's diffusion--and possibly even to the rate of innovation--the authors conclude that it is important to understand clearly the process by which this type of technology assessment is performed.

Technological change and clinical laboratory utilization

Many believe that improvement in laboratory automation has been responsible for the considerable growth in the volume of tests that has occurred in recent years. Results are presented from an 8-year national survey of hospital laboratory utilization that show no definitive correlation between technological change and growth in volume of well-established clinical laboratory tests. These results leave room for hypothesizing other major contributory factors to volume increases such as a behavioral change on the part of practitioners who order tests and place increased diagnostic importance on laboratory results in addition to medical histories and physical examinations. If the findings prove correct, successful regulatory strategies for the containment of laboratory costs might be as likely to come from those that directly address practitioners' behavior as from those that limit capacity by requiring prior approval for acquisition of new laboratory equipment.