Optimizing therapeutic decision-making for off-label medicines use: A scoping review and consensus recommendations for improving practice and research.

PURPOSE: Off-label medicines use is a common and sometimes necessary practice in many populations, with important clinical, ethical and financial consequences, including potential unintended harm or lack of effectiveness. No internationally recognized guidelines exist to aid decision-makers in applying research evidence to inform off-label medicines use. We aimed to critically evaluate current evidence informing decision-making for off-label use and to develop consensus recommendations to improve future practice and research. METHODS: We conducted a scoping review to summarize the literature on available off-label use guidance, including types, extent and scientific rigor of evidence incorporated. Findings informed the development of consensus recommendations by an international multidisciplinary Expert Panel using a modified Delphi process. Our target audience includes clinicians, patients and caregivers, researchers, regulators, sponsors, health technology assessment bodies, payers and policy makers. RESULTS: We found 31 published guidance documents on therapeutic decision-making for off-label use. Of 20 guidances with general recommendations, only 35% detailed the types and quality of evidence needed and the processes for its evaluation to reach sound, ethical decisions about appropriate use. There was no globally recognized guidance. To optimize future therapeutic decision-making, we recommend: (1) seeking rigorous scientific evidence; (2) utilizing diverse expertise in evidence evaluation and synthesis; (3) using rigorous processes to formulate recommendations for appropriate use; (4) linking off-label use with timely conduct of clinically meaningful research (including real-world evidence) to address knowledge gaps quickly; and (5) fostering partnerships between clinical decision-makers, researchers, regulators, policy makers, and sponsors to facilitate cohesive implementation and evaluation of these recommendations. CONCLUSIONS: We provide comprehensive consensus recommendations to optimize therapeutic decision-making for off-label medicines use and concurrently drive clinically relevant research. Successful implementation requires appropriate funding and infrastructure support to engage necessary stakeholders and foster relevant partnerships, representing significant challenges that policy makers must urgently address.

Pharmacogenomic testing in paediatrics: Clinical implementation strategies.

Pharmacogenomics (PGx) relates to the study of genetic factors determining variability in drug response. Implementing PGx testing in paediatric patients can enhance drug safety, helping to improve drug efficacy or reduce the risk of toxicity. Despite its clinical relevance, the implementation of PGx testing in paediatric practice to date has been variable and limited. As with most paediatric pharmacological studies, there are well-recognised barriers to obtaining high-quality PGx evidence, particularly when patient numbers may be small, and off-label or unlicensed prescribing remains widespread. Furthermore, trials enrolling small numbers of children can rarely, in isolation, provide sufficient PGx evidence to change clinical practice, so extrapolation from larger PGx studies in adult patients, where scientifically sound, is essential. This review paper discusses the relevance of PGx to paediatrics and considers implementation strategies from a child health perspective. Examples are provided from Canada, the Netherlands and the UK, with consideration of the different healthcare systems and their distinct approaches to implementation, followed by future recommendations based on these cumulative experiences. Improving the evidence base demonstrating the clinical utility and cost-effectiveness of paediatric PGx testing will be critical to drive implementation forwards. International, interdisciplinary collaborations will enhance paediatric data collation, interpretation and evidence curation, while also supporting dedicated paediatric PGx educational initiatives. PGx consortia and paediatric clinical research networks will continue to play a central role in the streamlined development of effective PGx implementation strategies to help optimise paediatric pharmacotherapy.

Big Data in the Assessment of Pediatric Medication Safety.

Big data (BD) in pediatric medication safety research provides many opportunities to improve the safety and health of children. The number of pediatric medication and device trials has increased in part because of the past 20 years of US legislation requiring and incentivizing study of the effects of medical products in children (Food and Drug Administration Modernization Act of 1997, Pediatric Rule in 1998, Best Pharmaceuticals for Children Act of 2002, and Pediatric Research Equity Act of 2003). There are some limitations of traditional approaches to studying medication safety in children. Randomized clinical trials within the regulatory context may not enroll patients who are representative of the general pediatric population, provide the power to detect rare safety signals, or provide long-term safety data. BD sources may have these capabilities. In recent years, medical records have become digitized, and cell phones and personal devices have proliferated. In this process, the field of biomedical science has progressively used BD from those records coupled with other data sources, both digital and traditional. Additionally, large distributed databases that include pediatric-specific outcome variables are available. A workshop entitled "Advancing the Development of Pediatric Therapeutics: Application of 'Big Data' to Pediatric Safety Studies" held September 18 to 19, 2017, in Silver Spring, Maryland, formed the basis of many of the ideas outlined in this article, which are intended to identify key examples, critical issues, and future directions in this early phase of an anticipated dramatic change in the availability and use of BD.

Incidence rates of narcolepsy diagnoses in Taiwan, Canada, and Europe: The use of statistical simulation to evaluate methods for the rapid assessment of potential safety issues on a population level in the SOMNIA study.

BACKGROUND & OBJECTIVES: Vaccine safety signals require investigation, which may be done rapidly at the population level using ecological studies, before embarking on hypothesis-testing studies. Incidence rates were used to assess a signal of narcolepsy following AS03-adjuvanted monovalent pandemic H1N1 (pH1N1) influenza vaccination among children and adolescents in Sweden and Finland in 2010. We explored the utility of ecological data to assess incidence of narcolepsy following exposure to pandemic H1N1 virus or vaccination in 10 sites that used different vaccines, adjuvants, and had varying vaccine coverage. METHODS: We calculated incidence rates of diagnosed narcolepsy for periods defined by influenza virus circulation and vaccination campaign dates, and used Poisson regression to estimate incidence rate ratios (IRRs) comparing the periods during which wild-type virus circulated and after the start of vaccination campaigns vs. the period prior to pH1N1 virus circulation. We used electronic health care data from Sweden, Denmark, the United Kingdom, Canada (3 provinces), Taiwan, Netherlands, and Spain (2 regions) from 2003 to 2013. We investigated interactions between age group and adjuvant in European sites and conducted a simulation study to investigate how vaccine coverage, age, and the interval from onset to diagnosis may impact the ability to detect safety signals. RESULTS: Incidence rates of narcolepsy varied by age, continent, and period. Only in Taiwan and Sweden were significant time-period-by-age-group interactions observed. Associations were found for children in Taiwan (following pH1N1 virus circulation) and Sweden (following vaccination). Simulations showed that the individual-level relative risk of narcolepsy was underestimated using ecological methods comparing post- vs. pre-vaccination periods; this effect was attenuated with higher vaccine coverage and a shorter interval from disease onset to diagnosis. CONCLUSIONS: Ecological methods can be useful for vaccine safety assessment but the results are influenced by diagnostic delay and vaccine coverage. Because ecological methods assess risk at the population level, these methods should be treated as signal-generating methods and drawing conclusions regarding individual-level risk should be avoided.

Narcolepsy and adjuvanted pandemic influenza A (H1N1) 2009 vaccines - Multi-country assessment.

BACKGROUND: In 2010, a safety signal was detected for narcolepsy following vaccination with Pandemrix, an AS03-adjuvanted monovalent pandemic H1N1 influenza (pH1N1) vaccine. To further assess a possible association and inform policy on future use of adjuvants, we conducted a multi-country study of narcolepsy and adjuvanted pH1N1 vaccines. METHODS: We used electronic health databases to conduct a dynamic retrospective cohort study to assess narcolepsy incidence rates (IR) before and during pH1N1 virus circulation, and after pH1N1 vaccination campaigns in Canada, Denmark, Spain, Sweden, Taiwan, the Netherlands, and the United Kingdom. Using a case-control study design, we evaluated the risk of narcolepsy following AS03- and MF59-adjuvanted pH1N1 vaccines in Argentina, Canada, Spain, Switzerland, Taiwan, and the Netherlands. In the Netherlands, we also conducted a case-coverage study in children born between 2004 and 2009. RESULTS: No changes in narcolepsy IRs were observed in any periods in single study sites except Sweden and Taiwan; in Taiwan incidence increased after wild-type pH1N1 virus circulation and in Sweden (a previously identified signaling country), incidence increased after the start of pH1N1 vaccination. No association was observed for Arepanrix-AS03 or Focetria-MF59 adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the case-control study nor for children born between 2004 and 2009 in the Netherlands case-coverage study for Pandemrix-AS03. CONCLUSIONS: Other than elevated narcolepsy IRs in the period after vaccination campaigns in Sweden, we did not find an association between AS03- or MF59-adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the sites studied, although power to evaluate the AS03-adjuvanted Pandemrix brand vaccine was limited in our study.

Assessment of hair cortisol as a potential biomarker for possible adrenal suppression due to inhaled corticosteroid use in children with asthma: A retrospective observational study.

BACKGROUND: Inhaled corticosteroids (ICS) are the recommended long-term control therapy for asthma in children. However, concern exists regarding potential adrenal suppression with chronic ICS use. Our pilot study reported that hair cortisol in children was 50% lower during ICS therapy than prior to therapy, suggestive of adrenal suppression. OBJECTIVE: To evaluate hair cortisol concentration (HCC) as a potential biomarker for possible adrenal suppression from ICS use in children with asthma. METHODS: A retrospective observational study was performed at asthma clinics in Vancouver, Winnipeg, and Toronto, Canada. Children (n = 586) were recruited from July 2012 to December 2014 inclusive of those without asthma, with asthma not using ICS, and with asthma using ICS. The most recent three-month HCC was measured by enzyme immunoassay and compared among the groups. Quantile regression analysis was performed to identify factors potentially affecting HCC. RESULTS: The median HCC was not significantly different among the children: No ICS (n = 47, 6.7 ng/g, interquartile range (IQR) 3.7-9.8 ng/g), ICS Treated (n = 360, 6.5 ng/g, IQR 3.8-14.3 ng/g), and Controls (n = 53, 5.8 ng/g, IQR 4.6-16.7 ng/g). 5.6% of the children using ICS had hair cortisol <2.0 ng/g compared to none in the control groups (P < .05, comparing ICS Treated (20/360) to all Controls combined (0/100)) and only half had been exposed to systemic corticosteroids. Age, sex, BMI, and intranasal corticosteroid use were significantly associated with HCC. CONCLUSIONS: Results suggest HCC may be a potential biomarker for adrenal suppression as a population of children using ICS with HCC < 2.0 ng/g was identified compared to none in the control groups. Further research is needed to determine if those children have or are at risk of adrenal suppression or insufficiency.

An initial health economic evaluation of pharmacogenomic testing in patients treated for childhood cancer with anthracyclines.

BACKGROUND: Anthracyclines are a class of highly effective chemotherapeutic drugs commonly used to treat cancer patients. Anthracyclines, however, are associated with the development of serious adverse reactions, including anthracycline-induced cardiotoxicity (ACT). It is not possible, within current practice, to accurately individualize treatment to minimize risk. PROCEDURE: Recently, genetic variants have been associated with the risk of ACT in children. Building on these findings and the related genetic test, a predictive model was developed which classifies pediatric patients by their risk of developing ACT. We assessed the value of this ACT-predictive risk classification in addressing ACT. RESULTS: With current care, the estimated average lifetime cost of ACT is $8,667 per anthracycline-treated patient and approximately 7% of patients are expected to die from ACT. The projected impact of the information from the new predictive model is a 17% reduction in the risk of mortality from ACT and savings of about 6%: lives saved and lower costs. CONCLUSION: The newly identified genetic variants associated with the risk of ACT provide information that allows a more reliable prediction of the risk of ACT for a given patient and can be obtained at a very moderate cost, which is expected to lead to meaningful progress in reducing harm and costs associated with ACT.

Risk of Extrapyramidal Adverse Events With Aripiprazole.

Aripiprazole is a unique atypical antipsychotic with partial agonist activity on the dopamine-2 (D2) receptor. This unique pharmacological profile of aripiprazole was thought to lead to a lower incidence of extrapyramidal symptoms (EPSs). However, recent case reports have alluded to an increase in the risk of EPS in aripiprazole users compared with nonusers of the drug. No epidemiologic studies to date have quantified this risk. We conducted a pharmacoepidemiologic study composed of a nested case-control study using a large health claims database (IMS Health) in the United States. In the nested case-control analysis, there were 5242 cases of EPS with 50,532 corresponding controls in the entire cohort. The odds ratio (OR) for EPS among those with any prescription of aripiprazole was 5.38 (95% confidence interval [CI], 3.03-9.57). The OR was lower among those taking 2 to 3 prescriptions (OR, 2.9; 95% CI, 1.07-7.85) but increased in those receiving greater than 4 prescriptions (OR, 8.64; 95% CI, 2.63-28.38). All risk periods were compared with those of subjects who had not used aripiprazole or other antipsychotics. For the secondary outcome of dyskinesia, the risk for aripiprazole was 8.50 (95% CI, 8.53-2.27-31.97) compared with that of nonusers. In conclusion, we found an increase in the risk of EPS and dyskinesias among users of aripiprazole.

Pharmacogenomics in Pediatric Patients: Towards Personalized Medicine.

It is well known that drug responses differ among patients with regard to dose requirements, efficacy, and adverse drug reactions (ADRs). The differences in drug responses are partially explained by genetic variation. This paper highlights some examples of areas in which the different responses (dose, efficacy, and ADRs) are studied in children, including cancer (cisplatin), thrombosis (vitamin K antagonists), and asthma (long-acting ß2 agonists). For childhood cancer, the replication of data is challenging due to a high heterogeneity in study populations, which is mostly due to all the different treatment protocols. For example, the replication cohorts of the association of variants in TPMT and COMT with cisplatin-induced ototoxicity gave conflicting results, possibly as a result of this heterogeneity. For the vitamin K antagonists, the evidence of the association between variants in VKORC1 and CYP2C9 and the dose is clear. Genetic dosing models have been developed, but the implementation is held back by the impossibility of conducting a randomized controlled trial with such a small and diverse population. For the long-acting ß2 agonists, there is enough evidence for the association between variant ADRB2 Arg16 and treatment response to start clinical trials to assess clinical value and cost effectiveness of genotyping. However, further research is still needed to define the different asthma phenotypes to study associations in comparable cohorts. These examples show the challenges which are encountered in pediatric pharmacogenomic studies. They also display the importance of collaborations to obtain good quality evidence for the implementation of genetic testing in clinical practice to optimize and personalize treatment.

Integrating Personalized Medicine in the Canadian Environment: Efforts Facilitating Oncology Clinical Research.

There is currently a rapid evolution of clinical practices based on the introduction of patient stratification and molecular diagnosis that is likely to improve health outcomes. Building on a strong research base, complemented by strong support from clinicians and health authorities, the oncology field is at the forefront of this evolution. Yet, clinical research is still facing many challenges that need to be addressed in order to conduct necessary studies and effectively translate medical breakthroughs based on personalized medicine into standards of care. Leveraging its universal health care system and on resources developed to support oncology clinical research, Canada is well positioned to join the international efforts deployed to address these challenges. Available resources include a broad range of structures and funding mechanisms, ranging from direct clinical trial support to post-marketing surveillance. Here, we propose a clinical model for the introduction of innovation for precision medicine in oncology that starts with patients' and clinicians' unmet needs to initiate a cycle of discovery, validation, translation and sustainability development.

High use of health services in patients with suboptimal asthma drug regimens: a population-based assessment in British Columbia, Canada.

BACKGROUND: Despite numerous clinical guidelines on asthma management, patients often receive suboptimal drug therapy. This study identified patients who received suboptimal regimens according to the National Heart, Lung and Blood Institute (NHLBI) Guidelines for the Diagnosis and Management of Asthma in a complete population (residents of British Columbia, Canada) and determined the association between patients' regimens and utilization of healthcare services. METHODS: A total of 65,345 asthma patients were identified using provincial health service utilization data (including all respiratory-related prescription medication dispensings, physician and hospital visits) for the 2009 fiscal year. Patient-specific regimens of inhaled short-acting bronchodilators (SABA) with or without inhaled corticosteroids (ICS) were categorized as optimal or suboptimal. Logistic regression models were used to determine the association between regimen optimality and health service utilization, adjusted for socioeconomic status, prior year hospital and emergency department (ED) visits for asthma. RESULTS: Patients with suboptimal regimens had significantly greater risk of using health services than patients with optimal regimens of SABA and/or ICS. In particular, adolescents with suboptimal regimens were the most likely to have hospital admissions (odds ratio (OR) 3.8; 95% confidence interval (CI) 1.8-7.8), visit the ED (OR 2.2; 95% CI 1.6-3.1) and be high users of family physician services (OR 5.7; 95% CI 4.0-8.1) compared with patients in other age groups. CONCLUSIONS: Suboptimal regimens are associated with significantly high usage of health services. Identifying patients with suboptimal regimens and improving their medication management in accordance with asthma clinical guidelines are likely to result in lower health service utilization.

Diagnostic testing for vaccinomics: is the regulatory approval framework adequate? A comparison of Canada, the United States, and Europe.

Vaccinomics aims to integrate variability information from multiple levels of the biological hierarchy from genome to proteome to metabolome, and ways in which these biological parts interact with each other and the environment. Vaccinomics holds significant promise as a new public health tool in designing safer and more effective vaccines for both developed and developing countries. Vaccinomics tests that are envisioned to be used in tandem with vaccine-based health interventions could permit an informed forecast of individual and subpopulation variations in immune responses to vaccines, reduce adverse effects, and contribute to a foundation for rational and directed use of vaccines. A proactive, multidisciplinary engagement with vaccinomics is now timely and much needed in order to develop regulations that best ensure the protection of the public and promote the transition of vaccinomics innovations from discovery to real-life public health applications. This article examines and compares the regulatory oversight of vaccinomics tests in Canada, the United States, and Europe. Recent trends in these jurisdictions suggest that regulatory agencies view personalized genomics/omics medicine, such as vaccinomics, as a desirable goal. At the same time, proposals to increase oversight could impact progress in the field and affect the availability of vaccinomics tests in public health practice and the diagnostic test market. The comparative analysis of vaccinomics in three jurisdictions presented in this article highlights both the convergence and divergence of regulatory oversight. In a rapidly emerging field such as vaccinomics that is pivotal for global public health, achieving better harmonization of policies may be an advantageous target, while ensuring that symmetry exists between the goals of public safety and promoting public health innovation. We suggest it is now timely to proactively initiate a constructive dialogue among all stakeholders (publics, policymakers, researchers, private sector, governments) to foster the development of appropriately targeted regulatory policies in this field.

The use of conferencing technologies to support drug policy group knowledge exchange processes: an action case approach.

OBJECTIVES: To describe experiences, lessons and the implications related to the use of conferencing technology to support three drug policy research groups within a three-year period, using the action case research method. DESIGN: An action case research field study was executed. Three different drug policy groups participated: research, educator, and decision-maker task groups. There were a total of 61 participants in the study. The study was conducted between 2004 and 2007. Each group used audio-teleconferencing, web-conferencing or both to support their knowledge exchange activities. MEASUREMENTS: Data were collected over three years and consisted of observation notes, interviews, and meeting transcripts. Content analysis was used to analyze the data using NIVIO qualitative data analysis software. RESULTS: The study found six key lessons regarding the impact of conferencing technologies on knowledge exchange within drug policy groups. We found that 1) groups adapt to technology to facilitate group communication, 2) web-conferencing communication is optimal under certain conditions, 3) audio conferencing is convenient, 4) web-conferencing forces group interactions to be "within text", 5) facilitation contributes to successful knowledge exchange, and 6) technology impacts information sharing. CONCLUSIONS: This study highlights lessons related to the use of conferencing technologies to support distant knowledge exchange within drug policy groups. Key lessons from this study can be used by drug policy groups to support successful knowledge exchange activities using conferencing technologies.

A literature review on distance knowledge exchange in healthcare groups: what can we learn from the ICT literature?

As healthcare groups continue to communicate and collaborate at a distance on knowledge exchange activities, Information and Communication Technology (ICT) has come to play an increasingly important role in supporting such interactions. However, to date, the literature on knowledge exchange appears disconnected from that of ICT. Research on the effects of ICT on knowledge exchange activities is needed. The literature review explores the potential impacts ICTs can have on knowledge exchange groups, and especially, the social interaction process. A discussion of how ICTs could impact the social interaction process of knowledge exchange activities is made.

Regulatory approval for new pharmacogenomic tests: a comparative overview.

Pharmacogenomics is the study of how genetic variants affect the way in which an individual or subgroup responds to drugs. This developing field aims to inform individual drug therapy and to minimize adverse drug reactions (ADRs). It also promises great benefits in the drug development process. Innovation in pharmacogenomics and its translation into clinical practice is desirable, but appropriate regulation of the safety and effectiveness of pharmacogenomics testing is necessary. This article will describe the current regulatory framework applicable to pharmacogenomic tests in Canada, the United States and Europe. In particular, it will examine the different regulatory pathways for pharmacogenomic tests marketed as test kits and for laboratory-developed tests (LDTs). Recent and upcoming changes to the regulation of pharmacogenomic tests will also be discussed. For example, FDA's proposal to regulate LDTs could have a major impact on the development and availability of pharmacogenomic tests. This review will lead to an evaluation of the issues raised by the regulatory framework and the impact of regulatory changes in relation to meeting the goals of ensuring public safety and promoting the advancement of pharmacogenomics. Regulatory policies which successfully achieve the dual objectives of ensuring public safety and promoting innovation in health technology are imperative in order to reap the benefits of this emerging field.

Direct health care costs associated with asthma in British Columbia.

BACKGROUND: A better understanding of health care costs associated with asthma would enable the estimation of the economic burden of this increasingly common disease. OBJECTIVE: To determine the direct medical costs of asthma-related health care in British Columbia (BC). METHODS: Administrative health care data from the BC Linked Health Database and PharmaNet database from 1996 to 2000 were analyzed for BC residents five to 55 years of age, including the billing information for physician visits, drug dispensations and hospital discharge records. A unit cost was assigned to physician/emergency department visits, and government reimbursement fees for prescribed medications were applied. The case mix method was used to calculate hospitalization costs. All costs were reported in inflation-adjusted 2006 Canadian dollars. RESULTS: Asthma resulted in $41,858,610 in annual health care-related costs during the study period ($331 per patient-year). The major cost component was medications, which accounted for 63.9% of total costs, followed by physician visits (18.3%) and hospitalization (17.8%). When broader definitions of asthma-related hospitalizations and physician visits were used, total costs increased to $56,114,574 annually ($444 per patient-year). There was a statistically significant decrease in the annual per patient cost of hospitalizations (P<0.01) over the study period. Asthma was poorly controlled in 63.5% of patients, with this group being responsible for 94% of asthma-related resource use. CONCLUSION: The economic burden of asthma is significant in BC, with the majority of the cost attributed to poor asthma control. Policy makers should investigate the reason for lack of proper asthma control and adjust their policies accordingly to improve asthma management.

The added burden of comorbidity in patients with asthma.

OBJECTIVE: Compare the prevalence of comorbidities in adults with and without asthma in Canada and investigate the association between comorbidities in patients with asthma and the occurrence of asthma symptoms or attacks. METHODS: Survey data from the 2005 Canadian Community Health Survey (CCHS) were analyzed. A total of 132,221 Canadians participated in the national survey; 10,089 adult respondents from 10 Canadian provinces and 3 territories reported having asthma. Analyses focused on 11 major chronic comorbidities. RESULTS: Respondents with asthma were more likely to have comorbidities except cancer; 31% of respondents with asthma and comorbidities reported their health status to be fair or poor. For respondents with asthma, non-asthma chronic respiratory disease, mental illness, and allergy were significantly associated with having asthma symptoms or attacks. CONCLUSIONS: Many Canadians with asthma report a high comorbidity burden. These patients will likely require more health services and more complex health management strategies. Comorbid conditions should be clearly identified with particular emphasis on management of mood disorders and anxiety because these conditions are likely to increase asthma symptomatology and may be unrecognized by clinicians.

A case study examining the impacts of conferencing technologies in distributed healthcare groups.

As healthcare groups continue to communicate and collaborate at a distance, information and communication technology (ICT) has come to play an increasingly important role in supporting such interactions. In this paper, we describe key lessons learned from a two-year case study (2004-2006) on the impacts of conferencing technologies on social interaction norms within knowledge exchange groups.

Identifying persons with treated asthma using administrative data via latent class modelling.

OBJECTIVE: To develop a parsimonious model of the respiratory patient population in British Columbia (BC), Canada through latent class modelling (LCM), using administrative data records and to assess conventional case definitions for asthma in relation to model-based case selection. DATA SOURCES: 1996-2001 data from linked provincial databases containing fee-for-service physician billing records, hospital inpatient separation abstracts, and prescription drug purchase records for 1.9 million BC respiratory patients. STUDY DESIGN: This is a retrospective methodological/descriptive study that assesses case definitions for asthma in terms of sensitivity and specificity using a model fitted to seven physician, hospital and medication utilization markers in place of a conventional gold standard. DATA COLLECTION: We computed values of the treatment markers for each of the 5 years for each patient aged 5-55 years who had had at least one occurrence of a respiratory diagnosis code. PRINCIPAL FINDINGS: The marker for prescription of short-acting beta agonists (SABAs) consistently had the highest sensitivity. Markers' specificities ranged from 0.97 to 1.0. The conventional case definitions' sensitivities were 0.41-0.87; specificities ranged from 0.98 to 0.997. Model-based estimates of asthma prevalence increased from 827/10,000 in 1996 to 992/10,000 in 2001. Conventional case definitions' estimates were consistently lower. CONCLUSIONS: The linkage between utilization and case status is more complex than conventional case definitions allow for. LCM-based case classification was consistent over time and tends to lead to larger prevalence estimates than conventional definitions. The estimated increases in asthma prevalence are reliable. LCM provides health services planners with a useful probability-based approach for developing and assessing case definitions and estimating case prevalence.

Designed delays versus rigorous pragmatic trials: lower carat gold standards can produce relevant drug evaluations.

BACKGROUND: Centralized administrative databases enable low-cost pragmatic randomized trials (PRTs) of drug effectiveness and safety. We simplified the PRT strategy by using designed delays (DD) to evaluate drug policies. OBJECTIVES: To reassess our DD trial of a cost-saving nebulizer-to-inhaler conversion policy and a proposed DD trial of reduced restrictions on Cox-2 inhibitors. RESEARCH DESIGN: We randomized 52 pairs of communities and clusters of physician practices to the policy either on time or after a 6-month delay. Our 2-stage qualitative reassessment comprised: (1) applying criteria for reporting PRTs and (2) assessing DD trials in 3 domains of responsibility: policymakers' decisions, researchers' decisions, and joint decisions involving negotiation. MEASURES: A draft checklist of 22 Consolidated Standards of Reporting Trials (CONSORT). Researchers' recollections of their degree of influence on decisions. RESULTS: DD trials deviated from ideal PRTs in the policymakers' domain: the policies affected mixtures of drugs, users, and illnesses, and implementation was not by strict protocol. Aspects negotiated by researchers and policymakers also deviated from ideal: length of delay; size and location of control group; unit of randomization; additional data collection; and communications to physicians. The DD trials complied better with CONSORT in the researchers' domain of analysis and interpretation. CONCLUSIONS: DD trials can be negotiated with policymakers. Low cost and simplicity of DD trials partly compensate for some limitations for evaluating drug safety and effectiveness. The ethics question of whether a DD is routine evaluation or research depends on its purpose and generalizability.