Biomedical subjects

Johan van der Lei

Publications and source records attributed to Johan van der Lei.

At least 19 recordsLinked to original sources

PubMed2006

Cost consequences of implementing an electronic decision support system for ordering laboratory tests in primary care: evidence from a controlled prospective study in the Netherlands.

BACKGROUND: The economic consequences of interventions to promote rational, evidence-based use of laboratory tests by physicians are not yet fully understood. We evaluated the cost consequences of a computer-based, guideline-driven decision-support system (CDSS) for ordering blood tests in primary care. METHODS: We installed the CDSS in 118 practices [159 general practitioners (GPs)] throughout The Netherlands and calculated the costs of the intervention in this group. During a period of 6 months before and 6 months after installation of the CDSS, the test-ordering behavior of 87 (109 GPs) of these 118 study practices was studied and the results were compared with those of a nonhistorical control group that did not receive the CDSS. In addition the costs of laboratory requests were calculated for both groups. RESULTS: Total intervention costs, comprising development costs and installation costs, amounted to 79,000 euro (670 euro per practice). Whereas the introduction of the CDSS did not affect the number of order forms submitted to the laboratories, it did reduce the number of blood tests per order form. As a result, the CDSS yielded mean savings on the costs of laboratory requests of 847 euro per practice per 6 months. CONCLUSIONS: This study demonstrates that providing electronic decision support for ordering blood tests in primary care represents an economically promising concept. Savings on laboratory costs are achievable and not offset by disproportionally high intervention costs.

Adult↗

PubMed2006

Annual influenza vaccination in community-dwelling elderly individuals and the risk of lower respiratory tract infections or pneumonia.

BACKGROUND: Influenza vaccination has been associated with a reduction in the number of hospitalizations for respiratory conditions in elderly persons over the period from 1996 to 2002. Little is known, however, about the effect of influenza vaccination on the whole range of severity of respiratory tract infections. METHODS: We investigated the effect of annual influenza vaccination on the occurrence of lower respiratory tract infections (LRTIs) in community-dwelling elderly individuals. From 1996 to 2002, we performed a population-based cohort study, using the computerized Integrated Primary Care Information database in the Netherlands, of community-dwelling subjects who were 65 years or older on January 1 of the year of study entry. For each year, the individual cumulative exposure to influenza vaccination since study entry was computed. We compared the risk of LRTI after a first vaccination or revaccination with the risk for no vaccination using a time-varying multivariate Cox proportional hazard model, adjusted for age, sex, smoking, and underlying disease. RESULTS: In the study population of 26 071 subjects, 3412 developed LRTIs during follow-up. During the influenza epidemic periods, a first vaccination did not reduce risk for LRTI. In the total population, the hazard ratio following a first vaccination was 0.86 (95% confidence interval [CI], 0.71 to 1.05); in the population without or with comorbidity, these ratios were 0.90 (95% CI, 0.56 to 1.45) and 0.83 (95% CI, 0.66 to 1.04), respectively. During epidemic periods, revaccination reduced risk of LRTI by 33% (95% CI, 8% to 52%) in individuals without comorbidity. In individuals with comorbidity, the risk reduction of 5% was nonsignificant (95% CI, -10% to 18%). CONCLUSION: In this study, annual influenza revaccination was associated with a reduction in LRTI in community-dwelling elderly individuals.

Age Factors↗

PubMed2006

Channeling and prevalence of cardiovascular contraindications in users of cyclooxygenase 2 selective nonsteroidal antiinflammatory drugs.

OBJECTIVE: To assess use and channeling of cyclooxygenase 2 selective inhibitors (coxibs) over time and to estimate the percentage of coxib users with cardiovascular contraindications. METHODS: The study population comprised all coxib and nonselective nonsteroidal antiinflammatory drug (NSAID) users in the Integrated Primary Care Information project between January 2000 and December 2004. The prevalence of risk factors for NSAID-related upper gastrointestinal ulcer complications, cardiovascular disease, and cerebrovascular disease at the start of treatment was compared between users of coxibs and users of nonselective NSAIDs. RESULTS: The study population included 72,841 nonselective NSAID users and 10,739 coxib users. The prevalence of risk factors for NSAID-related gastrointestinal complications was higher in coxib users than nonselective NSAID users (odds ratio [OR] 1.18, 95% confidence interval [95% CI] 1.10-1.26). Similarly, the prevalence of prior cardiovascular disease was higher in coxib users than in nonselective NSAID users (OR 1.35, 95% CI 1.28-1.43). Channeling of coxibs to patients with NSAID-related gastrointestinal risk factors declined after 2001 but increased again in 2004, whereas the channeling of coxibs to patients with cardiovascular disease remained constant. Less than 15% of all coxib users had history of ischemic coronary or cerebrovascular disease. Among coxib users with increased risk for NSAID-related gastrointestinal disorders, 27% had history of ischemic coronary or cerebrovascular disease. CONCLUSION: This study demonstrates that coxibs were preferentially prescribed to patients with risk factors for NSAID-related gastrointestinal disorders and/or cardiovascular diseases. Only one-quarter of coxib users with increased risk for NSAID-related gastrointestinal complications had cardiovascular conditions compatible with recent European safety contraindications for coxibs.

Adolescent↗

PubMed2006

Structured data entry for narrative data in a broad specialty: patient history and physical examination in pediatrics.

BACKGROUND: Whereas an electronic medical record (EMR) system can partly address the limitations, of paper-based documentation, such as fragmentation of patient data, physical paper records missing and poor legibility, structured data entry (SDE, i.e. data entry based on selection of predefined medical concepts) is essential for uniformity of data, easier reporting, decision support, quality assessment, and patient-oriented clinical research. The aim of this project was to explore whether a previously developed generic (i.e. content independent) SDE application to support the structured documentation of narrative data (called OpenSDE) can be used to model data obtained at history taking and physical examination of a broad specialty. METHODS: OpenSDE was customized for the broad domain of general pediatrics: medical concepts and its descriptors from history taking and physical examination were modeled into a tree structure. RESULTS: An EMR system allowing structured recording (OpenSDE) of pediatric narrative data was developed. Patient history is described by 20 main concepts and physical examination by 11. In total, the thesaurus consists of about 1800 items, used in 8648 nodes in the tree with a maximum depth of 9 levels. Patient history contained 6312 nodes, and physical examination 2336. User-defined entry forms can be composed according to individual needs, without affecting the underlying data representation. The content of the tree can be adjusted easily and sharing records among different disciplines is possible. Data that are relevant in more than one context can be accessed from multiple branches of the tree without duplication or ambiguity of data entry via "shortcuts". CONCLUSION: An expandable EMR system with structured data entry (OpenSDE) for pediatrics was developed, allowing structured documentation of patient history and physical examination. For further evaluation in other environments, the tree structure for general pediatrics is available at the Erasmus MC Web site (in Dutch, translation into English in progress) 1. The generic OpenSDE application is available at the OpenSDE Web site 2.

Child↗

PubMed2006

A randomized database study in general practice yielded quality data but patient recruitment in routine consultation was not practical.

OBJECTIVE: To assess patient recruitment and quality of data in a randomized database study. STUDY DESIGN AND SETTING: A randomized database study was conducted in the Integrated Primary Care Information (IPCI) general practice research database. Software was built to allow for automated patient identification and recruitment, and randomization. As an application, we compared gastrointestinal tolerability in persons treated with diclofenac and celecoxib for osteoarthritis. The outcomes were assessed in the IPCI database. To assess accuracy of exposure and outcome, we also collected information by self-administrated patient questionnaires. For all eligible subjects, we assessed the main reason for noninclusion. Physicians were interviewed to evaluate the study and to identify the major obstacles. RESULTS: Forty-two general practice physicians collaborated with the study and 7,127 potential study subjects were identified. Among these subjects, 170 were eligible for recruitment and 20 (11.8%) were randomized. Of the eligible patients, 96 (56.5%) were not recruited because the physician was too busy or the patient was treated by another healthcare provider and 54 (31.8%) were not recruited because of exclusion criteria. CONCLUSION: Concordance between questionnaires and IPCI data and the outcome was good (kappa=0.7; SD=0.14). The physicians reported that recruitment during routine visits was too time-consuming, in particular because of the need for informed consent. Although a randomized database study is feasible, patient recruitment during routine consultations should be avoided.

Adult↗

PubMed2006

Paper versus computer: feasibility of an electronic medical record in general pediatrics.

BACKGROUND: Implementation of electronic medical record systems promises significant advances in patient care, because such systems enhance readability, availability, and data quality. Structured data entry (SDE) applications can prompt for completeness, provide greater accuracy and better ordering for searching and retrieval, and permit validity checks for data quality monitoring, research, and especially decision support. A generic SDE application (OpenSDE) to support documentation of patient history and physical examination findings was developed and tailored for the domain of general pediatrics. OBJECTIVE: To evaluate OpenSDE for its completeness, uniformity of reporting, and usability in general pediatrics. METHODS: Four (trainee) pediatricians documented data for 8 first-visit patients in the traditional, paper-based, medical record and immediately thereafter in OpenSDE (electronic record). The 32 paper records obtained served as the common data source for data entry in OpenSDE by the other 3 physicians (transcribed record). Data entered by 2 experienced users, with all patient information present in the paper record, served as the control record. Data entry times were recorded, and a questionnaire was used to assess users' experiences with OpenSDE. RESULTS: Clinicians documented 44% of all available patient information identically in the paper and electronic records. Twenty-five percent of all patient information was documented only in the paper record, and 31% was present only in the electronic record. Differences were found in patient history and physical examination documentation in the electronic record; more information was missing for patient history (38%) than for physical examination (15%). Furthermore, physical examination contained more additional information (39%) than did patient history (21%). The interobserver agreement of documentation of patient information from the same data source was fair to moderate, with kappa values of 0.39 for patient history and 0.40 for physical examination. Data entry times in OpenSDE decreased from 25 minutes to <15 minutes, indicating a learning effect. The questionnaire revealed a positive attitude toward the use of OpenSDE in daily practice. CONCLUSION: OpenSDE seems to be a promising application for the support of physician data entry in general pediatrics.

Documentation↗

PubMed2005

Databases for knowledge discovery. Examples from biomedicine and health care.

Examples are given of the use of large research databases for knowledge discovery. Such databases are not only increasingly used for research in the 'hard' mathematics-based disciplines such as physics and engineering but also in more 'soft' disciplines, such as sociology, psychology and, in general, the humanities. In between the 'hard' and the 'soft' disciplines lie disciplines such as biomedicine and health care, from which we have selected our illustrations. This latter area can be subdivided into: (1) fundamental biomedical research, related to the 'hard' scientific approach; (2) clinical research, using both 'hard' and 'soft' data and (3) population-based research, which can be subdivided into prospective and retrospective research. The examples that we shall offer are representative for using computers in scientific research in general, but in medical and health informatics in particular.

Biomedical Research↗

PubMed2005

A technical infrastructure to conduct randomized database studies facilitated by a general practice research database.

General practice research databases are increasingly used to study intended and unintended effects of treatments. However, confounding by indication remains a major problem. The randomized database study methodology has been proposed as a method to combine the strengths of observational database (generalizability) and the strength of the randomized clinical trial (RCT) design (randomization). We developed an infrastructure that enables the execution of randomized database studies with treatment randomization facilitated by a general practice research database. The requirements posed by the methodology of randomized database studies were facilitated by software components. Our assessment showed that it is technically possible to conduct randomized trials in general practice according to the randomized database design. The infrastructure facilitated the conduct of randomized database studies in general practice but some practical difficulties and methodological issues remain. The technical infrastructure seems to be both promising and potentially feasible to facilitate future randomized database studies, although the methodology needs to be evaluated in more detail.

Biomedical Research↗

PubMed2005

Nonsteroidal anti-inflammatory drugs and increased risk of acute urinary retention.

BACKGROUND: Acute urinary retention (AUR) is characterized by the sudden inability to urinate, which is usually extremely painful and requires catheterization. Prostaglandins play an important role in the genitourinary function as they provoke contractions of the detrusor muscle. Relaxation of the detrusor muscle, via the inhibition of the prostaglandin synthesis, could result in AUR. METHODS: We conducted a population-based case-control study within the Integrated Primary Care Information project in the Netherlands to investigate whether the use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with an increased risk of AUR. All men 45 years or older registered in the database between 1995 and 2002 and with at least 6 months of valid history were included. Cases were all men with a validated diagnosis of AUR. To each case, up to 10 controls were matched on age and calendar time. RESULTS: Within the source population of 72 114 men, we identified 536 cases of AUR and 5348 matched controls. Risk of AUR was 2.02-fold higher in current users of NSAIDs than in nonusers (95% confidence interval, 1.23-3.31). The highest risk for AUR (adjusted odds ratio, 3.3; 95% confidence interval, 1.2-9.2) was observed in patients who recently started using NSAIDs and in those using a dose equal to or higher than the recommended daily dose. CONCLUSION: This study shows that the risk of AUR is about 2-fold higher in men who use NSAIDs.

Acute Disease↗

PubMed2005

Non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death.

AIMS: To assess the association between the use of non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death. METHODS AND RESULTS: A population-based case-control study was performed in the Integrated Primary Care Information (IPCI) project, a longitudinal observational database with complete medical records from more than 500,000 persons. All deaths between 1 January 1995 and 1 September 2003 were reviewed. Sudden cardiac death was classified based on the time between onset of cardiovascular symptoms and death. For each case, up to 10 random controls were matched for age, gender, date of sudden death, and general practice. The exposure of interest was the use of non-cardiac QTc-prolonging drugs. Exposure at the index date was categorized into three mutually exclusive groups of current use, past use, and non-use. The study population comprised 775 cases of sudden cardiac death and 6297 matched controls. Current use of any non-cardiac QTc-prolonging drug was associated with a significantly increased risk of sudden cardiac death (adjusted OR: 2.7; 95% CI: 1.6-4.7). The risk of death was highest in women and in recent starters. CONCLUSION: The use of non-cardiac QTc-prolonging drugs in a general population is associated with an increased risk of sudden cardiac death.

Adult↗

PubMed2005

Design and implementation considerations for a personalized patient education system in burn care.

Patient education is a significant factor in the provision of health care services, contributing to improved disease management and health care outcomes. Personalization has been suggested as a means for increasing patient education effectiveness and computer-based approaches have been explored as a possible means of achieving this goal. The success and capabilities of the resulting applications have been restricted by the absence of a direct link to patient data and the reliance on locally produced written material, which is expensive to produce, update and tailor. In our research project STructured Evaluated Personalized Patient Support (STEPPS), we are investigating the potential of a novel strategy for personalized or tailored patient education, based on the integration of electronic patient record data and material derived from online health information resources. In this paper we present an overview of the pertinent technical issues and the way we have addressed them in the context of our development work in the domain of burn care. Further, we discuss how the choices made in the design of the system interrelate with the considerations for its implementation in health care practice settings.

Burns↗

PubMed2005

Extracting data recorded with OpenSDE: possibilities and limitations.

PURPOSE: OpenSDE is an application intended to support structured data entry in a variety of settings, such as routine care and clinical research. The past years development has focused on data entry to support expressiveness and flexibility. The focus is now shifting to data extraction: what are the possibilities for extracting the data and does the adopted strategy pose limitations? METHODS: Data extraction is supported by presenting the concepts for extraction in the same tree structure as for data entry. Users can select all or a sub selection of these concepts for extraction. Selected concepts are extracted and converted to a table format that can be queried using conventional tools. RESULTS: The extraction tool (entity export) provides a successful technical solution for data extraction. Using the extracted data, however, leads to obstacles that are a result of a fundamental design principle of OpenSDE.

Computer Simulation↗

PubMed2005

OpenSDE: a strategy for expressive and flexible structured data entry.

PURPOSE: This description focuses on the expressiveness and flexibility of OpenSDE: an application that supports recording of structured narrative data. METHODS: OpenSDE enables data entry with (customizable) forms based on trees of medical concepts. The relevant scope for data entry can be tailored per medical domain by construction of a domain-specific tree. OpenSDE is intended for structuring narrative data to make these available for both care and research. RESULTS: The OpenSDE application is currently in use at several departments in our academic hospital, including radiology, neurology, pediatrics, and child psychiatry. OpenSDE is available for all in open source.

Humans↗

PubMed2005

Why are structured data different? Relating differences in data representation to the rationale of OpenSDE.

OpenSDE is an application that supports clinicians with structured recording of narrative patient data to enable use of data in both clinical practice and research. OpenSDE is based on a rationale and requirements for structured data entry. In this study, we analyse the impact of the rationale and the requirements on data representation using OpenSDE. Three paediatricians transcribed 20 paper patient records using OpenSDE. The transcribed records were compared; the findings that were the same in content but differed in representation (e.g. recorded as free text instead of in a structured manner) were categorized in one of three categories of difference in representation. The transcribed records contained 1764 findings in total. The medical content of 302 of these findings was represented differently by at least one clinician and was thus included in this study. In OpenSDE, clinicians are free to determine the degree of detail at which patient data are described. This flexibility accounts for 87% of the differences in data representation. Thirteen per cent of the differences are due to clinicians interpreting and translating phrases from the source text and transcribing these to (different) concepts in OpenSDE. The differences in data representation largely result from initial design decisions for OpenSDE.

Data Interpretation, Statistical↗

PubMed2005

Management of hypertension and hypercholesterolaemia in primary care in The Netherlands.

OBJECTIVE: Screening, treatment and monitoring guidelines for hypertension and hypercholesterolaemia have been developed to assist physicians in providing evidence-based health care. We conducted a retrospective study to assess the management of patients with these single or combined conditions. RESEARCH DESIGN AND METHODS: This was a retrospective cohort study conducted using data from the Integrated Primary Care Information (IPCI) project based in The Netherlands. Management of hypertension and hypercholesterolaemia was assessed from 2000-2003 by measuring the numbers of patients screened for these conditions, treated pharmacologically and monitored for treatment success. RESULTS: Approximately 11%, 3% and 10% of participants were eligible for screening for hypertension alone, hypercholesterolaemia alone and both conditions, respectively. Blood pressure screening was high in patients eligible for both blood pressure and cholesterol screening (> 86%), whereas cholesterol screening was low (< 56%). Among patients newly identified with hypertension or hypercholesterolaemia who were eligible for pharmacotherapy, 29% and 43% respectively were not treated within one year of diagnosis. Undertreatment was significantly lower in patients with both conditions (24% and 37% for antihypertensive and lipid-lowering treatment, respectively and 28% were not treated for both). Among newly treated patients, in the first year of treatment there was no record of a blood pressure or cholesterol assessment, for 35% and 72%, respectively. CONCLUSION: Management was sub-optimal in patients with hypertension or hypercholesterolaemia as well as in those with both of these conditions. The results of this study are likely to be widely applicable, particularly to other European and industrialised countries that have similar free-access health care systems to The Netherlands.

Adolescent↗

PubMed2005

Identification of the four conventional cardiovascular disease risk factors by Dutch general practitioners.

BACKGROUND: Detecting and managing the four major conventional risk factors, smoking, hypertension, diabetes mellitus, and hypercholesterolemia, is pivotal in the primary and secondary prevention of cardiovascular disease (CVD). OBJECTIVE: To assess the preventive activities of general practitioners (GPs) regarding the four conventional risk factors and the associated measurements for cardiovascular risk factors by GPs in relation to the time of the first clinical presence of CVD. SETTING: Large longitudinal general practice research database (the Integrated Primary Care Information database) in the Netherlands from September 1999 to August 2003. PARTICIPANTS AND METHODS: Patients > 18 year of age with newly diagnosed CVD with a valid history of at least 1 year before and after the first clinical diagnosis of CVD. Details on conventional risk factors and associated measurements for the four cardiovascular risk factors were assessed in relation to the first clinical diagnosis of CVD. RESULTS: In total, 157,716 patients met the study inclusion criteria. Of the 2,594 patients with newly diagnosed CVD, at least one of the four investigated risk factors was observed in 76% of women and 73% of men. In 40% of cases, no risk factor was recorded before the date of the first CVD diagnosis. In 16% of cases, no associated measurements were present before the first CVD diagnosis. CONCLUSION: In daily practice, GPs seem to focus on the secondary prevention of CVD. Intervention strategies that aim to influence GPs' case finding behavior should focus on increasing the awareness of physicians in performing risk factor-associated measurements in patients who are eligible for the primary prevention of CVD. Further research will have to show the feasibility and effectiveness of such intervention strategies.

Aged↗

PubMed2005

Randomised studies in general practice: how to integrate the electronic patient record.

The 'randomised database study' strategy was first proposed in 1997, with the aim of combining the generalisability of observational database studies based on electronic patient records (EPRs) with the validity of randomised clinical trials (RCTs). The key feature was to randomly assign treatments and to use routine care data, as available in the observational database, for patient identification and follow-up. To our knowledge, however, the idea of the randomised database study has not been implemented yet. The conduct of a randomised study in an observational database requires adjustments to methods of medical information processing in the general practice. We developed a software system that facilitates the conduct of an RCT with observational databases based on EPRs. It identifies eligible subjects and presents them one by one to the physician once their EPR is accessed. The general practitioner can then start an interactive recruitment process; after completion, the computer randomises the patients. Follow-up is documented by normal routine care in the EPR. Although the randomised database study has many methodological advantages, it has never been tested. Our software system is meant as a tool to implement and facilitate evaluation of the randomised database approach.

Data Collection↗

PubMed2005

Chemical and biological profiling of an annotated compound library directed to the nuclear receptor family.

Nuclear receptors form a family of ligand-activated transcription factors that regulate a wide variety of biological processes and are thus generally considered relevant targets in drug discovery. We have constructed an annotated compound library directed to nuclear receptors (NRacl) as a means for integrating the chemical and biological data being generated within this family. Special care has been put in the appropriate storage of annotations by using hierarchical classification schemes for both molecules and nuclear receptors, which takes the ability to extract knowledge from annotated compound libraries to another level. Analysis of NRacl has ultimately led to the identification of scaffolds with highly promiscuous nuclear receptor profiles and to the classification of nuclear receptor groups with similar scaffold promiscuity patterns. This information can be exploited in the design of probing libraries for deorphanization activities as well as for devising screening batteries to address selectivity issues.

Combinatorial Chemistry Techniques↗