Routine Health Insurance Data Research Articles

Personalized therapy in rheumatoid arthritis (PETRA): a protocol for a randomized controlled trial to test the effect of a psychological intervention in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects cartilage and bone. Psychological stress can both trigger disease exacerbation and result from disease activity. As standard pharmacological interventions alone have limited success in treating RA, a more comprehensive biopsychosocial approach to treatment has been recommended. In this prospective randomized controlled trial (RCT), a psychotherapeutically guided, group-based intervention program will be conducted with RA patients over a period of 9 months. This program combines a dynamic-interactional model with disorder-specific coping-oriented perspectives to improve patients’ social, emotional, and problem-solving competencies as well as stress system functional status. The enrolment of 440 patients, randomly allocated to either an intervention (n = 220) or control group (n = 220), is planned. To evaluate the intervention effect, various indicators of RA disease activity, stress system activity, and psychological condition will be assessed through sets of standardized questionnaires and biochemical analyses of blood and saliva samples. Moreover, healthcare-related costs for each patient will be obtained using routine health insurance data. Outcome variables will be measured in all patients at regular intervals prior to intervention (baseline), during the 9-month intervention (five time points), and during a 9-month follow-up phase (three time points), allowing the comprehensive analysis of within- and between-subject effects, i.e. trajectories of the target variables in the intervention and control groups. In addition, to investigate the intervention effects on real-life stress system functioning in RA, 10 integrative single-case studies (n = 5 from the intervention group, n = 5 from the control group) will be conducted. In each study, once before and after the 9-month intervention, urine samples will be collected, and patients will fill out questionnaires for approximately 1 month at 12-h intervals. Moreover, weekly in-depth interviews will be conducted with patients to determine their previous week’s emotionally positive and negative incidents. Using time series analysis, it is then possible to investigate whether and how stress system function in these RA patients has improved from the applied intervention. By using both an investigational macro- and microperspective, this project aims to evaluate a psychological intervention in the routine care of individuals with RA.Trial registration German Clinical Trials Register DRKS00028144. Registered on 1 March 2022.

Disease Management Program in patients with type 2 diabetes mellitus, long-term results of the early and established program cohort: A population-based retrospective cohort study.

The aim of this study was to evaluate the long-term follow up of the early and the effectiveness of the established program of the Austrian Disease Management Program (DMP) 'Therapie aktiv-Diabetes im Griff' for patients with type 2 diabetes mellitus concerning mortality, major macrovascular complications, costs and process quality of care parameters. We conducted a propensity score matched cohort study based on routine health insurance data for type 2 diabetic patients. The observational period from the matched early program cohort starts from January 1, 2009 to December 31, 2017 and includes 7181 DMP participants and 21543 non-participants. In the established matched program cohort, 3087 DMP participants and 9261 non-participants were observed within January 1, 2014 to December 31, 2017. In the early program cohort, 22.1% of the patients in the DMP-group and 29.7% in the control-group died after 8 years follow-up (HR = 0.70; 95% CI: 0.66-0.73). A difference of € 1070 (95% bootstrap-T interval: € 723 - € 1412) in mean total costs per year was observed. In the established program cohort, 10.4% DMP participants died 4 years after enrollment, whereas in the control-group 11.9% of the patients died (HR = 0.88, 95% CI: 0.78-0.99). Healthcare utilization is higher in the DMP-group (75%-96%) compared to the control-group (63%-90%). The 8-year long-term follow up of the DMP program showed a relevant improvement of survival and healthcare costs of patients with type 2 diabetes. The established program cohort had improved survival and quality of care. Our findings indicate that the DMP "Therapie aktiv" provides a long-term advantage for type 2 diabetes patients.

Reduction of care-relevant risks to older patients during and after acute hospital care (ReduRisk) – study protocol of a cluster randomized efficacy trial in a stepped wedge design

BackgroundOlder patients are at an increased risk of hospitalization, negatively affecting their health and quality of life. Such patients also experience a lack of physical activity during their inpatient stay, as well as being at increased risk of delirium and inappropriate prescribing. These risk factors can accumulate, promoting a degree of morbidity and the development of cognitive impairment.MethodsThrough the ReduRisk-program, patients at risk of functional impairment, immobility, falls, delirium or re-hospitalization shortly after hospital discharge, will be identified via risk-screening. These patients will receive an individually tailored, multicomponent and risk-adjusted prevention program. The trial will compare the effectiveness of the ReduRisk-program against usual care in a stepped-wedge-design, with quarterly cluster randomization of six university hospital departments into intervention and control groups. 612 older adults aged 70 years or more are being recruited. Patients in the intervention cluster (n = 357) will receive the ReduRisk-program, comprising risk-adjusted delirium management, structured mobility training and digitally supported planning of post-inpatient care, including polypharmacy management. This study will evaluate the impact of the ReduRisk-program on the primary outcomes of activities of daily living and mobility, and the secondary outcomes of delirium, cognition, falls, grip strength, health-related quality of life, potentially inappropriate prescribing, health care costs and re-hospitalizations. Assessments will be conducted at inpatient admission (t0), at discharge (t1) and at six months post-discharge (t2). In the six-month period following discharge, a health-economic evaluation will be carried out based on routine health insurance data (t3).DiscussionDespite the importance of multicomponent, risk-specific approaches to managing older patients, guidelines on their effectiveness are lacking. This trial will seek to provide evidence for the effectiveness of a multicomponent, risk-adjusted prevention program for older patients at risk of functional impairment, immobility, falls, delirium and re-hospitalization. Positive study results would support efforts to improve multicomponent prevention and the management of older patients.Trial registrationGerman Clinical Trials Register, DRKS00025594, date of registration: 09/08/2021.

SLEEP WELL

BackgroundThe standard treatment of obstructive sleep apnea (OSA) is nocturnal positive airway pressure (PAP) therapy, which only has positive effects on symptoms and sequelae with regular and long-term use. Interface problems in existing care lead to incorrect treatment and long waiting times in the diagnostics and therapy, which are aggravated by the pandemic.ObjectiveBased on the existing structures a cross-sectoral care treatment model for the diagnostics and therapy of OSA will be evaluated. The central goals are a timely, needs-oriented care with optimized quality and efficiency. Furthermore, treatment adherence and thus quality of life should be improved as well as the cross-sectoral collaboration. The SLEEP WELL project is funded by the G-BA Innovation Fund (funding reference 01NVF20020).Material and methodsThe evaluation will be carried out based on a prospective, randomized, controlled, multicenter study in North Rhine-Westphalia, Germany, in which 4448 patients with suspected OSA receive guideline-compliant care with telemedicine (telemedicine group) or without telemedicine (control group). The 1:1 randomization takes place after initial suspicion by the primary physician. The two groups are compared in terms of quality of life (primary endpoint), PAP therapy adherence, and medical resource use (secondary outcomes).Results and discussionQuantitative data collation occurs at 5 time points. In an intention to treat analysis the results are analyzed using statistical evaluation methods. Patient and provider satisfaction will be assessed using qualitative methods. The cost-benefit relation is examined on the basis of routine health insurance data. In addition, remuneration concepts for standard care will be developed. Project completion is planned for September 2025.

Utilizing Routine Health Insurance Data for Calculation of Disease Frequencies in the Project BURDEN 2020

The concept of disease burden enables a comprehensive analysis of the health status of a population. Key indicators are years of life lost due to mortality (YLL) and morbidity (years lived with disability, YLD), summarised in the DALY indicator (disability adjusted life years). These indicators are suitable for planning prevention, health care or provision of health services. With the project BURDEN 2020, funded by the German Federal Joint Committee's Innovation Fund, a national and regionalised calculation of burden of disease for Germany is being carried out for the first time, based on the methodology of the international "Global Burden of Disease" study. Calculation of YLD requires data on the frequency and severity of diseases, with routine health insurance data constituting an important data source. Case definitions for 18 selected diseases and severity levels for 11 of these diseases were developed in expert meetings. Based on these case definitions, the AOK Research Institute (WIdO) calculated disease frequencies from health utilisation data of patients insured with the AOK. A specific concept for prevalence calculation takes into account the dynamics of an open cohort of insurees. For severity levels, the results of the AOK insurees were extrapolated to the total population in Germany according to age and gender groups. For disease frequencies, the results were additionally adjusted for morbidity and estimated on regional levels. Disease frequencies measured by prevalences or rates are available for 18 diseases from seven categories (cardiovascular diseases, diabetes, cancer, mental disorders, dementia, COPD and lower respiratory tract infections) at the regional levels of the 16 federal states and 96 regional planning areas. Severity distributions are provided on the national level stratified by age groups and gender. The results and documentation of methods are available at www.krankheitslage-deutschland.de (in German language). Routine health insurance data are an important data source in the BURDEN 2020 project because regional figures and, in some cases, severity levels can be determined on the basis of a large number of cases. A comprehensive publication of results creates transparency and allows reutilisation of methods in further projects. Future research should extend burden of disease calculations to other diseases. In addition, there is an increasing demand for health data linkage.

Nursing home-sensitive conditions: analysis of routine health insurance data and modified Delphi analysis of potentially avoidable hospitalizations.

Background:Hospitalizations of nursing home residents are associated with various health risks. Previous research indicates that, to some extent, hospitalizations of this vulnerable population may be inappropriate and even avoidable. This study aimed to develop a consensus list of hospital discharge diagnoses considered to be nursing home-sensitive, i.e., avoidable. Methods:The study combined analyses of routine data from six statutory health insurance companies in Germany and a two-stage Delphi panel, enhanced by expert workshop discussions, to identify and corroborate relevant diagnoses. Experts from four different disciplines estimated the proportion of hospitalizations that could potentially have been prevented under optimal conditions. Results:We analyzed frequencies and costs of data for hospital admissions from 242,236 nursing home residents provided by statutory health insurance companies. We identified 117 hospital discharge diagnoses, which had a frequency of at least 0.1%. We recruited experts (primary care physicians, hospital specialists, nursing home professionals and researchers) to estimate the proportion of potentially avoidable hospitalizations for the 117 diagnoses deemed avoidable in two Delphi rounds (n=107 in Delphi Round 1 and n=96 in Delphi Round 2, effective response rate=91%). A total of 35 diagnoses with high and consistent estimates of the proportion of potentially avoidable hospitalizations were identified as nursing home-sensitive. In an expert workshop (n=16), a further 25 diagnoses were discussed that had not reached the criteria, of which another 23 were consented to be nursing home-sensitive conditions. Extrapolating the frequency and mean costs of these 58 diagnoses to the national German context yielded total potentially avoidable care costs of €768,304,547, associated with 219,955 nursing home-sensitive hospital admissions. Conclusion:A total of 58 nursing home-relevant diagnoses (ICD-10-GM three-digit level) were classified as nursing home-sensitive using an adapted Delphi procedure. Interventions should be developed to avoid hospital admission from nursing homes for these diagnoses.

Nursing home-sensitive conditions: analysis of routine health insurance data and modified Delphi analysis of potentially avoidable hospitalizations

Background: Hospitalizations of nursing home residents are associated with various health risks. Previous research indicates that, to some extent, hospitalizations of this vulnerable population may be inappropriate and even avoidable. This study aimed to develop a consensus list of hospital discharge diagnoses considered to be nursing home-sensitive, i.e., avoidable. Methods: The study combined analyses of routine data from six statutory health insurance companies in Germany and a two-stage Delphi panel, enhanced by expert workshop discussions, to identify and corroborate relevant diagnoses. Experts from four different disciplines estimated the proportion of hospitalizations that could potentially have been prevented under optimal conditions. Results: We analyzed frequencies and costs of data for hospital admissions from 242,236 nursing home residents provided by statutory health insurance companies. We identified 117 hospital discharge diagnoses, which had a frequency of at least 0.1%. We recruited experts (primary care physicians, hospital specialists, nursing home professionals and researchers) to estimate the proportion of potentially avoidable hospitalizations for the 117 diagnoses deemed avoidable in two Delphi rounds (n=107 in Delphi Round 1 and n=96 in Delphi Round 2, effective response rate=91%). A total of 35 diagnoses with high and consistent estimates of the proportion of potentially avoidable hospitalizations were identified as nursing home-sensitive. In an expert workshop (n=16), a further 25 diagnoses were discussed that had not reached the criteria, of which another 23 were consented to be nursing home-sensitive conditions. Extrapolating the frequency and mean costs of these 58 diagnoses to the national German context yielded total potentially avoidable care costs of €768,304,547, associated with 219,955 nursing home-sensitive hospital admissions. Conclusion: A total of 58 nursing home-relevant diagnoses (ICD-10-GM three-digit level) were classified as nursing home-sensitive using an adapted Delphi procedure. Interventions should be developed to avoid hospital admission from nursing homes for these diagnoses.

Influenza vaccination in patients with dementia and Parkinson’s disease—an analysis of routine health insurance data for the years 2014–2019

Influenza vaccination in patients with dementia and Parkinson’s disease—an analysis of routine health insurance data for the years 2014–2019

Nursing home-sensitive conditions: analysis of routine health insurance data and modified Delphi analysis of potentially avoidable hospitalizations

Background:Hospitalizations of nursing home residents are associated with various health risks. Previous research indicates that, to some extent, hospitalizations of this vulnerable population may be inappropriate and even avoidable. This study aimed to develop a consensus list of hospital discharge diagnoses considered to be nursing home-sensitive, i.e., avoidable. Methods:The study combined analyses of routine data from six statutory health insurance companies in Germany and a two-stage Delphi panel, enhanced by expert workshop discussions, to identify and corroborate relevant diagnoses. Experts from four different disciplines estimated the proportion of hospitalizations that could potentially have been prevented under optimal conditions. Results:We analyzed frequencies and costs of data for hospital admissions from 242,236 nursing home residents provided by statutory health insurance companies. We identified 117 hospital discharge diagnoses, which had a frequency of at least 0.1%. We recruited experts (primary care physicians, hospital specialists, nursing home professionals and researchers) to estimate the proportion of potentially avoidable hospitalizations for the 117 diagnoses deemed avoidable in two Delphi rounds (n=107 in Delphi Round 1 and n=96 in Delphi Round 2, effective response rate=91%). A total of 35 diagnoses with high and consistent estimates of the proportion of potentially avoidable hospitalizations were identified as nursing home-sensitive. In an expert workshop (n=16), a further 25 diagnoses were discussed that had not reached the criteria, of which another 23 were consented to be nursing home-sensitive conditions. Extrapolating the frequency and mean costs of these 58 diagnoses to the national German context yielded total potentially avoidable care costs of €768,304,547, associated with 219,955 nursing home-sensitive hospital admissions. Conclusion:A total of 58 nursing home-relevant diagnoses (ICD-10-GM three-digit level) were classified as nursing home-sensitive using an adapted Delphi procedure. Interventions should be developed to avoid hospital admission from nursing homes for these diagnoses.

Multiperspective and Multimethod Evaluation of Flexible and Integrative Psychiatric Care Models in Germany: Study Protocol of a Prospective, Controlled Multicenter Observational Study (PsychCare).

Background: New cross-sectoral mental health care models have been initiated in Germany to overcome the fragmentation of the German health care system. Starting in 2013, flexible and integrative psychiatric care model projects according to §64b SGB V German Social Law (FIT64b) have been implemented. The study “PsychCare” combines quantitative and qualitative primary data with routine health insurance data for the evaluation of these models. Effects, costs and cost-effectiveness from the perspectives of patients, relatives and care providers are compared with standard care. Additionally, quality indicators for a modern, flexible and integrated care are developed. This article describes the rationale, design and methods of the project.Methods: “PsychCare” is built on a multiperspective and multimethod design. A controlled prospective multicenter cohort study is conducted with three data collection points (baseline assessment, follow-up after 9 and 15 months). A total of 18 hospitals (10 FIT64b model and 8 matched control hospitals) have consecutively recruited in- and outpatients with pre-specified common and/or severe psychiatric disorders. Primary endpoints are differences in change of health-related quality of life and treatment satisfaction. Sociodemographic and service receipt data of the primary data collection are linked with routine health insurance data. A cost-effectiveness analysis, a mixed method, participatory process evaluation by means of qualitative surveys and the development of quality indicators are further elements of “PsychCare.”Discussion and Practical Implications: The results based on data from different methodological approaches will provide essential conclusions for the improvement of hospital based mental health care in Germany. This should result in the identification of key FIT64b elements that can be efficiently implemented into standard care in Germany and re-structure the care strongly aligned to patient needs.Clinical Trial Registration: German Clinical Trial Register, identifier DRKS 00022535.

A Comparison of Matching and Weighting Methods for Causal Inference Based on Routine Health Insurance Data, or: What to do If an RCT is Impossible.

Due to a multitude of reasons Randomized Control Trials on the basis of so-called "routine data" provided by insurance companies cannot be conducted. Therefore the estimation of "causal effects" for any kind of treatment is hampered since systematic bias due to specific selection processes must be suspected. The basic problem of counterfactual, which is to evaluate the difference between two potential outcomes for the same unit, is discussed. The focus lies on the comparison of the performance of different approaches to control for systematic differences between treatment and control group. These strategies are all based on propensity scores, namely matching or pruning, IPTW (inverse probability treatment weighting) and entropy balancing. Methods to evaluate these strategies are presented. A logit model is employed with 87 predictors to estimate the propensity score or to estimate the entropy balancing weights. All analyses are restricted to estimate the ATT (Average Treatment Effect for the Treated) Exemplary data come from a prospective controlled intervention-study with two measurement occasions. Data contain 35 857 chronically ill insurants with diabetes, congestive heart failure, arteriosclerosis, coronary heart disease or hypertension of one German sickness fund. The intervention group was offered an individual telephone coaching to improve health behavior and slow down disease progression while the control group received treatment as usual. Randomization took place before the insurants' consent to participate was obtained so assumptions of an RCT are violated. A weighted mixture model (difference-in-difference) as the causal model of interest is employed to estimate treatment effects in terms of costs distinguishing the categories outpatient costs, medication costs, and total costs. It is shown that entropy balancing performs best with respect to balancing treatment and control group at baseline for the first three moments of all 87 predictors. This will result in least biased estimates of the treatment effect.

The Prevalence, Comorbidity, Management and Costs of Irritable Bowel Syndrome.

Insufficient data are available on the administrative incidence and prevalence of irritable bowel syndrome (IBS) in Germany, as well as on its comorbidities, diagnostic evaluation, treatment, and costs. We analyzed routine data from a statutory health insurance carrier with approximately eight million insurees. IBS was identified from the ICD-10 codes K58.0, K58.9, and F45.32 (outpatient care by a physician, outpatient and inpatient care in a hospital). The cumulative incidence for the year 2017 was determined by the exclusion of insurees who had carried the diagnosis of IBS in any of the preceding 12 years. The frequencies of comorbid diseases and of diagnostic and therapeutic measures were compared with those of persons in age- and sex- matched control groups without IBS. In 2017, the administrative incidence of IBS was 0.36%, and its prevalence was 1.34%. Persons with IBS were often documented as having other gastrointes- tinal diseases, headache, back pain, and mental disorders. There was evidence for the insufficient use of ultrasound and colonoscopy and for the excessive use of computed tomography and magnetic resonance imaging for diagnostic evaluation. The costs of medical care for insurees with IBS in the year of their initial diagnosis were higher than those of other insurees without the diagnosis of IBD (€ 3770 vs. € 2788) and rose in each of the eight years preceding the initial diagnosis. Patients with IBS in Germany are likely not receiving sufficient diag- nostic evaluation in conformity with the relevant guidelines. The high prevalence of comorbid mental disorders and other pain syndromes implies that the complaints of patients with IBS need to be more comprehensively evaluated and treated.

The Evaluation of the Effectiveness of Austrians Disease Management Program in Patients with Type 2 Diabetes Mellitus - A Population-Based Retrospective Cohort Study.

AimTo evaluate the effectiveness of the Austrian Disease Management Program (DMP) ‘Therapie aktiv—Diabetes im Griff’ for patients with type 2 diabetes mellitus concerning patient-relevant outcomes (mortality, myocardial infarction and stroke) and costs.MethodsBased on routine health insurance data, we conducted a population-based retrospective cohort study using a propensity score (PS) matched control group design. The DMP-group consists of participants enrolled in the program during 2008 and 2009 (n = 7181). Out of 208.532 patients with no participation in the DMP up to 2013, PS-matched controls were selected with a matching ratio 1:3. In the PS-model, patient’s characteristics, form of antidiabetic drug therapy, several prescriptions, the number of hospital admissions and days, main discharge diagnoses and costs at baseline were included.ResultsOver a follow-up period of four years, we observed a significantly lower mortality rate in the DMP-group (9.4%) in comparison with the control group (15.9%, p<0.001). The cumulative number of hospital days and mean annual hospital costs were lower for DMP-participants resulting in significantly lower mean annual total costs, amounting to € 8226.80 per patient in the DMP-group and € 9231.10 in the control group respectively (p<0.001).ConclusionsThe evaluation shows a survival benefit and an average reduction of costs for participants in the DMP compared with the control-group. Despite we took great effort to ensure comparable groups, we cannot entirely rule out an influence by residual and unmeasured confounding due to the observational study design and the use of routine data. However, the results indicate that the disease management program implemented in Austria improves quality of care for patients with type 2 diabetes mellitus.

Respondents in an epidemiologic survey had fewer psychotropic prescriptions than nonrespondents: an insight into health-related selection bias using routine health insurance data

ObjectivesUsing register-based insurance data, we aimed to evaluate health-related differences between respondents and nonrespondents in a mailed epidemiologic survey, with a particular focus on mental health. Study Design and SettingIn 2005, 19,406 adults covered by the national education system health insurance plan were sent a general health questionnaire including a significant part devoted to mental health. Of them, 52% responded. Using multivariable logistic regression models, we compared participants and nonparticipants on various sociodemographic characteristics, morbidity variables, and health care utilization indicators derived from the routine health insurance databases, regardless of response status. Mental health was appraised through the reimbursement of psychiatric services and the volume of psychotropic prescriptions received in 2004–05. ResultsIn addition to traditional sociodemographic covariates of participation, we observed that respondents used more medical services than nonrespondents (visits to general practitioners, dentists, and specialists other than psychiatrists) but essentially for somatic disorders, as they also were prescribed significantly fewer psychotropic drugs. ConclusionResponse bias may impact estimation quality even in apparently sociodemographically homogeneous populations. Our results confirmed that persons with mental complaints are less likely to respond to a survey focused on their troubles and illustrate the risk of underestimation of psychiatric disease in population-based surveys.

Routine health insurance data for scientific research: potential and limitations of the Agis Health Database

Objective Observational studies performed within routine health care databases have the advantage of their large size and, when the aim is to assess the effect of interventions, can offer a completion to randomized controlled trials with usually small samples from experimental situations. Institutional Health Insurance Databases (HIDs) are attractive for research because of their large size, their longitudinal perspective, and their practice-based information. As they are based on financial reimbursement, the information is generally reliable. Study Design The database of one of the major insurance companies in the Netherlands, the Agis Health Database (AHD), is described in detail. Whether the AHD data sets meet the specific requirements to conduct several types of clinical studies is discussed according to the classification of the four different types of clinical research; that is, diagnostic, etiologic, prognostic, and intervention research. The potential of the AHD for these various types of research is illustrated using examples of studies recently conducted in the AHD. Conclusion HIDs such as the AHD offer large potential for several types of clinical research, in particular etiologic and intervention studies, but at present the lack of detailed clinical information is an important limitation.

Diabetes—prevalence and cost of illness in Germany: a study evaluating data from the statutory health insurance in Germany

This population-based study assesses the prevalence and cost of illness as a result of diabetes mellitus in Germany by retrospectively analysing routine health insurance data. Prevalence and costs were analysed from statutory health insurance (GKV) and societal perspectives. The analysis comprises data of all insured persons of six large sickness funds. The insured with diabetes were identified via ICD-9 diagnosis and Anatomical Therapeutic Chemical Classification System (ATC) code for regular medication prescriptions. Costs for inpatient stay, medication and sickness benefits were taken from claims data. Costs for rehabilitation, premature death and early retirement were calculated using the human capital approach and data from national statistics. Overall diabetes prevalence in this age and sex standardized census of six large sickness funds was 6.45%. The cost of illness for sickness funds including hospital cost, medication and sickness benefits, and excluding ambulatory doctor care, were Euro 3.69bn . The total cost of diabetes from a societal perspective was calculated at Euro 5.71bn for the year 1999. In accordance with the results of recent studies using routinely collected health insurance data, our study suggests that the prevalence of diabetes mellitus has increased steadily in the past years. The prevalence in our population of 14.7 million insured was 6.45%. Total costs of diabetes mellitus amounted to Euro 5.71bn.

Asthma: prevalence and cost of illness

The purpose of this study was to estimate the prevalence and cost of illness of asthma in Germany by retrospectively analysing routine health insurance data. This analysis investigated claims data from all insured persons of six large sickness funds. Insurants with asthma were identified via the International Classification of Diseases (ninth revision) diagnosis and the Anatomical Therapeutic Chemical Classification System Code for regular medication prescriptions. Costs for hospital care, medication and sick benefit were taken from claims data. Costs for rehabilitation, premature death and early retirement were estimated using the human capital approach and data from national statistics. Prevalence of asthma in the German statutory health insurance was 6.34%. Total costs for asthma, including direct and indirect costs, were calculated at euro 2.74 billion during 1999. The prevalence of asthma in the German statutory health insurance has previously been estimated to be 4-6%. The results of this large study show the prevalence of asthma in the German social insurance system to be approximately 6%. The study also indicates that there is room for substantial savings in the German social insurance system, with indirect costs amounting to 74.8% of total costs and payment of sick benefits through the sickness funds amounting to 58.3% of indirect costs. These costs may be reduced with better asthma control in patients.