Impact of BMI and BMI change on future drug expenditures in adults: results from the MONICA/KORA cohort study.

BACKGROUND: The evidence on the long-term economic effects of obesity is still scarce. This study aims to analyse the impact of body mass index (BMI) and BMI-change on future pharmaceutical utilisation and expenditures. METHODS: Based on data from 2,946 participants in a German population-based health survey (MONICA/KORA, 1994/95) and the follow-up study (2004/05), drug intake and expenditures were estimated using a bottom-up approach. Using univariate and multivariate methods, we analysed the impact of baseline BMI and BMI-change on drug utilisation and expenditures after 10 years. RESULTS: The use of pharmaceuticals was more likely in moderately and severely obese compared to the normal weight group (OR 1.8 and 4.0, respectively). In those who reported pharmaceutical intake, expenditures were about 40% higher for the obese groups. A 1-point BMI-gain in 10 years was, on average, associated with almost 6% higher expenditures compared to a constant BMI. CONCLUSION: The results suggest that obesity as well as BMI-gain are strong predictors of future drug utilisation and associated expenditures in adults, and thus highlight the necessity of timely and effective intervention and prevention programmes. This study complements the existing literature and provides important information on the relevance of obesity as a health problem.

The association of smoking status with healthcare utilisation, productivity loss and resulting costs: results from the population-based KORA F4 study.

BACKGROUND: Smoking is seen as the most important single risk to health today, and is responsible for a high financial burden on healthcare systems and society. This population-based cross-sectional study compares healthcare utilisation, direct medical costs, and costs of productivity losses for different smoking groups: current smokers, former smokers, and never smokers. METHODS: Using a bottom-up approach, data were taken from the German KORA F4 study (2006/2008) on self-reported healthcare utilisation and work absence due to illness for 3,071 adults aged 32-81 years. Unit costs from a societal perspective were applied to utilisation. Utilisation and resulting costs were compared across different smoking groups using generalised linear models to adjust for age, sex, education, alcohol consumption and physical activity. RESULTS: Average annual total costs per survey participant were estimated as €3,844 [95% confidence interval: 3,447-4,233], and differed considerably between smoking groups with never smokers showing €3,237 [2,802-3,735] and former smokers causing €4,398 [3,796-5,058]. There was a positive effect of current and former smoking on the utilisation of healthcare services and on direct and indirect costs. Total annual costs were more than 20% higher (p<0.05) for current smokers and 35% higher (p<0.01) for former smokers compared with never smokers, which corresponds to annual excess costs of €743 and €1,108 per current and former smoker, respectively. CONCLUSIONS: Results indicate that excess costs for current and former smokers impose a large burden on society, and that previous top-down cost approaches produced lower estimates for the costs of care for smoking-related diseases. Efforts must be focused on prevention of smoking to achieve sustainable containment on behalf of the public interest.

Are community-living and institutionalized dementia patients cared for differently? Evidence on service utilization and costs of care from German insurance claims data.

BACKGROUND: Dementia patients are often cared for in institutional arrangements, which are associated with substantial spending on professional long-term care services. Nevertheless, there is little evidence on the exact cost differences between community-based and institutional dementia care, especially when it comes to the distinct health care services. Adopting the perspective of the German social security system, which combines Statutory Health Insurance and Compulsory Long-Term Care Insurance (payer perspective), our study aimed to compare community-living and institutionalized dementia patients regarding their health care service utilization profiles and to contrast the respective expenditures. METHODS: We analysed 2006 claims data for 2,934 institutionalized and 5,484 community-living individuals stratified by so-called care levels, which reflect different needs for support in activities of daily living. Concordant general linear models adjusting for clinical and demographic differences were run for each stratum separately to estimate mean per capita utilization and expenditures in both settings. Subsequently, spending for the community-living and the institutionalized population as a whole was compared within an extended overall model. RESULTS: Regarding both settings, health and long-term care expenditures rose the higher the care level. Thus, long-term care spending was always increased in nursing homes, but health care spending was comparable. However, the underlying service utilization profiles differed, with nursing home residents receiving more frequent visits from medical specialists but fewer in-hospital services and anti-dementia drug prescriptions. Altogether, institutional care required additional yearly per capita expenses of ca. €200 on health and ca. €11,200 on long-term care. CONCLUSION: Community-based dementia care is cost saving from the payer perspective due to substantially lower long-term care expenditures. Health care spending is comparable but community-living and institutionalized individuals present characteristic service utilization patterns. This apparently reflects the existence of setting-specific care strategies. However, the bare economic figures do not indicate whether these different concepts affect the quality of care provision and disregard patient preferences and caregiver-related aspects. Hence, additional research combining primary and secondary data seems to be required to foster both, sound allocation of scarce resources and the development of patient-centred dementia care in each setting.

The cost-effectiveness of tracking newborns with bilateral hearing impairment in Bavaria: a decision-analytic model.

BACKGROUND: Although several countries, including Germany, have established newborn hearing screening programmes for early detection and treatment of newborns with hearing impairments, nationwide tracking systems for follow-up of newborns with positive test results until diagnosis of hearing impairment have often not been implemented. However, a recent study on universal newborn hearing screening in Bavaria showed that, in a high proportion of newborns, early diagnosis was only possible with the use of a tracking system. The aim of this study was, therefore, to assess the cost-effectiveness of tracking newborns with bilateral hearing impairment in Bavaria. METHODS: Data from a Bavarian pilot project on newborn hearing screening and Bavarian newborn hearing screening facilities were used to assess the cost-effectiveness of the inclusion of a tracking system within a newborn hearing screening programme. A model-based cost-effectiveness analysis was conducted. The time horizon of the model was limited to the newborn hearing screening programme. Costs of the initial hearing screening test and subsequent tests were included, as well as costs of diagnosis and costs of tracking. The outcome measure of the economic analysis was the cost per case of bilateral hearing impairment detected. In order to reflect uncertainty, deterministic and probabilistic sensitivity analyses were performed. RESULTS: The incremental cost-effectiveness ratio of tracking vs. no tracking was €1,697 per additional case of bilateral hearing impairment detected. CONCLUSIONS: Compared with no tracking, tracking resulted in more cases of bilateral hearing impairment detected as well as higher costs. If society is willing to pay at least €1,697 per additional case of bilateral hearing impairment detected, tracking can be recommended.

Body weight changes and outpatient medical care utilisation: Results of the MONICA/KORA cohorts S3/F3 and S4/F4.

OBJECTIVES: To test the effects of body weight maintenance, gain, and loss on health care utilisation in terms of outpatient visits to different kinds of physicians in the general adult population. METHODS: Self-reported utilisation data were collected within two population-based cohorts (baseline surveys: MONICA-S3 1994/95 and KORA-S4 1999/2001; follow-ups: KORA-F3 2004/05 and KORA-F4 2006/08) in the region of Augsburg, Germany, and were pooled for present purposes. N=5,147 adults (complete cases) aged 25 to 64 years at baseline participated. Number of visits to general practitioners (GPs), internists, and other specialists as well as the total number of physician visits at follow-up were compared across 10 groups defined by body mass index (BMI) category maintenance or change. Body weight and height were measured anthropometrically. Hierarchical generalized linear regression analyses with negative binomial distribution adjusted for sex, age, socioeconomic status (SES), survey, and the need factors incident diabetes and first cancer between baseline and follow-up were conducted. RESULTS: In fully adjusted models, compared to the group of participants that maintained normal weight from baseline to follow-up, the following groups had significantly higher GP utilisation rates: weight gain from normal weight (+36%), weight loss from preobesity (+39%), maintained preobesity (+34%), weight gain after preobesity (+43%), maintained moderate obesity (+48%), weight gain from moderate obesity (+107%), weight loss from severe obesity (+114%), and maintained severe obesity (+83%). Regarding internists, those maintaining moderate obesity reported +107% more visits; those with weight gain from moderate obesity reported +91%. The latter group also had +41% more consultations with other physicians. Across all physicians, mean number of visits were estimated at 7.8 per year for maintained normal weight, 9 for maintained preobesity, 11 for maintained moderate obesity, and 12 for maintained severe obesity. Among those with weight loss, the mean number of visits were 8.7, 10.6 and 10.8 for baseline preobesity, moderate obesity, and severe obesity, respectively. Finally, those with weight gain from normal weight and preobesity reported 9.4 and 9.3 visits, respectively, and those with baseline moderate and follow-up severe obesity reported 13.1 visits (the most overall). Women reported higher GP and other physician utilisation. While all utilisation rates increased with age, GP utilisation was lower in middle to high SES groups. CONCLUSION: Compared to maintained normal weight over a 7- to 10-year period, maintained overweight, weight gain and weight loss are associated with higher outpatient physician utilisation in adults, especially after baseline obesity. These effects only partly became insignificant after inclusion of incident diabetes or first cancer into the model. Future research should further elucidate the associations between weight development and health care utilisation by BMI status and the mechanisms underlying these associations.

Exposure to second-hand smoke and direct healthcare costs in children - results from two German birth cohorts, GINIplus and LISAplus.

BACKGROUND: Although the negative health consequences of the exposure to second hand tobacco smoke during childhood are already known, evidence on the economic consequences is still rare. The aim of this study was to estimate excess healthcare costs of exposure to tobacco smoke in German children. METHODS: The study is based on data from two birth cohort studies of 3,518 children aged 9-11 years with information on healthcare utilisation and tobacco smoke exposure: the GINIplus study (German Infant Study On The Influence Of Nutrition Intervention Plus Environmental And Genetic Influences On Allergy Development) and the LISAplus study (Influence of Life-Style Factors On The Development Of The Immune System And Allergies In East And West Germany Plus The Influence Of Traffic Emissions And Genetics). Direct medical costs were estimated using a bottom-up approach (base year 2007). We investigated the impact of tobacco smoke exposure in different environments on the main components of direct healthcare costs using descriptive analysis and a multivariate two-step regression analysis. RESULTS: Descriptive analysis showed that average annual medical costs (physician visits, physical therapy and hospital treatment) were considerably higher for children exposed to second-hand tobacco smoke at home (indoors or on patio/balcony) compared with those who were not exposed. Regression analysis confirmed these descriptive trends: the odds of positive costs and the amount of total costs are significantly elevated for children exposed to tobacco smoke at home after adjusting for confounding variables. Combining the two steps of the regression model shows smoking attributable total costs per child exposed at home of €87 [10-165] (patio/balcony) and €144 [6-305] (indoors) compared to those with no exposure. Children not exposed at home but in other places showed only a small, but not significant, difference in total costs compared to those with no exposure. CONCLUSIONS: This study shows adverse economic consequences of second-hand smoke in children depending on proximity of exposure. Tobacco smoke exposure seems to affect healthcare utilisation in children who are not only exposed to smoke indoors but also if parents reported exclusively smoking on patio or balcony. Preventing children from exposure to second-hand tobacco smoke might thus be desirable not only from a health but also from an economic perspective.

Dementia care in the general practice setting: a cluster randomized trial on the effectiveness and cost impact of three management strategies.

OBJECTIVE: To compare a complex nondrug intervention including actively approaching counseling and caregiver support groups with differing intensity against usual care with respect to time to institutionalization in patients with dementia. METHODS: Within this three-armed cluster-randomized controlled trial, 390 community-dwelling patients aged 65 years or older with physician-diagnosed mild to moderate dementia and their caregivers were enrolled via 129 general practitioners in Middle Franconia, Germany. The intervention included general practitioners' training in dementia care and their recommendation of support groups and actively approaching caregiver counseling. Primary study end point was time to institutionalization over 2 years. In addition, long-term intervention effects were assessed over a time horizon of 4 years. Secondary end points included cognitive functioning, (instrumental) activities of daily living, burden of caregiving, and health-related quality of life after 2 years. Frailty models with strict intention-to-treat approach and mixed linear models were applied to account for cluster randomization. Health care costs were assessed from the societal perspective. RESULTS: After 2 (4) years, 12% (24%) of the patients were institutionalized and another 21% (35%) died before institutionalization. No significant differences between study groups were observed with respect to time to institutionalization after 2 and 4 years (P 0.25 and 0.71, respectively). Secondary end points deteriorated, but differences were not significant between study groups. Almost 80% of the health care costs were due to informal care. Total annual costs amounted to more than €47,000 per patient and did not differ between study arms. CONCLUSION: The intervention showed no effects on time to institutionalization and secondary outcomes.

A lifetime Markov model for the economic evaluation of chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death worldwide. It has serious health effects and causes substantial costs for society. OBJECTIVES: The aim of the present paper was to develop a state-of-the-art decision-analytic model of COPD whereby the cost effectiveness of interventions in Germany can be estimated. To demonstrate the applicability of the model, a smoking cessation programme was evaluated against usual care. METHODS: A seven-stage Markov model (disease stages I to IV according to the GOLD [Global Initiative for Chronic Obstructive Lung Disease] classification, states after lung-volume reduction surgery and lung transplantation, death) was developed to conduct a cost-utility analysis from the societal perspective over a time horizon of 10, 40 and 60 years. Patients entered the cohort model at the age of 45 with mild COPD. Exacerbations were classified into three levels: mild, moderate and severe. Estimation of stage-specific probabilities (for smokers and quitters), utilities and costs was based on German data where possible. Data on effectiveness of the intervention was retrieved from the literature. A discount rate of 3% was applied to costs and effects. Probabilistic sensitivity analysis was used to assess the robustness of the results. RESULTS: The smoking cessation programme was the dominant strategy compared with usual care, and the intervention resulted in an increase in health effects of 0.54 QALYs and a cost reduction of &U20AC;1115 per patient (year 2007 prices) after 60 years. In the probabilistic analysis, the intervention dominated in about 95% of the simulations. Sensitivity analyses showed that uncertainty primarily originated from data on disease progression and treatment cost in the early stages of disease. CONCLUSIONS: The model developed allows the long-term cost effectiveness of interventions to be estimated, and has been adapted to Germany. The model suggests that the smoking cessation programme evaluated was more effective than usual care as well as being cost-saving. Most patients had mild or moderate COPD, stages for which parameter uncertainty was found to be high. This raises the need to improve data on the early stages of COPD.

Excess costs of dementia disorders and the role of age and gender - an analysis of German health and long-term care insurance claims data.

BACKGROUND: Demographic ageing is associated with an increasing number of dementia patients, who reportedly incur higher costs of care than individuals without dementia. Regarding Germany, evidence on these excess costs is scarce. Adopting a payer perspective, our study aimed to quantify the additional yearly expenditures per dementia patient for various health and long-term care services. Additionally, we sought to identify gender-specific cost patterns and to describe age-dependent cost profiles. METHODS: The analyses used 2006 claims data from the AOK Bavaria Statutory Health Insurance fund of 9,147 dementia patients and 29,741 age- and gender-matched control subjects. Cost predictions based on two-part regression models adjusted for age and gender and excess costs of dementia care refer to the difference in model-estimated means between both groups. Corresponding analyses were performed stratified for gender. Finally, a potentially non-linear association between age and costs was investigated within a generalized additive model. RESULTS: Yearly spending within the social security system was circa €12,300 per dementia patient and circa €4,000 per non-demented control subject. About two-thirds of the additional expenditure for dementia patients occurred in the long-term care sector. Within our study sample, male and female dementia patients incurred comparable total costs. However, women accounted for significantly lower health and significantly higher long-term care expenditures. Long-term care spending increased in older age, whereupon health care spending decreased. Thus, at more advanced ages, women incurred greater costs than men of the same age. CONCLUSIONS: Dementia poses a substantial additional burden to the German social security system, with the long-term care sector being more seriously challenged than the health care sector. Our results suggest that female dementia patients need to be seen as a key target group for health services research in an ageing society. It seems clear that strategies enabling community-based care for this vulnerable population might contribute to lowering the financial burden caused by dementia. This would allow for the sustaining of comprehensive dementia care within the social security system.

Direct medical costs of COPD--an excess cost approach based on two population-based studies.

AIM: While it is known that severe COPD has substantial economic consequences, evidence on resource use and costs in mild disease is scarce. The objective of this study was to investigate excess costs of early stages of COPD. METHODS: Using data from two population-based studies in Southern Germany, current GOLD criteria were applied to pre-bronchodilator spirometry for COPD diagnosis and staging in 2255 participants aged 41 to 89. Utilization of physician visits, hospital stays and medication was compared between participants with COPD stage I, stage II+ (II or higher) and controls. Costs per year were calculated by applying national unit costs. In controlling for confounders, two-part generalized regression analyses were used to account for the skewed distribution of costs and the high proportion of subjects without costs. RESULTS: Utilization in all categories was significantly higher in COPD patients than in controls. After adjusting for confounders, these differences remained present in physician visits and medication, but not in hospital days. Adjusted annual costs did not differ between stage I (€ 1830) and controls (€ 1822), but increased by about 54% to € 2812 in stage II+. CONCLUSION: The finding that utilization and costs are considerably higher in moderate but not in mild COPD highlights the economic importance of prevention and of interventions aiming at early diagnosis and delayed disease progression.

Juvenile obesity and its association with utilisation and costs of pharmaceuticals--results from the KiGGS study.

BACKGROUND: According to a national reference, 15% of German children and adolescents are overweight (including obese) and 6.3% are obese. An earlier study analysed the impact of childhood overweight and obesity on different components of direct medical costs (physician, hospital and therapists). To complement the existing literature for Germany, this study aims to explore the association of body mass index (BMI) with utilisation of pharmaceuticals and related costs in German children and adolescents. METHODS: Based on data from 14, 836 respondents aged 3-17 years in the German Interview and Examination Survey for Children and Adolescents (KiGGS), drug intake and associated costs were estimated using a bottom-up approach. To investigate the association of BMI with utilisation and costs, univariate analyses and multivariate generalised mixed models were conducted. RESULTS: There was no significant difference between BMI groups regarding the probability of drug utilisation. However, the number of pharmaceuticals used was significantly higher (14%) for obese children than for normal weight children. Furthermore, there was a trend for more physician-prescribed medication in obese children and adolescents. Among children with pharmaceutical intake, estimated costs were 24% higher for obese children compared with the normal weight group. CONCLUSIONS: This is the first study to estimate excess drug costs for obesity based on a representative cross-sectional sample of the child and adolescent population in Germany. The results suggest that obese children should be classified as a priority group for prevention. This study complements the existing literature and provides important information concerning the relevance of childhood obesity as a health problem.

Costs of care for dementia patients in community setting: an analysis for mild and moderate disease stage.

OBJECTIVE: Rising life expectancy is associated with higher prevalence rates of dementia disorders. When disease progresses the patients' call on formal health care services and on social support grows which imposes increasing costs of care. The aim of this study was to investigate the costs for patients with mild and moderate dementia in community setting in Germany. METHODS: We assessed total costs of care and individual cost components for 383 community-living dementia patients alongside a cluster-randomized trial from societal and health insurance perspective. Utilization of formal health care services was based on insurance claims data and time dedicated to informal care was assessed within caregiver interviews. We estimated costs using a two-part regression model adjusting for age, gender and cluster-effects. RESULTS: Costs of care equal €47,747 (Euros) from societal perspective which is almost the 4.7-fold of health insurance expenditures. Valued informal care covers 80.2% of societal costs and increases disproportionally when disease progresses. In moderate dementia the corresponding amount exceeds the one in mild dementia by 69.9%, whereas costs for formal health care services differ by 14.3%. CONCLUSION: Due to valued informal care, costs of care for community-living patients with moderate dementia are significantly higher than for patients with mild dementia. Informal care is a non-cash item saving expenditures for professional care. To relieve social security system and family caregivers as well as to allow dementia patients to stay at home as long as possible, concepts fostering community-based dementia care and support to family caregivers need to be further developed.

Multimorbidity and health-related quality of life in the older population: results from the German KORA-age study.

BACKGROUND: Multimorbidity in the older population is well acknowledged to negatively affect health-related quality of life (HRQL). Several studies have examined the independent effects of single diseases; however, little research has focused on interaction between diseases. The purpose of this study was to assess the impact of six self-reported major conditions and their combinations on HRQL measured by the EQ-5D. METHODS: The EQ-5D was administered in the population-based KORA-Age study of 4,565 Germans aged 65 years or older. A generalised additive regression model was used to assess the effects of chronic conditions on HRQL and to account for the nonlinear associations with age and body mass index (BMI). Disease interactions were identified by a forward variable selection method. RESULTS: The conditions with the greatest negative impact on the EQ-5D index were the history of a stroke (regression coefficient -11.3, p < 0.0001) and chronic bronchitis (regression coefficient -8.1, p < 0.0001). Patients with both diabetes and coronary disorders showed more impaired HRQL than could be expected from their separate effects (coefficient of interaction term -8.1, p < 0.0001). A synergistic effect on HRQL was also found for the combination of coronary disorders and stroke. The effect of BMI on the mean EQ-5D index was inverse U-shaped with a maximum at around 24.8 kg/m². CONCLUSIONS: There are important interactions between coronary problems, diabetes mellitus, and the history of a stroke that negatively affect HRQL in the older German population. Not only high but also low BMI is associated with impairments in health status.

Relative weight-related costs of healthcare use by children--results from the two German birth cohorts, GINI-plus and LISA-plus.

Obesity among children and adolescents is a growing public health burden. According to a national reference among German children and adolescents aged 3-17 years, 15% are overweight (including obese) and 6.3% are obese. This study aims to assess the economic burden associated with overweight and obesity in children based on a cross-sectional survey from two birth cohort studies: the GINI-plus - German Infant Nutritional Intervention plus Non-Intervention study (3287 respondents aged 9 to <12 years) and the LISA-plus study - Influence of life-style factors on the development of the immune system and allergies in East and West Germany (1762 respondents aged 9 to <12 years). Using a bottom-up approach, we analyse direct costs induced by the utilisation of healthcare services and indirect costs emerging from parents' productivity losses. To investigate the impact of Body Mass Index (BMI) on costs, we perform various descriptive analyses and estimate a two-part regression model. Average annual total direct medical costs of healthcare use are estimated to be €418 (95% CI [346-511]) per child, split between physician (22%), therapist (29%), hospital (41%) and inpatient rehabilitation costs (8%). Bivariate analysis shows considerable differences between BMI groups: €469 (severely underweight), €468 (underweight), €402 (normal weight), €468 (overweight) and €680 (obese). Indirect costs make up €101 per year on average and tend to be higher for obese children, although this was not statistically significant. Drawing on these results, differences in healthcare costs between BMI groups are already apparent in children.

Effects of general practitioner training and family support services on the care of home-dwelling dementia patients--results of a controlled cluster-randomized study.

BACKGROUND: More than 90% of dementia patients are cared for by their general practitioners, who are decisively involved in the diagnosis, therapy and recommendation of support services. OBJECTIVE: To test whether special training of general practitioners alters the care of dementia patients through their systematic recommendation of caregiver counseling and support groups. METHOD: 129 general practitioners enrolled 390 dementia patients and their informal caregivers in a prospective, three-arm cluster-randomized 2-year study. Arm A constituted usual care, in Arm B and C support groups and caregiver counseling (in Arm B one year after baseline, in Arm C at baseline) were recommended by the general practitioners. The general practitioners received arm-specific training. Diagnostic and therapeutic behavior of physicians was recorded at baseline. Informal caregivers were questioned in follow-up after 2 years about the utilization of support services. RESULTS: The diagnostic behavior of the general practitioners conforms to relevant guidelines. The procedure in newly-diagnosed patients does not differ from previously diagnosed patients with the exception of the rate of referral to a specialist. About one-third of the newly-diagnosed dementia patients are given an anti-dementia drug. The utilization of support groups and counseling increased five- and fourfold, respectively. Utilization of other support services remained low (< 10%), with the exception of home nursing and institutional short-term nursing. CONCLUSION: Trained general practitioners usually act in conformity with guidelines with respect to diagnosing dementia, and partly in conformity with the guidelines with respect to recommended drug therapy. Recommendations of support services for informal caregivers by the general practitioner are successful. They result in a marked increase in the utilization rate for the recommended services compared to offers which are not recommended by the general practitioner. TRIAL REGISTRATION: ISRCTN68329593.

Health-related quality of life in patients with severe COPD hospitalized for exacerbations - comparing EQ-5D, SF-12 and SGRQ.

BACKGROUND: The aim of this study was to measure HrQoL during acute exacerbations of COPD using generic and disease-specific instruments, and to assess completeness, proportion with best or worst health state, sensitivity to change and discriminative ability for each instrument. METHODS: EQ-5D, SF-12 and SGRQ were obtained from COPD patients with GOLD stage III and IV hospitalized for an acute exacerbation both at admission and discharge. To assess the instruments' properties, utility values were calculated for EQ-5D and SF-12, and a total score was derived from the SGRQ. RESULTS: Mean utilities ranged from 0.54 (SF-12, stage IV) to 0.62 (EQ-5D, stage III) at admission, and from 0.58 (SF-12, stage IV) to 0.84 (EQ-5D, stage III) at discharge. Completeness was best for EQ-5D and SGRQ, while no utility value for the SF-12 could be calculated for more than 30%. For SGRQ subscales, the minimal score occurred in up to 11% at admission, while full health was observed for the EQ-5D at discharge in 13%. Sensitivity to change was generally good, whereas discrimination between COPD stages was low for the EQ-5D. CONCLUSIONS: Acute exacerbations seriously impair health status and quality of life. The EQ-5D is generally suitable to measure HrQoL in exacerbations of severe COPD, although the high proportion of patients reporting full health at discharge poses a problem. The main issue with the SF-12 is the high proportion of missing values in a self-assessed setting. Properties of the SGRQ were satisfactory. However, since no utility values can be derived from this disease-specific instrument, it is not suitable for cost-utility analyses in health-economic evaluations.

Comparing three software tools for implementing markov models for health economic evaluations.

BACKGROUND: Various software packages are commonly used for the implementation and calculation of decision-analytic models for health economic evaluations. However, comparison of these programs with regard to ease of implementing a model is lacking. OBJECTIVES: (i) to compare the assets and drawbacks of three commonly used software packages for Markov models with regard to ease of implementation; and (ii) to investigate how a technical model validation can be conducted by comparing the results of the three implementations. METHODS: A Markov model on chronic obstructive pulmonary disease was implemented in TreeAge, Microsoft Excel and Arena with the same assumptions on model structure, transition probabilities and costs. A hypothetical smoking cessation programme for patients in stage 1 was evaluated against usual care. The packages were compared with respect to time and effort for implementation, run-time, features for the presentation of results, and flexibility. Agreement between the packages on average costs and life-years gained and on the incremental cost-effectiveness ratio was considered for technical validation in the form of expected values (between TreeAge and Excel only) and Monte Carlo simulations. RESULTS: Ease of implementation was best in TreeAge, whereas Arena offered the highest flexibility. Deterministic results were in agreement between TreeAge and Excel, as were simulated values between all three packages. CONCLUSIONS: Excel offers an intuitive spreadsheet interface, but the acquisition of and the training in TreeAge or Arena is worthwhile for more complex models. Double implementation is a practicable validation technique that should be conducted to ensure correct model implementation.

A valid instrument for measuring informal care time for people with dementia.

OBJECTIVE: An economic evaluation of dementia-related interventions from a societal perspective should take account of informal caregiving. We assessed informal caregiving time and report our findings on the validity and stability of our results. METHODS: Within the German IDA study ('Dementia Care Initiative in Primary Practice'), informal care time for people with dementia living at home is assessed. We applied a German adaptation of the Resource Utilization in Dementia (RUD) questions on informal care, which distinguishes three categories of informal care activities: Activities of Daily Living (ADL), Instrumental ADL (IADL), and supervision. In contrast to the original version, we included the time of all informal caregivers who are involved in caring for the patient. The questionnaire was completed as a computer-assisted telephone interview at baseline and after 1 year. To test the plausibility of the questionnaire, we proposed seven hypotheses about the reported informal care time. RESULTS: Nearly all results confirmed our hypotheses. Informal care time as well as changes over time correlated with the physical and mental health status of the patient. Considering the time of other informal caregivers led to slightly higher correlations (not significant). The results indicate that interviewees seem to underestimate particularly the time of supervision of other informal caregivers. CONCLUSION: In sum, the instrument gives plausible results and is suited for measuring informal care time, as well as changes over time. If it is not possible to directly interview each caregiver involved, it is of great importance to identify and interview the primary informal caregiver in order to prevent an underestimation of total informal care time.

Measurement of informal care time in a study of patients with dementia.

BACKGROUND: Previous assessments of informal care time have tended to consider only the amount of time spent with the patient by the primary informal caregiver; however, in many cases, more than one person is providing care for the patient. We assess total informal care time of people caring for patients with dementia, and estimate the bias that can arise if consideration is not made of the time spent by all participating informal caregivers. METHOD: We used an extended version of the questions on informal care time from the Resource Utilization in Dementia (RUD) instrument. Caregivers were asked to state the number of days and the number of hours on a typical day they had assisted the patient in activities of daily living (ADL), instrumental ADL (IADL), and supervision during the last four weeks. Multivariate regression analyses were conducted to identify factors that could account for the amount of informal care time. RESULTS: 357 informal caregivers took part. Values were missing from only 4.5% of all interviews. On average, the primary informal caregiver cared for the patient 1.5, 2.1 and 1.9 hours per day in ADL, IADL and supervision respectively. Fifty-seven percent of all patients had more than one informal caregiver. Total informal care time was underestimated by about 14% if the time of caregivers other than the primary caregiver was not taken into account. The informal care time was significantly higher if the caregiver was the patient's partner and the patient's health status was lower. CONCLUSION: Our results show that most previous studies probably underestimated costs of informal care because the time of informal caregivers other than the primary caregiver was not considered.