Leida Lamers - Academia.edu (original) (raw)

Papers by Leida Lamers

Pharmacoeconomics, Feb 1, 2007

The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable ... more The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable patient questionnaire that evaluates and quantifies quality of life (QOL) across several domains, including lung cancer-related symptoms. The FACT-L was not designed for use in economic evaluation and does not incorporate preferences into its scoring system. To derive a set of Dutch preference weights for FACT-L health states that can be used to convert FACT-L into a single value that can be used in cost-utility analyses. A representative sample of the Dutch population (n = 1076) directly valued an orthogonal set of eight FACT-L health states on a 100-point rating scale with the anchor points 'worst imaginable health state' and 'best imaginable health state'. Eleven FACT-L items were selected to describe the FACT-L health states that were directly valued. Regression analysis was used to interpolate values for all other possible health states. Scores were transformed into values on a scale where 0 indicated dead and 1 indicated full health. The estimated values for FACT-L health states ranged from 0.08 to 0.93. The estimated value sets were applied to FACT-L data of lung cancer patients participating in a clinical study. Significant differences in the mean value and mean gain of 0.12 and 0.07, respectively, were found between patients in remission and patients with progressive disease at 4 weeks' follow-up. Our results reaffirmed that the methodology used here is a feasible option to convert data collected with a disease-specific outcome measure into preferences. We concluded that the sensitivity of the derived set of societal preferences to capture differences and changes in clinical health states is an indication of its construct validity.

Health Services Research, Feb 1, 1999

To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey ... more To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey information. Longitudinal data collected for a sample of members of a Dutch sickness fund. In the Netherlands the sickness funds provide compulsory health insurance coverage for the 60 percent of the population in the lowest income brackets. A demographic model and DCG capitation models are estimated by means of ordinary least squares, with an individual's annual healthcare expenditures in 1994 as the dependent variable. For subgroups based on health survey information, costs predicted by the models are compared with actual costs. Using stepwise regression procedures a subset of relevant survey variables that could improve the predictive accuracy of the three-year DCG model was identified. Capitation models were extended with these variables. For the empirical analysis, panel data of sickness fund members were used that contained demographic information, annual healthcare expenditures, and diagnostic information from hospitalizations for each member. In 1993, a mailed health survey was conducted among a random sample of 15,000 persons in the panel data set, with a 70 percent response rate. The predictive accuracy of the demographic model improves when it is extended with diagnostic information from prior hospitalizations (DCGs). A subset of survey variables further improves the predictive accuracy of the DCG capitation models. The predictable profits and losses based on survey information for the DCG models are smaller than for the demographic model. Most persons with predictable losses based on health survey information were not hospitalized in the preceding year. The use of diagnostic information from prior hospitalizations is a promising option for improving the demographic capitation payment formula. This study suggests that diagnostic information from outpatient utilization is complementary to DCGs in predicting future costs.

Health services research, 1999

To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey ... more To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey information. Longitudinal data collected for a sample of members of a Dutch sickness fund. In the Netherlands the sickness funds provide compulsory health insurance coverage for the 60 percent of the population in the lowest income brackets. A demographic model and DCG capitation models are estimated by means of ordinary least squares, with an individual's annual healthcare expenditures in 1994 as the dependent variable. For subgroups based on health survey information, costs predicted by the models are compared with actual costs. Using stepwise regression procedures a subset of relevant survey variables that could improve the predictive accuracy of the three-year DCG model was identified. Capitation models were extended with these variables. For the empirical analysis, panel data of sickness fund members were used that contained demographic information, annual healthcare expenditure...

Non-response bias can distort the results of health surveys. The occurrence of selective non-resp... more Non-response bias can distort the results of health surveys. The occurrence of selective non-response can be assessed when data are available for both respondents and non-respondents. The objective of this study was to compare the medical consumption of respondents and non-respondents to a mailed health survey. A mailed health survey was conducted among approximately 13,500 adults and among parents of approximately 1,500 children aged 5-15 years. The net response rate was 70.4%. A panel data set that could be matched with the health survey data was available for all eligible persons. This data set comprises administrative information on hospitalizati ons, annual health care expenditures and demographic variables. The results of this study show that response was associated with age, sex, degree of urbanization and type of insurance. After correcting for differences in demographic variables, respondents and non-respondents differ in the utilization of several types of care. Relatively...

PharmacoEconomics, 2007

The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable ... more The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable patient questionnaire that evaluates and quantifies quality of life (QOL) across several domains, including lung cancer-related symptoms. The FACT-L was not designed for use in economic evaluation and does not incorporate preferences into its scoring system. To derive a set of Dutch preference weights for FACT-L health states that can be used to convert FACT-L into a single value that can be used in cost-utility analyses. A representative sample of the Dutch population (n = 1076) directly valued an orthogonal set of eight FACT-L health states on a 100-point rating scale with the anchor points 'worst imaginable health state' and 'best imaginable health state'. Eleven FACT-L items were selected to describe the FACT-L health states that were directly valued. Regression analysis was used to interpolate values for all other possible health states. Scores were transformed into values on a scale where 0 indicated dead and 1 indicated full health. The estimated values for FACT-L health states ranged from 0.08 to 0.93. The estimated value sets were applied to FACT-L data of lung cancer patients participating in a clinical study. Significant differences in the mean value and mean gain of 0.12 and 0.07, respectively, were found between patients in remission and patients with progressive disease at 4 weeks' follow-up. Our results reaffirmed that the methodology used here is a feasible option to convert data collected with a disease-specific outcome measure into preferences. We concluded that the sensitivity of the derived set of societal preferences to capture differences and changes in clinical health states is an indication of its construct validity.

Medical Care, 2007

Utilities for health are measured on an interval scale, where 1 refers to full health and 0 refer... more Utilities for health are measured on an interval scale, where 1 refers to full health and 0 refers to death. No theoretical lower boundary on the utilities for states worse than death exists. As a consequence, negative values receive greater weight in the calculation of mean utilities. To avoid this, negative values often are bound at -1. The objective of this study was to compare the effect of 3 methods to bound negative values at -1 on the estimation of EQ-5D value sets: truncation, monotonic, and linear transformation. Data of the Dutch EQ-5D valuation study were used. A total of 298 respondents directly valued 17 EQ-5D health states using the time trade-off (TTO) method. Random effects regression analysis was used to interpolate TTO values for all possible EQ-5D states. In the regression analysis the dependent variable is 1 minus the TTO value and the independent variables describe the health state. Two widely used models to estimate EQ-5D value were applied after truncation of negative values and monotonic and linear transformation of negative values. Both models also were estimated on medians. Truncation of negative values gave the largest mean absolute error (MAE); the linear transformation resulted in the smallest MAE. When medians were used for estimation, the MAEs were comparable with the estimation on means. The choice of a method to bound negative values is arbitrary and affects the resulting value set. For the estimation of EQ-5D value sets from a societal perspective the use of medians should be considered.

Inquiry, 2001

Adequate risk adjustment is critical to the success of market-oriented health care reforms in man... more Adequate risk adjustment is critical to the success of market-oriented health care reforms in many countries. Currently used risk adjusters based on demographic and diagnostic cost groups (DCGs) do not reflect expected costs accurately. This study examines the simultaneous predictive accuracy of inpatient and outpatient morbidity measures and prior costs. DCGs, pharmacy cost groups (PCGs), and prior year's costs improve the predictive accuracy of the demographic model substantially. DCGs and PCGs seem complementary in their ability to predict future costs. However, this study shows that the combination of DCGs and PCGs still leaves room for cream skimming.

Health Policy, 1998

In many countries market-oriented health care reforms are high on the political agenda. A common ... more In many countries market-oriented health care reforms are high on the political agenda. A common element of these reforms is that the consumers may choose among competing health insurers or health plans, which are largely financed through premium-replacing capitation payments. Since 1993, Dutch sickness funds receive risk-adjusted capitation payments based on demographic factors. It has been shown that the predictive accuracy of a demographic capitation model improves when it is extended with diagnostic information from prior hospitalizations, in the form of Diagnostic Costs Groups (DCGs). In this study a DCG classification is developed using Dutch cost data of sickness fund members of all ages. The study also dealt with the question of how to handle high discretion diagnoses. For the Dutch situation high discretion diagnoses may be defined as those diagnoses for which day case treatment is a possible alternative for a hospital admission. Grouping persons with a hospital admission for high discretion diagnoses together with people without an admission resulted in a slight reduction of the predictive accuracy of the DCG model. Adequate risk-adjustment is critical to the success of market-oriented health care reforms. The use of diagnostic information from prior hospitalizations seems a promising option for improving the capitation formula.

The European Journal of Public Health, 1997

Health Affairs the Policy Journal of the Health Sphere, May 1, 2004

Nederlands Tijdschrift Voor Geneeskunde, 1993

Medical Care, Oct 1, 2007

Background: Several studies revealed difficulties with the valuation and analysis of health state... more Background: Several studies revealed difficulties with the valuation and analysis of health states deemed worse than dead. These problems may be linked to maximal endurable time (MET) preferences, the phenomenon that for severe states better than dead (BTD), shorter durations are often preferred to longer durations. Objective: To test the association between the duration of health states and their valuation. Methods: A representative sample of 123 Dutch respondents (age range, 18 -45 years) valued 5 EQ-5D health states. With a straightforward method using BTD preferences, respondents indicated whether a state of a certain duration is better, equal to, or worse than dead. To validate these BTD preferences, MET preferences (whether a longer duration of a health state is better, equal, or worse than a shorter duration) were collected. Results: BTD and MET preferences were strongly related (P Ͻ 0.001). For severe health states, although still judged as better than dead, BTD preferences curved downwards with increasing duration. Such curved BTD patterns occurred in 28% of the respondents, especially for more severe states (P Ͻ 0.001). Conclusions: BTD preferences revealed that the value of moderate and severe states declines with increasing duration, suggesting that health and duration interact. For states worse than dead versus states better than dead, traditional valuation techniques have the drawback that different preference questions are used. Using BTD preferences, however, a single simple preference question can assess states better than dead, as well as states worse than dead.

Health Economics, Jul 1, 2005

Background: The assessment of health states considered to be worse than dead is a controversial i... more Background: The assessment of health states considered to be worse than dead is a controversial issue.

The journal of mental health policy and economics, 2001

BACKGROUND: Several studies have found that depressive complaints are associated with limitations... more BACKGROUND: Several studies have found that depressive complaints are associated with limitations in functioning that are at least comparable with those of chronic medical conditions, such as diabetes or lung diseases. However, the consequences of these associations for the utilization of general health care services are not known, certainly not for health care settings outside the United States. AIMS OF THE STUDY: To investigate the association of depressive complaints with functioning and health care utilization, comparing this with the association of chronic medical conditions with functioning and health care utilization. METHODS: In a community-based sample of Dutch adults (N=9428), chronic conditions (21 types) and depressive complaints were assessed by self-report. Only active conditions and depressive complaints, for which treatment was taking place, were selected for the analyses. Health status and disabilities were also assessed by self-report. Information on the utilizatio...

Social science & medicine (1982), 2007

Many studies report higher levels of health care utilization among women. Understanding how gende... more Many studies report higher levels of health care utilization among women. Understanding how gender influences health care utilization is still unresolved. We developed a model that could explain these gender-related differences. The possible pathways assumed by this model that relate gender to utilization, can be summarized as follows: (1) utilization may be influenced by somatic morbidity, mental distress, perceived symptoms, poor subjective health and propensity to use services; (2) women have higher levels of these variables than men (mediating effect); and (3) the direct effects of some of these variables on utililization are moderated by gender, i.e. they are stronger for women than for men (moderating effect). Data were drawn from a community-based sample of adult enrollees of a sickness fund in the Netherlands, who had responded to a mailed health survey (N = 8698). This survey contained questions on somatic morbidity, mental distress and other mediating variables. Health car...

Health care management science, 2000

Under inadequate capitation formulae competing health insurers have an incentive for cream skimmi... more Under inadequate capitation formulae competing health insurers have an incentive for cream skimming, i.e., the selection of enrollees whom the insurer expects to be profitable. When evaluating different capitation formulae, previous studies used various indicators of incentives for cream skimming. These conventional indicators are based on all actual profits and losses or on all predictable profits and losses. For the latter type of indicators, this paper proposes, as a new approach, to ignore the small predictable profits and losses. We assume that this new approach provides a better indication of the size of the cream skimming problem than the conventional one, because an insurer has to take into account its costs of cream skimming and the (statistical) uncertainties about the net benefits of cream skimming. Both approaches are applied in theoretical and empirical analyses. The results show that, if our assumption is right, the problem of cream skimming is overestimated by the con...

Medical Care, 2007

Background: Several studies revealed difficulties with the valuation and analysis of health state... more Background: Several studies revealed difficulties with the valuation and analysis of health states deemed worse than dead. These problems may be linked to maximal endurable time (MET) preferences, the phenomenon that for severe states better than dead (BTD), shorter durations are often preferred to longer durations. Objective: To test the association between the duration of health states and their valuation. Methods: A representative sample of 123 Dutch respondents (age range, 18 -45 years) valued 5 EQ-5D health states. With a straightforward method using BTD preferences, respondents indicated whether a state of a certain duration is better, equal to, or worse than dead. To validate these BTD preferences, MET preferences (whether a longer duration of a health state is better, equal, or worse than a shorter duration) were collected. Results: BTD and MET preferences were strongly related (P Ͻ 0.001). For severe health states, although still judged as better than dead, BTD preferences curved downwards with increasing duration. Such curved BTD patterns occurred in 28% of the respondents, especially for more severe states (P Ͻ 0.001). Conclusions: BTD preferences revealed that the value of moderate and severe states declines with increasing duration, suggesting that health and duration interact. For states worse than dead versus states better than dead, traditional valuation techniques have the drawback that different preference questions are used. Using BTD preferences, however, a single simple preference question can assess states better than dead, as well as states worse than dead.

Spine, 2007

Design. An economic evaluation alongside a randomized clinical trial in primary care. A total of ... more Design. An economic evaluation alongside a randomized clinical trial in primary care. A total of 135 patients were randomly allocated to physical therapy added to general practitioners' care (n ϭ 67) or to general practitioners' care alone (n ϭ 68).

Pharmacoeconomics, Feb 1, 2007

The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable ... more The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable patient questionnaire that evaluates and quantifies quality of life (QOL) across several domains, including lung cancer-related symptoms. The FACT-L was not designed for use in economic evaluation and does not incorporate preferences into its scoring system. To derive a set of Dutch preference weights for FACT-L health states that can be used to convert FACT-L into a single value that can be used in cost-utility analyses. A representative sample of the Dutch population (n = 1076) directly valued an orthogonal set of eight FACT-L health states on a 100-point rating scale with the anchor points 'worst imaginable health state' and 'best imaginable health state'. Eleven FACT-L items were selected to describe the FACT-L health states that were directly valued. Regression analysis was used to interpolate values for all other possible health states. Scores were transformed into values on a scale where 0 indicated dead and 1 indicated full health. The estimated values for FACT-L health states ranged from 0.08 to 0.93. The estimated value sets were applied to FACT-L data of lung cancer patients participating in a clinical study. Significant differences in the mean value and mean gain of 0.12 and 0.07, respectively, were found between patients in remission and patients with progressive disease at 4 weeks' follow-up. Our results reaffirmed that the methodology used here is a feasible option to convert data collected with a disease-specific outcome measure into preferences. We concluded that the sensitivity of the derived set of societal preferences to capture differences and changes in clinical health states is an indication of its construct validity.

Health Services Research, Feb 1, 1999

To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey ... more To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey information. Longitudinal data collected for a sample of members of a Dutch sickness fund. In the Netherlands the sickness funds provide compulsory health insurance coverage for the 60 percent of the population in the lowest income brackets. A demographic model and DCG capitation models are estimated by means of ordinary least squares, with an individual's annual healthcare expenditures in 1994 as the dependent variable. For subgroups based on health survey information, costs predicted by the models are compared with actual costs. Using stepwise regression procedures a subset of relevant survey variables that could improve the predictive accuracy of the three-year DCG model was identified. Capitation models were extended with these variables. For the empirical analysis, panel data of sickness fund members were used that contained demographic information, annual healthcare expenditures, and diagnostic information from hospitalizations for each member. In 1993, a mailed health survey was conducted among a random sample of 15,000 persons in the panel data set, with a 70 percent response rate. The predictive accuracy of the demographic model improves when it is extended with diagnostic information from prior hospitalizations (DCGs). A subset of survey variables further improves the predictive accuracy of the DCG capitation models. The predictable profits and losses based on survey information for the DCG models are smaller than for the demographic model. Most persons with predictable losses based on health survey information were not hospitalized in the preceding year. The use of diagnostic information from prior hospitalizations is a promising option for improving the demographic capitation payment formula. This study suggests that diagnostic information from outpatient utilization is complementary to DCGs in predicting future costs.

Health services research, 1999

To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey ... more To evaluate the predictive accuracy of the Diagnostic Cost Group (DCG) model using health survey information. Longitudinal data collected for a sample of members of a Dutch sickness fund. In the Netherlands the sickness funds provide compulsory health insurance coverage for the 60 percent of the population in the lowest income brackets. A demographic model and DCG capitation models are estimated by means of ordinary least squares, with an individual's annual healthcare expenditures in 1994 as the dependent variable. For subgroups based on health survey information, costs predicted by the models are compared with actual costs. Using stepwise regression procedures a subset of relevant survey variables that could improve the predictive accuracy of the three-year DCG model was identified. Capitation models were extended with these variables. For the empirical analysis, panel data of sickness fund members were used that contained demographic information, annual healthcare expenditure...

Non-response bias can distort the results of health surveys. The occurrence of selective non-resp... more Non-response bias can distort the results of health surveys. The occurrence of selective non-response can be assessed when data are available for both respondents and non-respondents. The objective of this study was to compare the medical consumption of respondents and non-respondents to a mailed health survey. A mailed health survey was conducted among approximately 13,500 adults and among parents of approximately 1,500 children aged 5-15 years. The net response rate was 70.4%. A panel data set that could be matched with the health survey data was available for all eligible persons. This data set comprises administrative information on hospitalizati ons, annual health care expenditures and demographic variables. The results of this study show that response was associated with age, sex, degree of urbanization and type of insurance. After correcting for differences in demographic variables, respondents and non-respondents differ in the utilization of several types of care. Relatively...

PharmacoEconomics, 2007

The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable ... more The Functional Assessment of Cancer Therapy-Lung (FACT-L) is a validated, sensitive and reliable patient questionnaire that evaluates and quantifies quality of life (QOL) across several domains, including lung cancer-related symptoms. The FACT-L was not designed for use in economic evaluation and does not incorporate preferences into its scoring system. To derive a set of Dutch preference weights for FACT-L health states that can be used to convert FACT-L into a single value that can be used in cost-utility analyses. A representative sample of the Dutch population (n = 1076) directly valued an orthogonal set of eight FACT-L health states on a 100-point rating scale with the anchor points 'worst imaginable health state' and 'best imaginable health state'. Eleven FACT-L items were selected to describe the FACT-L health states that were directly valued. Regression analysis was used to interpolate values for all other possible health states. Scores were transformed into values on a scale where 0 indicated dead and 1 indicated full health. The estimated values for FACT-L health states ranged from 0.08 to 0.93. The estimated value sets were applied to FACT-L data of lung cancer patients participating in a clinical study. Significant differences in the mean value and mean gain of 0.12 and 0.07, respectively, were found between patients in remission and patients with progressive disease at 4 weeks' follow-up. Our results reaffirmed that the methodology used here is a feasible option to convert data collected with a disease-specific outcome measure into preferences. We concluded that the sensitivity of the derived set of societal preferences to capture differences and changes in clinical health states is an indication of its construct validity.

Medical Care, 2007

Utilities for health are measured on an interval scale, where 1 refers to full health and 0 refer... more Utilities for health are measured on an interval scale, where 1 refers to full health and 0 refers to death. No theoretical lower boundary on the utilities for states worse than death exists. As a consequence, negative values receive greater weight in the calculation of mean utilities. To avoid this, negative values often are bound at -1. The objective of this study was to compare the effect of 3 methods to bound negative values at -1 on the estimation of EQ-5D value sets: truncation, monotonic, and linear transformation. Data of the Dutch EQ-5D valuation study were used. A total of 298 respondents directly valued 17 EQ-5D health states using the time trade-off (TTO) method. Random effects regression analysis was used to interpolate TTO values for all possible EQ-5D states. In the regression analysis the dependent variable is 1 minus the TTO value and the independent variables describe the health state. Two widely used models to estimate EQ-5D value were applied after truncation of negative values and monotonic and linear transformation of negative values. Both models also were estimated on medians. Truncation of negative values gave the largest mean absolute error (MAE); the linear transformation resulted in the smallest MAE. When medians were used for estimation, the MAEs were comparable with the estimation on means. The choice of a method to bound negative values is arbitrary and affects the resulting value set. For the estimation of EQ-5D value sets from a societal perspective the use of medians should be considered.

Inquiry, 2001

Adequate risk adjustment is critical to the success of market-oriented health care reforms in man... more Adequate risk adjustment is critical to the success of market-oriented health care reforms in many countries. Currently used risk adjusters based on demographic and diagnostic cost groups (DCGs) do not reflect expected costs accurately. This study examines the simultaneous predictive accuracy of inpatient and outpatient morbidity measures and prior costs. DCGs, pharmacy cost groups (PCGs), and prior year's costs improve the predictive accuracy of the demographic model substantially. DCGs and PCGs seem complementary in their ability to predict future costs. However, this study shows that the combination of DCGs and PCGs still leaves room for cream skimming.

Health Policy, 1998

In many countries market-oriented health care reforms are high on the political agenda. A common ... more In many countries market-oriented health care reforms are high on the political agenda. A common element of these reforms is that the consumers may choose among competing health insurers or health plans, which are largely financed through premium-replacing capitation payments. Since 1993, Dutch sickness funds receive risk-adjusted capitation payments based on demographic factors. It has been shown that the predictive accuracy of a demographic capitation model improves when it is extended with diagnostic information from prior hospitalizations, in the form of Diagnostic Costs Groups (DCGs). In this study a DCG classification is developed using Dutch cost data of sickness fund members of all ages. The study also dealt with the question of how to handle high discretion diagnoses. For the Dutch situation high discretion diagnoses may be defined as those diagnoses for which day case treatment is a possible alternative for a hospital admission. Grouping persons with a hospital admission for high discretion diagnoses together with people without an admission resulted in a slight reduction of the predictive accuracy of the DCG model. Adequate risk-adjustment is critical to the success of market-oriented health care reforms. The use of diagnostic information from prior hospitalizations seems a promising option for improving the capitation formula.

The European Journal of Public Health, 1997

Health Affairs the Policy Journal of the Health Sphere, May 1, 2004

Nederlands Tijdschrift Voor Geneeskunde, 1993

Medical Care, Oct 1, 2007

Background: Several studies revealed difficulties with the valuation and analysis of health state... more Background: Several studies revealed difficulties with the valuation and analysis of health states deemed worse than dead. These problems may be linked to maximal endurable time (MET) preferences, the phenomenon that for severe states better than dead (BTD), shorter durations are often preferred to longer durations. Objective: To test the association between the duration of health states and their valuation. Methods: A representative sample of 123 Dutch respondents (age range, 18 -45 years) valued 5 EQ-5D health states. With a straightforward method using BTD preferences, respondents indicated whether a state of a certain duration is better, equal to, or worse than dead. To validate these BTD preferences, MET preferences (whether a longer duration of a health state is better, equal, or worse than a shorter duration) were collected. Results: BTD and MET preferences were strongly related (P Ͻ 0.001). For severe health states, although still judged as better than dead, BTD preferences curved downwards with increasing duration. Such curved BTD patterns occurred in 28% of the respondents, especially for more severe states (P Ͻ 0.001). Conclusions: BTD preferences revealed that the value of moderate and severe states declines with increasing duration, suggesting that health and duration interact. For states worse than dead versus states better than dead, traditional valuation techniques have the drawback that different preference questions are used. Using BTD preferences, however, a single simple preference question can assess states better than dead, as well as states worse than dead.

Health Economics, Jul 1, 2005

Background: The assessment of health states considered to be worse than dead is a controversial i... more Background: The assessment of health states considered to be worse than dead is a controversial issue.

The journal of mental health policy and economics, 2001

BACKGROUND: Several studies have found that depressive complaints are associated with limitations... more BACKGROUND: Several studies have found that depressive complaints are associated with limitations in functioning that are at least comparable with those of chronic medical conditions, such as diabetes or lung diseases. However, the consequences of these associations for the utilization of general health care services are not known, certainly not for health care settings outside the United States. AIMS OF THE STUDY: To investigate the association of depressive complaints with functioning and health care utilization, comparing this with the association of chronic medical conditions with functioning and health care utilization. METHODS: In a community-based sample of Dutch adults (N=9428), chronic conditions (21 types) and depressive complaints were assessed by self-report. Only active conditions and depressive complaints, for which treatment was taking place, were selected for the analyses. Health status and disabilities were also assessed by self-report. Information on the utilizatio...

Social science & medicine (1982), 2007

Many studies report higher levels of health care utilization among women. Understanding how gende... more Many studies report higher levels of health care utilization among women. Understanding how gender influences health care utilization is still unresolved. We developed a model that could explain these gender-related differences. The possible pathways assumed by this model that relate gender to utilization, can be summarized as follows: (1) utilization may be influenced by somatic morbidity, mental distress, perceived symptoms, poor subjective health and propensity to use services; (2) women have higher levels of these variables than men (mediating effect); and (3) the direct effects of some of these variables on utililization are moderated by gender, i.e. they are stronger for women than for men (moderating effect). Data were drawn from a community-based sample of adult enrollees of a sickness fund in the Netherlands, who had responded to a mailed health survey (N = 8698). This survey contained questions on somatic morbidity, mental distress and other mediating variables. Health car...

Health care management science, 2000

Under inadequate capitation formulae competing health insurers have an incentive for cream skimmi... more Under inadequate capitation formulae competing health insurers have an incentive for cream skimming, i.e., the selection of enrollees whom the insurer expects to be profitable. When evaluating different capitation formulae, previous studies used various indicators of incentives for cream skimming. These conventional indicators are based on all actual profits and losses or on all predictable profits and losses. For the latter type of indicators, this paper proposes, as a new approach, to ignore the small predictable profits and losses. We assume that this new approach provides a better indication of the size of the cream skimming problem than the conventional one, because an insurer has to take into account its costs of cream skimming and the (statistical) uncertainties about the net benefits of cream skimming. Both approaches are applied in theoretical and empirical analyses. The results show that, if our assumption is right, the problem of cream skimming is overestimated by the con...

Medical Care, 2007

Background: Several studies revealed difficulties with the valuation and analysis of health state... more Background: Several studies revealed difficulties with the valuation and analysis of health states deemed worse than dead. These problems may be linked to maximal endurable time (MET) preferences, the phenomenon that for severe states better than dead (BTD), shorter durations are often preferred to longer durations. Objective: To test the association between the duration of health states and their valuation. Methods: A representative sample of 123 Dutch respondents (age range, 18 -45 years) valued 5 EQ-5D health states. With a straightforward method using BTD preferences, respondents indicated whether a state of a certain duration is better, equal to, or worse than dead. To validate these BTD preferences, MET preferences (whether a longer duration of a health state is better, equal, or worse than a shorter duration) were collected. Results: BTD and MET preferences were strongly related (P Ͻ 0.001). For severe health states, although still judged as better than dead, BTD preferences curved downwards with increasing duration. Such curved BTD patterns occurred in 28% of the respondents, especially for more severe states (P Ͻ 0.001). Conclusions: BTD preferences revealed that the value of moderate and severe states declines with increasing duration, suggesting that health and duration interact. For states worse than dead versus states better than dead, traditional valuation techniques have the drawback that different preference questions are used. Using BTD preferences, however, a single simple preference question can assess states better than dead, as well as states worse than dead.

Spine, 2007

Design. An economic evaluation alongside a randomized clinical trial in primary care. A total of ... more Design. An economic evaluation alongside a randomized clinical trial in primary care. A total of 135 patients were randomly allocated to physical therapy added to general practitioners' care (n ϭ 67) or to general practitioners' care alone (n ϭ 68).