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M L Essink-Bot

Publications and source records attributed to M L Essink-Bot.

At least 37 records · Page 2Linked to original sources
PubMed1999

The effect of adding a cognitive dimension to the EuroQol multiattribute health-status classification system.

A methodological study was conducted to examine the effect of extending a frequently used simple multiattribute health-status classification system by adding a cognitive dimension. The EQ-5D questionnaire is a generic instrument to value health, developed by the EuroQol Group. The EQ-5D defines health according to five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. We defined 18 different health states according to the standard EQ-5D classification. A second set of health states was constructed similar to the first, except for the addition of a cognitive dimension (EQ-5D+C). Valuations of both sets of health states were statistically analyzed to detect the effect of the additional dimension. The cognitive dimension generated systematically different values compared with the standard EQ-5D version, whereas the content validity improved. Both systems evoked equally reliable values. Analyses showed that a simple additive model to predict summary values for health states was not optimal for both systems. Although there is a current lack of consensus regarding the domains that are selected to represent health status, this study has shown the importance of considering the inclusion of a cognitive domain.

Activities of Daily Living↗
PubMed1998

Short-term effects of population-based screening for prostate cancer on health-related quality of life.

BACKGROUND: Population-based screening for prostate cancer is currently being evaluated in randomized clinical trials in the United States and in Europe. Side effects arising from the process of screening and from the earlier treatment of screen-detected prostate cancer may be important factors in the evaluation. To examine health-related quality of life (or health status) among men screened for prostate cancer, we conducted a longitudinal study of 626 attenders to the Rotterdam (The Netherlands) prostate cancer screening program and of 500 nonparticipants. METHODS: Attenders of the screening program and nonparticipants completed self-assessment questionnaires (SF-36 [i.e., Medical Outcomes Study 36-Item Short-Form Health Survey] and EQ-5D [i.e., EuroQol measure for health-related quality of life] health surveys) to measure generic health status, as well as an additional questionnaire for anxiety and items relating to prostate cancer screening. RESULTS: Physical discomfort during digital rectal examination and during transrectal ultrasound was reported by 181 (37%) of 491 men and by 139 (29%) of 487 men, respectively; discomfort during prostate biopsy was reported by 64 (55%) of 116 men. Mean scores for health status and anxiety indicated that the participants did not experience relevant changes in physical, psychological, and social functioning during the screening procedure. However, high levels of anxiety were observed throughout the screening process among men with a high predisposition to anxiety. Similar scores for anxiety predisposition were observed among attenders and nonparticipants. CONCLUSIONS: At the group level, we did not find evidence that prostate cancer screening induced important short-term health-status effects, despite the short-lasting side effects related to the biopsy procedure. However, subgroups may experience high levels of anxiety. The implication is that unfavorable health-status effects of prostate cancer screening occur mainly in the treatment phase.

Anxiety↗
PubMed1998

Translation, validation, and norming of the Dutch language version of the SF-36 Health Survey in community and chronic disease populations.

The primary objectives of this research were to translate, validate, and generate normative data on the SF-36 Health Survey for use among Dutch-speaking residents of the Netherlands. Translation of the SF-36 into Dutch followed the stepwise, iterative procedures developed by the IQOLA Project. Following extensive pilot testing, the SF-36 was administered to: (1) a random sample of adult residents of Amsterdam (n = 4172); (2) a random, nationwide sample of adults (n = 1742); (3) a sample of migraine sufferers (n = 423); and (4) a sample of cancer patients undergoing active anti-neoplastic treatment (n = 485). Data quality across the four studies was consistently high. The rates of missing data ranged from 1% to 5% at the item level, and from 1.2% to 2.6% at the scale level. Multitrait scaling analysis confirmed the hypothesized scale structure of the SF-36 and associated scale scoring in all four samples. Cronbach's alpha coefficients surpassed the 0.70 criterion for group comparisons in all but one case (the Social Functioning scale in the cancer sample), with a mean alpha coefficient across all scales and samples of 0.84. Known-group comparisons yielded consistent support for the validity of the SF-36. In the two community samples, statistically significant differences in SF-36 mean scale scores were observed as a function of age, gender, and the prevalence of chronic health conditions. In the migraine and cancer samples, mean SF-36 scale scores varied significantly as a function of various indicators of disease severity. The SF-36 profiles for the two community samples were highly similar. The cancer sample yielded the lowest SF-36 scores, with the migraine sample holding an intermediate position. On-going studies will generate data on the responsiveness of the SF-36 to within-group changes in health over time. Efforts are underway to translate and validate the questionnaire for use among ethnic minority groups in the Netherlands.

Adolescent↗
PubMed1998

The effect of lung transplantation on health-related quality of life: a longitudinal study.

STUDY OBJECTIVES: To assess the change in health-related quality of life (HRQL) among Dutch lung transplant patients before and after transplantation. DESIGN: Prospective longitudinal study on HRQL among 24 Dutch lung transplant patients who participated first as transplant candidates, and later as recipients in the study. This study design provides an accurate estimate of the change in HRQL as a result of lung transplantation because there is no confounding between change due to differences in composition between groups of patients at the different points of follow-up and the true change as a result of the transplantation. Patients completed self-administered questionnaires before transplantation, and at 1, 4, 7, 13, and 19 months after transplantation. The main HRQL measures were: the Nottingham health profile (NHP), the State-trait Anxiety Inventory, the Self-rating Depression Scale-Zung, the Karnofsky Performance Index, the index of well-being, and activities of daily living (ADL). SETTING: University Hospital Groningen, the Netherlands. RESULTS: Before transplantation, patients report major restrictions on the dimensions mobility and energy of the NHP, a low level of experienced well-being, and depressive symptoms. In addition, patients experience difficulties in performing ADL and report a low ability to take care of themselves. About 4 months after transplantation, mobility, energy, sleep, ADL dependency level, and dyspnea were particularly positively affected by the lung transplantation. These improvements were maintained in the following 15 months. CONCLUSIONS: Lung transplantation contributes positively to the HRQL of surviving patients over time.

Activities of Daily Living↗
PubMed1997

The comparability and reliability of five health-state valuation methods.

The objective of the study was to consider five methods for valuing health states with respect to their comparability (convergent validity, value functions) and reliability. Valuation tasks were performed by 104 student volunteers using five frequently used valuation methods: standard gamble (SG), time trade-off (TTO), rating scale (RS), willingness-to-pay (WTP) and the paired comparisons method (PC). Throughout the study, the EuroQol classification system was used to construct 13 health-state descriptions. Validity was investigated using the multitrait-multimethod (MTMM) methodology. The extent to which results of one method could be predicted by another was examined by transformations. Reliability of the methods was studied parametrically with Generalisability Theory (an ANOVA extension), as well as non-parametrically. Mean values for SG were slightly higher than TTO values. The RS could be distinguished from the other methods. After a simple power transformation, the RS values were found to be close to SG and TTO. Mean values of WTP were linearly related to SG and TTO, except at the extremes of the scale. However, the reliability of WTP was low and the number of inconsistencies substantial. Valuations made by the RS proved to be the most reliable. Paired comparisons did not provide stable results. In conclusion, the results of the parametric transformation function between RS and SG/TTO provide evidence to justify the current use of RS (with transformations) not only for reasons of feasibility and reliability but also for reasons of comparability. A definite judgement on PC requires data of a complete design. Due to the specific structure of the correlation matrix which is inherent in valuing health states, we believe that full MTMM is not applicable for the standard analysis of health-state valuations.

Adult↗
PubMed1997

Health-related quality of life: an indicator of quality of care?

There is an increasing interest in the use of outcome indicators to monitor the quality of care. Traditionally, outcome indicators have been based mainly on biological indicators reflecting death or disease. Now that various instruments for health status measurement have become available, questions have been raised as to the potential application of health status scores in monitoring the quality of care. This paper identifies conditions which should be fulfilled before such applications can be recommended. Firstly, the relationship between care delivery processes and health status outcomes must be established. In order to achieve this, health status measures which are clearly able to detect health status variations between groups of patients (i.e. discriminative ability) and variations over time (i.e. sensitivity to change) are needed. Secondly, health status data should be available, preferably from established data collection registries (e.g. computerized hospital records or national registries) where data relating to the description of variations in health status (between physicians, hospitals, regions, etc.) are routinely collected. Thirdly, methods should be found to collect additional data, including 'case-mix' information and health status reference data, in order to enable the interpretation of variations in health status. Because most of these conditions are currently not being fulfilled, we conclude that the state-of-the-art of health status measurement has not yet matured sufficiently to allow for the use of health status as an indicator of quality of care. The present paper provides a framework for both future research and data collection that is needed to improve the applicability of health status measures as quality-of-care indicators.

Decision Making↗
PubMed1997

An empirical comparison of four generic health status measures. The Nottingham Health Profile, the Medical Outcomes Study 36-item Short-Form Health Survey, the COOP/WONCA charts, and the EuroQol instrument.

OBJECTIVES: An empirical, head-to-head comparison of the performance characteristics of four generic health status measures. METHODS: The Nottingham Health Profile, the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36), the COOP/WONCA charts, and the EuroQol instrument were simultaneously employed in a controlled survey measuring the impact of migraine on health status. The feasibility (number of missing cases per item), internal consistency (Cronbach's alpha), construct validity (correlation patterns and common factor analysis), and discriminative ability (Receiver Operating Characteristics analyses) of the four measures were investigated. RESULTS: The Nottingham Health Profile produced the lowest missing value rate. The internal consistency of the Nottingham Health Profile scales was lower than the scales of the SF-36. Combined factor analyses with data of the four instruments together resulted in two-factor solutions with a physical and a mental factor, explaining approximately 50% of variance. The SF-36 exhibited the best ability to discriminate between groups. Test-retest reliability and sensitivity to change over time could not be tested because of the cross-sectional character of the study. CONCLUSIONS: None of the instruments performed uniformly as "best" or "worst." Purely on the basis of the results of the psychometric analyses, the SF-36 appeared to be the most suitable measure of health status in this relatively healthy population. In general, the choice of the most suitable instrument for generic health status assessment in a particular study should be guided by the special features of each candidate instrument under consideration.

Adult↗
PubMed1997

Sacral rhizotomies and electrical bladder stimulation in spinal cord injury. 2. Cost-effectiveness and quality of life analysis. Dutch Study Group on Sacral Anterior Root Stimulation.

OBJECTIVES: To present a cost-effectiveness analysis of sacral rhizotomies and electrical bladder stimulation compared with conventional care of neurogenic bladder dysfunction in patients with spinal cord injury. METHODS: During a 3-year inclusion period, data on costs and quality of life before the intervention were collected to describe conventional care. Data on the pre-implantation period, the implantation and a follow-up period of 2 years were collected following a strict protocol simultaneous with medical and urodynamic data and were used to calculate the costs and effects on quality of life of the implantation of the stimulator. RESULTS: Between June 1991 and June 1994, 52 patients with complete cervical or thoracic spinal cord lesions underwent sacral posterior rhizotomies and implantation of a Finetech-Brindley sacral anterior root stimulator. Although the initial costs of sacral anterior root stimulation are high, they are earned back in this series in about 8 years after the implantation. General indicators of the quality of life show no significant changes after the implantation. Factors related to psychological well-being and the patients' satisfaction with the emptying of the bladder increased significantly whereas the experienced problems of micturition and incontinence all decreased significantly. CONCLUSION: Sacral rhizotomies and electrical bladder stimulation make a cost-effective method of treatment of lower urinary tract dysfunction in patients with spinal cord injury. Considerable savings on health care costs are possible in the long run with simultaneous positive effects on aspects of health status.

Adolescent↗
PubMed1996

NHP or SIP--a comparative study in renal insufficiency associated anemia.

In this study we compared the feasibility, internal structure and psychometric characteristics (internal consistency, test-retest reliability, construct validity) of two widely used generic health status measures, i.e. the Nottingham Health Profile (NHP) and the Sickness Impact Profile (SIP) when employed among a sample of patients on renal dialysis (n = 63). The NHP was found to be more feasible, i.e. shorter and less difficult, than the SIP. The NHP scales showed somewhat higher levels of internal consistency (mean alpha = 0.67, range = 0.39-0.80) than the SIP scales (mean alpha = 0.65, range = 0.14-0.82). Test-retest reliability with a 24-hour interval was acceptable for most NHP scales (not available for the SIP in this study). Intercorrelations between the NHP scales were somewhat weaker than those for the SIP, and the expected patterns of scale intercorrelations were largely confirmed. The overall pattern of correlations between NHP scales and SIP scales was consistent with expectations, although the correlations were generally rather weak. Correlations between NHP scales and SIP scales and instruments measuring mainly physical functioning (ADL, Karnofsky) were largely as expected. Similarly, correlations between NHP scales and SIP scales and instruments measuring mainly psychological functioning [STAI (anxiety), SDS-Zung (depression)] were also as expected, although here the correlations were weaker for the SIP when compared with the NHP. The Index of Well-being exhibited intra-class correlations > 0.3 with one SIP scale and with five out of six NHP scales. Common factor analysis, yielding a two-factor solution with a physical and a mental factor of equal importance, showed the SIP scales to load more on the physical factor, while the NHP scales loaded more on the mental factor. The NHP generally performed better than the SIP in terms of feasibility and internal consistency. Physical functioning is emphasized in the SIP, whereas the emphasis of the NHP lies on mental functioning. The analysis confirmed to some extent the intentions of the constructors of NHP and SIP respectively, i.e. the NHP to be a measure of perceived health and the SIP to be a more functional measure.

Adult↗
PubMed1995

The impact of migraine on health status.

PROBLEMS: What is the effect of migraine on health status, defined as the patient's physical, psychological, and social functioning? And, suppose that the health status of migraine sufferers appears to be impaired, to what extent is this a consequence of migraine-associated comorbidity rather than of migraine itself? METHODS: A group of 846 migraineurs, selected from the general population following IHS criteria, and a control group were surveyed with the Medical Outcomes Study 36-item Short-Form Health Survey, Nottingham Health Profile, EuroQol instrument, and the COOP/WONCA charts. Questions on demographic characteristics and comorbidity were included. RESULTS: The health status of migraineurs appeared to be significantly impaired in comparison to the control group. Because statistical significance is distinct from relevance, effect size estimators were employed. Although the direction of the differences indicated consistently a worse health status of the migraineurs, regardless of the instrument used, the sizes of the differences were small to medium. Self-reported comorbidity, especially depression, was more prevalent in the migraine group. However, this offered only a partial explanation for the impaired health status of the migraine group. CONCLUSIONS: Migraine has an independent moderately deteriorating effect on the daily functioning of individuals.

Adult↗
PubMed1995

Societal perspective on the burden of migraine in The Netherlands.

This study presents a comprehensive overview of the societal burden of migraine in The Netherlands. We assessed the direct and indirect costs of this disease, and the health status of patients with migraine. We developed the 'illness and labour' (I&L) questionnaire to collect data on the effect of illness on labour performance. 846 migraine patients and 834 controls were selected from the general population. Participants completed an I&L questionnaire as well as generic health status questionnaires. The direct costs of migraine amounted to 134 million Netherlands guilders (NLG) [$US1 = NLG1.68, October 1994]. Conservative calculations of the costs of absence from work and reduced productivity at work were NLG264 and NLG277 million per year, respectively. Our study did not indicate that migraine caused household productivity losses. The baseline estimate of the total societal costs of migraine in The Netherlands was NLG675 million per year. The assessment of health status showed considerable impairment of psychological and social functioning in migraine patients.

Absenteeism↗
PubMed1994

Test-retest reliability of health state valuations collected with the EuroQol questionnaire.

This study is a contribution by the Dutch participants to the research programme of the EuroQol Group. This collaborative group of researchers engaged in outcome measurement is working towards the development of a standardized, non-disease-specific instrument for describing and particularly valuing health-related quality of life. The present article analyses the test-retest reliability of the valuations collected with the EuroQol questionnaire in a population survey (n = 208). The choice of the appropriate method for test-retest analysis is discussed and the results of several approaches with the EuroQol data are shown. Generalizability Theory is proposed as the most suitable method. This method is the most comprehensive, giving distinct information about the relative contributions of different sources of variance. The EuroQol valuations appear to have good test-retest reliability.

Adult↗
PubMed1993

Generalizability of valuations on health states collected with the EuroQolc-questionnaire.

PROBLEM: Non-response and non-usable response were found in population surveys on valuation of health states. If non-response is selective regarding valuations, then generalization of the resulting values to the whole survey population is not permitted. This could limit the use of empirical utility values in resource allocation in health care. METHODS: Response behaviour of a sample of 1400 from the Dutch general population to the mailed EuroQolc-questionnaire was analyzed by four methods. I. Phoning resolute non-respondents; II. comparison of zip code characteristics of respondents and non-respondents (because individual data on background characteristics were not available for the non-respondents); III. analysis of response over time (wave-analysis); IV: comparison of background variables of successful (less than two valuations missing) and unsuccessful respondents, combined with analysis of the effect of these background variables on valuations. RESULTS: No indications for selective non-response were found, although the phenomenon appeared hard to investigate. The successful response came from a slightly younger and better educated subsample. However, a general influence of age and educational level on valuations could not be shown. This finding is consistent with the literature. CONCLUSION: Although the existence of selective non-response cannot be excluded, its relevance can be considered to be small. This finding is encouraging for the use of empirical utility values in allocative decisions.

Adult↗
PubMed1992

Assessment of the quality of life before and following liver transplantation. First results.

Analysis of quality-of-life effects is part of the current technology assessment of the Dutch orthotopic liver transplant-program. Data are collected by means of computer-assisted interviewing, including one interview before transplantation and annual follow-up interviews. Data on psychiatric morbidity are obtained from medical records. This article shows preliminary results of a cross-sectional analysis of data collected from 1987 to 1989. Eighty-eight measurements were obtained from 46 adult patients (response rate 82%). Pretransplant scores suggest major restrictions on all domains of life, especially a low amount of energy. After transplantation all indicators show improvement, although the level of the general population is not always attained. Improvement of subjective quality of life is more marked, possibly due to euphoria at surviving the hazardous procedure. Psychiatric events occurred only infrequently. We conclude that orthotopic liver transplantation contributes positively to the quality of life of surviving patients. In addition, computer-assisted interviewing proved to be a feasible survey technique, even when very ill patients were involved.

Adult↗
PubMed1990

Orthotopic liver transplantation in The Netherlands. The results and impact of a medical technology assessment.

In 1985 Dutch health care authorities and health insurance companies initiated a large-scale technology assessment (TA) of liver transplantation (LTx) in The Netherlands. The 10-year experience of the existing programme in the University Hospital Groningen was investigated. Topics included were patient flow, selection policies, survival, quality-of-life, costs, need, supply of donor organs and organisational aspects. Estimation of the consequences of a non-transplantation scenario allowed for the execution of a cost-effectiveness analysis. Results showed clear improvement by LTx of survival and quality-of-life, though to a lesser degree than expected. Costs of the first transplantation year amounted to Dfl 180,000 (approx US $90,000). The cost-effectiveness ratio ranged from Dfl 47,000 to Dfl 133,000 per life year gained. No overt imbalance between need and donor supply existed or was expected in the near future. The impact of this study is related to the informational value and to the contribution to the decision-process. Even at its appearance in 1988, the final report provided health policy makers with new information. Health policy concerning LTx was considerably influenced, as a rule in agreement with the study conclusions. We conclude the Dutch case study to be an example of a useful and efficient TA.

Costs and Cost Analysis↗
PubMed1990

Valuation of health states by the general public: feasibility of a standardized measurement procedure.

In the context of an international collaborative study we tested the feasibility of a utility measurement procedure in the Dutch general population. A postal questionnaire was sent to a random sample of 200 households in a town in the Netherlands (+/- 50,000 inh.). Respondents were requested to value 14 six-dimensional health states by means of visual analogue scaling (VAS). The response was satisfactory (57%), though about a fifth of those willing to complete the questionnaire did not manage to use a VAS to express their opinion. Inconsistent answers occurred relatively seldom. Generally consensus existed with regard to relative (ranking) and absolute values of different health states. These first results encourage us to go on with the development of this international instrument for the valuation of health states. We conclude the present instrument to be a feasible tool for valuation research, although questions relating to its measuring properties, as well as its reliability and validity remain to be answered.

Adolescent↗