Marie-Louise Essink-Bot

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.

Quality-of-Life Effects of Prostate-Specific Antigen Screening

BACKGROUND After 11 years of follow-up, the European Randomized Study of Screening for Prostate Cancer (ERSPC) reported a 29% reduction in prostate-cancer mortality among men who underwent screening for prostate-specific antigen (PSA) levels. However, the extent to which harms to quality of life resulting from overdiagnosis and treatment counterbalance this benefit is uncertain. METHODS On the basis of ERSPC follow-up data, we used Microsimulation Screening Analysis (MISCAN) to predict the number of prostate cancers, treatments, deaths, and quality-adjusted life-years (QALYs) gained after the introduction of PSA screening. Various screening strategies, efficacies, and quality-of-life assumptions were modeled. RESULTS Per 1000 men of all ages who were followed for their entire life span, we predicted that annual screening of men between the ages of 55 and 69 years would result in nine fewer deaths from prostate cancer (28% reduction), 14 fewer men receiving palliative therapy (35% reduction), and a total of 73 life-years gained (average, 8.4 years per prostate-cancer death avoided). The number of QALYs that were gained was 56 (range, -21 to 97), a reduction of 23% from unadjusted life-years gained. To prevent one prostate-cancer death, 98 men would need to be screened and 5 cancers would need to be detected. Screening of all men between the ages of 55 and 74 would result in more life-years gained (82) but the same number of QALYs (56). CONCLUSIONS The benefit of PSA screening was diminished by loss of QALYs owing to postdiagnosis long-term effects. Longer follow-up data from both the ERSPC and quality-of-life analyses are essential before universal recommendations regarding screening can be made. (Funded by the Netherlands Organization for Health Research and Development and others.).

Labor and Health Status in Economic Evaluation of Health Care: The Health and Labor Questionnaire

A health care program may influence both costs and health effects. We developed the Health and Labor Questionnaire (HLQ), which consists of four modules, to collect data on absence from work, reduced productivity, unpaid labor production, and labor-related problems. We applied the HLQ in several studies, and the results are encouraging.

Health-Related Quality-of-Life Effects of Radical Prostatectomy and Primary Radiotherapy for Screen-Detected or Clinically Diagnosed Localized Prostate Cancer

PURPOSE The current study was undertaken within the framework of a screening trial to compare the health-related quality-of-life (HRQOL) outcomes of two primary treatment modalities for localized prostate cancer: radical prostatectomy and external-beam radiotherapy. PATIENTS AND METHODS We conducted a prospective longitudinal cohort study among 278 patients with early screen-detected (59%) or clinically diagnosed (41%) prostate cancer using both generic and disease-specific HRQOL measures (SF-36, UCLA Prostate Cancer Index [urinary and bowel modules] and items relating to sexual functioning) at three points in time: t1 (baseline), t2 (6 months later), and t3 (12 months after t1). RESULTS Questionnaires were completed by 88% to 93% of all initially enrolled patients. Patients referred for primary radiotherapy were significantly older than prostatectomy patients (63 v 68 years, P <.01). Analyses (adjusted for age and pretreatment level of functioning) revealed poorer levels of generic HRQOL after radiotherapy. Prostatectomy patients reported significantly higher (P <.01) posttreatment incidences of urinary incontinence (39% to 49%) and erectile dysfunction (80% to 91%) than radiotherapy patients (respectively, 6% to 7% and 41% to 55%). Bowel problems (urgency) affected 30% to 35% of the radiotherapy group versus 6% to 7% of the prostatectomy group (P <.01). Patients with screen-detected and clinically diagnosed cancer reported similar posttreatment HRQOL. CONCLUSION Prostatectomy and radiotherapy differed in the type of HRQOL impairment. Because the HRQOL effects may be valued differently at the individual level, patients should be made fully aware of the potential benefits and adverse consequences of therapies for early prostate cancer. Differences in posttreatment HRQOL were not related to the method of cancer detection.

Five-year follow-up of health-related quality of life after primary treatment of localized prostate cancer

Although with earlier detection of prostate cancer more men face the long‐term consequences of primary treatment, studies on the impact of treatment on long‐term health‐related quality of life (HRQoL) are scarce. We followed 314 men with newly diagnosed localized prostate cancer from 1 month before until 5 years after radical prostatectomy (n = 127) or external beam radiotherapy (n = 187; median follow‐up = 52 months). Questionnaires addressing disease‐specific (UCLA PCI) and generic (SF‐36, EQ‐5D) HRQoL were sent 1 month before and 6, 12 and 52 months after treatment. Repeated‐measures modeling was used to study HRQoL over time. Regular urinary leakage was reported by 12% of prostatectomy patients before treatment and by 31% at the 52‐month assessment. Erectile dysfunction before treatment was reported by 31% of prostatectomy patients and by 40% of radiotherapy patients; at the 52‐month assessment, these percentages were 88% and 64%, respectively. Erectile dysfunction present at 1 year posttreatment can be considered permanent. Prostatectomy patients reported better generic functioning both before and after treatment than radiotherapy patients, who were on average 5.9 years older and had more comorbid conditions. General physical functioning of prostatectomy patients slightly improved over time, but declined in radiotherapy patients. The relation between age and physical scores was found to be nonlinear. The long‐term physical decline in radiotherapy patients partly resulted from aging and its nonlinear impact on health, although treatment effects cannot be excluded. Scores of both patient groups remained above those of norm populations. Innovative graphs describing disease‐specific and generic functions after treatment can help patients and physicians in their treatment choices.

Anxiety and Distress During Active Surveillance for Early Prostate Cancer

Patients on active surveillance (AS) for early prostate cancer (PC) may experience feelings of anxiety and distress while living with “untreated” cancer. In this study, these feelings were quantified, and their associations with various psychologic, medical, demographic, and decision‐related factors were assessed.

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.

Distribution and determinants of health and work status in a comprehensive population of injury patients.

BACKGROUND Insight into the distribution and determinants of both short- and long-term disability can be used to prioritize the development of prevention policies and to improve trauma care. We report on a large follow-up study in a comprehensive population of injury patients. METHODS We fielded a postal questionnaire in a stratified sample of 4,639 nonhospitalized and hospitalized injury patients aged 15 years and older, at 2, 5, and 9 months after injury. We gathered sociodemographic information, data on functional outcome with a generic instrument for health status measurement (EuroQol EQ-5D+) and data on work absence. RESULTS The response rates were 39%, 75%, and 68% after 2, 5, and 9 months, respectively. The reported data were adjusted for response bias and stratification. The 2-month health status of nonhospitalized patients was comparable to the general populations health when measured by the EQ-5D summary score, although considerable prevalence of restrictions in usual activities (24.0%) and pain and discomfort (34.8%) were reported. Hospitalized patients reported higher prevalences of disability in all health domains. Their mean EQ-5D summary score increased from 0.62 at 2 months to 0.74 at 5 months but remained below the population norm at 9 months, particularly for patients with a long hospital stay. Patients with injuries of the spinal cord and vertebral column, hip fracture, and other lower extremity fractures reported the worst health status, also when adjusted for age, sex, and educational level. Age, sex, type of injury, length of stay, educational level, motor vehicle injury, medical operation, intensive care unit admission, and number of injuries were all significant predictors of functioning. Nonhospitalized and hospitalized injury patients lost on average 5.2 and 72.1 work days, respectively. Of nonhospitalized patients, 5% had not yet returned to work after 2 months, and 39%, 20%, and 10% of hospitalized patients had not yet returned to work after 2, 5, and 9 months, respectively. In a multivariate regression analysis, length of stay, type of injury, level of education, and intensive care unit admission appeared to be significant predictors of absence duration and return to work. CONCLUSION Injury is a major source of disease burden and work absence. Both hospitalized and nonhospitalized patients contribute significantly to this burden.

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.

Reliability and validity of the child health questionnaire-child form (CHQ-CF87) in a Dutch adolescent population

Feasibility, reliability, and discriminative validity of the cross-culturally adapted Dutch version of the originally US child health questionnaire-child form (CHQ-CF87), an 87-item generic pediatric health-related quality of life instrument, were assessed. The success criterion in this first evaluation was the equivalence of psychometric properties of the adapted and the original CHQ. A total of 466 schoolchildren (9–17 years) were invited to complete the questionnaire in the classroom. Test–retest reliability was measured after 14 days in a subgroup (n = 71). Response was 96%. Four scales had ceiling effects (> 50%), as was reported in an Australian study. Cronbach α-values were adequate (> 0.70), except for ‘physical functioning’ (0.56). Test–retest correlations, not previously reported, were not statistically significant for two CHQ-scales, whereas average retest scores indicated better health for five scales (p < 0.01). The CHQ scales discriminated significantly (p < 0.01) between children without (n = 281) and children with two or more self-reported chronic diseases (n = 59). This is in correspondence with US and Australian reports. Conclusions: The current data support application of the Dutch CHQ-CF in predominantly healthy populations, e.g. in school settings. Given the limitations of this study and some less favorable results (score distributions, internal consistency; test–retest reliability), further evaluation of the CHQ-CF is recommended, preferably by analyses of item performance and scale validity in international data sets that include varied clinical subgroups.