Do individuals consider expected income when valuing health states?

A cross-sectional survey of work and income loss consideration among patients with herpes zoster when completing a quality of life questionnaire

BACKGROUND

Prior research suggests that many patients do not spontaneously include work/income loss when responding to utility assessments, although this remains unconfirmed in the US due to almost no published US-based studies to date, and has not been previously studied among patients with herpes zoster (HZ). The objective of this study was to examine whether patients with HZ consider work and income loss when completing a quality of life survey.

METHODS

A cross-sectional survey was administered to 2000 US adult commercial health plan enrollees aged 50-64 years with ≥ 1 HZ medical claim during 2014. The survey collected information related to health status (EQ-5D), work productivity, and HZ severity and clinical features.

RESULTS

Mean respondent age was 58.4 years [standard deviation (SD) 4.1] and 62.0% were female. About 3 in 4 (76.8%) patients (N = 772) were employed either full (69.9%) or part time (6.9%). Less than half (45%) spontaneously considered work/income loss when responding to EQ-5D, and mean EQ-5D scores for patients who considered work/income loss were lower than for patients who did not [0.56 (SD = 0.28) vs. 0.69 (SD = 0.24); p < 0.001]. Overall, 43% of patients reported at least one full day missed (mean = 9 full days) and 29% reported at least one partial day missed (mean = 6 partial days) during the most recent shingles episode. Patients who considered work loss were more likely to have missed full (76.4% vs 26.0%, p < 0.001) or partial (70.9% vs. 35.2%, p < 0.001) days. Patients with absenteeism were more likely to consider work/income loss when completing EQ-5D [odds ratio (OR) = 7.91, 95% confidence interval (CI) 5.01-12.31]. Odds of absenteeism/presenteeism increased significantly with increasing levels of HZ severity, and higher odds were associated with pain located on the face/scalp/neck/eye/ear (OR 1.90, 95% CI 1.06-3.40) and with pain lasting 12+ months (OR = 2.91, 95% CI 1.14-7.42).

CONCLUSIONS

HZ has considerable impact on the work and productivity of adults aged 50-64 years old. However, many patients with HZ do not spontaneously consider work/income loss when completing a standardized quality of life questionnaire. Studies that use health state utilities in HZ based on EQ-5D may not fully reflect the societal costs of work loss.

Do the Washington Panel recommendations hold for Europe: investigating the relation between quality of life versus work-status, absenteeism and presenteeism

BACKGROUND

The question of how to value lost productivity in economic evaluations has been subject of debate in the past twenty years. According to the Washington panel, lost productivity influences health-related quality of life and should thus be considered a health effect instead of a cost to avoid double counting. Current empirical evidence on the inclusion of income loss when valuing health states is not decisive. We examined the relationship between three aspects of lost productivity (work-status, absenteeism and presenteeism) and patient or social valuation of health-related quality of life (HRQoL).

METHODS

Cross-sectional survey data were collected from a total of 830 respondents with a rheumatic disorder from four West-European countries. Health-related quality of life was expressed in either the European societal utility using EQ-5D-3L or the patient valuation using EQ-VAS. The impact of work-status (four categories), absenteeism (absent from paid work during the past three months), and presenteeism (QQ method) on EQ-5D utilities and VAS scores was examined in linear regression analyses taking into account demographic characteristics and disease severity (duration, pain and restriction).

RESULTS

The relationship between work-status, absenteeism or presenteeism and HRQoL was stronger for patient valuation than societal valuation. Compared to work-status and presenteeism the relationship between absenteeism and HRQoL was even less explicit. However, results for all measures of lost productivity are only marginally significant and negligible compared to the influence of disease-related restrictions.

CONCLUSIONS

This survey study in patients with a rheumatic disorder in four European countries, does not fully support the Washington panel's claim that lost productivity is a significantly related with HRQoL, and this is even more apparent for absenteeism than for work-status and presenteeism. For West-European countries, there is no reason, to include absenteeism in the QALY. Findings need to be confirmed in other disease areas.

How to estimate productivity costs in economic evaluations

Productivity costs are frequently omitted from economic evaluations, despite their often strong impact on cost-effectiveness outcomes. This neglect may be partly explained by the lack of standardization regarding the methodology of estimating productivity costs. This paper aims to contribute to standardization of productivity cost methodology by offering practical guidance on how to estimate productivity costs in economic evaluations. The paper discusses the identification, measurement and valuation of productivity losses. It is recommended to include not only productivity losses related to absenteeism from and reduced productivity at paid work, but also those related to unpaid work. Hence, it is recommended to use a measurement instrument including questions about both paid and unpaid productivity, such as the iMTA Productivity Cost Questionnaire (iPCQ) or the Valuation of Lost Productivity (VOLP). We indicate how to apply the friction cost and the human capital approach and give practical guidance on deriving final cost estimates.

Productivity costs in economic evaluations: past, present, future

Productivity costs occur when the productivity of individuals is affected by illness, treatment, disability or premature death. The objective of this paper was to review past and current developments related to the inclusion, identification, measurement and valuation of productivity costs in economic evaluations. The main debates in the theory and practice of economic evaluations of health technologies described in this review have centred on the questions of whether and how to include productivity costs, especially productivity costs related to paid work. The past few decades have seen important progress in this area. There are important sources of productivity costs other than absenteeism (e.g. presenteeism and multiplier effects in co-workers), but their exact influence on costs remains unclear. Different measurement instruments have been developed over the years, but which instrument provides the most accurate estimates has not been established. Several valuation approaches have been proposed. While empirical research suggests that productivity costs are best included in the cost side of the cost-effectiveness ratio, the jury is still out regarding whether the human capital approach or the friction cost approach is the most appropriate valuation method to do so. Despite the progress and the substantial amount of scientific research, a consensus has not been reached on either the inclusion of productivity costs in economic evaluations or the methods used to produce productivity cost estimates. Such a lack of consensus has likely contributed to ignoring productivity costs in actual economic evaluations and is reflected in variations in national health economic guidelines. Further research is needed to lessen the controversy regarding the estimation of health-related productivity costs. More standardization would increase the comparability and credibility of economic evaluations taking a societal perspective.

QALY and productivity loss: empirical evidence for "double counting"

OBJECTIVES

When quality-adjusted life-years are used for economic evaluation, the controversial issue of "double counting" of productivity loss emerges, particularly given the lack of empirical data.

METHODS

In this study, we performed a Web-based, large-sample survey to address the issue of double counting. To determine the influence of income reduction on utility scores, we obtained utility scores of eight health states with three instruction types: a) no instruction, b) instructed to consider income reduction, and c) instructed not to consider income reduction (compensated). Respondents were randomly sampled from the online panel and asked to evaluate 1 of 24 patterns by both standard gamble and time trade-off methods.

RESULTS

A total of 6551 respondents completed the questionnaire. First, despite the lack of instruction on income reduction, many respondents spontaneously assumed lost income. The proportion tended to be higher when considering more severe health states. Second, the degree of assumed income reduction was related to utility scores. For a 10% income reduction, respondents assumed a 0.02- to 0.04-decrease in utility score (both standard gamble and time trade-off methods). Third, utility scores did not change significantly when instruction was given not to consider income reduction (compensated) compared with when no instruction was given.

CONCLUSIONS

An assumed income reduction clearly influenced utility scores; however, compensation for lost income failed to sufficiently improve utility scores. In our view, the effect of income on utility scores does not only reflect wage loss. Our results suggest that the impact of double counting is negligible.

Does the EQ-5D reflect lost earnings?

BACKGROUND

An important methodological issue in economic evaluations of healthcare is how to include productivity costs (the costs related to reduced productivity due to illness, disability and premature death). Traditionally, they were included in the numerator of a cost-effectiveness analysis, through either the human-capital or the friction-cost method. It has been argued, however, that productivity costs are already included in the denominator (i.e. in the QALY measure) because respondents consider the effect a given health state will have on their income when valuing health states. If that is the case, many previous economic evaluations might have double counted productivity costs by including them in both the numerator and the denominator.

AIM

The aim of this study was to determine whether respondents valuing EQ-5D health states using the time trade-off (TTO) method spontaneously consider income effects, whether this consideration influences subsequent valuations and whether explicit ex post instructions influence valuations.

METHODS

Through an online survey, we asked 321 members of the Dutch general population to value four EQ-5D health states through three different TTO exercises. The first exercise was a standard TTO question. Respondents were then asked whether they had included income effects. Depending on their answer, the second TTO exercise instructed them to either include or exclude income effects. The third TTO exercise provided explicit information regarding the income loss associated with the health state.

RESULTS

Data were available from 321 members of the Dutch general public. Of these respondents, 49% stated they had spontaneously included income effects. Twenty-five percent of the sample did not trade any time in any of the TTO exercises and these respondents were excluded from the analysis. Results of t-tests showed there were only weakly significant differences in valuations for one health state between those who spontaneously included income effects and those who did not. Explicit instruction led to some significant differences at the aggregate level, but the effect was inconsistent at the individual level. When explicit information on the amount of income loss was provided, all states were valued lower when associated with a larger income loss.

CONCLUSIONS

This study offers further evidence indicating that income losses do not significantly affect health state valuations.

Do productivity costs matter?: the impact of including productivity costs on the incremental costs of interventions targeted at depressive disorders

BACKGROUND

When guidelines for health economic evaluations prescribe that a societal perspective should be adopted, productivity costs should be included. However, previous research suggests that, in practice, productivity costs are often neglected. This may considerably bias the results of cost-effectiveness studies, particularly those regarding treatments targeted at diseases with a high incidence rate in the working population, such as depressive disorders.

OBJECTIVES

This study aimed to, first, investigate whether economic evaluations of treatments for depressive disorders include productivity costs and, if so, how. Second, to investigate how the inclusion or exclusion of productivity costs affects incremental costs.

METHODS

A systematic literature review was performed. Included articles were reviewed to determine (i) whether productivity costs had been included and (ii) whether the studies adhered to national health economic guidelines about the inclusion or exclusion of these costs. For those studies that did include productivity costs, we calculated what proportion of total costs were productivity costs. Subsequently, the incremental costs, excluding productivity costs, were calculated and compared with the incremental costs presented in the original article, to analyse the impact of productivity costs on final results. Regression analyses were used to investigate the relationship between the level of productivity costs and the type of depressive disorder, the type of treatment and study characteristics such as time horizon used and productivity cost valuation method.

RESULTS

A total of 81 unique economic evaluations of treatments for adults with depressive disorders were identified, 24 of which included productivity costs in the numerator and one in the denominator. Approximately 69% of the economic evaluations ignored productivity costs. Two-thirds of the studies complied with national guidelines regarding the inclusion of productivity costs. For the studies that included productivity costs, these costs reflected an average of 60% of total costs per treatment arm. The inclusion or exclusion of productivity costs substantially affected incremental costs in a number of studies. Regression analyses showed that the level of productivity costs was significantly associated with study characteristics such as average age, the methods of data collection regarding work time lost, the values attached to lost work time, the type of depressive disorder, the type of treatment provided and the level of direct costs.

CONCLUSIONS

Studies that do not include productivity costs may, in many cases, poorly reflect full societal costs (or savings) of an intervention. Furthermore, when comparing total costs reported in studies that include productivity costs, it should be noted that study characteristics such as the methods used to assess productivity costs may affect their level.

In or out? Income losses in health state valuations: a review

BACKGROUND

In 1996 the Washington Panel controversially recommended valuing productivity costs (PC) in terms of quality-adjusted life years. The Panel's assumption that respondents in health state valuation (HSV) exercises take income losses into account could not be countered since there was no evidence regarding what people consider in HSV exercises. If they do consider income losses and if this changes HSVs, then all economic evaluations that have included PC in the numerator may have double-counted these costs. Alternatively, if respondents do not consider income losses then all past economic evaluations that have not included PC in the numerator have failed to account for sizeable societal costs.

OBJECTIVES

Through a review we aim to recapture the debate surrounding the appropriate method for including PC in health economic evaluations, to identify empirical evidence addressing the assumptions of the Panel, and recommend a future research agenda.

METHODS

Through a review we identify, outline, and critically appraise the existing empirical studies that attempt to address whether respondents include income effects in HSV exercises.

RESULTS AND CONCLUSION

Seven empirical studies were identified. Overall, it seems that not explicitly mentioning the inclusion of income will induce a minority of respondents to include these effects and this appears not to influence results. More empirical work is needed, using generic instruments, larger samples, and using the interview method of administration.