engleski

Economic evaluations of health technologies: insights into the valuation and measurement of benefits.

The overall aim of this thesis is to address several methodological issues related to the measurement and valuation of benefits in economic evaluations of healthcare technologies. The issues addressed can be separated in several subheadings: the issue of the scope of benefits to be included in economic evaluations (i.e., measuring and valuing the health and well-being of “significant others” alongside patients’), the issue of valuing health gains in monetary terms, the issue of valuing (or weighting) health of future generations versus current generations and the issue of valuing the health gains in one group in society relative to those gained in other groups. This thesis provides an empirical inquiry into the above-mentioned issues of value in health. In doing so, it yields insight in terms of outcome and methodology, and discusses the implications for economic evaluations in healthcare. By improving the methodology of economic evaluations, ultimately, this thesis hopes to contribute to a stronger, more decisive role of economic evaluations in healthcare decision-making processes. 1.7 Research questions and the outline of the thesis Given the background presented under previous subheadings, specific research questions can be formulated. These research questions contribute to the overall aim of this thesis, as indicated above. a. Does a patient’s health affect the well-being of significant others? If so, can we distinguish between different sources of that effect? b. Does a patient’s health affect the health status of significant others? Can we disentangle the source of the effect? c. What is the average value of QALY gains, derived under certainty from the individual perspective, in the Netherlands? d. How valid are the individual WTP per QALY estimates obtained under certainty? e. What is the average value of an individual QALY gain obtained under uncertainty in the Netherlands and how valid are these estimates? f. What is the relationship between distributional concerns and the social value of QALYs, in theory and in empirical studies? g. What is the value of a QALY elicited from a societal perspective? h. How does the growth in life expectancy of future generations affect the discount rate applied to future health? Each chapter of this thesis answers a particular research question. The outline of this thesis is highlighted below. Chapters 2 and 3 will address the issue of the scope of benefits to be included in economic evaluations. Two distinct research questions (aan db) are addressed in these chapters. Chapter 2 focuses on the well-being effects of patients’ health on informal caregivers and write attempts to find supporting evidence for the claim that these well-being effects stem from two distinct sources, termed the family effect and the caregiving effect. Such well-being spillover effects of patient’s health significant others are relevant for the general discussion about the scope of benefits included in economic evaluations and the practice of conducting economic evaluations from the societal perspective. Chapter 3 investigates whether patient’s health can affect also the health of informal caregivers. It is investigated whether these effects also stem from two distinct sources: the family and the caregiving effect. Confirming such effects on health of significant others has important implications also for economic evaluations taking a narrower healthcare system perspective. Chapter 4 investigates individual valuations of health gains, derived under certainty (research question c). Relevant values are obtained using the contingent valuation, a common method for deriving monetary valuations of health gains. We compare our empirical findings to those currently available in the literature and discuss the most important implications. Chapter 5 subsequently focuses on the validity of the estimates presented in Chapter 4 (research question d). This chapter also considers the standard for judging validity of WTP per QALY estimates and the implications of obtaining (in)valid empirical estimates of WTP for their usefulness in healthcare decision-making. Chapter 6 discusses research question e by presenting a study that derived the willingness to pay for a QALY from an individual perspective under uncertainty. Introducing decision-making under risk in a contingent valuation implies dealing with probabilities in a theoretically sound manner, which has consequences both for the estimates of the value of a QALY and the validity of these estimates. Chapter 6 provides an in-depth empirical inquiry into these issues. Chapter 7 of this thesis presents an overview of the literature on the issues of distributional concerns in healthcare and the methods for their inclusion in economic evaluations with the aim of understanding how the empirical literature eliciting WTP per QALY estimates addresses relevant distributional considerations. In light of the recent empirical interest in equity-related concerns as well as the nature and height of the ICER threshold, this question is one of great interest (research question f). Chapter 8 presents the final step in the series of empirical studies on WTP per QALY. It reports on the valuation of QALY gains from a societal perspective, under uncertainty (research question g). Such valuations can be considered especially relevant in the context of collectively funded healthcare systems. Different estimates (relating to different operationalisations of “social value”) are presented and their validity discussed. Chapter 9 addresses research question h by presenting the results of an empirical test of the influence of the growth in life expectancy on discount rates for health. Finally, Chapter 10 discusses the findings of this thesis.

value; health; WTP; QALY; prioritty setting; resource distribution

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