Completed PhD projects

Willem de Boer
Sport as a medicine for health and health inequalities

Status: Completed. Defended in March 2022.

It is important to get a better understanding of the relationship between sport participation on the one hand and health and health care costs on the other. For that purpose, the research in this thesis shows that sport participation is positively associated to significantly lower risks of morbidity, type 2 diabetes, prediabetes and obesity. However, the relationship between sport participation and health differs between groups. For several health outcomes, the positive effects of sport participation are significantly greater for people with a healthy weight than for obese persons. Another finding is that socioeconomic inequalities in sports participation (with the most vulnerable groups participating the least) seem contribute considerably, and much more than physical activity, to the socioeconomic inequalities in health outcomes. The research also shows that there exists a strong socioeconomic gradient in health care costs in the Netherlands: controlling for the population structure, poor neighborhoods have substantially higher costs than affluent neighborhoods. In addition, neighborhoods with a higher percentage of voluntary sports club members have significantly lower average health care costs. This relationship seems to be independent of the socioeconomic level of a neighborhood. Finally, the research shows that the socioeconomic inequalities in physical activity behavior have increased significantly in the Netherlands due to the Covid-19 pandemic and the measures to prevent the spread of the virus. In conclusion, the research in this thesis demonstrates that sports participation can be an important preventive medicine for improving health, reducing socioeconomic health inequalities, as well as lowering health care costs.

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Marit Drijfhout
Consumer Food Waste: Understanding Why Consumers Do Not Eat the Food They Acquire

Status: Completed. Defended in November 2020.

One-third of all food suitable for human consumption is wasted or lost in the supply chain, causing substantial negative economic, social and environmental consequences. In developed countries, consumers are the single biggest producers of food waste.

This dissertation aims to increase the theoretical understanding of the complex issue of consumer food waste. The fundamental research question concerns why consumers acquire food that they ultimately do not consume, but waste instead. Chapter 2 presents an extensive literature review of theoretical and empirical findings concerning consumer food waste and identifies promising future research directions. Chapters 3 and 4 draw on construal level theory and demonstrate that the temporal distance between a consumption decision (e.g., when making weekly food purchases in the grocery store) and the actual consumption moment (e.g., when preparing the meal) is critical in explaining why consumers acquire food that ends up being wasted. Chapter 4 further demonstrates that food is less likely to be wasted when consumers opt for more convenient food options—food options that require little time and effort to be prepared. Finally, Chapter 5 presents a general discussion of this research and its outcomes, explores both managerial and practical implications, and offers directions for future research.

This dissertation provides new insights into the behavioral mechanisms underlying consumer food waste and directions on how to minimize food waste. Decreasing food waste is contingent on, for instance, the consumer’s ability to make realistic and smart decisions in the grocery store, and to stick to previously made consumption plans.

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Monique Eissens-van der Laan
The feasibility of modularity in professional service design: Towards low cost person-centred care

Status: Completed. Defended in June 2015.

A challenge facing many professional service organizations, and especially healthcare institutes, is how to meet the heterogeneous and complex demands of customers while, at the same time, minimizing costs. Recently, attention has been drawn to the managerial concept of modularity as a means of providing low-cost person-centred variety. However, only limited conceptual clarity exists as to what constitutes a module in a service offering and how to appropriately design a modular professional service offering. This thesis starts with a theoretical analysis of the literature seeking conceptual clarity on service modularity, and identifies six ways to decompose a service offering into modules. Subsequently, a two-stage design process for service modularity is described. The first step involved a segmentation study in the healthcare sector that used a finite mixture model to group older adults into five segments based on their experienced biopsychosocial needs. In the second step, a multidisciplinary group of professionals, using the results of the person-centred segmentation study, developed a set of care and service modules. Finally, in a multiple case study, various modular professional service architectures were identified, each with its own merits. This final element highlighted the role of interfaces in modular design as well as boundaries to applying modularity in professional services. In explicating the underlying central design choices, I stress that modular service design is not something that ‘just happens’ or slowly evolves. This thesis demonstrates the influence of design choices made within a modular design on how person-centred variety and costs are balanced

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Daniel Gallardo Albarrán
Health, well-being and inequality over the long term

Status: Completed. Defended in October 2018.

Citizens’ lives have greatly improved during the 20th century in terms of income and health, but the uneven pace of improvement has led to substantial cross-country inequality.

This dissertation explores the idea that citizens’ well-being is a much broader concept than income. A broader perspective on welfare is important for understanding its evolution during the first half of the 20th century in Europe. During this period, most improvements in living standards did not come from increases in income, but rather from higher life expectancy, less inequality and shorter working hours.

This research also shows that historically – in contrast to more recent developments – global differences in income can be accounted for to the same extent by differences in human and physical capital as by differences in productivity. In addition, the effect of health on labor productivity is of great importance for explaining both the growing income inequality since 1900 and part of its decline during the second half of the 20th century.

As far as health is concerned, this thesis shows that clean water provision at the turn of the 20th century had a limited influence on health. Using Germany as a case study, a drastic reduction in disease and mortality only took place when water supply was provided in combination with modern sewerage networks.

Taking a historical perspective, this thesis sheds new light on current developments. For example, the discussion about sanitation in India can learn from the lessons of Germany from a hundred years ago.

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Rachel Gifford
Through the physician’s lens: A microlevel perspective on the structural adaptation of professional work

Status: Completed. Defended in 2021.

To sustain costs while also improving care quality, scholars and policymakers alike have highlighted the need for the reorganization of hospital care delivery, with increased emphasis on implementing new models of financing and restructuring care delivery processes. However, despite a wide range of scholarship, how best to organize hospital care in order to improve care delivery processes remains an open question. The restructuring of secondary care continues to face many challenges, and many proposed solutions prove difficult to translate from theory to practice, indicating a potential mismatch between the two. With this thesis, I attempt to bridge this divide by offering a micro-level view into the challenges, effects, and complexities of organizing secondary care delivery. Three in-depth case studies were conducted in hospital organizations that recently underwent a structural change. Each study focuses centrally on how to organize hospital based medical specialists and brings forward the often-overlooked perspective of clinicians themselves. The empirical results reveal the relational and cultural barriers that are often overlooked, but play a crucial role in determining the outcome of reform efforts. In Chapter 2 and 3 we examine how physicians respond to proposed employment reform. Our findings indicate that while physicians recognize the need to be accountable for costs and care quality, they may view the move to employment as a threat to their core professional values. In Chapter 4 we unveil importance structural, interpersonal, and cultural barriers that undermine integration efforts and disrupt processes of care in the emergency care chain.

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Eveline Hage
How can online communication enhance older adults' social connectivity? Implementation and adoption issues

Status: Completed. Defended in September 2015.

It is often assumed online communication can enhance older adults’ social connectivity. However, previous studies have indicated two obstacles. First, older adults tend to be late adopters, or laggards. This raises the question how online communication tools can be implemented among a population that on average is less likely to adopt. Second, the effects of online communication on older adults’ social connectivity are debated. This thesis addresses both issues in a multi-method study of a project implementing online communication tools among the older population of three villages in the north of The Netherlands. This thesis underlines that, first, caution is in place with generic investments in, and promotion of, online communication when aiming to enhance the social connectivity of older laggards. Second, without interventions that aim to change pre-existing socio-economic structures, the implementation of online communication tools reinforces socio-economic inequality. Third, online communication tends to have a disproportional negative effect on the older “have nots” because it benefits the well connected while harming isolated older adults. Fourth, to understand the effect of online communication on older laggards’ social connectivity, a situated change perspective on adoption is required that goes beyond the identification of adoption factors. Finally, implementation and adoption mechanisms are proposed that implementers can use to stir local change.

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Martine van der Heide
Deserving to indulge and donate: drivers of virtuous consumer behavior

Status: Completed. Defended December 2021.

Societal challenges such as growing obesity rates and income inequality demand changes in consumer behavior. This dissertation specifically focuses on virtuous consumer behavior, which provides delayed benefits to the self or indirect benefits to society at a (short-term) cost to the self. The overall aims are to better understand, predict, and ultimately promote such behavior based on the inherent trade-offs it involves.

One example of virtuous consumer behavior is healthy eating. This dissertation suggests that trade-offs between health goals and indulgence goals may cause the relative healthiness of food choices to evolve dynamically throughout shopping trips. Indeed, consumers balance the relative healthiness of their food choices—when they initially select a healthier option (e.g., low-fat milk), this choice is typically partly offset by an unhealthier subsequent choice (e.g., a sugary soft drink), whereas unhealthier choices are in turn followed by healthier subsequent choices. The strength of this balancing pattern depends on the nature of the food category and the stage of the (physical) shopping trip.

Another example of virtuous consumer behavior is prosocial behavior. This dissertation examines whether consumers high in psychological entitlement, who have a sense that they deserve more than others, volunteer and help more when the opportunity to do so is framed as a selective opportunity (i.e., “offered specifically to you”). Selectivity indeed increases prosocial behavior among consumers high (but not those low) in entitlement.

Together, these findings illustrate that countering negative balancing effects and using targeted marketing appeals may enhance diets, donations, and societal well-being.

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Jan Koch
Utterly Disgusting! How the Experience of Disgust Can Both Prevent and Stimulate Societal Change

Status: Completed. Defended in October 2021.

Achieving a sustainable lifestyle is arguably humanity’s biggest challenge to date. While most consumers are aware of this situation, key issues remain unaffected. For instance, as a major driver of global CO2 emissions, the steadily rising consumption of meat fuels the pollution of air, water, and soil, and threatens biodiversity. Why is it so difficult for consumers to abandon current unsustainable behaviors, and adopt more sustainable behaviors instead? This dissertation examines how change may be promoted by introducing disgust as both an underrecognized barrier and key to behavior change.

On the one hand, this dissertation shows that disgust can be a reason why consumers reject sustainable behaviors such as consuming sustainable food alternatives. Consumers, for instance, intuitively reject edible insects and lab-meat due to disgust. This disgust, I show, may not be the result of any of the foods’ inherent qualities like taste or texture, but may simply result from the perception that such foods deviate from what consumers have internalized to be the norm. If sustainable food alternatives were perceived to be more normal, consumers would no longer feel disgusted in response to these foods and consequently accept them.

Disgust can, on the other hand, also be used to make people refrain from unsustainable behavior. For instance, graphic warning labels can visually link the consumption of meat to its detrimental consequences and thereby make people reduce it. Importantly, previously voiced concerns that the use of graphic warning labels may stigmatize the target group were not supported by my research.

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Sara Kremer
Examining the effectiveness of promotional expenditures for pharmaceutical products

Status: Completed. Defended in February 2010.

In this thesis dissertation, promotional effectiveness for pharmaceutical products is studied. Several studies attempt to determine this effectiveness, but defining generalisations remains difficult or impossible. Meta-analytic findings are that pharmaceutical promotional elasticities are modest in size and differ among promotional instruments. Effects of instruments aimed at prescribers (DTP) are higher than effects of instruments aimed at consumers (DTC), but relative effectiveness of DTP instruments depends on the disease category. Higher elasticities appear in studies that include price as an independent variable in the models, whereas studies that account for endogeneity find lower elasticities. New empirical results are based on a large database, while accounting for endogeneity and heterogeneous parameters over two regimes. Price reveals the expected negative sign, DTC advertising has a negative sign, and the DTP instrument has an expected positive sign. The effects of both types of advertising are greater during the market development period compared to the introductory period. Prescribers appear less price sensitive when DTC investments are higher. Deploying both instruments simultaneously positively affects sales.

Bart Noort
The healthcare purchaser as a care chain orchestrator: Healthcare system limitations and opportunities

Healthcare purchasing, as carried out by health insurers and governmental organisations, contributes to ensuring qualitative, accessible and affordable care. Financial incentives, outcome monitoring and collaboration with care providers are known ways for purchasing organisations to drive better collaboration and task division between care providers. However, purchasers appear to struggle to adopt what we label an orchestrator’s role. To date, there is still limited understanding of how purchaser’s strategies and actions develop in practice, and whether they can be explained by differences between healthcare systems.

Comparing England, Sweden and the Netherlands, this thesis shows that purchaser competition, internal governance and patient choice have a particularly strong impact on the role that purchaser’s adopt. These three characteristics determine the extent to which purchasers focus on costs as against health, have a short or long-term vision, support care providers and are able to influence care providers.

We saw that, with the support of a Dutch health insurance company, the implementation of out-of-hospital coaching for patients with Chronic Obstructive Pulmonary Disease (COPD) can be both feasible and effective. However, sustainable implementation requires the government to provide the right macro-level incentives and policy context. Further, we found, in a longitudinal case study, that three stakeholder groups strongly influence the strategies adopted by the health insurer: governments, care providers and insurance policyholders. Given the sometimes conflicting medical, financial, relational and public interests of these stakeholders, the health insurer was inclined to fall back on its traditional bookkeeping strategy, despite initial attempts to adopt an orchestrating role.

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Raun van Ooijen
Life cycle behavior under certainty; Essays on savings, mortgages and health

Status: Completed. Defended in January 2016.

Households must take into account various sources of uncertainty when making financial decisions. In the aftermath of the financial crisis of 2007-2008 some of these uncertainties have increased and, arguably, households may have become more aware of the uncertainties they encounter. The purpose of this thesis is to examine to what extent different sources of uncertainty influence household financial decision making, in particular regarding saving, portfolio choice and the choice of financial products such as mortgages.

We show that uncertainty related to the outcome of future policies (limiting the mortgage interest deduction) induce households to save more than optimal to absorb possible financial setbacks. We further demonstrate that financially less sophisticated households, who do not fully understand the complex nature of mortgage loans, tend to choose less risky mortgages, unless they consult a mortgage broker.

Using detailed tax records, we provide evidence that elderly households are on average wealthy, but do not dissave. This contrasts with the prediction of the life-cycle theory of saving and cannot be explained by uncertainty regarding income or out-of-pocket medical expenses. Health plays an important role in explaining differences in wealth between households.

Using self-reported health combined with objective health measures from medical records, we show that health is more persistent and deteriorates at a faster rate in old age than can be inferred from subjective health measures alone. We further show that mental ill-health combined with an unhealthy lifestyle (smoking and being overweight) is a major contributor to long-term sickness among self-employed (with income insurance).

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Katrin Reber
Studies on pharmaceutical markets

Status: Completed. Defended in February 2013

The pharmaceutical market is a complex system in which various participants meet and which is continually changing: new drugs enter the market, public health issues are reassessed, and regulatory guidelines change.

This thesis aims to contribute to the development of new and relevant knowledge in the field of healthcare and pharmaceutical marketing. In Chapter 2, we investigate which product, store, customer, and competitor characteristics enhance over-the-counter sales in a retail pharmacy setting. We find that assortment and promotions are crucial determinants of pharmacy performance. The results further suggest that store and location factors that are critical for traditional retailers may be less important for pharmacies.

In Chapters 3 and 4, we assess the impact of Direct Healthcare Professional Communications (DHPCs) on new drug use. Half of the drugs that received a DHPC show a decrease in use in the short-term, but only a minority of drugs with a DHPC show substantial long-term reductions in use. Moreover, the impact of a DHPC on drug use varies greatly depending on drug and DHPC characteristics.

Drug innovation success depends on how fast a new drug is adopted by how many prescribers. In Chapter 5, we analyse the interplay between stage in the adoption process, marketing efforts, and physician characteristics on prescriptions. We find considerable variation in physicians’ propensity to prescribe and their detailing sensitivity. These differences can be related to physician characteristics and their stage in the adoption process. The results of our analyses may help pharmaceutical marketing managers target physicians more effectively.

Beatriz Rodriguez Sanchez
The economic approach to diabetes among older adults: A Focus on European Countries

Status: Completed. Defended in July 2018.

Given the projected increase in the costs associated with the management of people with diabetes due to the ageing of the population and the higher costs per capita among older adults, this thesis aims to contribute to the existing literature by bringing a new and broader insight on the diabetes burden among older populations. I examine the traditional healthcare resource use and costs associated with diabetes in older people (costs of care for people with diabetes), and other costs less frequently evaluated, such as nursing home expenditures, and the impact of diabetes on quality of life and productive activities. Additionally, I build on the existing literature by including in the analysis not only the clinical complications that might be suffered at the same time and due to diabetes, but also functional impairment.

Functional status not only helps to explain the associations between diabetes and the different outcomes studied in the thesis (productive activities, nursing home cost and quality of life), but it is the main one. Moreover, the findings from this thesis shows that this relationship is age-dependent, being more prominent among the oldest old individuals. Through prevention of chronic diseases, as it is diabetes, and prevention of disability would avoid quality of life losses due to these conditions, leading to a healthy and active ageing process. More specific data covering the particularities of ageing individuals would help to increase the existing economic evidence on this certain and relevant population.

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Oskar Roemeling
Lean beyond waste: Towards the reduction of variability and buffers in healthcare

Being Lean has become a popular approach towards process improvement in health care. The reduction of waste is considered central to a Lean approach. Next to the reduction of obvious waste, Lean initiatives are expected to reduce variability and consequential buffers. Variability can be classified as natural or artificial. The latter stems from one’s own actions and should be reduced. Where variability leads to buffering in general, time and capacity buffers are especially prevalent in health care. In addition to these well-established buffer types, this thesis also exposes the role of an unexplored buffering mechanism through adjustments of processing times.

Findings in this thesis contribute to the grounding of Lean theory, based on four research projects that investigated the roles of variability and buffers, mature Lean aspects, in a Lean context. Despite the large number of interventions investigated in the first project, only a few are shown to reduce variability and improve throughput time performance. Instead, the focus of interventions is skewed towards reducing specific types of obvious waste. Yet, knowledge on the roles of variability and buffers is shown to broaden the focus of interventions. This thesis shows several opportunities for improved lean applications in healthcare.

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Stefanie Salmon
Health on Impulse: Exploring low self-control and its consequences for food choice

Status: Completed. Defended in September 2015.

Impulsive tendencies towards temptations sometimes seem stronger than wise deliberations. People succumb to a tempting dessert, they postpone getting out of bed and arrive late for work, or scream at someone they are angry with. Such self-control failures are often explained by a limited capacity or limited willingness to exert self-control. After exerting self-control on an initial occasion (e.g., suppressing emotions for the sake of being polite), people are less able or willing to exert self-control in another task (e.g., resisting to buy a new pair of shoes, because one needs to save money). The state that results from this impaired exertion of self-control after repeated self-control exertion has been labeled ego-depletion. In the first part of this dissertation, the focus is on an antecedent of the ego-depletion effect. We demonstrate that people differ in their sensitivity to ego-depleting tasks and situations, and that as a consequence some individuals are better able to repeatedly exert self-control than others. In the second part of the present dissertation, we aimed to qualify a consequence of self-control failures. Contrary to the predominant view on the negative consequences of self-control failures, we demonstrated that ego-depletion does not necessarily have to result in unhealthy choices. Impulsive food choices under low self-control conditions can be steered into the direction of healthy ones, by associating healthy food products with social cues. Applying these social cues to food products in everyday purchase settings may be a new and promising method to provoke more health on impulse.

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Edin Smailhodzic
Transformative effects of social media: How patients’ use of social media affects roles and relationships in healthcare

Status: Completed. Defended in October 2018.

Social media have started changing the way that many industries work. However, there is a lack of understanding of these changes, particularly in the context of healthcare, which is known for high information asymmetry between healthcare providers and patients, and authoritative relationships. Yet, the high proliferation of social media in healthcare enables patients to easily communicate with one another, exchanging informational and emotional support. However, it remains unclear how social media is used by patients, how it affects their behavior, their identities and their relationships with healthcare providers. We conduct a literature review and four empirical studies. First, we conduct a systematic literature review on patients’ use of social media and effects of such use. Second, we explore patients’ use of various categories of social media and propose a taxonomy of interactions enabled by social media in healthcare. Third, we explore how the use of social media by two chronic disease patient communities changes their behaviors and identities as well as their relationships with their healthcare providers. Fourth, we explore how healthcare providers’ interactions with patients who use social media change those providers’ occupational identity. Finally, we test to what extent, and through which mechanism, patients’ use of social media changes their relationships with healthcare providers. Taken together, these findings provide a new explanation of the developing role of social media in changing - and strengthening - organization-customer relationships.

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Julia Storch
The pursuit of health: motivating healthy food choices and physical activity

Status: Completed. Defended in November 2022.

Nowadays, most people live in countries where overweight and obesity kill more people than being underweight, rendering obesity one of the biggest global health crises of the 21st century. The increasing prevalence of overweight and obesity can be traced back to the overconsumption of unhealthy foods that are highly palatable, yet energy-dense and simultaneous decreases in physical activity.

This dissertation approaches the question of how consumers can be motivated to implement healthy food choices and physical activity into their daily lives and touches on several forces that influence consumers’ motivation to engage in such health behaviors.

In Chapter 2, I demonstrate that the notion of “no pain, no gain” that is ubiquitous in the market place for fitness products mostly undermines exercisers’ self-efficacy and thus their exercise intentions. Chapter 3 shows that specifically consumers with low expectancies of managing their body weight can be motivated to make healthier food choices through pride recall. Chapter 4 presents a conceptual framework that informs our understanding of how the emotions pride and guilt can guide consumers during their goal pursuit. In Chapter 5, I provide a comparison of three common online workout formats and show that workouts characterized by higher levels of trainer social presence are particularly conducive to exercise motivation.

Together these findings illustrate that motivating consumers to engage in healthy food choices and physical activity depends both on their perceived ability to successfully engage in these health behaviors and how much they prioritize their health goals at any given moment.

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Laura Viluma
Economy and health: essays on early-life conditions, health, and health insurance

Status: Completed. Defended in April 2019.

This thesis focuses on two aspects of the interactions between economy and health. First, based on the fetal programming hypothesis that suggests a relationship between the economic circumstances before birth and health later in life, I analyze the impact of macroeconomic conditions around birth on infant health and on adult cardiovascular disease risk. The results in chapters 2 and 3 show that high provincial unemployment rates decrease fertility, improve the socio-economic cohort composition of mothers and lead to a lower birthweight in boys. Moreover, girls exposed to unfavorable business-cycle conditions at birth are at an increased risk for fatal CVD events in adult life. Chapter 4 focuses on one of the potential mechanisms linking the economic conditions and health – ambient stress. There, I show that stress caused by high unemployment levels can increase the probability of Cesarean delivery for male babies.

The second part of this thesis takes a different look at the interactions of economy and health by investigating incentives for moral hazard and selection in health insurance. Chapter 5 investigates whether the voluntary deductible in the Dutch health insurance system reduces excessive use of healthcare services or acts only as a cost reduction tool for low-risk individuals. The results show that even though healthier people are more likely to opt for a higher deductible, overall, the voluntary deductible reduces moral hazard in healthcare utilization in the Netherlands.

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Shuye Yu
Staying Healthy and Happy at Work: how Job Flexibility Can Help

Status: Completed. Defended in December 2022.

Working conditions are important determinants of the health and well-being of the working population. This thesis examines the relationship between flexible employment and health and well-being in the workplace using longitudinal household survey data from Australia and Germany. Chapter 2 examines the effect of three forms of flexible employment on parental subjective well-being during the transition into parenthood. Chapter 3 studies the effect of unexpected health shocks on the uptake of home-based work. Chapter 4 studies how the burden of commuting impacts employees' life satisfaction and health. The three chapters jointly highlight the crucial role of flexible working arrangements in improving health and well-being in the workplace by reducing work-life conflicts, satisfying demands for healthcare and avoiding the burden of commuting.

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