21 research outputs found
The Implications of Sequential Investment in the Property Rights Theory of the Firm
In the property rights theory of the firm, control over assets (ownership) affords bargaining power in the case of re-negotiation, providing incentives for parties to make relationship specific investments. The models predict that property rights will be allocated so as to maximise surplus generated from investment. However, these models assume that investments are made simultaneously. In this thesis I extend the standard property-rights framework to allow for sequential investment; the model allows for two investment periods. If a party invests first (ex-ante), they sink their investment before any contracting is possible. The parties that invest second (ex-post) do so after some aspects of the project are tangible, so that they can contract on (at least some) of their investment costs. As well as being empirically relevant, sequencing has several important theoretical implications. First, if a party gets to invest second, then – ceteris paribus – it has a greater incentive to invest. Second, the investment of parties that invest first are affected by a more than one influence. Anticipating higher ex-post investment, they can have a greater incentive to increase their investments. However, higher ex-post investment leads to greater costs being borne by the ex-ante investors (via the cost sharing contracts); this reduces ex-ante incentives to invest. Overall either effect can dominate so that ex-ante investment can either increase or decrease as a result of sequential investment. Third, as noted, sequencing of investment provides the possibility to (partially) contract on ex-post investment and costs. This is an additional method of providing incentives to invest, beyond the allocation of property rights themselves. Consequently, ex-post investors can be protected (and be provided incentives to invest) via these contracts, whereas ex-ante investors –who can not contract on their investments at all – are more likely to require the protection of property rights (through the allocation of asset ownership). The addition of sequential investment alters some of the predictions of the standard models. For example, previously the literature found that if all assets are complements at the margin all agents should have access to all assets (Bel (2005)). However, when investment sequencing is possible, making a control structure more inclusive (increasing the number of agents who have access to assets) can reduce the incentives of the ex-ante investors, decreasing overall surplus; this is because increasing the property rights of ex-post investors increases the marginal costs borne by ex-ante investors, effectively reducing their claim on surplus, diminishing their incentives to invest. This result contradicts Bel (2005), and shows that even when all assets are complimentary at the margin allocating access rights can be detrimental to incentives. Furthermore, if assets are substitutes at the margin then transfer of assets from ex-ante investors to ex-post investors can increase ex-ante investment and surplus. This counter intuitive result can occur in the case when decreasing ex-post investment is necessary to provide an incentive to ex-ante investors to increase their investments.Discipline of Economic
Functional decline after surgery in older patients with head and neck cancer
Introduction: In addition to classical endpoints such as survival and complication rates, other outcomes such as quality of life and functional status are increasingly recognized as important endpoints, especially for elderly patients. However, little is known about the long-term effect of surgery with regard to these other outcomes. Our aim is to investigate the functional status and self-reported health status of patients > 70 years one year after surgery for head and neck cancer. Methods: We present one-year follow-up data of patients > 70 year who underwent surgery for HNC. During an interview by telephone, functional status was evaluated by using the Katz-15 Index of Independence questionnaire including six items covering basic Activities of Daily Living (ADL) and nine items covering Instrumental Activities of Daily Living (IADL). Measurements were compared with those obtained preoperatively. Results: In total, 126 patients were included and eventually we collected follow-up data of 68 patients. There was a statistically significant decrease in functional status on the total Katz-15 and on the IADL questionnaire scores one year after surgery (mean 1.34 versus 2.42, p -value 0.00 and mean 1.21 versus 1.94, p- value 0.00). There was no significant change concerning ADL dependence ( p -value 0.18) and cognitive status ( p -value 0.11). The self-reported health status improved postoperatively, although not statistically significantly so (mean 67.36 versus 71.25, p -value 0.12). Conclusion: Approximately-one year after surgery for HNC, there is a significant decline in functional status indicating a higher level of dependency.Pathophysiology, epidemiology and therapy of agein
Osteoporosis care during the COVID-19 pandemic in the Netherlands: a national survey
This is a survey study concerning osteoporosis care during the COVID-19 pandemic in the Netherlands. Respondents reported that osteoporosis care stagnated and lower quality of care was provided. This leads to the conclusion that standardization of osteoporosis care delivery in situations of crisis is needed.Purpose: During the initial phase of the COVID-19 pandemic, there was no guidance of professional societies or guidelines on the organization of osteoporosis care in case of such a crisis, and treatment relied on local ad hoc strategies. Experiences from the current pandemic need to be taken into account for the near future, and therefore, a national multidisciplinary survey was carried out in the Netherlands.Methods: A survey of 17 questions concerning the continuation of bone mineral density measurements by Dual Energy X-ray absorptiometry (DXA), outpatient clinic visits, and prescription of medication was sent to physicians, nurses, nurse practitioners, and physician assistants working in the field of osteoporosis.Results: 77 respondents finished the questionnaire, of whom 39 (50.6%) reported a decline in DXA-scanning and 36 (46.8%) no scanning at all during the pandemic. There was an increase in remote consultations for both new and control patient visits (n = 48, 62.3%; n = 62, 81.7% respectively). Lower quality of care regarding fracture prevention was reported by more than half of the respondents (n = 44, 57.1%). Treatment with intravenous bisphosphonates and denosumab was delayed according to 35 (45.4%) and 6 (6.3%) of the respondents, respectively.Conclusion: During the COVID-19 pandemic, osteoporosis care almost completely arrested, especially because of the discontinuation of DXA-scanning and closing of outpatient clinics. More than half of the respondents reported a substantial lower quality of osteoporosis care during the COVID pandemic. To prevent an increase in fracture rates and a decrease in patient motivation, adherence and satisfaction, standardization of osteoporosis care delivery in situations of crisis is needed.Diabetes mellitus: pathophysiological changes and therap
DIALysis or not: outcomes in older kidney patients with GerIatriC Assessment (DIALOGICA): rationale and design
Background The incidence and prevalence of older patients with kidney failure who are dependent on dialysis is increasing. However, observational studies showed limited or no benefit of dialysis on mortality in subgroups of these patients when compared to conservative care. As the focus is shifting towards health-related quality of life (HRQoL), current evidence of effects of conservative care or dialysis on HRQoL in older patients is both limited and biased. Dialysis comes with both high treatment burden for patients and high costs for society; better identification of patients who might not benefit from dialysis could result in significant cost savings. The aim of this prospective study is to compare HRQoL, clinical outcomes, and costs between conservative care and dialysis in older patients.MethodsThe DIALysis or not: Outcomes in older kidney patients with GerIatriC Assessment (DIALOGICA) study is a prospective, observational cohort study that started in February 2020. It aims to include 1500 patients from 25 Dutch and Belgian centres. Patients aged >= 70years with an eGFR of 10-15mL/min/1.73m(2) are enrolled in the first stage of the study. When dialysis is initiated or eGFR drops to 10mL/min/1.73m(2) or lower, the second stage of the study commences. In both stages nephrogeriatric assessments will be performed annually, consisting of questionnaires and tests to assess most common geriatric domains, i.e. functional, psychological, somatic, and social status. The primary outcome is HRQoL, measured with the Twelve-item Short-Form Health Survey. Secondary outcomes are clinical outcomes (mortality, hospitalisation, functional status, cognitive functioning, frailty), cost-effectiveness, and decisional regret. All outcomes are (repeated) measures during the first year of the second stage. The total follow-up will be a maximum of 4 years with a minimum of 1 year in the second stage.DiscussionBy generating more insight in the effects of conservative care and dialysis on HRQoL, clinical outcomes, and costs, findings of this study will help patients and physicians make a shared decision on the best individual treatment option for kidney failure.Trial registrationThe study was registered in the Netherlands Trial Register (NL-8352) on 5 February 2020.Clinical epidemiolog
DIALysis or not: Outcomes in older kidney patients with GerIatriC Assessment (DIALOGICA): rationale and design (vol 22, 39, 2021)
An amendment to this paper has been published and can be accessed via the original article.Nephrolog
SCORE2-OP risk prediction algorithms: estimating incident cardiovascular event risk in older persons in four geographical risk regions
Aims The aim of this study was to derive and validate the SCORE2-Older Persons (SCORE2-OP) risk model to estimate 5- and 10-year risk of cardiovascular disease (CVD) in individuals aged over 70 years in four geographical risk regions.Methods and results Sex-specific competing risk-adjusted models for estimating CVD risk (CVD mortality, myocardial infarction, or stroke) were derived in individuals aged over 65 without pre-existing atherosclerotic CVD from the Cohort of Norway (28 503 individuals, 10 089 CVD events). Models included age, smoking status, diabetes, systolic blood pressure, and total- and high-density lipoprotein cholesterol. Four geographical risk regions were defined based on country-specific CVD mortality rates. Models were recalibrated to each region using region-specific estimated CVD incidence rates and risk factor distributions. For external validation, we analysed data from 6 additional study populations {338 615 individuals, 33 219 CVD validation cohorts, C-indices ranged between 0.63 [95% confidence interval (CI) 0.61-0.65] and 0.67 (0.64-0.69)}. Regional calibration of expected-vs.-observed risks was satisfactory. For given risk factor profiles, there was substantial variation across the four risk regions in the estimated 10-year CVD event risk.Conclusions The competing risk-adjusted SCORE2-OP model was derived, recalibrated, and externally validated to estimate 5- and 10-year CVD risk in older adults (aged 70 years or older) in four geographical risk regions. These models can be used for communicating the risk of CVD and potential benefit from risk factor treatment and may facilitate shared decision-making between clinicians and patients in CVD risk management in older persons.Cardiolog
Frailty is associated with in-hospital mortality in older hospitalised COVID-19 patients in the Netherlands: the COVID-OLD study
BackgroundDuring the first wave of the COVID-19 pandemic older patients had an increased risk of hospitalisation and death. Reports on the association of frailty with poor outcome have been conflicting.ObjectiveThe aim of the present study was to investigate the independent association between frailty and in-hospital mortality in older hospitalised COVID-19 patients in the Netherlands.MethodsThis was a multi-centre retrospective cohort study in 15 hospitals in the Netherlands, including all patients aged ≥70 years, who were hospitalised with clinically confirmed COVID-19 between February and May 2020. Data were collected on demographics, co-morbidity, disease severity and Clinical Frailty Scale (CFS). Primary outcome was in-hospital mortality.ResultsA total of 1,376 patients were included (median age 78 years (IQR 74-84), 60% male). In total, 499 (38%) patients died during hospital admission. Parameters indicating presence of frailty (CFS 6-9) were associated with more co-morbidities, shorter symptom duration upon presentation (median 4 vs. 7 days), lower oxygen demand and lower levels of CRP. In multivariable analyses, the CFS was independently associated with in-hospital mortality: compared to patients with CFS 1-3, patients with CFS 4-5 had a two times higher risk (odds ratio (OR) 2.0 (95%CI 1.3-3.0) and patients with CFS 6-9 had a three times higher risk of in-hospital mortality (OR 2.8 (95%CI 1.8-4.3)).ConclusionsThe in-hospital mortality of older hospitalised COVID-19 patients in the Netherlands was 38%. Frailty was independently associated with higher in-hospital mortality, even though COVID-19 patients with frailty presented earlier to the hospital with less severe symptoms.Pathophysiology, epidemiology and therapy of agein
Testosterone and frailty in elderly men
With aging, there is an increase of the incidence of frailty. Frailty is associated with adverse health outcomes, like falls and fractures, disabilities, hospitalization, institutionalization and mortality. It is generally accepted that frailty, unlike the aging process, is in part reversible and amenable to interventions. Two physical changes appear to be the main cause of frailty, namely loss of muscle mass (sarcopenia) and bone mineral density. The last decades more attention has been raised to the potential importance of androgens in etiology, prevention of treatment of frailty. In this thesis, we investigated the relation between androgens, sarcopenia, bone mineral density and frailty in men and we assessed the effects of testosteron supplementation on these parameters. For the first research question, we found that testosterone was indirectly associated with sarcopeniq and bone mineral density. Low testosterone levels leads to inflammation, disturbances of the glucose metabolism and changes of body composition, which results to sarcopenia and low bone mineral density, and finally to frailty. For the second research question, we found that testosterone supplementation during 6 months to elderly men with low-normal testosterone levels had a positive effect on body composition (increase of lean body mass, decrease of fat mass), glucose metabolism and hormone-related quality of life. There were no beneficial effects on muscle strength and functional mobility, cognitive function, bone mineral density and sexual functioning. Testosterone supplementation was safe and well tolerated
Raloxifene improves verbal memory in late postmenopausal women: a randomized, double-blind, placebo-controlled trial.
Item does not contain fulltextOBJECTIVE: The aim of this study was to examine the effects of raloxifene compared with those of placebo on verbal memory, mental processing speed, depression, anxiety, and quality of life. METHODS: A randomized, double-blind, placebo-controlled trial of 213 healthy women 70 years or older was conducted between July 2003 and January 2008 at the University Medical Centre Utrecht, the Netherlands. Participants were randomly assigned to receive raloxifene (60 mg) or placebo daily for 12 months. Measurements were taken at baseline and after 3, 6, and 12 months. The change in scores from baseline was calculated. The main outcome measures were direct and delayed verbal memory (Groningen 15 Words test), mental processing speed (Trails B test), mood/depression (Geriatric Depression Scale), anxiety (State-Trait Anxiety Inventory 1 and 2), and quality of life (Women's Health Questionnaire and EuroQol-5 dimensional questionnaire). RESULTS: Direct verbal memory improved significantly with raloxifene compared with placebo: the women receiving raloxifene repeated more words in the words A + B test than did the women receiving placebo (P = 0.025). At 12 months, the change from baseline was 16 words in the raloxifene group and 10 words in the placebo group. In the words A test, direct repetition was also significantly better among women receiving raloxifene than among women receiving placebo (P = 0.023), with the change from baseline in the number of words repeated being nine words in the raloxifene group and six words in the placebo group at 12 months. CONCLUSIONS: In postmenopausal women, raloxifene gave significantly improved verbal memory when compared with placebo.1 maart 201
Frailty: defining and measuring of a concept
Older, more vulnerable individuals are increasingly often described in the literature as being frail. Because frailty is often perceived as being undesirable and associated with high health risks, it is important to establish how we can predict, recognize, and treat frailty. Frailty is predisposed by advancing age in combination with physiological deterioration, especially a loss of muscle mass and bone density. Although the symptoms of frailty are diverse, the most common symptoms are a deterioration of activities of daily living (ADL), mobility, nutritional status, cognition, and endurance. The consequences of frailty are institutionalization, morbidity, and mortality. The main determinants of frailty are limitations in ADL, weight loss, diminished mobility or patterns of activity, lowered serum cholesterol level, and sensitivity to change. There is no gold standard for the measurement of frailty, and often studies use a combination of instruments. Although a couple of multidimensional instruments have been developed to measure frailty in its totality, the reliability and validity of these instruments have yet to be established. Successful interventions against frailty include increasing muscle strength through training and individualized recommendations made on the basis of an extensive geriatric assessment