13 research outputs found

    How to juggle priorities? An interactive tool to provide quantitative support for strategic patient-mix decisions: an ophthalmology case

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    An interactive tool was developed for the ophthalmology department of the Academic Medical Center to quantitatively support management with strategic patient-mix decisions. The tool enables management to alter the number of patients in various patient groups and to see the consequences in terms of key performance indicators. In our case study, we focused on the bottleneck: the operating room. First, we performed a literature review to identify all factors that influence an operating room's utilization rate. Next, we decided which factors were relevant to our study. For these relevant factors, two quantitative methods were applied to quantify the impact of an individual factor: regression analysis and computer simulation. Finally, the average duration of an operation, the number of cancellations due to overrun of previous surgeries, and the waiting time target for elective patients all turned out to have significant impact. Accordingly, for the case study, the interactive tool was shown to offer management quantitative decision support to act proactively to expected alterations in patient-mix. Hence, management can anticipate the future situation, and either alter the expected patient-mix or expand capacity to ensure that the key performance indicators will be met in the future

    UvA-DARE (Digital Academic Repository) Can statisticians beat surgeons at the planning of operations? Can statisticians beat surgeons at the planning of operations? Can statisticians beat surgeons at the planning of operations?

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    Abstract The planning of operations in the Academic Medical Center is primarily based on the assessments of the length of the operation by the surgeons. We investigate whether duration models employing the information available at the moment the planning is made, offer a better alternative. We conclude that substantial cost reductions can be achieved by employing statistical techniques. This does not imply that the surgeons' predictions do not contain valuable information. This information is a key explanatory variable in our statistical models. What our conclusion does entail is that a correction of the predictions of surgeons is possible because they are often underestimating the actual length of operations. 1 All ML-routines used in this paper are either performed by using standard routines from Stata or are carried out using R (free software, for information see http://www.r-project.org/)

    UvA-DARE (Digital Academic Repository) Can statisticians beat surgeons at the planning of operations? Can statisticians beat surgeons at the planning of operations?

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    Abstract The planning of operations in the Academic Medical Center is primarily based on the assessments of the length of the operation by the surgeons. We investigate whether duration models employing the information available at the moment the planning is made, offer a better alternative. Our empirical results indicate that statistical methods often do better than surgeons. This does not imply that the surgeons' predictions do not contain valuable information. This information is a key explanatory variable in our statistical models. What our conclusion does entail is that a correction of the predictions of surgeons is possible because they are often under-or overestimating the actual length of operations. All ML-routines used in this paper are either performed by using standard routines from Stata or are carried out using R (free software, for information see http://www.r-project.org/)

    Reducing MRI access times by tackling the appointment-scheduling strategy

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    BACKGROUND: High access times for MRI facilities have a negative impact on quality of care and patient service. Since these resources are both scarce and expensive, better utilising the capacity is the most economical way of reducing these access times. As a rule, patient appointments are not scheduled efficiently. Consequently, the most promising way of reducing access times is to optimise the scheduling strategy. The aim of this study was to reduce MRI access times by optimising the scheduling strategy and by implementing this strategy in practice in a university hospital in the Netherlands. ASSESSMENT OF PROBLEMS: The scheduling process was analysed to define the improvement potentials and to simulate the process. Computer simulation was used to copy the process and experiment with scheduling strategies in theory. Promising scenarios were defined and run in the simulation model. Based on the simulation results, a new scheduling strategy was designed and implemented. RESULTS OF ASSESSMENT: The simulation experiments showed that block reduction leads to a maximum decrease in access time of 93%. STRATEGIES FOR CHANGE: Implementing a scheduling strategy with a practically applicable minimum number of blocks resulted in an actual decrease from 36, 22, 28, 9 and 9 to 7, 2, 10, 3 and 1 calendar days, respectively, depending on the patient group. LESSONS AND MESSAGES: This study proved that modelling the scheduling process can contribute to optimising the scheduling strategy, which can lead to a reduction in access times for imaging facilities such as MRI scanner

    Pituitary Hormone Secretion Profiles in IGSF1 Deficiency Syndrome

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    Loss-of-function mutations in immunoglobulin superfamily member 1 (IGSF1) cause an X-linked syndrome of central hypothyroidism, macroorchidism, delayed pubertal testosterone rise, variable prolactin deficiency and variable partial GH deficiency in childhood. The clinical features and gene expression pattern suggest a pivotal role for IGSF1 in the pituitary, but detailed knowledge on pituitary hormone secretion in this syndrome is lacking. We therefore aimed to study the 24-hour pituitary hormone secretion in male patients with IGSF1 deficiency. We collected blood samples every 10 min for 24 h in eight adult male IGSF1-deficient patients and measured circulating TSH, prolactin and gonadotropins. Deconvolution, modified cosinor and approximate entropy analyses were applied to quantify secretion rates, diurnal rhythmicity and regularity of hormone release. Results were compared to healthy controls matched for age and body mass index. Compared to healthy controls, IGSF1-deficient patients showed decreased pulsatile secretion of TSH with decreased disorderliness and reduced diurnal variation. Basal and pulsatile secretion of FSH was increased by over 200%, while LH secretion did not differ from healthy controls. We observed a bimodal distribution of prolactin secretion, i.e. severe deficiency in three and increased basal and total secretion in the other five patients. The altered TSH secretion pattern is consistent with the previously hypothesized defect in thyrotropin-releasing hormone signaling in IGSF1 deficiency. However, the phenotype is more extensive and includes increased FSH secretion without altered LH secretion as well as either undetectable or increased prolactin secretio

    Mutations in TBL1X Are Associated With Central Hypothyroidism

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    Context: Isolated congenital central hypothyroidism (CeH) can result from mutations in TRHR, TSHB, and IGSF1, but its etiology often remains unexplained. We identified a missense mutation in the transducin ␤-like protein 1, X-linked (TBL1X) gene in three relatives diagnosed with isolated CeH. TBL1X is part of the thyroid hormone receptor-corepressor complex. Objective: The objectives of the study were the identification of TBL1X mutations in patients with unexplained isolated CeH, Sanger sequencing of relatives of affected individuals, and clinical and biochemical characterization; in vitro investigation of functional consequences of mutations; and mRNA expression in, and immunostaining of, human hypothalami and pituitary glands. Design: This was an observational study. Setting: The study was conducted at university medical centers. Patients: Nineteen individuals with and seven without a mutation participated in the study. Main Outcome Measures: Outcome measures included sequencing results, clinical and biochemical characteristics of mutation carriers, and results of in vitro functional and expression studies. Results: Sanger sequencing yielded five additional mutations. All patients (n ϭ 8; six males) were previously diagnosed with CeH (free T 4 [FT4] concentration below the reference interval, normal thyrotropin). Eleven relatives (two males) also carried mutations. One female had CeH, whereas 10 others had low-normal FT4 concentrations. As a group, adult mutation carriers had 20%-25% lower FT4 concentrations than controls. Twelve of 19 evaluated carriers had hearing loss. Mutations are located in the highly conserved WD40-repeat domain of the protein, influencing its expression and thermal stability. TBL1X mRNA and protein are expressed in the human hypothalamus and pituitary. C entral hypothyroidism (CeH) is characterized by suboptimal thyroid hormone (TH) secretion due to insufficient stimulation by TSH of an otherwise normal thyroid gland. CeH may be caused by congenital or acquired disorders of the pituitary gland or hypothalamus (1). The diagnosis is based on a plasma free T 4 (FT4) concentration below the reference interval in combination with an inappropriately normal TSH. Congenital CeH has an esti- Conclusion

    The IGSF1 deficiency syndrome: Characteristics of male and female patients

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    Context: Ig superfamily member1 (IGSF1) deficiency was recently discovered as a novel X-linked cause of central hypothyroidism (CeH) and macro-orchidism. However, clinical and biochemical data regarding growth, puberty, and metabolic outcome, as well as features of female carriers, are scarce. Objective: Our objective was to investigate clinical and biochemical characteristics associated with IGSF1 deficiency in both sexes.Methods: All patients (n=42, 24 males) from 10 families examined in the university clinics of Leiden, Amsterdam, Cambridge, and Milan were included in this case series. Detailed clinical data were collected with an identical protocol, and biochemical measurements were performed in a central laboratory. Results: Male patients (age 0-87 years, 17 index cases and 7 from family studies) showed CeH (100%), hypoprolactinemia (n = 16, 67%), and transient partial GH deficiency (n = 3, 13%). Pubertal testosterone productionwasdelayed, aswerethe growth spurtandpubic hair development. However, testicular growth started at a normal age and attained macro-orchid size in all evaluable adults. Body mass index, percent fat, and waist circumference tended to be elevated. The metabolic syndrome was present in 4 of 5 patients over 55 years of age. Heterozygous female carriers (age 32-80 years) showed CeH in 6 of 18 cases (33%), hypoprolactinemia in 2 (11%), and GH deficiency in none. As in men, body mass index, percent fat, and waist circumference were relatively high, and the metabolic syndrome was present in 3 cases. Conclusion: In male patients, the X-linked IGSF1 deficiency syndrome is characterized by CeH, hypoprolactinemia, delayed puberty, macro-orchidism, and increased body weight. A subset of female carriers also exhibits CeH
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