Flexible nurse staffing based on hourly bed census predictions

Workload on nursing wards depends highly on patient arrivals and patient lengths of stay, which are both inherently variable. Predicting this workload and staffing nurses accordingly is essential for guaranteeing quality of care in a cost effective manner. This paper introduces a stochastic method that uses hourly census predictions to derive efficient nurse staffing policies. The generic analytic approach minimizes staffing levels while satisfying so-called nurse-to-patient ratios. In particular, we explore the potential of flexible staffing policies which allow hospitals to dynamically respond to their fluctuating patient population by employing float nurses. The method is applied to a case study of the surgical inpatient clinic of the Academic Medical Center (AMC) Amsterdam. This case study demonstrates the method's potential to study the complex interaction between staffing requirements and several interrelated planning issues such as case mix, care unit partitioning and size, and surgical block planning. Inspired by the numerical results, the AMC decided that this flexible nurse staffing methodology will be incorporated in the redesign of the inpatient care operations during the upcoming years

Integral resource capacity planning for inpatient care services based on hourly bed census predictions

The design and operations of inpatient care facilities are typically largely historically shaped. A better match with the changing environment is often possible, and even inevitable due to the pressure on hospital budgets. Effectively organizing inpatient care requires simultaneous consideration of several interrelated planning issues. Also, coordination with upstream departments like the operating theater and the emergency department is much-needed. We present a generic analytical approach to predict bed census on nursing wards by hour, as a function of the Master Surgical Schedule (MSS) and arrival patterns of emergency patients. Along these predictions, insight is gained on the impact of strategic (i.e., case mix, care unit size, care unit partitioning), tactical (i.e., allocation of operating room time, misplacement rules), and operational decisions (i.e., time of admission/discharge). The method is used in the Academic Medical Center Amsterdam as a decision support tool in a complete redesign of the inpatient care operations

Systematic review and meta-analysis of measurement properties of the Hip disability and Osteoarthritis Outcome Score - Physical Function Shortform (HOOS-PS) and the Knee Injury and Osteoarthritis Outcome Score - Physical Function Shortform (KOOS-PS)

Objective: The aim of this systematic review and meta-analysis was to evaluate all evidence on measurement properties of the Hip disability and Osteoarthritis Outcome Score - Physical function Shortform (HOOS-PS) and the Knee Injury and Osteoarthritis Outcome Score - Physical function Shortform (KOOS-PS). Design: This study was conducted according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews of PROMs. MEDLINE, EMBASE, The Cochrane Library, CINAHL and PsychINFO through February 2019 were searched. Eligible studies evaluated patients with hip or knee complaints and described a measurement property, interpretability, feasibility, or the development of either the HOOS-PS or KOOS-PS. Results: Twenty-three studies were included. For both questionnaires, the content validity was found inconsistent and the quality evidence was moderate for a sufficient reliability and high for an insufficient construct validity. The HOOS-PS had a high quality evidence of sufficient structural validity and internal consistency (pooled Cronbach's alpha 0.80; n = 3761) and low quality evidence of sufficient measurement error and indeterminate responsiveness. Concerning the KOOS-PS, the quality evidence was high for an insufficient responsiveness, moderate for an inconsistent structural validity and internal consistency and low for an inconsistent measurement error. Conclusions: The inconsistent evidence for content validity implies that scores on the HOOS-PS and KOOS-PS may inadequately reflect physical functioning. Furthermore, there is evidence for insufficient construct validity and responsiveness in patients with knee osteoarthritis receiving conservative treatment. Using the HOOS-PS or KOOS-PS as outcome measurement instruments for comparing outcomes, measuring improvements or benchmarking in patients with hip or knee complaints or undergoing arthroplasty should only be done with great caution. Review registration: PROSPERO number CRD4201706953

The vector-valued big q-Jacobi transform

Big $q$-Jacobi functions are eigenfunctions of a second order $q$-difference operator $L$. We study $L$ as an unbounded self-adjoint operator on an $L^2$-space of functions on $\mathbb R$ with a discrete measure. We describe explicitly the spectral decomposition of $L$ using an integral transform $\mathcal F$ with two different big $q$-Jacobi functions as a kernel, and we construct the inverse of $\mathcal F$.Comment: 35 pages, corrected an error and typo

Energy- and charge-state-resolved spectrometry of tin laser-produced plasma using a retarding field energy analyzer

We present a method to obtain the individual charge-state-dependent kinetic-energy distributions of tin ions emanating from a laser-produced plasma from their joint overlapping energy distributions measured by means of a retarding field energy analyzer (RFA). The method of extracting charge state specific parameters from the ion signals is described mathematically, and reinforced with experimental results. The absolute charge-state-resolved ion energy distributions is obtained from ns-pulse Nd:YAG-laser-produced microdroplet tin plasmas in a setting relevant for state-of-the-art extreme ultraviolet nanolithography

Samen werken aan samenwerking

Op het gebied van horizontale samenwerking is er veel mogelijk qua vorm, intensiteit, werkterrein en juridische constructie, zowel in de agrosector als in het mkb. De vele mogelijkheden bieden veel aangrijpingspunten om privé- en bedrijfsdoelen beter te kunnen bereiken, onder andere door meer denk- en slagkracht, ook financieel, en sociale voordelen als steun en meer vrije tijd. Samenwerking vraagt echter ook veel van de ondernemers en hun competenties. In dit onderzoek is vooral gekeken naar horizontale samenwerking: tussen soortgelijke ondernemers onderlin

Are critical finite-size scaling functions calculable from knowledge of an appropriate critical exponent?

Critical finite-size scaling functions for the order parameter distribution of the two and three dimensional Ising model are investigated. Within a recently introduced classification theory of phase transitions, the universal part of the critical finite-size scaling functions has been derived by employing a scaling limit that differs from the traditional finite-size scaling limit. In this paper the analytical predictions are compared with Monte Carlo simulations. We find good agreement between the analytical expression and the simulation results. The agreement is consistent with the possibility that the functional form of the critical finite-size scaling function for the order parameter distribution is determined uniquely by only a few universal parameters, most notably the equation of state exponent.Comment: 11 pages postscript, plus 2 separate postscript figures, all as uuencoded gzipped tar file. To appear in J. Phys. A

Beyond series expansions: mathematical structures for the susceptibility of the square lattice Ising model

We first study the properties of the Fuchsian ordinary differential equations for the three and four-particle contributions $\chi^{(3)}$ and $\chi^{(4)}$ of the square lattice Ising model susceptibility. An analysis of some mathematical properties of these Fuchsian differential equations is sketched. For instance, we study the factorization properties of the corresponding linear differential operators, and consider the singularities of the three and four-particle contributions $\chi^{(3)}$ and $\chi^{(4)}$, versus the singularities of the associated Fuchsian ordinary differential equations, which actually exhibit new ``Landau-like'' singularities. We sketch the analysis of the corresponding differential Galois groups. In particular we provide a simple, but efficient, method to calculate the so-called ``connection matrices'' (between two neighboring singularities) and deduce the singular behaviors of $\chi^{(3)}$ and $\chi^{(4)}$. We provide a set of comments and speculations on the Fuchsian ordinary differential equations associated with the $n$-particle contributions $\chi^{(n)}$ and address the problem of the apparent discrepancy between such a holonomic approach and some scaling results deduced from a Painlev\'e oriented approach.Comment: 21 pages Proceedings of the Counting Complexity conferenc

A solution to the Al-Salam--Chihara moment problem

We study the $q$-hypergeometric difference operator $L$ on a particular Hilbert space. In this setting $L$ can be considered as an extension of the Jacobi operator for $q^{-1}$-Al-Salam--Chihara polynomials. Spectral analysis leads to unitarity and an explicit inverse of a $q$-analog of the Jacobi function transform. As a consequence a solution of the Al-Salam--Chihara indeterminate moment problem is obtained.Comment: 22 page