title: Predictive Risk Modelling for Hospital Readmissions

authors: Forsythe, Claire Elizabeth

subjects: Logistic regression

abstract: This thesis is concerned with developing a predictive risk model to identify patients that are at high risk of readmission to hospital. Such a model should have a desirable level of predictive accuracy but also, should be financially beneficial to the DHB. Logistic regression and Naive Bayes probabilistic classification methods were both considered to build the predictive model. Performance measures such as the positive predictive value (PPV) and cost savings analysis were used to find the optimal days between initial admission and readmission and the optimal threshold for prediction of high risk patients. This study is concerned with Waikato District Health Board (DHB) domiciled patients discharged between 1 July 2009 and 31 October 2013. The dataset includes information about the patients initial admission and the response variable is whether a readmission occurred or not. 

Using logistic regression, this study found the model that fits the data best includes 21 variables that contain information about the patients initial admission. The two classification methods used produce a risk probability between 0 and 1 for each patient in the study. The logistic regression model performance was better than Naive Bayes as shown by the PPV (the proportion of patients correctly identified as at risk over the total at risk). The 56 day readmission data PPV at a risk threshold of 0.5 for the logistic regression was 48.4% and 30.8% for Naive Bayes. Analysis of the PPV identifies the risk threshold level of 0.5 and readmission period of 56 days as optimal predictive criteria in this study. Cost savings analysis also supports the 56 day model with an intervention cost of $500. The 0.5 cut off point in the 56 day model identifies a reasonable number of patients at risk for intervention, approximately 3,000, which equates to about 2 patients at risk per day over the period of this analysis.

This analysis found the optimal model for predicting patients at risk of readmission is a logistic regression model using 56 day readmission data and a risk threshold of 0.5. A key recommendation of this study is that the DHB needs to introduce a method that correctly flags patient admissions. The model should be used on a trial basis at the DHB to see how accurate it performs.

text: Predictive Risk Modelling for Hospital Readmissions This thesis is concerned with developing a predictive risk model to identify patients that are at high risk of readmission to hospital. Such a model should have a desirable level of predictive accuracy but also, should be financially beneficial to the DHB. Logistic regression and Naive Bayes probabilistic classification methods were both considered to build the predictive model. Performance measures such as the positive predictive value (PPV) and cost savings analysis were used to find the optimal days between initial admission and readmission and the optimal threshold for prediction of high risk patients. This study is concerned with Waikato District Health Board (DHB) domiciled patients discharged between 1 July 2009 and 31 October 2013. The dataset includes information about the patients initial admission and the response variable is whether a readmission occurred or not. 

Using logistic regression, this study found the model that fits the data best includes 21 variables that contain information about the patients initial admission. The two classification methods used produce a risk probability between 0 and 1 for each patient in the study. The logistic regression model performance was better than Naive Bayes as shown by the PPV (the proportion of patients correctly identified as at risk over the total at risk). The 56 day readmission data PPV at a risk threshold of 0.5 for the logistic regression was 48.4% and 30.8% for Naive Bayes. Analysis of the PPV identifies the risk threshold level of 0.5 and readmission period of 56 days as optimal predictive criteria in this study. Cost savings analysis also supports the 56 day model with an intervention cost of $500. The 0.5 cut off point in the 56 day model identifies a reasonable number of patients at risk for intervention, approximately 3,000, which equates to about 2 patients at risk per day over the period of this analysis.

This analysis found the optimal model for predicting patients at risk of readmission is a logistic regression model using 56 day readmission data and a risk threshold of 0.5. A key recommendation of this study is that the DHB needs to introduce a method that correctly flags patient admissions. The model should be used on a trial basis at the DHB to see how accurate it performs.

year: 2014

title: Visualising Location-Based Information using Augmented Reality

authors: Zhang, Qimo

subjects: Narrative Navigation

abstract: The use of augmented reality extends navigation in location-based mobile applications. This thesis introduces the concept of narrative navigation and describes the design and testing of four mobile application prototypes that explore the proof-of-concept for narrative navigation. 
We explored the work related to Augmented Reality and navigation and found that no scholars have focused on the use of Augmented Reality by navigating users in the context of location-based stories. This thesis aims to answer the research question of how Augmented Reality visualisations can reflect location-based data to tell a story on mobile devices. While typical navigation only involves guidance to a single point, narrative navigation requires navigation that focuses on the linearity of the story. The goal of our research is to investigate how augmented reality can be used to visualize location-based information for navigation in a storytelling environment.
We carried out the design, development, and testing of the Initial Digital Prototype, exploring the use of Augmented Reality technology to display the Point of Interest (POI) position, direction, distance, and story chapter order, and guide users to the next location in the story. In the subsequent Paper Prototype, we explored four navigation visualisations, showing the next story element through stylized flags of varying heights. We found that showing the next story location nearer to the bottom of the screen was the most successful way to guide users, but also found that many participants preferred to show location order by distance. In the Narrative Navigation Prototype, further POI design options are explored. We improved details such as size, quantity, description and the spacing of POIs, the camera tilt display, and the use of indicator arrows. In the Final Prototype, the concept of narrative navigation was confirmed by the positive evaluation of participants and confirmation of user interactions provided by our behavioural tracking maps that were used to observe participant movements and prototype interactions.
The thesis contributions include four insights into the concept of narrative navigation. The first is the use of augmented reality to visualise location-based stories on mobile phones; the second is to highlight the importance of showing the next location in the story sequence, which has been almost absent in related work. Removing visited story chapters will facilitate navigation and narrative ordering; and finally, the use of directional indicators that guide the small phone screen to connect to the real world.
We have shown that narrative navigation is a promising concept that can expand application scenarios based on location information.

text: Visualising Location-Based Information using Augmented Reality The use of augmented reality extends navigation in location-based mobile applications. This thesis introduces the concept of narrative navigation and describes the design and testing of four mobile application prototypes that explore the proof-of-concept for narrative navigation. 
We explored the work related to Augmented Reality and navigation and found that no scholars have focused on the use of Augmented Reality by navigating users in the context of location-based stories. This thesis aims to answer the research question of how Augmented Reality visualisations can reflect location-based data to tell a story on mobile devices. While typical navigation only involves guidance to a single point, narrative navigation requires navigation that focuses on the linearity of the story. The goal of our research is to investigate how augmented reality can be used to visualize location-based information for navigation in a storytelling environment.
We carried out the design, development, and testing of the Initial Digital Prototype, exploring the use of Augmented Reality technology to display the Point of Interest (POI) position, direction, distance, and story chapter order, and guide users to the next location in the story. In the subsequent Paper Prototype, we explored four navigation visualisations, showing the next story element through stylized flags of varying heights. We found that showing the next story location nearer to the bottom of the screen was the most successful way to guide users, but also found that many participants preferred to show location order by distance. In the Narrative Navigation Prototype, further POI design options are explored. We improved details such as size, quantity, description and the spacing of POIs, the camera tilt display, and the use of indicator arrows. In the Final Prototype, the concept of narrative navigation was confirmed by the positive evaluation of participants and confirmation of user interactions provided by our behavioural tracking maps that were used to observe participant movements and prototype interactions.
The thesis contributions include four insights into the concept of narrative navigation. The first is the use of augmented reality to visualise location-based stories on mobile phones; the second is to highlight the importance of showing the next location in the story sequence, which has been almost absent in related work. Removing visited story chapters will facilitate navigation and narrative ordering; and finally, the use of directional indicators that guide the small phone screen to connect to the real world.
We have shown that narrative navigation is a promising concept that can expand application scenarios based on location information.

year: 2023

title: The concept of partnership and The Treaty of Waitangi: Three case studies

authors: Morrison, Sandy

subjects: Te Tiriti o Waitangi

abstract: There has been, and continues to be, considerable debate about the meaning and intent of different versions of the Treaty of Waitangi and about the extent of its relevance to contemporary New Zealand. It is in this context that a number of organisations and institutions in New Zealand, anxious to demonstrate their positive support for the creation of a just society, have attempted to restructure in ways that allow for a 'partnership' between Māori and Pākehā. With reference to three different case studies, I argue here that such restructuring, although generally very well intentioned and very welcome, should not be seen - as it frequently is - as an expression of the fulfilment of partnership obligations arising out of the Treaty of Waitangi. To treat organisational restructuring in this way, particularly where it does not provide both 'partners' with an equal right to determine the operational parameters and future direction of the organisation, is to misrepresent (often wholly unintentionally) the nature of the Treaty. Nevertheless, one way of resolving some of the debates concerning the meaning and intent of the Treaty of Waitangi might be to establish a principle of equal partnership in the governance and management of state institutions.

text: The concept of partnership and The Treaty of Waitangi: Three case studies There has been, and continues to be, considerable debate about the meaning and intent of different versions of the Treaty of Waitangi and about the extent of its relevance to contemporary New Zealand. It is in this context that a number of organisations and institutions in New Zealand, anxious to demonstrate their positive support for the creation of a just society, have attempted to restructure in ways that allow for a 'partnership' between Māori and Pākehā. With reference to three different case studies, I argue here that such restructuring, although generally very well intentioned and very welcome, should not be seen - as it frequently is - as an expression of the fulfilment of partnership obligations arising out of the Treaty of Waitangi. To treat organisational restructuring in this way, particularly where it does not provide both 'partners' with an equal right to determine the operational parameters and future direction of the organisation, is to misrepresent (often wholly unintentionally) the nature of the Treaty. Nevertheless, one way of resolving some of the debates concerning the meaning and intent of the Treaty of Waitangi might be to establish a principle of equal partnership in the governance and management of state institutions.

year: 2005