Re-analysis and generation of Overstay2 model

This page is about the development of the model for generating scores/colours for Project Overstay2. Since our data collection and the healthcare system changed since the first iteration, we did a re-analysis and generation of Overstay2 model, resulting in the Overstay2 scoring model that generates the colour.

Defining the contributing factors data

The model depends on a regression analysis of a number of possible factors in our regularly collected data. Our data structure had changed since the original project, so we cleaned up our definitions, resulting in the Data definition for contributing factors for the Overstay2 project.

Still needs: considerations values we considered and rejected

• SMW

• Cargo

• Categories

Model dataset and date range

• Dataset: We used the file 2025-2-3_13.56.31_Centralized_data.accdb as a basis for the project. A copy for future reference is at

\ad.wrha.mb.ca\WRHA\HSC\shared\MED\MED_CCMED\Julie\MedProjects\Overstay_Project_2025

• Date Range: We based the date range on the first medicine admit date during a hospitalization, based on the earliest Boarding Loc dttm of a (PHIN and Visit Admit DtTm) combination
• This resulted in a dataset with the following:

add a table of admission numbers by year and site

• SMW

• Cargo

• Categories

   first Med admit dttm >=2020-11-01 and <2025-01-01 and are Vetted  

   JM had found Vetted n=226 cases with  Last discharge DtTm (in ICU or Med) after 2024 until Feb 3,2025.  Only 13 did not leave own site, 19 expired, 194 left the site. From the 213,  some are long stayed patients admitted Aug –1, Sept-3, Oct-8, Nov-18, Dec=196. (DR agreed in the meeting with JM Feb10).   

• First Med Admits who were RecordStatus = incomplete but with Dispo DtTm present are excluded.
• First Med Admits who were still in the unit are excluded.
• First Med Admits who were RecordStatus = incomplete vetted are included.

Analysis and model generation

Dataset split into training and validation data

We separated the population into two datasets based on the odd/even status of the last digit of the Chart number:

• Even: Training set
• Odd: validation set

Model generation and testing

we should add some basic info details can remain in other files such as SAS, but this should include file links

• SMW

• Cargo

• Categories

Decision on a model

the statistical tests that were done to evaluate the model the factors leading to our decision on "Model 8"

• SMW

• Cargo

• Categories

This resulted in Overstay2 scoring model.

Decision on a probability threshold

The overstay score generated by Overstay2 scoring model is used to assign an Overstay2 colour based on a threshold value, which affects the patient care team activities of the Overstay2 processes on the units to reduce overstay. This section explains how we decided on that threshold value.

Optimal threshold

What was the consideration for the initial choice of, I think, 0.051?

• SMW

• Cargo

• Categories

Pragmatic threshold

The drives a process that requires additional work form the patient care team. There are limits to those resources. The #optimal threshold would have resulted in a assigning xxx% of patients an Overstay2 colour of "red". This would have overwhelmed the Overstay2 processes on the units to reduce overstay.

initial thoughts were "15-17% being red, with an aim to get 60-75% of overstay patients"

• SMW

• Cargo

• Categories

It was determined that a xxx-yyy% of "red" would be the maximum we could assign, at least during the initial phase of the project. To achieve this, we chose a threshold of 0.069

For the selected Overstay2 scoring model this led to the following predicted values

• Overstay2 colour = "red": xxxx%

Do you have numbers for something like false positives/ false negatives/ positive predictive value/ etc? Will rely on you to make this something that would satisfy someone questioning this from a statistical angle. Ttenbergen 15:19, 23 February 2025 (CST)

• SMW

• Cargo

• Categories

Does this page miss anything that is not addressed elsewhere as per pages either linked from here or from Overstay2 Index? If not feel free to delete this question. Ttenbergen 15:19, 23 February 2025 (CST)

• SMW

• Cargo

• Categories