User Guide

This section is designed to increase the accessibility of the pellucid2 data set. Here you will find a number of pages that elaborate on the entities, the measures reported, and the fields in the various tables. This section will also contain information on the calculations used to determine ranking and statistical significance.

Digestible

Basic Structure

Every piece of recorded data for pellucid is stored in the 'entity_values' table. It's key is comprised of measure_id, entity_id, date_start and date_end and must be unique;

The measure_id links the data to the 'measures' table, which stores all of our measures. This is used to determine which measurement the data represents.
The entity_id links the table the 'entities' table, which is the master table for all entity types. The 'entities' table is further linked to specific entity tables for hospitals, calculations, geographical regions, etc. This is used to determine what is being measured.
The date_start and date_end are used to define over what time period the data represents.

Advanced Structure

Every entity table is linked to it own 'attributes' table. Attributes are pieces of useful information that are stored for an entity that have the potential to change constantly. As such, they are stored in their own table, and not kept as identifying/detailed information in the table with the entity itself. An example of an attribute could be bed count, as the amount of beds devoted to a specific unit of a hospital or entity can change regularly.

Records in the 'entity_values' table can be linked to the 'footnotes' table through the 'footnotes_values' table. Footnotes are used to make note of information relevant to the record, such as "Ten or less cases reported" or "Incomplete Reporting" etc.

Many of the measures in the 'measures' table are part of a larger group of measures such as HCAHPS or IQIs. We store these groups in the 'measure_groups' table and link them to specific measures through the 'measure_groups_measures' table.

The 'value_sources' table stores the information on who provided the data used to populate the 'entity_values' table; its primary key is the source_id. Each data point in the entity_values table can be linked to a source from this table.

The 'measure_authors' table provides information on where the measures originated; its primary key is the author_id. This table tracks the authors of measures and also provides a reference for our 'measures' table.

There are also multiple 'override' tables which link to different parent entity tables. Each defines whether or not a record should be suppressed from viewing for end users of public website. These tables are project specific and generally exist in shards of pellucid that power websites or projects.

On Measures

Links to more information on the measures used and reported in the pellucid database:

On Entities

Links to more information on the entity types reported in pellucid and the table structure used:

Evaluating Values

When considering the values reached for measures, these links may contain useful information about how data is calculated

Pellucid