Hospital Inpatient Admission Encounter
  • 16 May 2023
  • 5 Minutes to read
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Hospital Inpatient Admission Encounter

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Article Summary


An encounter taking place at an acute care hospital that includes a period of time during which the patient is considered to be inpatient status. The encounter is considered to start when the patient initially checks in at the hospital – even if the patient arrives in the emergency department or in observation status – and is considered to end when they are discharged from inpatient status.


Broadly used for many purposes.

Detailed Narrative of Logic

  • At a high level, hospital inpatient admission encounters are identified using the following logic: (1) “qualifying” documents representing direct evidence that a hospital inpatient admission encounter has occurred, are identified; (2) these qualifying documents for the same patient are compared to each other to determine whether they are associated with the same encounter, and identifiers for each distinct encounter, along with its start and end dates, are generated; (3) non-qualifying documents falling within the start and end dates of each encounter are identified; (4) all related children and grandchildren documents of these qualifying or non-qualifying-but-matched documents are added to the collection of documents associated with each encounter; and (5) all associated documents are synthesized to determine encounter-level characteristics, and a final set of encounter records are generated.
  • Step (1) described above is performed by Hospital Inpatient Admission Encounter Document Aggregator, Precursor 1 (Qualifying Documents). Qualifying documents may be records for institutional claims or bills, or EMR encounters. Institutional claims or bills are considered qualifying when the type of bill code starts with 11 and either the claim or bill contains at least one service line item with a qualifying revenue center code (see value set HOSPITAL INPATIENT SETTING) or has admit and discharge dates or claim covered start and end dates that imply an encounter length of 2+ elapsed midnights (i.e., 3 distinct calendar days). EMR encounters are considered qualifying if they have been flagged as Hospital Inpatient Admission encounters (i.e., Is Encounter Type Hospital Inpatient Admission = 1) during data integration.
  • In preparation for the matching in step (2), some qualifying institutional claims and bills identified in step (1) receive adjusted start and end dates to be used for the record matching. (Following matching, these adjusted dates are discarded.) If the record’s type of bill code ends with 2 (indicating the first claim in a sequence), the original document end date is advanced one day later; if the type of bill code ends with a 3 (indicating a continuing claim), the original document start date is set one day earlier and the original document end date is advanced one day later; if the type of bill code ends with a 4 (indicating the last claim in a sequence), the original document start date is set one day earlier. (The dates associated with EMR encounter records are not adjusted.)
  • Step (2) is primarily performed by Hospital Inpatient Admission Encounter Document Aggregator, Precursor 2 (Qualifying Document Matching); this step takes advantage of the Simple Episode object type, which constructs episodes from component events or interval objects that are sufficiently proximate or overlapping in time. (In this case, the “episode” to be created is the admission, and the components are the individual qualifying documents.) Qualifying records from step (1) are matched if they have the same patient and facility and have overlapping adjusted start and end dates. For example, two qualifying institutional claims for the same patient and facility, the first with type of bill code 111 and original covered end date of January 1 and the second with a type of bill code 114 and original covered start date of January 2 would match – the adjusted end date of the first claim would remain January 1, and the adjusted start date of the second claim, due to the type of bill code ending with a 4, would be set to January 1 as well, which is considered overlapping with the first claim. The Simple Episode logic also generates “episode” start and end dates, which are interpreted as the final encounter start and end dates.
  • Step (3) is performed by Hospital Inpatient Admission Encounter Document Aggregator, Precursor 3 (All Master Documents). Any professional claim or bill service line items with a matching patient and with service start and end dates falling strictly within the interior of the encounter start and end dates (i.e., service start date > encounter start date and service end date < encounter end date) are considered matched to that encounter. For otherwise matching professional claim or bill service line items that start or end on the encounter start or end date, respectively, professional service line items are only considered matched to the encounter when they have a place of service code consistent with hospital setting (see value set HOSPITAL INPATIENT OR OUTPATIENT). (The rationale for this logic is to avoid false positive assignment of professional services received outside the hospital immediately before or after the encounter.)
  • Step (4) is performed by Hospital Inpatient Admission Encounter Document Aggregator, which starts with all the documents identified in steps (1) – (3) and additionally gathers up any of their children and grandchildren documents. For example, ICD-10-PCS procedure codes and ICD-10-CM discharge diagnosis codes are both children of institutional claim headers; if a claim header document was identified in step (1), step (4) additionally collects all the ICD-10-PCS and ICD-10-CM codes under it. (So constructed, Hospital Inpatient Admission Encounter Document Aggregator represents a convenient inventory of all documents associated with these types of encounters, qualifying or not, which can be useful for downstream logic.)
  • Step (5) is performed by Hospital Inpatient Admission Encounters. The task here, broadly, is to collapse the grain from one record per document to one record per encounter, and to identify the best document-level values to use to populate the final encounter-level fields. The ranking criteria to identify the best document-level values differs from field to field, but generally favors non-NULL values, values on qualifying documents, documents with the highest paid amount, and more recently updated documents. Financial totals are also calculated in this step by summing up the amounts across all claim headers, summing up the amount across all bill headers, and taking the greater of the two amounts. This step also identifies hospital inpatient admission encounters that qualified as emergency department visit parent encounters and/or observation stay parent encounters (see fields Is Emergency Department Visit Parent Encounter and Is Observation Stay Parent Encounter); and identifies the earliest date of inpatient status during the encounter (see field Encounter Patient Inpatient Status Start Date).

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