Aspiration Pneumonia in Adults: Patient Characteristics, Diagnosis, Treatment, and Outcomes (ASPEN)

November 11, 2026 updated by: Region Örebro County

Aspiration Pneumonia in Adults: A Retrospective Cohort Study of Patient Characteristics, Risk Factors, Diagnosis, Treatment, and Clinical Outcomes

Aspiration pneumonia is a lung infection that can occur when food, liquid, saliva, or material from the stomach enters the airways. It is an important health problem, particularly among older adults and people with swallowing difficulties, neurological conditions, frailty, or reduced functional ability. Diagnosis can be challenging, and patients may differ in their risk factors, investigations, treatment, and outcomes.

The ASPEN study (Aspiration Pneumonia Evaluation Network) is a retrospective observational study of adults aged 18 years or older who were hospitalized in Region Örebro County, Sweden, with a registered diagnosis of aspiration pneumonia between September 2024 and September 2026.

The researchers will review existing medical records and collect information using a structured data collection form. Information will include patients' age and other characteristics, living situation and functional status, underlying diseases, risk factors for aspiration, clinical findings, imaging, microbiological investigations, antibiotic treatment, other healthcare interventions, and outcomes.

The study will describe the characteristics of patients hospitalized with aspiration pneumonia, how the condition is investigated and treated in routine clinical practice, and how patients' hospital stays and subsequent outcomes develop. Outcomes of interest include clinical deterioration, length of hospital stay, discharge destination, readmission, a new documented episode of aspiration pneumonia, and death within 90 days, where information is available.

The study will also explore associations between patient characteristics, clinical features, investigations, treatment patterns, and outcomes. As this is an observational study based on existing medical records, it is not designed to establish whether a particular treatment causes better or worse outcomes.

The overall aim is to improve knowledge of aspiration pneumonia and provide a foundation for future research, with particular attention to older adults, functional ability, and healthcare needs.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Background

Aspiration pneumonia is a clinically important condition in adults, particularly in older people and individuals with dysphagia, neurological disease, frailty, reduced functional ability, and other comorbidities. The diagnosis may be difficult to establish because aspiration is not always witnessed and documentation varies between patients and clinical settings. Diagnostic investigations, microbiological sampling, and antibiotic treatment may also vary in routine clinical practice.

A systematic description of patient characteristics, aspiration-related risk factors, diagnostic approaches, treatment patterns, and clinical outcomes may help identify gaps in clinical documentation and areas for future research. This is particularly relevant to older adults, in whom an episode of pneumonia may be associated with functional decline, prolonged hospitalization, increased care needs, and recurrent healthcare contacts.

Study design and setting

ASPEN (Aspiration Pneumonia Evaluation Network) is a retrospective, observational cohort study conducted in Region Örebro County, Sweden. The study uses existing medical records and does not assign interventions or alter patients' clinical care.

The study population comprises adults aged 18 years or older hospitalized during the period September 2024 through September 2026 with a registered diagnosis of aspiration pneumonia. Patients will be identified through diagnostic coding. The planned primary cohort includes each eligible patient once; subsequent admissions will be handled as follow-up events rather than as new primary cohort observations.

Data collection

Data will be collected through structured review of existing medical records using a predefined data collection form. Variables will include:

Demographic characteristics, living situation, functional status, cognition, communication, nutritional status, and relevant comorbidities.

Risk factors for aspiration and the documentation and classification of the suspected or documented aspiration event.

Clinical presentation, vital signs, laboratory results, radiological findings, and microbiological investigations.

Antibiotic treatment, including antibiotic selection, broad- or narrow-spectrum treatment, anaerobic coverage, treatment duration, changes in treatment, and treatment at discharge where documented.

Other healthcare interventions, clinical deterioration, level of care, intensive or intermediate care, and length of hospital stay.

Discharge destination and follow-up outcomes, including readmission, a new documented episode of aspiration pneumonia, and death within 90 days, where information is available in the records.

Only information documented in the medical record will be recorded. Missing or undocumented information will not be inferred by the reviewer.

Outcomes and analyses

The study will primarily provide a descriptive characterization of the cohort and its clinical course. Analyses will summarize patient characteristics, aspiration-related risk factors, diagnostic investigations, microbiological findings, antibiotic treatment patterns, healthcare utilization, and clinical outcomes.

Exploratory analyses will examine associations between patient and disease characteristics, diagnostic findings, treatment patterns, and documented outcomes where the available data and number of outcome events permit. Antibiotic treatment patterns, including anaerobic coverage and treatment duration, will be described to characterize clinical practice and variation. The study is not designed to establish causal treatment effects or determine which antibiotic regimen is superior.

Ethical considerations

The study involves retrospective review of existing medical records. Ethical review and the necessary approvals will be obtained before the medical record review begins. Data will be handled in accordance with applicable Swedish requirements for research ethics, confidentiality, and personal data protection. Study data will be coded using study-specific identifiers, and direct identifiers will not be included in the analysis dataset.

Purpose and expected contribution

The study aims to provide a structured description of adults hospitalized with aspiration pneumonia in Region Örebro County. It is expected to identify patterns in patient characteristics, diagnostic practice, treatment, clinical course, and outcomes, as well as limitations in the completeness of routinely documented data. The findings will inform future research and the development of more standardized data collection, with particular relevance to older adults, functional outcomes, and healthcare needs.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adults aged 18 years or older hospitalized in Region Örebro County, Sweden, with a registered diagnosis of aspiration pneumonia during September 2024 through September 2026. Patients will be identified retrospectively through medical records and diagnostic coding. The study will describe patient characteristics, aspiration risk factors, diagnostic findings, antibiotic treatment, and clinical outcomes.

Description

Inclusion Criteria:

  • Adults aged 18 years or older.
  • Hospitalized in Region Örebro County, Sweden, during the study period September 2024 through September 2026.
  • Registered diagnosis of aspiration pneumonia (ICD-10 code J69.0), subject to the study's final case-identification criteria.

Exclusion Criteria:

- Patients transferred to or from another hospital when the transfer results in insufficient medical record data to assess the study variables and follow-up outcomes.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: RETROSPECTIVE

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Retrospective Aspiration Pneumonia Cohort

Adults aged 18 years or older hospitalized in Region Örebro County, Sweden, with a registered diagnosis of aspiration pneumonia during September 2024 through September 2026. Eligible patients will be identified through diagnostic coding and described using retrospectively collected medical record data. Each patient will be included once in the primary cohort; subsequent admissions will be handled as follow-up events.
Drug: Antibiotic Treatment in Routine Clinical Care

Antibiotic treatment is not assigned by the study. Existing medical records will be reviewed to describe antibiotic treatment provided as part of routine clinical care, including antibiotic selection, broad- or narrow-spectrum treatment, anaerobic coverage, treatment duration, changes in treatment, and treatment at discharge where documented. These data will be used to characterize clinical practice and variation in treatment patterns. The study is not designed to establish causal treatment effects or determine the superiority of any antibiotic regimen.Kopiera beskrivning

Other Names:
  • Antibiotics; Antimicrobial therapy

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
All-cause mortality within 30 days
Time Frame: Within 30 days after the date of the index hospital admission.

Proportion of patients who die from any cause within 30 days of the index hospital admission for aspiration pneumonia.
Within 30 days after the date of the index hospital admission.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
In-hospital clinical deterioration
Time Frame: From the date of index hospital admission until discharge from the index hospitalization, up to a maximum of 90 days.

In-hospital clinical deterioration during the index hospital admission.
From the date of index hospital admission until discharge from the index hospitalization, up to a maximum of 90 days.
All-cause mortality within 90 days
Time Frame: From the date of the index hospital admission through 90 days after admission.

All-cause mortality within 90 days
From the date of the index hospital admission through 90 days after admission.
Hospital readmission within 90 days
Time Frame: Up to 90 days after discharge from the index hospitalization.

Proportion of patients with at least one hospital readmission within 90 days after discharge from the index hospitalization.
Up to 90 days after discharge from the index hospitalization.
Length of hospital stay
Time Frame: From hospital admission to discharge for the index admission.

Duration of the hospital admission, measured in days from hospital admission to hospital discharge.
From hospital admission to discharge for the index admission.
New documented aspiration pneumonia within 90 days
Time Frame: From the date of the index hospital admission through 90 days after admission.

Proportion of patients with at least one new episode of aspiration pneumonia documented in the medical record within 90 days after discharge from the index hospital admission.
From the date of the index hospital admission through 90 days after admission.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Region Örebro County

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 5, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 11, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 12, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ASPEN

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared with other researchers. The study uses data extracted retrospectively from medical records, and sharing individual-level data is not planned due to patient confidentiality, data protection requirements, and applicable regional regulations. Only aggregated study results may be reported in scientific publications.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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