A Prospective Observational Cohort Study Protocol for Disease Severity Stratification and Prognosis Assessment in Patients With Pneumonia

This is a prospective, multicenter observational cohort study involving approximately 2,700 patients, designed to delineate the natural history of pneumonia by tracking the complete clinical course and dynamic multi-omics evolution from the acute phase to recovery; the study aims to quantify severe conversion rates and mortality by comparing baseline characteristics, pathogen distribution, and immune response trajectories between severe and non-severe groups, ultimately revealing the underlying molecular mechanisms of disease progression and optimizing clinical risk stratification strategies.

Study Overview

• Status: Not yet recruiting
• Conditions: Pneumonia; Severe Pneumonia

• Study Type: Observational
• Enrollment (Estimated): 2700

Contacts and Locations

• Study Contact: Name: Liang Peng, Doctor; Phone Number: 86-020-85959142; Email: pl_206@126.com

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China
      • Fifth Affiliated Hospital of Guangzhou Medical University
      • Contact: Liang Peng, Doctor; Phone Number: 86-020-85959142; Email: pl_206@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Based on the reported overall hospital mortality rate of pneumonia of 0.80%1, to ensure the accuracy of the estimation of the primary outcome (overall hospital mortality rate), a two-sided significance level of α = 0.05 was set, with an allowable absolute error of δ = 0.6%. Using the single sample rate formula, the minimum sample size N ≈ 2010 cases was calculated. Considering that this study is a real-world observational cohort design and needs to meet requirements such as multi-subgroup analysis, sensitivity testing, and machine learning modeling, the final plan is to include at least 2400 patients with pneumonia. Given that severe pneumonia accounts for approximately 13.58% to 20.05% of pneumonia patients1,2, an epidemiological proportion of 15% (i.e., 1.5:8.5) was taken. It is estimated that there will be approximately 360 patients with severe pneumonia and about 2040 patients with non-severe pneumonia. Additionally, this study also included 300 hospitalized patients with suspected

Description

1. Inclusion and Exclusion Criteria for Pneumonia Patients 1.1 Inclusion Criteria 1) Age ≥ 18 years old; 2) Meeting the diagnostic criteria for pneumonia (acute onset + new infiltrates on imaging); 3) Time from onset to admission ≤ 72 hours; 4) Signed written informed consent. 1.1.1 Inclusion Criteria for Severe Pneumonia Patients A diagnosis of "severe pneumonia" can be made if one of the main criteria or ≥ 3 of the secondary criteria are met.

   Main Criteria:

   ① Requires mechanical ventilation with tracheal intubation

   ② Requires vasopressor drugs after aggressive fluid resuscitation for septic shock

   Secondary Criteria:

   • Respiratory rate ≥ 30 breaths/min

     • PaO₂/FiO₂ ≤ 250 mm Hg

       • Multiple lobe infiltrates

         • Confusion and/or disorientation

           ⑤ Blood urea nitrogen ≥ 20 mg/dL

           ⑥ Leukopenia (WBC < 4×10⁹/L)

           ⑦ Thrombocytopenia (PLT < 100×10⁹/L)

           ⑧ Decreased body temperature (central body temperature < 36 ℃)

           ⑨ Hypotension requiring fluid resuscitation 1.2 Exclusion Criteria

           1. End-stage diseases (such as expected survival < 48 hours);
           2. Long-term immunosuppressive therapy (prednisone > 20mg/d for more than 3 weeks, or neutropenia after chemotherapy);
           3. Pregnant or lactating women. 2. Inclusion and Exclusion Criteria for Patients with Suspected Infection but Negative Pathogen Testing 2.1 Inclusion Criteria
           1. Age ≥ 18 years old;
           2. Having infection-related symptoms or signs (such as fever, cough, sputum production, elevated white blood cells, etc.), clinically suspected of pneumonia;
           3. All pathogen tests are negative within 3 days after admission;
           4. Time from onset to admission ≤ 72 hours;
           5. Signed written informed consent. 2.2 Exclusion Criteria
           1. End-stage diseases (such as expected survival < 48 hours);
           2. Long-term immunosuppressive therapy;
           3. Pregnant or lactating women;

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
pneumonia
Severe pneumonia
Non-infection control group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
28-day all-cause mortality	28-day period following enrollment

Secondary Outcome Measures

Outcome Measure	Time Frame
The incidence rate of patients in the non-severe group progressing to severe condition	28-day period following enrollment
Time taken for the non-severe group to progress to the severe stage	28-day period following enrollment
Duration of ICU stay	28-day period following enrollment
Duration of mechanical ventilation	28-day period following enrollment
Total hospitalization days	28-day period following enrollment
28-day readmission rate	28-day period following enrollment

Other Outcome Measures

Outcome Measure	Time Frame
Multimodal omics analysis	Day 0

Collaborators and Investigators

• Sponsor: Zhonghao Fang
• Collaborators: Fifth Affiliated Hospital of Guangzhou Medical University
• Investigators: Study Chair: Zifeng Yang, Doctor, The First Affiliated Hospital of Guangzhou Medical University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): May 28, 2028

Study Registration Dates

• First Submitted: April 28, 2026
• First Submitted That Met QC Criteria: April 28, 2026
• First Posted (Actual): May 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: pneumonia; severe pneumonia
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Pneumonia
• Other Study ID Numbers: P-2026-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Due to concerns over patient privacy and confidentiality issues, the individual patient data (IPD) may not be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No