Assessment of the pneumonia severity score in community-acquired and nursing and healthcare-associated pneumonia due to COVID-19.

INTRODUCTION: The Japanese Respiratory Society (JRS) pneumonia guidelines recommend simple predictive rules, the A-DROP scoring system, for assessment of the severity of community-acquired pneumonia (CAP) and nursing and healthcare-associated pneumonia (NHCAP). We evaluated whether the A-DROP system can be adapted for assessment of the severity of coronavirus disease 2019 (COVID-19) pneumonia. METHODS: Data from 1141 patients with COVID-19 pneumonia were analyzed, comprising 502 patients observed in the 1st to 3rd wave period, 338 patients in the 4th wave and 301 patients in the 5th wave in Japan. RESULTS: The mortality rate and mechanical ventilation rate were 0% and 1.4% in patients classified with mild disease (A-DROP score, 0 point), 3.2% and 46.7% in those with moderate disease (1 or 2 points), 20.8% and 78.3% with severe disease (3 points), and 55.0% and 100% with extremely severe disease (4 or 5 points), indicating an increase in the mortality and mechanical ventilation rates in accordance with severity (Cochran-Armitage trend test; p = <0.001). This significant relationship between the severity in the A-DROP scoring system and either the mortality rate or mechanical ventilation rate was observed in patients with COVID-19 CAP and NHCAP. In each of the five COVID-19 waves, the same significant relationship was observed. CONCLUSIONS: The mortality rate and mechanical ventilation rate in patients with COVID-19 pneumonia increased depending on severity classified according to the A-DROP scoring system. Our results suggest that the A-DROP scoring system can be adapted for the assessment of severity of COVID-19 CAP and NHCAP.

Validation of JRS atypical pneumonia score in patients with community-acquired Chlamydia psittaci pneumonia.

INTRODUCTION: The Japanese Respiratory Society (JRS) atypical pneumonia score is a useful tool for the rapid presumptive diagnosis of atypical pneumonia. We investigated the clinical features of community-acquired pneumonia (CAP) due to Chlamydia psittaci and validated the JRS atypical pneumonia score in patients with C. psittaci CAP. METHODS: This study was conducted at 30 institutions and assessed a total of 72 sporadic cases with C. psittaci CAP, 412 cases with Mycoplasma pneumoniae CAP, and 576 cases with Streptococcus pneumoniae CAP. RESULTS: Sixty-two of 72 patients with C. psittaci CAP had a history of avian exposure. Among the six parameters of the JRS score, matching rates of four parameters were significantly lower in the C. psittaci CAP than the M. pneumoniae CAP in the following parameters: age <60 years, no or minor comorbid illness, stubborn or paroxysmal cough, and absence of chest adventitious sounds. The sensitivity of the diagnosis of atypical pneumonia in patients with C. psittaci CAP was significantly lower than the M. pneumoniae CAP (65.3% and 87.4%, p < 0.0001). When the diagnostic sensitivity was analyzed for different ages, the diagnostic sensitivities for the C. psittaci CAP were 90.5% for non-elderly patients and 30.0% for elderly patients. CONCLUSIONS: The JRS atypical pneumonia score is a useful tool for distinguishing between C. psittaci CAP and bacterial CAP in patients aged <60 years, but not in patients aged ≥60 years. A history of avian exposure in middle-aged patients with normal white blood cell count may be suggestive of C. psittaci pneumonia.

Alectinib in a patient with ALK-positive non-small lung cancer unable to swallow capsules.

INTRODUCTION: The treatment landscape of metastatic non-small-cell lung cancer (NSCLC) has changed dramatically in the last decade. Anaplastic lymphoma kinase (ALK) rearrangement has been a focus of interest since ALK inhibitors produced outstanding clinical results compared with chemotherapy with cytotoxic agents in patients with ALK-positive NSCLC. CASE REPORT: We present the case of a 56-year-old woman with metastatic ALK-positive NSCLC and an inability to swallow capsules or tablets. Unfortunately, all ALK inhibitors are capsule or tablet formulations. MANAGEMENT AND OUTCOME: We, therefore, decided to administer alectinib orally by opening the capsules and suspending the contents in water. Clinical imaging performed 12 months after initiating alectinib therapy indicated a complete response (CR). After 54 months of follow-up, CR has been maintained, and oral alectinib therapy has continued with no recurrence of the swallowing disturbance. DISCUSSION: There are no current guidelines for oral targeted therapy in patients with swallowing disturbance, but alectinib administered orally by opening the capsules and suspending the contents in water can be a treatment option in patients with ALK-positive NSCLC and swallowing difficulty.

Clinical efficacy of casirivimab-imdevimab antibody combination treatment in patients with COVID-19 Delta variant.

INTRODUCTION: Casirivimab-imdevimab, an antibody cocktail containing two severe acute respiratory syndrome coronavirus 2 neutralizing antibodies, reduces the viral load and the risk of coronavirus disease 2019 (COVID-19)-related hospitalization or death. The objective of this study was to evaluate the clinical efficacy of casirivimab-imdevimab in patients with COVID-19 Delta variant in Japan. METHODS: This study was conducted at five institutions and assessed a total of 461 patients with COVID-19 who met the inclusion criteria. The treatment group received a dose of casirivimab-imdevimab consisting of a cocktail of two monoclonal antibodies, (casirivimab 600 mg and imdevimab 600 mg intravenously). The control consisted of age- and sex-matched COVID-19 patients (n = 461) who sufficed the inclusion criteria but did not receive casirivimab-imdevimab. The outcome was the requirement of oxygen therapy. RESULTS: In the treatment group, patients received oxygen therapy (n = 30), nasal canula (n = 23), high flow nasal cannula (n = 5), and mechanical ventilation (n = 2). In the control group, patients received oxygen therapy (n = 56), nasal canula (n = 45), high flow nasal cannula (n = 8), and mechanical ventilation (n = 3). The administration of oxygen therapy was significantly lower in the treatment group than the control group (6.5% vs. 12.1%, P = 0.0044). All these patients admitted to our hospitals and received additional therapy and recovered. CONCLUSIONS: Our results demonstrate that the casirivimab-imdevimab combination antibody treatment is associated with reduced rates of requiring oxygen therapy among high-risk patients with COVID-19 Delta variant.

Changes in diagnostic usefulness of the JRS scoring system in COVID-19 pneumonia by SARS-CoV-2 vaccination.

INTRODUCTION: The Japanese Respiratory Society (JRS) scoring system is a useful tool for the rapid presumptive diagnosis of atypical pneumonia in non-elderly (aged <60 years) patients. As SARS-CoV-2 vaccination progresses, COVID-19 in elderly people has markedly reduced. We investigated changes in diagnostic usefulness of the JRS scoring system in COVID-19 pneumonia between the Delta variant group (vaccination period) and non-Delta variant group (before the vaccination period). METHODS: This study was conducted at five institutions and assessed a total of 1121 patients with COVID-19 pneumonia (298 had the Delta variant). During the vaccination period, the Delta variant has spread and replaced the Alfa variant. We evaluated the vaccination period as the Delta variant group. RESULTS: Among the six parameters of the JRS scoring system, matching rates of two parameters were higher in the Delta variant group than the non-Delta variant group (pre-vaccination period): age <60 years (77.5% vs 42.2%, P < 0.0001) and no or minor comorbid illness (69.1% vs 57.8%, p = 0.0007). The sensitivity of the diagnosis of atypical pneumonia in patients with COVID-19 pneumonia was significantly higher in the Delta variant group compared with the non-Delta variant group (80.2% vs 58.3%, p < 0.0001). When the diagnostic sensitivity was analyzed for different ages, the diagnostic sensitivities for the Delta variant and non-Delta variant groups were 92.6% and 95.5% for non-elderly patients and 39.1% and 32.5% for elderly patients, respectively. CONCLUSIONS: Our results demonstrated that the JRS scoring system is a useful tool for distinguishing between COVID-19 pneumonia and bacterial pneumonia in the COVID-19 vaccination period, but not before the vaccination period.

Clinical features of nursing and healthcare-associated pneumonia due to COVID-19.

INTRODUCTION: The objective of this study was to clarify the clinical differences between nursing and healthcare-associated pneumonia (NHCAP) and community-acquired pneumonia (CAP) due to COVID-19. We also investigated the clinical characteristics to determine whether there is a difference between the variant and non-variant strain in patients with NHCAP due to COVID-19. In addition, we analyzed the clinical outcomes in NHCAP patients with mental disorders who were hospitalized in a medical institution for treatment of mental illness. METHODS: This study was conducted at five institutions and assessed a total of 836 patients with COVID-19 pneumonia (154 cases were classified as NHCAP and 335 had lineage B.1.1.7.). RESULTS: No differences in patient background, clinical findings, disease severity, or outcomes were observed in patients with NHCAP between the non-B.1.1.7 group and B.1.1.7 group. The median age, frequency of comorbid illness, rates of intensive care unit stay, and mortality rate were significantly higher in patients with NHCAP than in those with CAP. Among the patients with NHCAP, the mortality rate was highest at 37.5% in patients with recent cancer treatment, followed by elderly or disabled patients receiving nursing care (24.3%), residents of care facilities (23.0%), patients receiving dialysis (13.6%), and patients in mental hospitals (9.4%). CONCLUSIONS: Our results demonstrated that there were many differences in the clinical characteristics between NHCAP patients and CAP patients due to COVID-19. It is necessary to consider the prevention and treatment content depending on the presence or absence of applicable criteria for NHCAP.

Early identification of novel coronavirus (COVID-19) pneumonia using clinical and radiographic findings.

INTRODUCTION: The Japanese Respiratory Society (JRS) scoring system is a useful tool for identifying Mycoplasma pneumoniae pneumonia. Most COVID-19 pneumonia in non-elderly patients (aged <60 years) are classified as atypical pneumonia using the JRS scoring system. We evaluated whether physicians could distinguish between COVID-19 pneumonia and M. pneumoniae pneumonia using chest computed tomography (CT) findings. In addition, we investigated chest CT findings if there is a difference between the variant and non-variant strain. METHODS: This study was conducted at five institutions and assessed a total of 823 patients with COVID-19 pneumonia (335 had lineage B.1.1.7.) and 100 patients with M. pneumoniae pneumonia. RESULTS: In COVID-19 pneumonia, at the first CT examination, peripheral, bilateral ground-glass opacity (GGO) with or without consolidation or crazy-paving pattern was observed frequently. GGO frequently had a round morphology (39.2%). No differences were observed in the radiological findings between the non-B.1.1.7 groups and B.1.1.7 groups. The frequency of pleural effusion, lymphadenopathy, bronchial wall thickening and nodules (tree-in-bud and centrilobular) was low. In contrast to COVID-19 pneumonia, bronchial wall thickening (84%) was observed most frequently, followed by nodules (81%) in M. pneumoniae pneumonia. These findings were significantly higher in M. pneumoniae pneumonia than COVID-19 pneumonia. CONCLUSIONS: Our results demonstrated that a combination of the JRS scoring system and chest CT findings is useful for the rapid presumptive diagnosis of COVID-19 pneumonia in patients aged <60 years. However, this clinical and radiographic diagnosis is not adapted to elderly people.

Effect of triple therapy in patients with asthma-COPD overlap
.

OBJECTIVE: Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is of increasing interest because ACO patients have significantly worse outcomes, leading to greater social and economic burdens compared with asthma or COPD alone. Some guidelines for ACO recommend triple therapy with inhaled corticosteroids, long-acting ß2 agonists, and long-acting muscarinic antagonists. However, this approach is based on extrapolating data from patients with asthma or COPD alone. Therapeutic studies for ACO have not previously been conducted. MATERIALS AND METHODS: A 12-week, randomized, open-label cross-over pilot study was conducted in 17 ACO patients to evaluate the effect of umeclidinium (UMEC) 62.5 µg once-daily added to fluticasone furoate/vilanterol (FF/VI) 200/25 µg once-daily. A 4-week run-in, a first and a second 4-week treatment period were included. Respiratory function, respiratory impedance, fractional exhaled nitric oxide, COPD assessment test, and asthma control test scores were evaluated 0, 4, and 8 weeks after randomization. RESULTS: Mean values of post-bronchodilator forced expiratory volume in 1 second as a percentage of the predicted value (%FEV1), after UMEC was added to FF/VI, were significantly higher than after the run-in (p < 0.01). Mean values of resonant frequency during inspiration (Fres), after UMEC was added to FF/VI, were significantly lower than after the run-in (p < 0.01). CONCLUSION: Adding UMEC to FF/VI provides greater improvement in lung function, indicating that triple therapy is a suitable regular treatment for ACO.

Efficacy of daikenchuto, a traditional Japanese Kampo medicine, for postoperative intestinal dysfunction in patients with gastrointestinal cancers: meta-analysis.

BACKGROUND: The Japan Society for Oriental Medicine makes a compilation of structured abstracts of randomized controlled trials (RCTs) of Kampo medicines available on its Evidence Reports of Kampo Treatment (EKAT) website. METHODS: Using EKAT, we conducted a systematic review and meta-analysis on the efficacy of using daikenchuto ( https://mpdb.nibiohn.go.jp/stork ) for bowel dysfunction after surgery for gastrointestinal cancer. The primary outcomes were the time to first postoperative flatus and the time to first postoperative bowel movement (BM). RESULTS: We found nine relevant RCTs. The mean differences between the daikenchuto group and control group (daikenchuto was not administered) were - 0.43 (95% CI: - 0.77 to - 0.09) days for the time to first postoperative flatus, - 0.29 (95% CI: - 0.59 to 0.01) days for the time to first postoperative BM, and - 0.95 (95% CI: - 1.70 to - 0.21) days for the length of postoperative hospital stay, and the risk ratio of the incidence of intestinal obstruction was 0.60 (95% CI: 0.35-1.03). The time to first postoperative flatus and the length of postoperative hospital stay were significantly shorter in the daikenchuto group than those in the control group (P = 0.01). However, only double-blind studies were evaluated; the results turned to be non-significant. CONCLUSION: As a result of meta-analysis by all retrieved according to the registered protocol, daikenchuto was efficacious in improving postoperative bowel dysfunction in patients with gastrointestinal cancers. However, limiting to articles with description of COI and blindness, significance disappeared.

[Effect of Japanese Traditional Medicine, Ninjin-Youei-To(TJ-108), on the Quality of Life of Patients with Non-Small Cell Lung Cancer Receiving Outpatient Chemotherapy].

An increasing number of patients with lung cancer are undergoing outpatient chemotherapy, and thus, it is very important to maintain the quality of life(QOL)of these patients. Ninjin-Youei-To(TJ-108), a Japanese traditional medicine, has been reported to improve the QOL of patients with advanced cancer. However, the effect of TJ-108 in patients with lung cancer undergoing outpatient chemotherapy is unknown. Therefore, we conducted this study. To investigate factors influencing the QOL of these patients, we administered a QOL questionnaire,"The QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs"(QOL-ACD)to 15 patients with non-small cell lung cancer. Factors related to the overall QOL scores and other categories indicating"activity","physical condition","psychological condition","social relationship", and"face scale" were analyzed. No significant decrease in each of the evaluated factors was observed in this study.

The measurement of cough response to bronchoconstriction induced by methacholine inhalation in healthy subjects: An examination using the Astograph method.

BACKGROUND: We demonstrated that heightened cough response to bronchoconstriction is a fundamental feature of cough variant asthma (CVA). To evaluate this physiological feature of CVA in daily clinical practice, it is necessary to clarify the cough response to bronchoconstriction in healthy subjects. We evaluated cough response to methacholine (MCh)-induced bronchoconstriction in healthy subjects. A forced oscillometry technique was used to measure airway resistance changes with Mch. METHODS: Healthy never-smokers (21 men, 20 women; mean 22.3 ± 3.7 years) participated. None had a >3-week cough history, clinically significant respiratory or cardiovascular disorders, or disorders that might put subjects at risk or influence the study results or the subjects' ability to participate. Twofold increasing concentrations of Mch chloride diluted in phosphate-buffered saline (0.039 to 160 mg/mL) were inhaled from nebulizers at 1-minute intervals during subjects' tidal breathing after the baseline respiratory resistance (Rrs) was recorded. Mch inhalation continued until Rrs reached twice the baseline value and forced expiratory volume in 1 second (FEV1) decreased to <90% of baseline value. Spirometry was measured before Mch inhalation and immediately after Rrs had increased twofold. Coughs were counted during and for 30 minutes after Mch inhalation. The cough reflex sensitivity to capsaicin was also examined. RESULTS: The number of coughs was 11.1 ± 14.3 (median, 7.0; range, 0 to 71; reference range, 0 to 39.7). There was no significant difference in the cough response between the sexes. The reproducibility of the cough response to bronchoconstriction was sufficient. No correlation existed between the bronchoconstriction-induced cough response and capsaicin cough-reflex sensitivity. CONCLUSIONS: Using the Astograph method, cough response to bronchoconstriction could be measured easily, safely and highly reproducibly in healthy subjects.

[Effect of Japanese Traditional Medicine, TJ-48, on the Quality of Life of Patients with Non-Small Cell Lung Cancer Receiving Outpatient Chemotherapy].

An increasing number of patients with lung cancer are undergoing outpatient chemotherapy.It is very important to retain the quality of life (QOL) of these patients.Japanese traditional medicine, TJ-48, has been reported to improve the QOL of patients with advanced cancer. However, the effect of TJ-48 in patients with lung cancer undergoing outpatient chemotherapy is unknown. The present study was conducted to investigate the factors influencing the QOL of these patients. We used "The QOL questionnaire for cancer patients treated with anticancer drugs" (QOL-ACD) with 16 patients with non-small cell lung cancer. The medical factors related to the overall QOL scores and other variables indicating "activity," "physical condition, "psychological condition,""social relationships," "psychological condition," and "face scale" were analyzed. Significant improvement was observed in the total QOL score, mainly owing to the improvement in the patients "physical condition."

A comparison of the efficacy of once-daily fluticasone furoate/vilanterole with twice-daily fluticasone propionate/salmeterol in asthma-COPD overlap syndrome.

BACKGROUND: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is important because patients with ACOS have significantly worse outcomes compared with those with asthma or chronic obstructive pulmonary disease (COPD) alone. Inhaled corticosteroids (ICS), together with a long-acting ß2 agonist (LABA), are recommended, but no therapeutic studies for ACOS have been conducted. Recently, fluticasone furoate/vilanterole (FF/VI) has been approved as the first once-daily ICS/LABA combination therapy for asthma and COPD. METHODS: A 12-week, randomized, open-label cross-over study was conducted in 16 patients with ACOS to compare the effectiveness of once-daily FF/VI 200/25 µg vs. twice-daily fluticasone propionate/salmeterol (FP/SAL) 500/50 µg. The study period included a 4-week run-in, the first 4-week treatment, and the second 4-week treatment. Respiratory functions, including forced expiratory volume in 1 s (FEV1) and respiratory impedance using the forced oscillation technique (FOT), were measured, as was fractional exhaled nitric oxide (FeNO). A COPD assessment test (CAT) scores and asthma control test (ACT) scores were recorded 0, 4, and 8 weeks after randomization. RESULTS: The mean values for the FEV1 were 1.33 (±0.29) L in the run-in period, 1.38 (±0.39) L after the FP/SAL treatment period, and 1.47 (±0.38) L after the FF/VI treatment period. The FEV1 value after the FF/VI treatment was significantly greater than the value after the run-in period (p < 0.01). FOT parameters, FeNO levels, CAT scores, ACT scores, and other blood tests were not significantly different during the run-in period, the FP/SAL treatment period, and the FF/VI treatment period. CONCLUSIONS: FF/VI, the first once-daily ICS/LABA, can provide substantial improvement in lung functions, indicating that FF/VI should be considered for the regular treatment of ACOS.

[Nab-Paclitaxel with platinum chemotherapy as sixth-line therapy for a non-small cell lung cancer patient].

A 48-year-old woman was admitted to our hospital for sixth-line chemotherapy. A chest X-ray film and computed tomographic (CT) scan revealed a right-sided massive tumor with multiple lung tumors. Repeated treatment with carboplatin (AUC 6) on day 1 and nab-paclitaxel (100mg/m2) on days 1, 8, and 15, every 28 days were effective in this patient. Chemotherapy with nab-paclitaxel may be effective for patients with multi-recurrent adenocarcinoma.

Beraprost, a stable analog of prostacyclin, enhances cough reflex sensitivity to capsaicin in bronchitic patients.

AIMS: Inflammatory mediators are involved in the pathophysiology of neutrophilic bronchial disorders presenting with chronic productive cough. Accumulating evidence indicates that prostanoids are key elements in the pathophysiology of these disorders. However, little is known about the role of prostacyclin in neutrophilic bronchial inflammation. METHODS: The effect of beraprost, a chemically and biologically stable analog of prostacyclin, on cough response to inhaled capsaicin was examined in 14 patients with chronic bronchitis, a neutrophilic bronchial disorder, in a randomized, placebo-controlled crossover study. Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of the airway cough reflex sensitivity. RESULTS: After a 2-week treatment with beraprost (80 µg twice a day orally), the cough threshold was significantly (P < .05) decreased as compared with placebo [12.2 (geometric standard error of the mean [GSEM] 1.5) µM vs. 24.4 (GSEM 1.3)]. CONCLUSIONS: These findings indicate that prostacyclin is involved in the pathophysiology of cough reflex sensitivity in patients with chronic bronchitis, a frequently encountered neutrophilic bronchial disorder presenting with chronic productive cough.

[Analysis of factors associated with the quality of life in patients with non-small cell lung cancer who received outpatient pemetrexed maintenance therapy].

Increasing number of patients with advanced non-small cell lung cancer are receiving outpatient maintenance chemotherapy. It is very important to maintain these patients' quality of life(QOL). Pemetrexed has been reported to be an effective maintenance chemotherapy. However, its effects on the QOL of patients with non-small cell lung cancer who are undergoing outpatient maintenance chemotherapy are unknown; therefore, we conducted this study. To investigate factors that influence the QOL of these patients, we provided a QOL questionnaire,"The QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs(QOL-ACD)"to 7 patients with non-small cell lung cancer. The medical factors related to the overall QOL scores, as well as other categories indicating"activity","physical condition","psychological condition","social relationship", and"face scale", were analyzed. No significant reductions in any of the factors were observed in this study.

Is the JRS atypical pneumonia prediction score useful in detecting COVID-19 pneumonia under nursing or healthcare settings?

BACKGROUND: SARS-CoV-2 causes frequent outbreaks in elderly care facilities that meet the criteria for nursing and healthcare-associated pneumonia (NHCAP). We evaluated whether the Japanese Respiratory Society (JRS) atypical pneumonia prediction score could be adapted to the diagnosis of nursing and healthcare acquired COVID-19 (NHA-COVID-19) with pneumonia. METHODS: We analyzed 516 pneumonia patients with NHA-COVID-19 and compared them with 1505 pneumonia patients with community-associated COVID-19 (CA-COVID-19). NHA-COVID-19 patients were divided into six groups; 80 cases had the ancestral strain, 76 cases had the Alfa variant, 30 cases had the Delta variant, 120 cases had the Omicron subvariant BA.1, 53 cases had the Omicron subvariant BA.2, and 157 cases had the Omicron subvariant BA.5. RESULTS: The sensitivities of the diagnosis of atypical pneumonia in patients with NHA-COVID-19 based on four or more predictors were 22.8 % in the ancestral strain group, 32.0 % in the Alfa variant group, 34.5 % in the Delta variant group, 23.1 % in the BA.1 subvariant group, 32.7 % in the BA.2 subvariant group, and 30.4 % in the BA.5 subvariant group. The diagnostic sensitivity for the presumptive diagnosis of atypical pneumonia was significantly lower for NHA-COVID-19 than for CA-COVID-19 (28.2 % vs 64.1 %, p < 0.0001). CONCLUSIONS: Our present study demonstrated that the JRS atypical pneumonia prediction score is not a useful tool in elderly patients even if there is a lot of atypical pneumonia in the NHCAP group. The caution is necessary that JRS atypical pneumonia prediction score was not fully applied to prediction for NHA-COVID-19 pneumonia.

Nursing and healthcare-associated pneumonia due to SARS-CoV-2 Omicron variant.

BACKGROUND: There were many differences in the clinical characteristics between nursing and healthcare-associated pneumonia (NHCAP) and community-acquired pneumonia (CAP) due to the SARS-CoV-2 ancestral strain, Alpha variant and Delta variant. With the replacement of the Delta variant by the Omicron variant, the Omicron variant showed decreased infectivity to lung and was less pathogenic. We investigated the clinical differences between NHCAP and CAP due to the Omicron variant. METHODS: We analyzed 516 NHCAP and 547 CAP patients with COVID-19 pneumonia. Of 516 patients with COVID-19 NHCAP, 330 cases were the Omicron variant (120 cases were BA.1, 53 cases were BA.2, and 157 cases were BA.5 subvariants) and 186 cases were non-Omicron variants. RESULTS: The median age, frequency of comorbid illness, rates of intensive care unit (ICU) stay, and mortality rate were significantly higher in Omicron patients with NHCAP than in those with CAP. Rates of ICU stay and in-hospital mortality were significantly higher in NHCAP patients with non-Omicron variants compared with those in the Omicron variant group. No clinical differences were observed in patients with NHCAP among the Omicron BA.1, BA.2, and BA.5 subvariant groups. CONCLUSIONS: The present study supported that the NHCAP category is necessary not only for bacterial pneumonia but also viral pneumonia. It is necessary to consider prevention and treatment strategies depending on the presence or absence of applicable criteria for NHCAP.