Study Populations for Modified ROX Index Predictive Value
Primary Study Populations
The modified ROX (Respiratory rate-Oxygenation) index has been primarily studied in adult patients with acute hypoxemic respiratory failure receiving high-flow nasal cannula (HFNC) therapy, with the most robust validation occurring in pneumonia patients admitted to intensive care units. 1
Core Patient Demographics
- Adult patients (≥18 years) with acute respiratory failure requiring non-invasive respiratory support in ICU settings 2, 1
- Mean age range: 61-70 years, with one large Indian cohort showing mean age of 65±8.80 years 3
- Male predominance observed across studies (approximately 79.5% male in some cohorts) 3
Primary Clinical Conditions Studied
- Pneumonia patients with acute hypoxemic respiratory failure represent the original validation cohort, with 191 patients in the multicenter prospective study 1
- COVID-19 pneumonia with ARDS has become a major study population, with cohorts ranging from 44 to 249 patients 4, 5, 3
- Patients requiring HFNC therapy across diverse ICU settings, including a large Indian study of 614 patients from 30 ICUs across 10 states 2
Specific Inclusion Characteristics
- Acute hypoxemic respiratory failure requiring oxygen supplementation beyond conventional methods 1
- Patients initiated on HFNC therapy as the primary non-invasive respiratory support modality 4, 2, 1
- ICU-level care requirements, with patients monitored continuously during the initial hours of respiratory support 4, 3
Geographic and Resource Diversity
- Multicenter international cohorts including validation studies across different healthcare systems 1
- Low-resource settings specifically studied in India, demonstrating the index's applicability across diverse resource contexts 5, 2
- High-income healthcare systems in the original validation studies 1
Severity Stratification
- Moderate to severe respiratory failure requiring escalation beyond conventional oxygen therapy 1, 3
- Patients at risk for intubation, with failure rates ranging from 29.5% to 46.2% depending on the respiratory support modality 3
- COVID-19 patients categorized as early responders (n=38), late responders (n=34), and non-responders (n=46) in outcome prediction studies 5
Key Exclusion Considerations
Studies typically excluded patients with immediate need for intubation at presentation, those unable to tolerate HFNC interface, and patients with contraindications to non-invasive ventilation, though specific exclusion criteria varied across studies 1, 3